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Author name code: auchere
ADS astronomy entries on 2022-09-14
author:"Auchere, Frederic" 

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Title: What drives decayless kink oscillations in active region
    coronal loops on the Sun?
Authors: Mandal, Sudip; Chitta, Lakshmi P.; Antolin, Patrick; Peter,
   Hardi; Solanki, Sami K.; Auchère, Frédéric; Berghmans, David;
   Zhukov, Andrei N.; Teriaca, Luca; Cuadrado, Regina A.; Schühle,
   Udo; Parenti, Susanna; Buchlin, Éric; Harra, Louise; Verbeeck, Cis;
   Kraaikamp, Emil; Long, David M.; Rodriguez, Luciano; Pelouze, Gabriel;
   Schwanitz, Conrad; Barczynski, Krzysztof; Smith, Phil J.
2022arXiv220904251M    Altcode:
  We study here the phenomena of decayless kink oscillations in a system
  of active region (AR) coronal loops. Using high resolution observations
  from two different instruments, namely the Extreme Ultraviolet Imager
  (EUI) on board Solar Orbiter and the Atmospheric Imaging Assembly
  (AIA) on board the Solar Dynamics Observatory, we follow these AR
  loops for an hour each on three consecutive days. Our results show
  significantly more resolved decayless waves in the higher-resolution
  EUI data compared with the AIA data. Furthermore, the same system of
  loops exhibits many of these decayless oscillations on Day-2, while on
  Day-3, we detect very few oscillations and on Day-1, we find none at
  all. Analysis of photospheric magnetic field data reveals that at most
  times, these loops were rooted in sunspots, where supergranular flows
  are generally absent. This suggests that supergranular flows, which
  are often invoked as drivers of decayless waves, are not necessarily
  driving such oscillations in our observations. Similarly, our findings
  also cast doubt on other possible drivers of these waves, such as a
  transient driver or mode conversion of longitudinal waves near the loop
  footpoints. In conclusion, through our analysis we find that none of
  the commonly suspected sources proposed to drive decayless oscillations
  in active region loops seems to be operating in this event and hence,
  the search for that elusive wave driver needs to continue.

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Title: Quiet Sun Center to Limb Variation of the Linear Polarization
    Observed by CLASP2 Across the Mg II h and k Lines
Authors: Rachmeler, L. A.; Bueno, J. Trujillo; McKenzie, D. E.;
   Ishikawa, R.; Auchère, F.; Kobayashi, K.; Kano, R.; Okamoto,
   T. J.; Bethge, C. W.; Song, D.; Ballester, E. Alsina; Belluzzi,
   L.; Pino Alemán, T. del; Ramos, A. Asensio; Yoshida, M.; Shimizu,
   T.; Winebarger, A.; Kobelski, A. R.; Vigil, G. D.; Pontieu, B. De;
   Narukage, N.; Kubo, M.; Sakao, T.; Hara, H.; Suematsu, Y.; Štěpán,
   J.; Carlsson, M.; Leenaarts, J.
2022ApJ...936...67R    Altcode: 2022arXiv220701788R
  The CLASP2 (Chromospheric LAyer Spectro-Polarimeter 2) sounding rocket
  mission was launched on 2019 April 11. CLASP2 measured the four Stokes
  parameters of the Mg II h and k spectral region around 2800 Å along a
  200″ slit at three locations on the solar disk, achieving the first
  spatially and spectrally resolved observations of the solar polarization
  in this near-ultraviolet region. The focus of the work presented here
  is the center-to-limb variation of the linear polarization across these
  resonance lines, which is produced by the scattering of anisotropic
  radiation in the solar atmosphere. The linear polarization signals of
  the Mg II h and k lines are sensitive to the magnetic field from the
  low to the upper chromosphere through the Hanle and magneto-optical
  effects. We compare the observations to theoretical predictions
  from radiative transfer calculations in unmagnetized semiempirical
  models, arguing that magnetic fields and horizontal inhomogeneities
  are needed to explain the observed polarization signals and spatial
  variations. This comparison is an important step in both validating and
  refining our understanding of the physical origin of these polarization
  signatures, and also in paving the way toward future space telescopes
  for probing the magnetic fields of the solar upper atmosphere via
  ultraviolet spectropolarimetry.

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Title: Automatic detection technique for solar filament oscillations
    in GONG data
Authors: Luna, Manuel; Merou Mestre, Joan-René; Auchère, Frédéric
2022arXiv220905087L    Altcode:
  Solar filament oscillations have been known for decades. Now thanks
  to the new capabilities of the new telescopes, these periodic motions
  are routinely observed. Oscillations in filaments show key aspects of
  their structure. A systematic study of filament oscillations over the
  solar cycle can shed light on the evolution of the prominences. This
  work is a proof of concept that aims to automatically detect and
  parameterise such oscillations using H$\alpha$ data from the GONG
  network of telescopes. The proposed technique studies the periodic
  fluctuations of every pixel of the H$\alpha$ data cubes. Using the FFT
  we compute the power spectral density (PSD). We define a criterion
  to consider whether it is a real oscillation or whether it is a
  spurious fluctuation. This consists in considering that the peak in
  the PSD must be greater than several times the background noise with
  a confidence level of 95\%. The background noise is well fitted to a
  combination of red and white noise. We applied the method to several
  observations already reported in the literature to determine its
  reliability. We also applied the method to a test case, which is a
  data set in which the oscillations of the filaments were not known a
  priori. The method shows that there are areas in the filaments with PSD
  above the threshold value. The periodicities obtained are in general
  agreement with the values obtained by other methods. In the test case,
  the method detects oscillations in several filaments. We conclude that
  the proposed spectral technique is a powerful tool to automatically
  detect oscillations in prominences using H$\alpha$ data.

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Title: A highly dynamic small-scale jet in a polar coronal hole
Authors: Mandal, Sudip; Chitta, Lakshmi Pradeep; Peter, Hardi;
   Solanki, Sami K.; Cuadrado, Regina Aznar; Teriaca, Luca; Schühle,
   Udo; Berghmans, David; Auchère, Frédéric
2022A&A...664A..28M    Altcode: 2022arXiv220602236M
  We present an observational study of the plasma dynamics at the base
  of a solar coronal jet, using high resolution extreme ultraviolet
  imaging data taken by the Extreme Ultraviolet Imager on board Solar
  Orbiter, and by the Atmospheric Imaging Assembly on board Solar
  Dynamics Observatory. We observed multiple plasma ejection events
  over a period of ∼1 h from a dome-like base that is ca. 4 Mm wide
  and is embedded in a polar coronal hole. Within the dome below the
  jet spire, multiple plasma blobs with sizes around 1−2 Mm propagate
  upwards to the dome apex with speeds of the order of the sound speed
  (ca. 120 km s<SUP>−1</SUP>). Upon reaching the apex, some of these
  blobs initiate flows with similar speeds towards the other footpoint
  of the dome. At the same time, high speed super-sonic outflows
  (∼230 km s<SUP>−1</SUP>) are detected along the jet spire. These
  outflows as well as the intensity near the dome apex appear to be
  repetitive. Furthermore, during its evolution, the jet undergoes
  many complex morphological changes, including transitions between
  the standard and blowout type eruption. These new observational
  results highlight the underlying complexity of the reconnection
  process that powers these jets and they also provide insights into
  the plasma response when subjected to rapid energy injection. <P
  />Movies associated to Figs. 1, 2, and 4 are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202243765/olm">https://www.aanda.org</A>

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Title: Linking Small-scale Solar Wind Properties with Large-scale
    Coronal Source Regions through Joint Parker Solar Probe-Metis/Solar
    Orbiter Observations
Authors: Telloni, Daniele; Zank, Gary P.; Sorriso-Valvo, Luca;
   D'Amicis, Raffaella; Panasenco, Olga; Susino, Roberto; Bruno, Roberto;
   Perrone, Denise; Adhikari, Laxman; Liang, Haoming; Nakanotani, Masaru;
   Zhao, Lingling; Hadid, Lina Z.; Sánchez-Cano, Beatriz; Verscharen,
   Daniel; Velli, Marco; Grimani, Catia; Marino, Raffaele; Carbone,
   Francesco; Mancuso, Salvatore; Biondo, Ruggero; Pagano, Paolo; Reale,
   Fabio; Bale, Stuart D.; Kasper, Justin C.; Case, Anthony W.; de Wit,
   Thierry Dudok; Goetz, Keith; Harvey, Peter R.; Korreck, Kelly E.;
   Larson, Davin; Livi, Roberto; MacDowall, Robert J.; Malaspina, David
   M.; Pulupa, Marc; Stevens, Michael L.; Whittlesey, Phyllis; Romoli,
   Marco; Andretta, Vincenzo; Deppo, Vania Da; Fineschi, Silvano; Heinzel,
   Petr; Moses, John D.; Naletto, Giampiero; Nicolini, Gianalfredo;
   Spadaro, Daniele; Stangalini, Marco; Teriaca, Luca; Capobianco,
   Gerardo; Capuano, Giuseppe E.; Casini, Chiara; Casti, Marta; Chioetto,
   Paolo; Corso, Alain J.; Leo, Yara De; Fabi, Michele; Frassati,
   Federica; Frassetto, Fabio; Giordano, Silvio; Guglielmino, Salvo L.;
   Jerse, Giovanna; Landini, Federico; Liberatore, Alessandro; Magli,
   Enrico; Massone, Giuseppe; Messerotti, Mauro; Pancrazzi, Maurizio;
   Pelizzo, Maria G.; Romano, Paolo; Sasso, Clementina; Schühle, Udo;
   Slemer, Alessandra; Straus, Thomas; Uslenghi, Michela; Volpicelli,
   Cosimo A.; Zangrilli, Luca; Zuppella, Paola; Abbo, Lucia; Auchère,
   Frédéric; Cuadrado, Regina Aznar; Berlicki, Arkadiusz; Ciaravella,
   Angela; Lamy, Philippe; Lanzafame, Alessandro; Malvezzi, Marco;
   Nicolosi, Piergiorgio; Nisticò, Giuseppe; Peter, Hardi; Solanki,
   Sami K.; Strachan, Leonard; Tsinganos, Kanaris; Ventura, Rita; Vial,
   Jean-Claude; Woch, Joachim; Zimbardo, Gaetano
2022ApJ...935..112T    Altcode:
  The solar wind measured in situ by Parker Solar Probe in the very
  inner heliosphere is studied in combination with the remote-sensing
  observation of the coronal source region provided by the METIS
  coronagraph aboard Solar Orbiter. The coronal outflows observed near
  the ecliptic by Metis on 2021 January 17 at 16:30 UT, between 3.5 and
  6.3 R <SUB>⊙</SUB> above the eastern solar limb, can be associated
  with the streams sampled by PSP at 0.11 and 0.26 au from the Sun,
  in two time intervals almost 5 days apart. The two plasma flows
  come from two distinct source regions, characterized by different
  magnetic field polarity and intensity at the coronal base. It follows
  that both the global and local properties of the two streams are
  different. Specifically, the solar wind emanating from the stronger
  magnetic field region has a lower bulk flux density, as expected,
  and is in a state of well-developed Alfvénic turbulence, with low
  intermittency. This is interpreted in terms of slab turbulence in the
  context of nearly incompressible magnetohydrodynamics. Conversely,
  the highly intermittent and poorly developed turbulent behavior of the
  solar wind from the weaker magnetic field region is presumably due to
  large magnetic deflections most likely attributed to the presence of
  switchbacks of interchange reconnection origin.

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Title: The observed large scale equatorial UV corona: new perspectives
    with 'recent', 'future' and 'old' data
Authors: Abbo, Lucia; Fineschi, Silvano; Parenti, Susanna; Romoli,
   Marco; Pancrazzi, Maurizio; Andretta, Vincenzo; Auchère, Frédéric;
   Susino, Roberto; Spadaro, Daniele; Nicolini, Gianalfredo; Giordano,
   Silvio; Zangrilli, Luca
2022cosp...44.1327A    Altcode:
  In order to understand the sources and the physical mechanisms for the
  propagation of the Slow Solar Wind (SSW), it is essential to analyze
  solar data in the region which shapes the large scale structure in
  corona where the SSW is accelerated, such as streamers and boundaries
  coronal hole/streamer. The focus of this work is to trace the channels
  where the SSW escapes from the solar disk up to 5 solar radii in
  corona. We give an overview on how Solar Orbiter observations (remote
  sensing and in-situ) together with other space missions (i.e. SPP and
  PROBA-3) can give a major contribution to the study of the evolution
  of the streamer belt and global corona, of the role of the coronal
  magnetic field topology in controlling the solar wind dynamics and
  abundance, and of abundance anomalies in streamers and in boundaries
  CH/streamer. In particular, we study how to trace back some equatorial
  features from the extended corona to the disk. We analyse recent Metis
  observations in corona together with the Extreme Ultraviolet Imager
  (EUI) observations on disk and corona (by using the occulter). We also
  present results from SOHO observations in 1996-1997 (solar minimum),
  during which was observed a stable equatorial streamer belt with a
  typical dipole magnetic structure. We have analyzed data by UVCS,
  SUMER, CDS to trace large scale features and also sub-structures at
  very high spatial resolution from the disk up to 3 solar radii. This
  comparison and overlapping is still unique in solar physics and it can
  improve our knowledge about the origin, acceleration and propagation
  of the solar wind.

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Title: The Magnetic Origin of Solar Campfires: Observations by Solar
    Orbiter and SDO
Authors: Panesar, Navdeep Kaur; Zhukov, Andrei; Berghmans, David;
   Auchere, Frederic; Müller, Daniel; Tiwari, Sanjiv Kumar; Cheung, Mark
2022cosp...44.2564P    Altcode:
  Solar campfires are small-scale, short-lived coronal brightenings,
  recently observed in 174 Å images by Extreme Ultraviolet Imager (EUI)
  on board Solar Orbiter (SolO). Here we investigate the magnetic origin
  of 52 campfires, in quiet-Sun, using line-of-sight magnetograms from
  Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager
  (HMI) together with extreme ultraviolet images from SolO /EUI and
  SDO/Atmospheric Imaging Assembly (AIA). We find that the campfires
  are rooted at the edges of photospheric magnetic network lanes; (ii)
  most of the campfires reside above neutral lines and 77% of them appear
  at sites of magnetic flux cancelation between the majority-polarity
  magnetic flux patch and a merging minority-polarity flux patch, with
  a flux cancelation rate of ∼1018 Mx hr‑1; some of the smallest
  campfires come from the sites where magnetic flux elements were barely
  discernible in HMI; (iii) some of the campfires occur repeatedly
  from the same neutral line; (iv) in the large majority of instances
  (79%), campfires are preceded by a cool-plasma structure, analogous to
  minifilaments in coronal jets; and (v) although many campfires have
  "complex" structure, most campfires resemble small-scale jets, dots,
  or loops. Thus, "campfire" is a general term that includes different
  types of small-scale solar dynamic features. They contain sufficient
  magnetic energy (∼1026-1027 erg) to heat the solar atmosphere
  locally to 0.5-2.5 MK. Their lifetimes range from about 1 minute to
  over 1 hour, with most of the campfires having a lifetime of &lt;10
  minutes. The average lengths and widths of the campfires are 5400 ±
  2500 km and 1600 ± 640 km, respectively. Our observations suggest that
  (a) the presence of magnetic flux ropes may be ubiquitous in the solar
  atmosphere and not limited to coronal jets and larger-scale eruptions
  that make CMEs, and (b) magnetic flux cancelation, most likely driven
  by magnetic reconnection in the lower atmosphere, is the fundamental
  process for the formation and triggering of most campfires.

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Title: Transient small-scale brightenings in the quiet solar corona:
    a model for campfires observed with Solar Orbiter
Authors: Chen, Yajie; Peter, Hardi; Berghmans, David; Tian, Hui;
   Auchère, Frédéric; Przybylski, Damien
2022cosp...44.2557C    Altcode:
  Recent observations by the Extreme Ultraviolet Imager (EUI) on
  board Solar Orbiter have revealed prevalent small-scale transient
  brightenings in the quiet solar corona termed "campfires". To
  understand the generation mechanism of these coronal brightenings,
  we constructed a self-consistent and time-dependent quiet-Sun
  model extending from the upper convection zone to the lower corona
  using a realistic three-dimensional radiation magnetohydrodynamic
  simulation. From the model we have synthesized the coronal emission
  in the EUI 174 passband. We identified several transient coronal
  brightenings similar to those in EUI observations. The size and
  lifetime of these coronal brightenings are mostly 0.5-4 Mm and ~2 min,
  respectively. These brightenings are generally located at a height of
  2-4 Mm above the photosphere, and the local plasma is often heated
  above 1 MK. By examining the magnetic field structures before and
  after the occurrence of brightenings, we concluded that these coronal
  brightenings are generated by component magnetic reconnection between
  interacting bundles of magnetic field lines or neighboring field lines
  within highly twisted flux ropes. Occurring in the coronal part of
  the atmosphere, these events generally reveal no obvious signature
  of flux emergence or cancellation in photospheric magnetograms. These
  transient coronal brightenings may play an important role in heating
  of the local coronal plasma.

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Title: Automated technique for detecting oscillations in solar
    filaments
Authors: Luna, Manuel; Auchere, Frederic; Mérou-Mestre, Joan-René
2022cosp...44.2425L    Altcode:
  Solar prominences/filaments are cold plasma hanging in the hot
  corona. There is a much larger magnetic structure that hosts this
  cold plasma: the filament channel. It has proved that oscillations in
  solar prominences are common and give information about their filament
  channels. The systematic study of these oscillations over several
  solar cycles will give us relevant information about the dynamics and
  structure of the prominences as the magnetic stress evolves during
  the cycle. In this study, we propose an efficient method to detect
  and characterize the oscillations in solar filaments using H alpha
  data. This technique uses spectral methods where the periodogram is
  calculated for each pixel of the images in the time sequence. It is
  necessary to calculate the background noise and we consider that we
  have a positive detection when the significance is higher than 95%. In
  this study, we set the basis for a future large-scale study of these
  periodic motions in solar filaments.

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Title: Automatic detection of small-scale EUV brightenings observed
    by the Solar Orbiter/EUI
Authors: Alipour, N.; Safari, H.; Verbeeck, C.; Berghmans, D.;
   Auchère, F.; Chitta, L. P.; Antolin, P.; Barczynski, K.; Buchlin,
   É.; Aznar Cuadrado, R.; Dolla, L.; Georgoulis, M. K.; Gissot, S.;
   Harra, L.; Katsiyannis, A. C.; Long, D. M.; Mandal, S.; Parenti,
   S.; Podladchikova, O.; Petrova, E.; Soubrié, É.; Schühle, U.;
   Schwanitz, C.; Teriaca, L.; West, M. J.; Zhukov, A. N.
2022A&A...663A.128A    Altcode: 2022arXiv220404027A
  Context. Accurate detections of frequent small-scale extreme ultraviolet
  (EUV) brightenings are essential to the investigation of the physical
  processes heating the corona. <BR /> Aims: We detected small-scale
  brightenings, termed campfires, using their morphological and
  intensity structures as observed in coronal EUV imaging observations
  for statistical analysis. <BR /> Methods: We applied a method based
  on Zernike moments and a support vector machine (SVM) classifier
  to automatically identify and track campfires observed by Solar
  Orbiter/Extreme Ultraviolet Imager (EUI) and Solar Dynamics Observatory
  (SDO)/Atmospheric Imaging Assembly (AIA). <BR /> Results: This method
  detected 8678 campfires (with length scales between 400 km and 4000 km)
  from a sequence of 50 High Resolution EUV telescope (HRI<SUB>EUV</SUB>)
  174 Å images. From 21 near co-temporal AIA images covering the same
  field of view as EUI, we found 1131 campfires, 58% of which were
  also detected in HRI<SUB>EUV</SUB> images. In contrast, about 16%
  of campfires recognized in HRI<SUB>EUV</SUB> were detected by AIA. We
  obtain a campfire birthrate of 2 × 10<SUP>−16</SUP> m<SUP>−2</SUP>
  s<SUP>−1</SUP>. About 40% of campfires show a duration longer than 5
  s, having been observed in at least two HRI<SUB>EUV</SUB> images. We
  find that 27% of campfires were found in coronal bright points and
  the remaining 73% have occurred out of coronal bright points. We
  detected 23 EUI campfires with a duration greater than 245 s. We found
  that about 80% of campfires are formed at supergranular boundaries,
  and the features with the highest total intensities are generated at
  network junctions and intense H I Lyman-α emission regions observed
  by EUI/HRI<SUB>Lya</SUB>. The probability distribution functions for
  the total intensity, peak intensity, and projected area of campfires
  follow a power law behavior with absolute indices between 2 and 3. This
  self-similar behavior is a possible signature of self-organization,
  or even self-organized criticality, in the campfire formation
  process. <P />Supplementary material (S1-S3) is available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202243257/olm">https://www.aanda.org</A>

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Title: Abundance diagnostics in active regions with Solar
    Orbiter/SPICE
Authors: Giunta, Alessandra; Peter, Hardi; Parenti, Susanna; Buchlin,
   Eric; Thompson, William; Auchere, Frederic; Kucera, Therese; Carlsson,
   Mats; Janvier, Miho; Fludra, Andrzej; Hassler, Donald M.; Grundy,
   Timothy; Sidher, Sunil; Guest, Steve; Leeks, Sarah; Fredvik, Terje;
   Young, Peter
2022cosp...44.2583G    Altcode:
  With the launch of Solar Orbiter in February 2020, we are now able to
  fully explore the link between the solar activity on the Sun and the
  inner heliosphere. Elemental abundance measurements provide a key tracer
  to probe the source regions of the solar wind and to track it from the
  solar surface and corona to the heliosphere. Abundances of elements
  with low first ionisation potential (FIP) are enhanced in the corona
  relative to high-FIP elements, with respect to the photosphere. This is
  known as the FIP effect, which is measured as abundance bias (FIP bias)
  of low and high FIP elements. This effect is vital for understanding the
  flow of mass and energy through the solar atmosphere. The comparison
  between in-situ and remote sensing composition data, coupled with
  modelling, will allow us to trace back the source of heliospheric
  plasma. Solar Orbiter has a unique combination of in-situ and remote
  sensing instruments that will help to make such a comparison. In
  particular, the SPICE (Spectral Imaging of the Coronal Environment)
  EUV spectrometer records spectra in two wavelength bands, 70.4-79.0
  nm and 97.3-104.9 nm. SPICE is designed to provide spectroheliograms
  using a core set of emission lines arising from ions of both low-FIP
  and high-FIP elements such as C, N, O, Ne, Mg, S and Fe. These lines
  are formed over a wide range of temperatures from 20,000 K to over 1
  million K, enabling the analysis of the different layers of the solar
  atmosphere. SPICE spectroheliograms can be processed to produce FIP
  bias maps, which can be compared to in-situ measurements of the solar
  wind composition of the same elements. During the Solar Orbiter Cruise
  Phase, SPICE observed several active regions. We will present some of
  these observations and discuss the SPICE diagnostic potential to derive
  relative abundances (e.g., Mg/Ne) and the FIP bias in those regions.

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Title: The SPICE spectrograph on Solar Orbiter: an introduction and
    results from the first Orbits
Authors: Auchère, Frédéric; Peter, Hardi; Parenti, Susanna; Buchlin,
   Eric; Thompson, William; Auchere, Frederic; Teriaca, Luca; Kucera,
   Therese; Carlsson, Mats; Janvier, Miho; Fludra, Andrzej; Giunta,
   Alessandra; Schuehle, Udo; Hassler, Donald M.; Grundy, Timothy;
   Sidher, Sunil; Fredvik, Terje; Plowman, Joseph; Aznar Cuadrado, Regina
2022cosp...44.1338A    Altcode:
  The Spectral Imaging of the Coronal Environment (SPICE) instrument is
  the EUV imaging spectrometer on board the Solar Orbiter mission. With
  its ability to derive physical properties of the coronal plasma,
  SPICE is a key component of the payload to establish the connection
  between the source regions and the in-situ measurements of the solar
  wind. The spacecraft was successfully launched in February 2020 and
  completed its cruise phase in December 2021. During this period,
  the remote sensing instruments were mostly operated during limited
  periods of time for 'checkout' engineering activities and synoptic
  observations. Nonetheless, several of these periods provided enough
  opportunities already to obtain new insights on coronal physics. During
  the march 2022 perihelion - close to 0.3 AU - SPICE will provide
  its highest spatial resolution data so far. Coordinated observations
  between the remote sensing and in-situ instruments will provide the
  first opportunity to use the full potential of the Solar Orbiter
  mission. We will review the instrument characteristics and present
  initial results from the cruise phase and first close encounter.

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Title: Prominence eruption observed in He II 304 Å up to &gt;6
    R<SUB>⊙</SUB> by EUI/FSI aboard Solar Orbiter
Authors: Mierla, M.; Zhukov, A. N.; Berghmans, D.; Parenti, S.;
   Auchère, F.; Heinzel, P.; Seaton, D. B.; Palmerio, E.; Jejčič, S.;
   Janssens, J.; Kraaikamp, E.; Nicula, B.; Long, D. M.; Hayes, L. A.;
   Jebaraj, I. C.; Talpeanu, D. -C.; D'Huys, E.; Dolla, L.; Gissot, S.;
   Magdalenić, J.; Rodriguez, L.; Shestov, S.; Stegen, K.; Verbeeck,
   C.; Sasso, C.; Romoli, M.; Andretta, V.
2022A&A...662L...5M    Altcode: 2022arXiv220515214M
  <BR /> Aims: We report observations of a unique, large prominence
  eruption that was observed in the He II 304 Å passband of the Extreme
  Ultraviolet Imager/Full Sun Imager telescope aboard Solar Orbiter on
  15-16 February 2022. <BR /> Methods: Observations from several vantage
  points - Solar Orbiter, the Solar-Terrestrial Relations Observatory,
  the Solar and Heliospheric Observatory, and Earth-orbiting satellites -
  were used to measure the kinematics of the erupting prominence and the
  associated coronal mass ejection. Three-dimensional reconstruction was
  used to calculate the deprojected positions and speeds of different
  parts of the prominence. Observations in several passbands allowed us
  to analyse the radiative properties of the erupting prominence. <BR />
  Results: The leading parts of the erupting prominence and the leading
  edge of the corresponding coronal mass ejection propagate at speeds
  of around 1700 km s<SUP>−1</SUP> and 2200 km s<SUP>−1</SUP>,
  respectively, while the trailing parts of the prominence are
  significantly slower (around 500 km s<SUP>−1</SUP>). Parts of the
  prominence are tracked up to heights of over 6 R<SUB>⊙</SUB>. The
  He II emission is probably produced via collisional excitation rather
  than scattering. Surprisingly, the brightness of a trailing feature
  increases with height. <BR /> Conclusions: The reported prominence
  is the first observed in He II 304 Å emission at such a great
  height (above 6 R<SUB>⊙</SUB>). <P />Movies are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202244020/olm">https://www.aanda.org</A>

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Title: Observation of Magnetic Switchback in the Solar Corona
Authors: Telloni, Daniele; Zank, Gary P.; Stangalini, Marco;
   Downs, Cooper; Liang, Haoming; Nakanotani, Masaru; Andretta,
   Vincenzo; Antonucci, Ester; Sorriso-Valvo, Luca; Adhikari, Laxman;
   Zhao, Lingling; Marino, Raffaele; Susino, Roberto; Grimani, Catia;
   Fabi, Michele; D'Amicis, Raffaella; Perrone, Denise; Bruno, Roberto;
   Carbone, Francesco; Mancuso, Salvatore; Romoli, Marco; Da Deppo, Vania;
   Fineschi, Silvano; Heinzel, Petr; Moses, John D.; Naletto, Giampiero;
   Nicolini, Gianalfredo; Spadaro, Daniele; Teriaca, Luca; Frassati,
   Federica; Jerse, Giovanna; Landini, Federico; Pancrazzi, Maurizio;
   Russano, Giuliana; Sasso, Clementina; Berghmans, David; Auchère,
   Frédéric; Aznar Cuadrado, Regina; Chitta, Lakshmi P.; Harra, Louise;
   Kraaikamp, Emil; Long, David M.; Mandal, Sudip; Parenti, Susanna;
   Pelouze, Gabriel; Peter, Hardi; Rodriguez, Luciano; Schühle, Udo;
   Schwanitz, Conrad; Smith, Phil J.; Verbeeck, Cis; Zhukov, Andrei N.
2022arXiv220603090T    Altcode:
  Switchbacks are sudden, large radial deflections of the solar wind
  magnetic field, widely revealed in interplanetary space by the Parker
  Solar Probe. The switchbacks' formation mechanism and sources are still
  unresolved, although candidate mechanisms include Alfvénic turbulence,
  shear-driven Kelvin-Helmholtz instabilities, interchange reconnection,
  and geometrical effects related to the Parker spiral. This Letter
  presents observations from the Metis coronagraph onboard Solar Orbiter
  of a single large propagating S-shaped vortex, interpreted as first
  evidence of a switchback in the solar corona. It originated above
  an active region with the related loop system bounded by open-field
  regions to the East and West. Observations, modeling, and theory provide
  strong arguments in favor of the interchange reconnection origin of
  switchbacks. Metis measurements suggest that the initiation of the
  switchback may also be an indicator of the origin of slow solar wind.

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Title: Validation of a Wave Heated 3D MHD Coronal-wind Model using
    Polarized Brightness and EUV Observations
Authors: Parenti, Susanna; Réville, Victor; Brun, Allan Sacha;
   Pinto, Rui F.; Auchère, Frédéric; Buchlin, Éric; Perri, Barbara;
   Strugarek, Antoine
2022ApJ...929...75P    Altcode: 2022arXiv220310876P
  The physical properties responsible for the formation and evolution
  of the corona and heliosphere are still not completely understood. 3D
  MHD global modeling is a powerful tool to investigate all the possible
  candidate processes. To fully understand the role of each of them,
  we need a validation process where the output from the simulations
  is quantitatively compared to the observational data. In this work,
  we present the results from our validation process applied to the
  wave turbulence driven 3D MHD corona-wind model WindPredict-AW. At
  this stage of the model development, we focus the work to the coronal
  regime in quiescent condition. We analyze three simulation results,
  which differ by the boundary values. We use the 3D distributions of
  density and temperature, output from the simulations at the time of
  around the first Parker Solar Probe perihelion (during minimum of
  the solar activity), to synthesize both extreme ultraviolet (EUV)
  and white-light-polarized (WL pB) images to reproduce the observed
  solar corona. For these tests, we selected AIA 193 Å, 211 Å, and
  171 Å EUV emissions, MLSO K-Cor, and LASCO C2 pB images obtained on
  2018 November 6 and 7. We then make quantitative comparisons of the
  disk and off limb corona. We show that our model is able to produce
  synthetic images comparable to those of the observed corona.

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Title: The magnetic drivers of campfires seen by the Polarimetric
    and Helioseismic Imager (PHI) on Solar Orbiter
Authors: Kahil, F.; Hirzberger, J.; Solanki, S. K.; Chitta, L. P.;
   Peter, H.; Auchère, F.; Sinjan, J.; Orozco Suárez, D.; Albert,
   K.; Albelo Jorge, N.; Appourchaux, T.; Alvarez-Herrero, A.; Blanco
   Rodríguez, J.; Gandorfer, A.; Germerott, D.; Guerrero, L.; Gutiérrez
   Márquez, P.; Kolleck, M.; del Toro Iniesta, J. C.; Volkmer, R.;
   Woch, J.; Fiethe, B.; Gómez Cama, J. M.; Pérez-Grande, I.; Sanchis
   Kilders, E.; Balaguer Jiménez, M.; Bellot Rubio, L. R.; Calchetti,
   D.; Carmona, M.; Deutsch, W.; Fernández-Rico, G.; Fernández-Medina,
   A.; García Parejo, P.; Gasent-Blesa, J. L.; Gizon, L.; Grauf, B.;
   Heerlein, K.; Lagg, A.; Lange, T.; López Jiménez, A.; Maue, T.;
   Meller, R.; Michalik, H.; Moreno Vacas, A.; Müller, R.; Nakai,
   E.; Schmidt, W.; Schou, J.; Schühle, U.; Staub, J.; Strecker, H.;
   Torralbo, I.; Valori, G.; Aznar Cuadrado, R.; Teriaca, L.; Berghmans,
   D.; Verbeeck, C.; Kraaikamp, E.; Gissot, S.
2022A&A...660A.143K    Altcode: 2022arXiv220213859K
  Context. The Extreme Ultraviolet Imager (EUI) on board the Solar Orbiter
  (SO) spacecraft observed small extreme ultraviolet (EUV) bursts,
  termed campfires, that have been proposed to be brightenings near the
  apexes of low-lying loops in the quiet-Sun atmosphere. The underlying
  magnetic processes driving these campfires are not understood. <BR
  /> Aims: During the cruise phase of SO and at a distance of 0.523
  AU from the Sun, the Polarimetric and Helioseismic Imager on Solar
  Orbiter (SO/PHI) observed a quiet-Sun region jointly with SO/EUI,
  offering the possibility to investigate the surface magnetic field
  dynamics underlying campfires at a spatial resolution of about 380
  km. <BR /> Methods: We used co-spatial and co-temporal data of the
  quiet-Sun network at disc centre acquired with the High Resolution
  Imager of SO/EUI at 17.4 nm (HRI<SUB>EUV</SUB>, cadence 2 s) and the
  High Resolution Telescope of SO/PHI at 617.3 nm (HRT, cadence 2.5
  min). Campfires that are within the SO/PHI−SO/EUI common field
  of view were isolated and categorised according to the underlying
  magnetic activity. <BR /> Results: In 71% of the 38 isolated events,
  campfires are confined between bipolar magnetic features, which seem to
  exhibit signatures of magnetic flux cancellation. The flux cancellation
  occurs either between the two main footpoints, or between one of the
  footpoints of the loop housing the campfire and a nearby opposite
  polarity patch. In one particularly clear-cut case, we detected the
  emergence of a small-scale magnetic loop in the internetwork followed
  soon afterwards by a campfire brightening adjacent to the location
  of the linear polarisation signal in the photosphere, that is to
  say near where the apex of the emerging loop lays. The rest of the
  events were observed over small scattered magnetic features, which
  could not be identified as magnetic footpoints of the campfire hosting
  loops. <BR /> Conclusions: The majority of campfires could be driven
  by magnetic reconnection triggered at the footpoints, similar to the
  physical processes occurring in the burst-like EUV events discussed
  in the literature. About a quarter of all analysed campfires, however,
  are not associated to such magnetic activity in the photosphere, which
  implies that other heating mechanisms are energising these small-scale
  EUV brightenings.

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Title: The role of asymmetries in coronal rain formation during
    thermal non-equilibrium cycles
Authors: Pelouze, Gabriel; Auchère, Frédéric; Bocchialini, Karine;
   Froment, Clara; Mikić, Zoran; Soubrié, Elie; Voyeux, Alfred
2022A&A...658A..71P    Altcode: 2021arXiv211009975P
  Context. Thermal non-equilibrium (TNE) produces several observables
  that can be used to constrain the spatial and temporal distribution
  of solar coronal heating. Its manifestations include prominence
  formation, coronal rain, and long-period intensity pulsations in
  coronal loops. The recent observation of abundant periodic coronal rain
  associated with intensity pulsations allowed for these two phenomena
  to be unified as the result of TNE condensation and evaporation
  cycles. On the other hand, many observed intensity pulsation events
  show little to no coronal rain formation. <BR /> Aims: Our goal is
  to understand why some TNE cycles produce such abundant coronal
  rain, while others produce little to no rain. <BR /> Methods:
  We reconstructed the geometry of the periodic coronal rain event,
  using images from the Extreme Ultraviolet Imager (EUVI) onboard the
  Solar Terrestrial Relations Observatory (STEREO), and magnetograms
  from the Helioseismic and Magnetic Imager (HMI). We then performed 1D
  hydrodynamic simulations of this event for different heating parameters
  and variations of the loop geometry (9000 simulations in total). We
  compared the resulting behaviour to simulations of TNE cycles that do
  not produce coronal rain. <BR /> Results: Our simulations show that
  both prominences and TNE cycles (with and without coronal rain) can
  form within the same magnetic structure. We show that the formation
  of coronal rain during TNE cycles depends on the asymmetry of the
  loop and of the heating. Asymmetric loops are overall less likely
  to produce coronal rain, regardless of the heating. In symmetric
  loops, coronal rain forms when the heating is also symmetric. In
  asymmetric loops, rain forms only when the heating compensates for
  the asymmetry. <P />Movie associated to Fig. 5 is available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202140477/olm">https://www.aanda.org</A>

---------------------------------------------------------
Title: Empirical relations between the intensities of Lyman lines
    of H and He<SUP>+</SUP>
Authors: Gordino, M.; Auchère, F.; Vial, J. -C.; Bocchialini, K.;
   Hassler, D. M.; Bando, T.; Ishikawa, R.; Kano, R.; Kobayashi, K.;
   Narukage, N.; Trujillo Bueno, J.; Winebarger, A.
2022A&A...657A..86G    Altcode: 2022arXiv220101519G
  Context. Empirical relations between major UV and extreme UV spectral
  lines are one of the inputs for models of chromospheric and coronal
  spectral radiances and irradiances. They are also needed for the
  interpretation of some of the observations of the Solar Orbiter
  mission. <BR /> Aims: We aim to determine an empirical relation between
  the intensities of the H I 121.6 nm and He II 30.4 nm Ly-α lines. <BR
  /> Methods: Images at 121.6 nm from the Chromospheric Lyman-Alpha
  Spectro Polarimeter (CLASP) and Multiple XUV Imager (MXUVI) sounding
  rockets were co-registered with simultaneous images at 30.4 nm from the
  EIT and AIA orbital telescopes in order to derive a spatially resolved
  relationship between the intensities. <BR /> Results: We have obtained
  a relationship between the H I 121.6 nm and He II 30.4 nm intensities
  that is valid for a wide range of solar features, intensities, and
  activity levels. Additional SUMER data have allowed the derivation of
  another relation between the H I 102.5 nm (Ly-β) and He II 30.4 nm
  lines for quiet-Sun regions. We combined these two relationships to
  obtain a Ly-α/Ly-β intensity ratio that is comparable to the few
  previously published results. <BR /> Conclusions: The relationship
  between the H I 121.6 nm and He II 30.4 nm lines is consistent with the
  one previously obtained using irradiance data. We have also observed
  that this relation is stable in time but that its accuracy depends on
  the spatial resolution of the observations. The derived Ly-α/Ly-β
  intensity ratio is also compatible with previous results.

---------------------------------------------------------
Title: Stereoscopy of extreme UV quiet Sun brightenings observed by
    Solar Orbiter/EUI
Authors: Zhukov, A. N.; Mierla, M.; Auchère, F.; Gissot, S.;
   Rodriguez, L.; Soubrié, E.; Thompson, W. T.; Inhester, B.; Nicula, B.;
   Antolin, P.; Parenti, S.; Buchlin, É.; Barczynski, K.; Verbeeck, C.;
   Kraaikamp, E.; Smith, P. J.; Stegen, K.; Dolla, L.; Harra, L.; Long,
   D. M.; Schühle, U.; Podladchikova, O.; Aznar Cuadrado, R.; Teriaca,
   L.; Haberreiter, M.; Katsiyannis, A. C.; Rochus, P.; Halain, J. -P.;
   Jacques, L.; Berghmans, D.
2021A&A...656A..35Z    Altcode: 2021arXiv210902169Z
  Context. The three-dimensional fine structure of the solar atmosphere
  is still not fully understood as most of the available observations
  are taken from a single vantage point. <BR /> Aims: The goal of the
  paper is to study the three-dimensional distribution of the small-scale
  brightening events ("campfires") discovered in the extreme-UV quiet Sun
  by the Extreme Ultraviolet Imager (EUI) aboard Solar Orbiter. <BR />
  Methods: We used a first commissioning data set acquired by the EUI's
  High Resolution EUV telescope on 30 May 2020 in the 174 Å passband and
  we combined it with simultaneous data taken by the Atmospheric Imaging
  Assembly (AIA) aboard the Solar Dynamics Observatory in a similar 171
  Å passband. The two-pixel spatial resolution of the two telescopes
  is 400 km and 880 km, respectively, which is sufficient to identify
  the campfires in both data sets. The two spacecraft had an angular
  separation of around 31.5° (essentially in heliographic longitude),
  which allowed for the three-dimensional reconstruction of the campfire
  position. These observations represent the first time that stereoscopy
  was achieved for brightenings at such a small scale. Manual and
  automatic triangulation methods were used to characterize the campfire
  data. <BR /> Results: The height of the campfires is located between
  1000 km and 5000 km above the photosphere and we find a good agreement
  between the manual and automatic methods. The internal structure of
  campfires is mostly unresolved by AIA; however, for a particularly
  large campfire, we were able to triangulate a few pixels, which are
  all in a narrow range between 2500 and 4500 km. <BR /> Conclusions: We
  conclude that the low height of EUI campfires suggests that they belong
  to the previously unresolved fine structure of the transition region and
  low corona of the quiet Sun. They are probably apexes of small-scale
  dynamic loops heated internally to coronal temperatures. This work
  demonstrates that high-resolution stereoscopy of structures in the
  solar atmosphere has become feasible.

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Title: Demonstration of Chromospheric Magnetic Mapping with CLASP2.1
Authors: McKenzie, David; Ishikawa, Ryohko; Trujillo Bueno, Javier;
   Auchere, F.; Kobayashi, Ken; Winebarger, Amy; Kano, Ryouhei; Song,
   Donguk; Okamoto, Joten; Rachmeler, Laurel; De Pontieu, Bart; Vigil,
   Genevieve; Belluzzi, Luca; Alsina Ballester, Ernest; del Pino Aleman,
   Tanausu; Bethge, Christian; Sakao, Taro; Stepan, Jiri
2021AGUFMSH52A..06M    Altcode:
  Probing the magnetic nature of the Suns atmosphere requires measurement
  of the Stokes I, Q, U and V profiles of relevant spectral lines (of
  which Q, U and V encode the magnetic field information). Many of the
  magnetically sensitive lines formed in the chromosphere and transition
  region are in the ultraviolet spectrum, necessitating observations
  above the absorbing terrestrial atmosphere. The Chromospheric
  Layer Spectro-Polarimeter (CLASP2) sounding rocket was flown
  successfully in April 2019, as a follow-on to the successful flight in
  September 2015 of the Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP). Both projects were funded by NASAs Heliophysics Technology
  and Instrument Development for Science (H-TIDeS) program to develop
  and test a technique for observing the Sun in ultraviolet light,
  and for quantifying the polarization of that light. By demonstrating
  successful measurement and interpretation of the polarization in
  hydrogen Lyman-alpha and the Mg II h and k spectral lines, the CLASP
  and CLASP2 missions are vital first steps towards routine quantitative
  characterization of the local thermal and magnetic conditions in the
  solar chromosphere. In October of 2021, we re-flew the CLASP2 payload
  with a modified observing program to further demonstrate the maturity
  of the UV spectropolarimetry techniques, and readiness for development
  into a satellite observatory. During the reflight, called CLASP2.1,
  the spectrograph slit was scanned across an active region plage to
  acquire a two-dimensional map of Stokes V/I, to demonstrate the ability
  of UV spectropolarimetry to yield chromospheric magnetic fields over
  a large area. This presentation will display preliminary results from
  the flight of CLASP2.1.

---------------------------------------------------------
Title: 3D modelling of Titov-Demoulin modified Flux Ropes propagation
    in the Solar Wind
Authors: Regnault, Florian; Janvier, Miho; Strugarek, Antoine; Auchere,
   F.; Al-Haddad, Nada
2021AGUFMSH33A..04R    Altcode:
  Interplanetary Coronal Mass Ejections (ICMEs) originate from the
  eruption of complex magnetic structures occurring in our stars
  atmosphere. They propagate in the interplanetary medium, where they
  can be probed by spacecraft. ICMEs are known to generate geomagnetic
  storms that can disturb our technologies on earth, this is why they
  are a subject of interest. Studying ICMEs could, therefore, allow us to
  predict and lower their impact in our technology. We present the results
  of the propagation simulation of a set of Titov-Demoulin flux ropes
  (Titov et al. 2014) with different magnetic fields and sizes at the
  initiation. This is done with the 3D MHD module of the PLUTO code. Our
  grid starts at the low corona and goes up to 2 astronomical units. This
  allows us to study the effect of the magnetic field intensity or the
  size of the flux rope at the initiation on its properties during the
  propagation, highlighting then the physical processes happening during
  their journey in the inner heliosphere. The evolution of the magnetic
  field of the flux rope during the propagation agrees with evolution
  laws deduced from in situ observations. We also simulate in situ
  profiles that spacecraft would have measured at Mercury and at Earth,
  and we compare with the results of Janvier et al. 2019 and Regnault et
  al. 2020. We find a good match between simulated in situ profiles and
  typical profiles obtained in these studies. The magnetic components
  of the simulated flux rope match well with what we are expecting from
  theory (Lundquist et al. 1950). This simulation helps us to have a
  better understanding of the physical mechanisms that happen during
  propagation of an ICME.

---------------------------------------------------------
Title: Full Vector Velocity Reconstruction Using Solar Orbiter
    Doppler Map Observations.
Authors: Podladchikova, Olena; Harra, Louise; Barczynski, Krzysztof;
   Mandrini, Cristina; Auchere, F.; Berghmans, David; Buchlin, Eric;
   Dolla, Laurent; Mierla, Marilena; Parenti, Susanna; Rodriguez, Luciano
2021AGUFMNG35B0432P    Altcode:
  The Solar Orbiter mission opens up opportunities forthe
  combined analysis of measurements obtained by solar imagers and
  spectrometers. For the first time, different space spectrometerswill
  be located at wide angles to each other, allowing three-dimensional
  (3D) spectroscopy of the solar atmosphere.The aim of this work is to
  prepare the methodology to facilitate the reconstruction of 3D vector
  velocities from two stereoscopicLOS Doppler velocity measurements using
  the Spectral Imaging of the Coronal Environment (SPICE) on board the
  Solar Orbiter andthe near-Earth spectrometers, while widely separated in
  space. We develop the methodology using the libraries designed earlier
  for the STEREO mission but applied to spectroscopicdata from the Hinode
  mission and the Solar Dynamics Observatory. We use well-known methods
  of static and dynamic solar rotationstereoscopy and the methods of
  EUV stereoscopic triangulation for optically-thin coronal EUV plasma
  emissions. We develop new algorithms using analytical geometry in
  space to determine the 3D velocity in coronal loops. We demonstrate
  our approach with the reconstruction of 3D velocity vectors in plasma
  flows along "open" and "closed"magnetic loops. This technique will be
  applied first to an actual situation of two spacecraft at different
  separations with spectrometers onboard (SPICE versus the Interface
  Region Imaging Spectrograph (IRIS) and Hinode imaging spectrometer)
  during the Solar Orbiternominal phase. We summarise how these
  observations can be coordinated.

---------------------------------------------------------
Title: Campfires observed by EUI: What have we learned so far?
Authors: Berghmans, David; Auchere, F.; Zhukov, Andrei; Mierla,
   Marilena; Chen, Yajie; Peter, Hardi; Panesar, Navdeep; Chitta, Lakshmi
   Pradeep; Antolin, Patrick; Aznar Cuadrado, Regina; Tian, Hui; Hou,
   Zhenyong; Podladchikova, Olena
2021AGUFMSH21A..02B    Altcode:
  Since its very first light images of the corona, the EUI/HRIEUV
  telescope onboard Solar Orbiter has observed small localised
  brightenings in the Quiet Sun. These small localised brightenings,
  have become known as campfires, and are observed with length scales
  between 400 km and 4000 km and durations between 10 sec and 200
  sec. The smallest and weakest of these HRIEUV brightenings have
  not been previously observed. Simultaneous observations from the
  EUI High-resolution Lyman- telescope (HRILYA) do not show localised
  brightening events, but the locations of the HRIEUV events clearly
  correspond to the chromospheric network. Comparisons with simultaneous
  AIA images shows that most events can also be identified in the
  17.1 nm, 19.3 nm, 21.1 nm, and 30.4 nm pass-bands of AIA, although
  they appear weaker and blurred. Some of the larger campfires have
  the appearance of small interacting loops with the brightening
  expanding from the contact point of the loops. Our differential
  emission measure (DEM) analysis indicated coronal temperatures. We
  determined the height for a few of these campfires to be between 1
  and 5 Mm above the photosphere. We interpret these events as a new
  extension to the flare-microflare-nanoflare family. Given their low
  height, the EUI campfires could stand as a new element of the fine
  structure of the transition region-low corona, that is, as apexes
  of small-scale loops that undergo internal heating all the way up to
  coronal temperatures. 3D MHD simulations with the MURaM code revealed
  brightenings that are in many ways similar to the campfires by EUI. The
  brightenings in the simulations suggest that campfires are triggered by
  component reconnection inside flux bundles rather than flux emergence
  or cancellation. Nevertheless, some of the observed campfires can
  be clearly linked to flux cancellation events and, intriguingly,
  are preceded by an erupting cool plasma structure. Analysis of the
  dynamics of campfires revealed that some have the appearance of coronal
  microjets, the smallest coronal jets observed in the quiet Sun. The
  HRIEUV images also reveal transient jets on a somewhat bigger scale
  with repeated outflows on the order of 100 km s1. In this paper we
  will provide an overview of the campfire related phenomena that EUI
  has observed and discuss the possible relevance for coronal heating.

---------------------------------------------------------
Title: Stereoscopy of extreme UV quiet Sun brightenings observed by
    Solar Orbiter/EUI
Authors: Zhukov, Andrei; Mierla, Marilena; Auchere, F.; Gissot,
   Samuel; Rodriguez, Luciano; Soubrie, Elie; Thompson, William; Inhester,
   Bernd; Nicula, Bogdan; Antolin, Patrick; Parenti, Susanna; Buchlin,
   Eric; Barczynski, Krzysztof; Verbeeck, Cis; Kraaikamp, Emil; Smith,
   Philip; Stegen, Koen; Dolla, Laurent; Harra, Louise; Long, David;
   Schuhle, Udo; Podladchikova, Olena; Aznar Cuadrado, Regina; Teriaca,
   Luca; Haberreiter, Margit; Katsiyannis, Athanassios; Rochus, Pierre;
   Halain, Jean-Philippe; Jacques, Lionel; Berghmans, David
2021AGUFMSH21A..03Z    Altcode:
  We study the three-dimensional distribution of small-scale brightening
  events (campfires) discovered in the extreme-ultraviolet (EUV) quiet Sun
  by the EUI telescope onboard the Solar Orbiter mission. We use one of
  the first commissioning data sets acquired by the HRI_EUV telescope of
  EUI on 2020 May 30 in the 174 A passband, combined with the simultaneous
  SDO/AIA dataset taken in the very similar 171 A passband. The spatial
  resolution of the two telescopes is sufficient to identify the campfires
  in both datasets. The angular separation between the two spacecraft of
  around 31.5 degrees allowed for the three-dimensional reconstruction
  of the position of campfires. This is the first time that stereoscopy
  was achieved for structures at such a small scale. Manual and automatic
  triangulation methods were used. The height of campfires is between 1000
  km and 5000 km above the photosphere, and there is a good agreement
  between the results of manual and automatic methods. The internal
  structure of campfires is mostly not resolved by AIA, but for a large
  campfire we could triangulate a few pixels, which are all in a narrow
  height range between 2500 and 4500 km. The low height of campfires
  suggests that they belong to the previously unresolved fine structure
  of the transition region and low corona of the quiet Sun. They are
  probably apexes of small-scale dynamic loops internally heated to
  coronal temperatures. This work demonstrates that high-resolution
  stereoscopy of structures in the solar atmosphere has become possible.

---------------------------------------------------------
Title: Extreme-UV quiet Sun brightenings observed by the Solar
    Orbiter/EUI
Authors: Berghmans, D.; Auchère, F.; Long, D. M.; Soubrié, E.;
   Mierla, M.; Zhukov, A. N.; Schühle, U.; Antolin, P.; Harra, L.;
   Parenti, S.; Podladchikova, O.; Aznar Cuadrado, R.; Buchlin, É.;
   Dolla, L.; Verbeeck, C.; Gissot, S.; Teriaca, L.; Haberreiter, M.;
   Katsiyannis, A. C.; Rodriguez, L.; Kraaikamp, E.; Smith, P. J.;
   Stegen, K.; Rochus, P.; Halain, J. P.; Jacques, L.; Thompson, W. T.;
   Inhester, B.
2021A&A...656L...4B    Altcode: 2021arXiv210403382B
  Context. The heating of the solar corona by small heating events
  requires an increasing number of such events at progressively smaller
  scales, with the bulk of the heating occurring at scales that are
  currently unresolved. <BR /> Aims: The goal of this work is to study the
  smallest brightening events observed in the extreme-UV quiet Sun. <BR />
  Methods: We used commissioning data taken by the Extreme Ultraviolet
  Imager (EUI) on board the recently launched Solar Orbiter mission. On
  30 May 2020, the EUI was situated at 0.556 AU from the Sun. Its
  High Resolution EUV telescope (HRI<SUB>EUV</SUB>, 17.4 nm passband)
  reached an exceptionally high two-pixel spatial resolution of 400
  km. The size and duration of small-scale structures was determined
  by the HRI<SUB>EUV</SUB> data, while their height was estimated
  from triangulation with simultaneous images from the Atmospheric
  Imaging Assembly (AIA) on board the Solar Dynamics Observatory
  mission. This is the first stereoscopy of small-scale brightenings
  at high resolution. <BR /> Results: We observed small localised
  brightenings, also known as `campfires', in a quiet Sun region with
  length scales between 400 km and 4000 km and durations between 10 s and
  200 s. The smallest and weakest of these HRI<SUB>EUV</SUB> brightenings
  have not been previously observed. Simultaneous observations from the
  EUI High-resolution Lyman-α telescope (HRI<SUB>Lya</SUB>) do not show
  localised brightening events, but the locations of the HRI<SUB>EUV</SUB>
  events clearly correspond to the chromospheric network. Comparisons with
  simultaneous AIA images shows that most events can also be identified
  in the 17.1 nm, 19.3 nm, 21.1 nm, and 30.4 nm pass-bands of AIA,
  although they appear weaker and blurred. Our differential emission
  measure analysis indicated coronal temperatures peaking at log T ≈
  6.1 − 6.15. We determined the height for a few of these campfires to
  be between 1000 and 5000 km above the photosphere. <BR /> Conclusions:
  We find that `campfires' are mostly coronal in nature and rooted in the
  magnetic flux concentrations of the chromospheric network. We interpret
  these events as a new extension to the flare-microflare-nanoflare
  family. Given their low height, the EUI `campfires' could stand as a
  new element of the fine structure of the transition region-low corona,
  that is, as apexes of small-scale loops that undergo internal heating
  all the way up to coronal temperatures.

---------------------------------------------------------
Title: Capturing transient plasma flows and jets in the solar corona
Authors: Chitta, L. P.; Solanki, S. K.; Peter, H.; Aznar Cuadrado,
   R.; Teriaca, L.; Schühle, U.; Auchère, F.; Berghmans, D.; Kraaikamp,
   E.; Gissot, S.; Verbeeck, C.
2021A&A...656L..13C    Altcode: 2021arXiv210915106C
  Intensity bursts in ultraviolet (UV) to X-ray wavelengths and plasma
  jets are typical signatures of magnetic reconnection and the associated
  impulsive heating of the solar atmospheric plasma. To gain new insights
  into the process, high-cadence observations are required to capture
  the rapid response of plasma to magnetic reconnection as well as the
  highly dynamic evolution of jets. Here, we report the first 2 s cadence
  extreme-UV observations recorded by the 174 Å High Resolution Imager of
  the Extreme Ultraviolet Imager on board the Solar Orbiter mission. These
  observations, covering a quiet-Sun coronal region, reveal the onset
  signatures of magnetic reconnection as localized heating events. These
  localized sources then exhibit repeated plasma eruptions or jet
  activity. Our observations show that this spatial morphological change
  from localized sources to jet activity could occur rapidly on timescales
  of about 20 s. The jets themselves are intermittent and are produced
  from the source region on timescales of about 20 s. In the initial
  phases of these events, plasma jets are observed to exhibit speeds,
  as inferred from propagating intensity disturbances, in the range of
  100 km s<SUP>−1</SUP> to 150 km s<SUP>−1</SUP>. These jets then
  propagate to lengths of about 5 Mm. We discuss examples of bidirectional
  and unidirectional jet activity observed to have been initiated from
  the initially localized bursts in the corona. The transient nature
  of coronal bursts and the associated plasma flows or jets along with
  their dynamics could provide a benchmark for magnetic reconnection
  models of coronal bursts and jets. <P />Movies are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202141683/olm">https://www.aanda.org</A>

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Title: Propagating brightenings in small loop-like structures in
the quiet-Sun corona: Observations from Solar Orbiter/EUI
Authors: Mandal, Sudip; Peter, Hardi; Chitta, Lakshmi Pradeep;
   Solanki, Sami K.; Aznar Cuadrado, Regina; Teriaca, Luca; Schühle,
   Udo; Berghmans, David; Auchère, Frédéric
2021A&A...656L..16M    Altcode: 2021arXiv211108106M
  Brightenings observed in solar extreme-ultraviolet images are generally
  interpreted as signatures of micro- or nanoflares occurring in the
  transition region or at coronal temperatures. Recent observations
  with the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter have
  revealed the smallest of such brightenings (called campfires) in the
  quiet-Sun corona. Analyzing EUI 174 Å data obtained at a resolution
  of about 400 km on the Sun with a cadence of 5 s on 30 May 2020,
  we report here a number of cases in which these campfires exhibit
  propagating signatures along their apparently small (3-5 Mm) loop-like
  structures. The measured propagation speeds are generally between 25
  km s<SUP>−1</SUP> and 60 km s<SUP>−1</SUP>. If the loop plasma is
  assumed to be at a million Kelvin, these apparent motions would be
  slower than the local sound speed. Furthermore, these brightenings
  exhibit nontrivial propagation characteristics such as bifurcation,
  merging, reflection, and repeated plasma ejections. We suggest that
  these features are manifestations of the internal dynamics of these
  small-scale magnetic structures and could provide important insights
  into the dynamic response (∼40 s) of the loop plasma to the heating
  events and also into the locations of the heating events themselves. <P
  />Movies associated to Figs 2-5, A.1, and B.1 are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202142041/olm">https://www.aanda.org</A>

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Title: The first coronal mass ejection observed in both visible-light
    and UV H I Ly-α channels of the Metis coronagraph on board Solar
    Orbiter
Authors: Andretta, V.; Bemporad, A.; De Leo, Y.; Jerse, G.; Landini,
   F.; Mierla, M.; Naletto, G.; Romoli, M.; Sasso, C.; Slemer, A.;
   Spadaro, D.; Susino, R.; Talpeanu, D. -C.; Telloni, D.; Teriaca, L.;
   Uslenghi, M.; Antonucci, E.; Auchère, F.; Berghmans, D.; Berlicki,
   A.; Capobianco, G.; Capuano, G. E.; Casini, C.; Casti, M.; Chioetto,
   P.; Da Deppo, V.; Fabi, M.; Fineschi, S.; Frassati, F.; Frassetto,
   F.; Giordano, S.; Grimani, C.; Heinzel, P.; Liberatore, A.; Magli, E.;
   Massone, G.; Messerotti, M.; Moses, D.; Nicolini, G.; Pancrazzi, M.;
   Pelizzo, M. -G.; Romano, P.; Schühle, U.; Stangalini, M.; Straus,
   Th.; Volpicelli, C. A.; Zangrilli, L.; Zuppella, P.; Abbo, L.; Aznar
   Cuadrado, R.; Bruno, R.; Ciaravella, A.; D'Amicis, R.; Lamy, P.;
   Lanzafame, A.; Malvezzi, A. M.; Nicolosi, P.; Nisticò, G.; Peter,
   H.; Plainaki, C.; Poletto, L.; Reale, F.; Solanki, S. K.; Strachan,
   L.; Tondello, G.; Tsinganos, K.; Velli, M.; Ventura, R.; Vial, J. -C.;
   Woch, J.; Zimbardo, G.
2021A&A...656L..14A    Altcode:
  Context. The Metis coronagraph on board Solar Orbiter offers a new
  view of coronal mass ejections (CMEs), observing them for the first
  time with simultaneous images acquired with a broad-band filter in
  the visible-light interval and with a narrow-band filter around the
  H I Ly-α line at 121.567 nm, the so-called Metis UV channel. <BR />
  Aims: We show the first Metis observations of a CME, obtained on 16
  and 17 January 2021. The event was also observed by the EUI/FSI imager
  on board Solar Orbiter, as well as by other space-based coronagraphs,
  such as STEREO-A/COR2 and SOHO/LASCO/C2, whose images are combined here
  with Metis data. <BR /> Methods: Different images are analysed here
  to reconstruct the 3D orientation of the expanding CME flux rope using
  the graduated cylindrical shell model. This also allows us to identify
  the possible location of the source region. Measurements of the CME
  kinematics allow us to quantify the expected Doppler dimming in the
  Ly-α channel. <BR /> Results: Observations show that most CME features
  seen in the visible-light images are also seen in the Ly-α images,
  although some features in the latter channel appear more structured
  than their visible-light counterparts. We estimated the expansion
  velocity of this event to be below 140 km s<SUP>−1</SUP>. Hence,
  these observations can be understood by assuming that Doppler dimming
  effects do not strongly reduce the Ly-α emission from the CME. These
  velocities are comparable with or smaller than the radial velocities
  inferred from the same data in a similar coronal structure on the
  east side of the Sun. <BR /> Conclusions: The first observations by
  Metis of a CME demonstrate the capability of the instrument to provide
  valuable and novel information on the structure and dynamics of these
  coronal events. Considering also its diagnostics capabilities regarding
  the conditions of the ambient corona, Metis promises to significantly
  advance our knowledge of such phenomena. <P />Movies are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202142407/olm">https://www.aanda.org</A>

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Title: First observations from the SPICE EUV spectrometer on Solar
    Orbiter
Authors: Fludra, A.; Caldwell, M.; Giunta, A.; Grundy, T.; Guest,
   S.; Leeks, S.; Sidher, S.; Auchère, F.; Carlsson, M.; Hassler, D.;
   Peter, H.; Aznar Cuadrado, R.; Buchlin, É.; Caminade, S.; DeForest,
   C.; Fredvik, T.; Haberreiter, M.; Harra, L.; Janvier, M.; Kucera, T.;
   Müller, D.; Parenti, S.; Schmutz, W.; Schühle, U.; Solanki, S. K.;
   Teriaca, L.; Thompson, W. T.; Tustain, S.; Williams, D.; Young, P. R.;
   Chitta, L. P.
2021A&A...656A..38F    Altcode: 2021arXiv211011252F
  <BR /> Aims: We present first science observations taken during the
  commissioning activities of the Spectral Imaging of the Coronal
  Environment (SPICE) instrument on the ESA/NASA Solar Orbiter
  mission. SPICE is a high-resolution imaging spectrometer operating at
  extreme ultraviolet (EUV) wavelengths. In this paper we illustrate
  the possible types of observations to give prospective users a
  better understanding of the science capabilities of SPICE. <BR />
  Methods: We have reviewed the data obtained by SPICE between April
  and June 2020 and selected representative results obtained with
  different slits and a range of exposure times between 5 s and 180
  s. Standard instrumental corrections have been applied to the raw
  data. <BR /> Results: The paper discusses the first observations
  of the Sun on different targets and presents an example of the full
  spectra from the quiet Sun, identifying over 40 spectral lines from
  neutral hydrogen and ions of carbon, oxygen, nitrogen, neon, sulphur,
  magnesium, and iron. These lines cover the temperature range between
  20 000 K and 1 million K (10 MK in flares), providing slices of the
  Sun's atmosphere in narrow temperature intervals. We provide a list
  of count rates for the 23 brightest spectral lines. We show examples
  of raster images of the quiet Sun in several strong transition region
  lines, where we have found unusually bright, compact structures in the
  quiet Sun network, with extreme intensities up to 25 times greater
  than the average intensity across the image. The lifetimes of these
  structures can exceed 2.5 hours. We identify them as a transition
  region signature of coronal bright points and compare their areas and
  intensity enhancements. We also show the first above-limb measurements
  with SPICE above the polar limb in C III, O VI, and Ne VIII lines, and
  far off limb measurements in the equatorial plane in Mg IX, Ne VIII,
  and O VI lines. We discuss the potential to use abundance diagnostics
  methods to study the variability of the elemental composition that can
  be compared with in situ measurements to help confirm the magnetic
  connection between the spacecraft location and the Sun's surface,
  and locate the sources of the solar wind. <BR /> Conclusions: The
  SPICE instrument successfully performs measurements of EUV spectra
  and raster images that will make vital contributions to the scientific
  success of the Solar Orbiter mission.

---------------------------------------------------------
Title: First light observations of the solar wind in the outer corona
    with the Metis coronagraph
Authors: Romoli, M.; Antonucci, E.; Andretta, V.; Capuano, G. E.; Da
   Deppo, V.; De Leo, Y.; Downs, C.; Fineschi, S.; Heinzel, P.; Landini,
   F.; Liberatore, A.; Naletto, G.; Nicolini, G.; Pancrazzi, M.; Sasso,
   C.; Spadaro, D.; Susino, R.; Telloni, D.; Teriaca, L.; Uslenghi,
   M.; Wang, Y. -M.; Bemporad, A.; Capobianco, G.; Casti, M.; Fabi, M.;
   Frassati, F.; Frassetto, F.; Giordano, S.; Grimani, C.; Jerse, G.;
   Magli, E.; Massone, G.; Messerotti, M.; Moses, D.; Pelizzo, M. -G.;
   Romano, P.; Schühle, U.; Slemer, A.; Stangalini, M.; Straus, T.;
   Volpicelli, C. A.; Zangrilli, L.; Zuppella, P.; Abbo, L.; Auchère,
   F.; Aznar Cuadrado, R.; Berlicki, A.; Bruno, R.; Ciaravella, A.;
   D'Amicis, R.; Lamy, P.; Lanzafame, A.; Malvezzi, A. M.; Nicolosi,
   P.; Nisticò, G.; Peter, H.; Plainaki, C.; Poletto, L.; Reale, F.;
   Solanki, S. K.; Strachan, L.; Tondello, G.; Tsinganos, K.; Velli,
   M.; Ventura, R.; Vial, J. -C.; Woch, J.; Zimbardo, G.
2021A&A...656A..32R    Altcode: 2021arXiv210613344R
  In this work, we present an investigation of the wind in the solar
  corona that has been initiated by observations of the resonantly
  scattered ultraviolet emission of the coronal plasma obtained with
  UVCS-SOHO, designed to measure the wind outflow speed by applying
  Doppler dimming diagnostics. Metis on Solar Orbiter complements the
  UVCS spectroscopic observations that were performed during solar
  activity cycle 23 by simultaneously imaging the polarized visible
  light and the H I Lyman-α corona in order to obtain high spatial and
  temporal resolution maps of the outward velocity of the continuously
  expanding solar atmosphere. The Metis observations, taken on May 15,
  2020, provide the first H I Lyman-α images of the extended corona
  and the first instantaneous map of the speed of the coronal plasma
  outflows during the minimum of solar activity and allow us to identify
  the layer where the slow wind flow is observed. The polarized visible
  light (580-640 nm) and the ultraviolet H I Lyα (121.6 nm) coronal
  emissions, obtained with the two Metis channels, were combined in
  order to measure the dimming of the UV emission relative to a static
  corona. This effect is caused by the outward motion of the coronal
  plasma along the direction of incidence of the chromospheric photons
  on the coronal neutral hydrogen. The plasma outflow velocity was then
  derived as a function of the measured Doppler dimming. The static
  corona UV emission was simulated on the basis of the plasma electron
  density inferred from the polarized visible light. This study leads
  to the identification, in the velocity maps of the solar corona, of
  the high-density layer about ±10° wide, centered on the extension
  of a quiet equatorial streamer present at the east limb - the coronal
  origin of the heliospheric current sheet - where the slowest wind
  flows at about 160 ± 18 km s<SUP>−1</SUP> from 4 R<SUB>⊙</SUB>
  to 6 R<SUB>⊙</SUB>. Beyond the boundaries of the high-density layer,
  the wind velocity rapidly increases, marking the transition between
  slow and fast wind in the corona.

---------------------------------------------------------
Title: Transient small-scale brightenings in the quiet solar corona:
    A model for campfires observed with Solar Orbiter
Authors: Chen, Yajie; Przybylski, Damien; Peter, Hardi; Tian, Hui;
   Auchère, F.; Berghmans, D.
2021A&A...656L...7C    Altcode: 2021arXiv210410940C
  Context. Recent observations by the Extreme Ultraviolet Imager (EUI) on
  board Solar Orbiter have characterized prevalent small-scale transient
  brightenings in the corona above the quiet Sun termed campfires. <BR />
  Aims: In this study we search for comparable brightenings in a numerical
  model and then investigate their relation to the magnetic field and the
  processes that drive these events. <BR /> Methods: We used the MURaM
  code to solve the 3D radiation magnetohydrodynamic equations in a box
  that stretches from the upper convection zone to the corona. The model
  self-consistently produces a supergranular network of the magnetic
  field and a hot corona above this quiet Sun. For the comparison with
  the model, we synthesized the coronal emission as seen by EUI in its
  174 Å channel, isolated the seven strongest transient brightenings,
  and investigated the changes of the magnetic field in and around these
  in detail. <BR /> Results: The transients we isolated have a lifetime of
  about 2 min and are elongated loop-like features with lengths around 1
  Mm to 4 Mm. They tend to occur at heights of about 2 Mm to 5 Mm above
  the photosphere, a bit offset from magnetic concentrations that mark
  the bright chromospheric network, and they reach temperatures of above
  1 MK. As a result, they very much resemble the larger campfires found
  in observations. In our model most events are energized by component
  reconnection between bundles of field lines that interact at coronal
  heights. In one case, we find that untwisting a highly twisted flux
  rope initiates the heating. <BR /> Conclusions: Based on our study, we
  propose that the majority of campfire events found by EUI are driven
  by component reconnection and our model suggests that this process
  significantly contributes to the heating of the corona above the quiet
  Sun. <P />Movies associated to Figs. 2, 4, 5, and A1 are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202140638/olm">https://www.aanda.org</A>

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Title: Stereoscopic measurements of coronal Doppler velocities
Authors: Podladchikova, O.; Harra, L.; Barczynski, K.; Mandrini,
   C. H.; Auchère, F.; Berghmans, D.; Buchlin, É.; Dolla, L.; Mierla,
   M.; Parenti, S.; Rodriguez, L.
2021A&A...655A..57P    Altcode: 2021arXiv210802280P
  Context. The Solar Orbiter mission, with an orbit outside the Sun-Earth
  line and leaving the ecliptic plane, opens up opportunities for
  the combined analysis of measurements obtained by solar imagers and
  spectrometers. For the first time different space spectrometers will be
  located at wide angles to each other, allowing three-dimensional (3D)
  spectroscopy of the solar atmosphere. <BR /> Aims: The aim of this
  work is to prepare a methodology to facilitate the reconstruction
  of 3D vector velocities from two stereoscopic line of sight (LOS)
  Doppler velocity measurements using the Spectral Imaging of the
  Coronal Environment (SPICE) on board the Solar Orbiter and the
  near-Earth spectrometers, while widely separated in space. <BR />
  Methods: We developed the methodology using the libraries designed
  earlier for the STEREO mission, but applied to spectroscopic data
  from the Hinode mission and the Solar Dynamics Observatory. We used
  well-known methods of static and dynamic solar rotation stereoscopy and
  the methods of extreme ultraviolet (EUV) stereoscopic triangulation
  for optically thin coronal EUV plasma emissions. We developed new
  algorithms using analytical geometry in space to determine the 3D
  velocity in coronal loops. <BR /> Results: We demonstrate our approach
  with the reconstruction of 3D velocity vectors in plasma flows along
  `open' and `closed' magnetic loops. This technique will be applied
  to an actual situation of two spacecraft at different separations
  with spectrometers on board during the Solar Orbiter nominal phase:
  SPICE versus the Interface Region Imaging Spectrograph (IRIS) and
  Hinode imaging spectrometer. We summarise how these observations can
  be coordinated. <P />Movies associated to Fig. 1 are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202140457/olm">https://www.aanda.org</A>

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Title: The Magnetic Origin of Solar Campfires
Authors: Panesar, Navdeep K.; Tiwari, Sanjiv K.; Berghmans, David;
   Cheung, Mark C. M.; Müller, Daniel; Auchere, Frederic; Zhukov, Andrei
2021ApJ...921L..20P    Altcode: 2021arXiv211006846P
  Solar campfires are fine-scale heating events, recently observed by
  Extreme Ultraviolet Imager (EUI) on board Solar Orbiter. Here we use EUI
  174 Å images, together with EUV images from Solar Dynamics Observatory
  (SDO)/Atmospheric Imaging Assembly (AIA), and line-of-sight magnetograms
  from SDO/Helioseismic and Magnetic Imager (HMI) to investigate the
  magnetic origin of 52 randomly selected campfires in the quiet solar
  corona. We find that (i) the campfires are rooted at the edges of
  photospheric magnetic network lanes; (ii) most of the campfires reside
  above the neutral line between majority-polarity magnetic flux patch and
  a merging minority-polarity flux patch, with a flux cancelation rate of
  ~10<SUP>18</SUP> Mx hr<SUP>-1</SUP>; (iii) some of the campfires occur
  repeatedly from the same neutral line; (iv) in the large majority of
  instances, campfires are preceded by a cool-plasma structure, analogous
  to minifilaments in coronal jets; and (v) although many campfires have
  "complex" structure, most campfires resemble small-scale jets, dots,
  or loops. Thus, "campfire" is a general term that includes different
  types of small-scale solar dynamic features. They contain sufficient
  magnetic energy (~10<SUP>26</SUP>-10<SUP>27</SUP> erg) to heat the solar
  atmosphere locally to 0.5-2.5 MK. Their lifetimes range from about 1
  minute to over 1 hr, with most of the campfires having a lifetime of
  &lt;10 minutes. The average lengths and widths of the campfires are 5400
  ± 2500 km and 1600 ± 640 km, respectively. Our observations suggest
  that (a) the presence of magnetic flux ropes may be ubiquitous in the
  solar atmosphere and not limited to coronal jets and larger-scale
  eruptions that make CMEs, and (b) magnetic flux cancelation is the
  fundamental process for the formation and triggering of most campfires.

---------------------------------------------------------
Title: Exploring the Solar Wind from Its Source on the Corona into
    the Inner Heliosphere during the First Solar Orbiter-Parker Solar
    Probe Quadrature
Authors: Telloni, Daniele; Andretta, Vincenzo; Antonucci, Ester;
   Bemporad, Alessandro; Capuano, Giuseppe E.; Fineschi, Silvano;
   Giordano, Silvio; Habbal, Shadia; Perrone, Denise; Pinto, Rui F.;
   Sorriso-Valvo, Luca; Spadaro, Daniele; Susino, Roberto; Woodham, Lloyd
   D.; Zank, Gary P.; Romoli, Marco; Bale, Stuart D.; Kasper, Justin C.;
   Auchère, Frédéric; Bruno, Roberto; Capobianco, Gerardo; Case,
   Anthony W.; Casini, Chiara; Casti, Marta; Chioetto, Paolo; Corso,
   Alain J.; Da Deppo, Vania; De Leo, Yara; Dudok de Wit, Thierry;
   Frassati, Federica; Frassetto, Fabio; Goetz, Keith; Guglielmino,
   Salvo L.; Harvey, Peter R.; Heinzel, Petr; Jerse, Giovanna; Korreck,
   Kelly E.; Landini, Federico; Larson, Davin; Liberatore, Alessandro;
   Livi, Roberto; MacDowall, Robert J.; Magli, Enrico; Malaspina, David
   M.; Massone, Giuseppe; Messerotti, Mauro; Moses, John D.; Naletto,
   Giampiero; Nicolini, Gianalfredo; Nisticò, Giuseppe; Panasenco,
   Olga; Pancrazzi, Maurizio; Pelizzo, Maria G.; Pulupa, Marc; Reale,
   Fabio; Romano, Paolo; Sasso, Clementina; Schühle, Udo; Stangalini,
   Marco; Stevens, Michael L.; Strachan, Leonard; Straus, Thomas; Teriaca,
   Luca; Uslenghi, Michela; Velli, Marco; Verscharen, Daniel; Volpicelli,
   Cosimo A.; Whittlesey, Phyllis; Zangrilli, Luca; Zimbardo, Gaetano;
   Zuppella, Paola
2021ApJ...920L..14T    Altcode: 2021arXiv211011031T
  This Letter addresses the first Solar Orbiter (SO)-Parker Solar
  Probe (PSP) quadrature, occurring on 2021 January 18 to investigate
  the evolution of solar wind from the extended corona to the inner
  heliosphere. Assuming ballistic propagation, the same plasma volume
  observed remotely in the corona at altitudes between 3.5 and 6.3
  solar radii above the solar limb with the Metis coronagraph on SO
  can be tracked to PSP, orbiting at 0.1 au, thus allowing the local
  properties of the solar wind to be linked to the coronal source region
  from where it originated. Thanks to the close approach of PSP to the
  Sun and the simultaneous Metis observation of the solar corona, the
  flow-aligned magnetic field and the bulk kinetic energy flux density
  can be empirically inferred along the coronal current sheet with an
  unprecedented accuracy, allowing in particular estimation of the Alfvén
  radius at 8.7 solar radii during the time of this event. This is thus
  the very first study of the same solar wind plasma as it expands from
  the sub-Alfvénic solar corona to just above the Alfvén surface.

---------------------------------------------------------
Title: Magnetic imaging of the outer solar atmosphere (MImOSA)
Authors: Peter, H.; Ballester, E. Alsina; Andretta, V.; Auchère, F.;
   Belluzzi, L.; Bemporad, A.; Berghmans, D.; Buchlin, E.; Calcines, A.;
   Chitta, L. P.; Dalmasse, K.; Alemán, T. del Pino; Feller, A.; Froment,
   C.; Harrison, R.; Janvier, M.; Matthews, S.; Parenti, S.; Przybylski,
   D.; Solanki, S. K.; Štěpán, J.; Teriaca, L.; Bueno, J. Trujillo
2021ExA...tmp...95P    Altcode:
  The magnetic activity of the Sun directly impacts the Earth and human
  life. Likewise, other stars will have an impact on the habitability of
  planets orbiting these host stars. Although the magnetic field at the
  surface of the Sun is reasonably well characterised by observations,
  the information on the magnetic field in the higher atmospheric layers
  is mainly indirect. This lack of information hampers our progress in
  understanding solar magnetic activity. Overcoming this limitation would
  allow us to address four paramount long-standing questions: (1) How
  does the magnetic field couple the different layers of the atmosphere,
  and how does it transport energy? (2) How does the magnetic field
  structure, drive and interact with the plasma in the chromosphere and
  upper atmosphere? (3) How does the magnetic field destabilise the outer
  solar atmosphere and thus affect the interplanetary environment? (4)
  How do magnetic processes accelerate particles to high energies? New
  ground-breaking observations are needed to address these science
  questions. We suggest a suite of three instruments that far exceed
  current capabilities in terms of spatial resolution, light-gathering
  power, and polarimetric performance: (a) A large-aperture UV-to-IR
  telescope of the 1-3 m class aimed mainly to measure the magnetic
  field in the chromosphere by combining high spatial resolution
  and high sensitivity. (b) An extreme-UV-to-IR coronagraph that is
  designed to measure the large-scale magnetic field in the corona with
  an aperture of about 40 cm. (c) An extreme-UV imaging polarimeter
  based on a 30 cm telescope that combines high throughput in the
  extreme UV with polarimetry to connect the magnetic measurements
  of the other two instruments. Placed in a near-Earth orbit, the data
  downlink would be maximised, while a location at L4 or L5 would provide
  stereoscopic observations of the Sun in combination with Earth-based
  observatories. This mission to measure the magnetic field will finally
  unlock the driver of the dynamics in the outer solar atmosphere and
  thereby will greatly advance our understanding of the Sun and the
  heliosphere.

---------------------------------------------------------
Title: Vector Velocities Measurements with the Solar Orbiter SPICE
    Spectrometer
Authors: Podladchikova, O.; Harra, L.; Barczynski, K.; Mandrini,
   C.; Auchère, F.; Berghmans, D.; Buchlin, E.; Dolla, L.; Mierla, M.;
   Parenti, S.; Rodriguez, L.
2021AAS...23831312P    Altcode:
  The Solar Orbiter mission, with an orbit outside the Sun-Earth
  line and leaving the ecliptic plane, opens up opportunities for
  the combined analysis of measurements obtained by solar imagers and
  spectrometers. For the first time, different spectrometers will be
  located at wide angles to each other, allowing three-dimensional (3D)
  spectroscopy of the solar atmosphere. Here we develop a methodology to
  prepare for this kind of analysis, by using data from the Hinode mission
  and the Solar Dynamics Observatory, respectively. We employ solar
  rotation to simulate measurements of spectrometers with different views
  of the solar corona. The resulting data allow us to apply stereoscopic
  tie-pointing and triangulation techniques designed for the STEREO
  spacecraft pair, and to perform 3D analysis of the Doppler shifts of
  a quasi-stationary active region. Our approach allows the accurate
  reconstruction of 3D velocity vectors in plasma flows along "open" and
  "closed" magnetic loops. This technique will be applied to the actual
  situation of two spacecraft at different separations with spectrometers
  on board (the Solar Orbiter Spectral Imaging of the Coronal Environment
  versus the Interface Region Imaging Spectrograph (IRIS) and Hinode
  imaging spectrometer) and we summarise how these observations can be
  coordinated to assess vector velocity measurements. This 3D spectroscopy
  method will facilitate the understanding of the complex flows that
  take place throughout the solar atmosphere.

---------------------------------------------------------
Title: Mapping of Solar Magnetic Fields from the Photosphere to the
    Top of the Chromosphere with CLASP2
Authors: McKenzie, D.; Ishikawa, R.; Trujillo Bueno, J.; Auchere, F.;
   del Pino Aleman, T.; Okamoto, T.; Kano, R.; Song, D.; Yoshida, M.;
   Rachmeler, L.; Kobayashi, K.; Narukage, N.; Kubo, M.; Ishikawa, S.;
   Hara, H.; Suematsu, Y.; Sakao, T.; Bethge, C.; De Pontieu, B.; Vigil,
   G.; Winebarger, A.; Alsina Ballester, E.; Belluzzi, L.; Stepan, J.;
   Asensio Ramos, A.; Carlsson, M.; Leenaarts, J.
2021AAS...23810603M    Altcode:
  Coronal heating, chromospheric heating, and the heating &amp;
  acceleration of the solar wind, are well-known problems in solar
  physics. Additionally, knowledge of the magnetic energy that
  powers solar flares and coronal mass ejections, important drivers
  of space weather, is handicapped by imperfect determination of the
  magnetic field in the sun's atmosphere. Extrapolation of photospheric
  magnetic measurements into the corona is fraught with difficulties and
  uncertainties, partly due to the vastly different plasma beta between
  the photosphere and the corona. Better results in understanding
  the coronal magnetic field should be derived from measurements of
  the magnetic field in the chromosphere. To that end, we are pursuing
  quantitative determination of the magnetic field in the chromosphere,
  where plasma beta transitions from greater than unity to less than
  unity, via ultraviolet spectropolarimetry. The CLASP2 mission, flown
  on a sounding rocket in April 2019, succeeded in measuring all four
  Stokes polarization parameters in UV spectral lines formed by singly
  ionized Magnesium and neutral Manganese. Because these ions produce
  spectral lines under different conditions, CLASP2 thus was able to
  quantify the magnetic field properties at multiple heights in the
  chromosphere simultaneously, as shown in the recent paper by Ishikawa
  et al. In this presentation we will report the findings of CLASP2,
  demonstrating the variation of magnetic fields along a track on
  the solar surface and as a function of height in the chromosphere;
  and we will illustrate what is next for the CLASP missions and the
  demonstration of UV spectropolarimetry in the solar chromosphere.

---------------------------------------------------------
Title: Signatures of coronal hole substructure in the solar wind:
    combined Solar Orbiter remote sensing and in situ measurements
Authors: Horbury, T. S.; Laker, R.; Rodriguez, L.; Steinvall, K.;
   Maksimovic, M.; Livi, S.; Berghmans, D.; Auchere, F.; Zhukov, A. N.;
   Khotyaintsev, Yu. V.; Woodham, L.; Matteini, L.; Stawarz, J.; Woolley,
   T.; Bale, S. D.; Rouillard, A.; O'Brien, H.; Evans, V.; Angelini,
   V.; Owen, C.; Solanki, S. K.; Nicula, B.; Muller, D.; Zouganelis, I.
2021arXiv210414960H    Altcode:
  Context. The Sun's complex corona is the source of the solar wind
  and interplanetary magnetic field. While the large scale morphology
  is well understood, the impact of variations in coronal properties
  on the scale of a few degrees on properties of the interplanetary
  medium is not known. Solar Orbiter, carrying both remote sensing
  and in situ instruments into the inner solar system, is intended
  to make these connections better than ever before. Aims. We combine
  remote sensing and in situ measurements from Solar Orbiter's first
  perihelion at 0.5 AU to study the fine scale structure of the solar
  wind from the equatorward edge of a polar coronal hole with the aim
  of identifying characteristics of the corona which can explain the in
  situ variations. Methods. We use in situ measurements of the magnetic
  field, density and solar wind speed to identify structures on scales
  of hours at the spacecraft. Using Potential Field Source Surface
  mapping we estimate the source locations of the measured solar wind
  as a function of time and use EUI images to characterise these solar
  sources. Results. We identify small scale stream interactions in the
  solar wind with compressed magnetic field and density along with speed
  variations which are associated with corrugations in the edge of the
  coronal hole on scales of several degrees, demonstrating that fine
  scale coronal structure can directly influence solar wind properties
  and drive variations within individual streams. Conclusions. This early
  analysis already demonstrates the power of Solar Orbiter's combined
  remote sensing and in situ payload and shows that with future, closer
  perihelia it will be possible dramatically to improve our knowledge
  of the coronal sources of fine scale solar wind structure, which is
  important both for understanding the phenomena driving the solar wind
  and predicting its impacts at the Earth and elsewhere.

---------------------------------------------------------
Title: Mapping solar magnetic fields from the photosphere to the
    base of the corona
Authors: Ishikawa, Ryohko; Bueno, Javier Trujillo; del Pino Alemán,
   Tanausú; Okamoto, Takenori J.; McKenzie, David E.; Auchère,
   Frédéric; Kano, Ryouhei; Song, Donguk; Yoshida, Masaki; Rachmeler,
   Laurel A.; Kobayashi, Ken; Hara, Hirohisa; Kubo, Masahito; Narukage,
   Noriyuki; Sakao, Taro; Shimizu, Toshifumi; Suematsu, Yoshinori; Bethge,
   Christian; De Pontieu, Bart; Dalda, Alberto Sainz; Vigil, Genevieve D.;
   Winebarger, Amy; Ballester, Ernest Alsina; Belluzzi, Luca; Štěpán,
   Jiří; Ramos, Andrés Asensio; Carlsson, Mats; Leenaarts, Jorrit
2021SciA....7.8406I    Altcode: 2021arXiv210301583I
  Routine ultraviolet imaging of the Sun's upper atmosphere shows the
  spectacular manifestation of solar activity; yet we remain blind to
  its main driver, the magnetic field. Here we report unprecedented
  spectropolarimetric observations of an active region plage and
  its surrounding enhanced network, showing circular polarization in
  ultraviolet (Mg II $h$ &amp; $k$ and Mn I) and visible (Fe I) lines. We
  infer the longitudinal magnetic field from the photosphere to the
  very upper chromosphere. At the top of the plage chromosphere the
  field strengths reach more than 300 gauss, strongly correlated with
  the Mg II $k$ line core intensity and the electron pressure. This
  unique mapping shows how the magnetic field couples the different
  atmospheric layers and reveals the magnetic origin of the heating in
  the plage chromosphere.

---------------------------------------------------------
Title: 20 years of ACE data: how superposed epoch analyses reveal
    generic features in interplanetary CME profiles
Authors: Regnault, Florian; Dasso, Sergio; Auchere, Frederic; Demoulin,
   Pascal; Janvier, Miho; Strugarek, Antoine
2021cosp...43E1017R    Altcode:
  Interplanetary Coronal Mass Ejections (ICMEs) result from solar flares
  occurring in our star's atmosphere. These large-scale magnetized
  structures propagate in the interplanetary medium where they can be
  probed by spacecraft. Depending on their speed, ICMEs may accumulate
  enough solar wind plasma to form a turbulent sheath ahead of them. They
  therefore consist of two main substructures : a sheath and a magnetic
  ejecta (ME). The magnetic ejecta is the main body of an ICME where
  the magnetic field is more intense and with less variance than that
  of the ambient solar wind. We present a statistical study using the
  superposed epoch analysis technique on a catalog of around 400 ICMEs
  where we consider the profiles of the physical parameters of the ICMEs
  (the magnetic field intensity, the speed, temperature, ...) seen at
  1 AU by the ACE spacecraft. In particular, we investigate different
  possible classifications of ICMEs, for example based on their speeds,
  the phase of the solar cycle when they are detected, and the detection
  of an associated magnetic cloud (MCs, a subset of MEs with a clear
  rotation of the magnetic field as well as a low plasma temperature
  compared with the solar wind). We confirm that slow ICMEs have a
  more symmetric profile than fast ICMEs, therefore generalizing the
  work made on a sample of 44 ICMEs with clearly identified magnetic
  clouds by Masias-Meza et al. (2016). We also find that fast ICMEs
  show signs of compression in both their magnetic ejecta and in their
  sheath. Furthermore, we do not find any impact of the solar cycle on the
  generic features of ICMEs. However, more extreme events are observed
  during the active parts of the cycle, widening the distributions of
  all parameters. Finally, we find that ICMEs with or without a detected
  magnetic cloud show similar profiles, which confirms the hypothesis
  that both types of events correspond to similar ICMEs, and that the
  ones with no detected magnetic clouds may be observed when crossed
  sufficiently away from the flux rope core.

---------------------------------------------------------
Title: The Extreme ultraviolet imager onboard Solar Orbiter
Authors: Berghmans, David; Harra, Louise K.; Zhukov, Andrei; Auchere,
   Frederic; Long, David; Schuehle, Udo; Rochus, Pierre
2021cosp...43E.949B    Altcode:
  The Extreme Ultraviolet Imager (EUI) is part of the remote sensing
  instrument package of the ESA/NASA Solar Orbiter mission that will
  explore the inner heliosphere and observe the Sun from vantage points
  close to the Sun and out of the ecliptic. With EUI we aim to improve our
  understanding of the structure and dynamics of the solar atmosphere,
  globally as well as at high resolution, and from high solar latitude
  perspectives. The EUI consists of three telescopes, the Full Sun Imager
  (FSI) and two High Resolution Imagers (HRIs), which are optimised
  to image in Lyman-$\alpha$ and EUV (174 \AA, 304 \AA) to provide a
  coverage from chromosphere up to corona. The EUI instrument design
  will be reviewed, and its scientific objectives and plans will be
  discussed. Early results of the EUI commissioning will be presented.

---------------------------------------------------------
Title: Magnetic Imaging of the Outer Solar Atmosphere (MImOSA):
    Unlocking the driver of the dynamics in the upper solar atmosphere
Authors: Peter, H.; Alsina Ballester, E.; Andretta, V.; Auchere, F.;
   Belluzzi, L.; Bemporad, A.; Berghmans, D.; Buchlin, E.; Calcines, A.;
   Chitta, L. P.; Dalmasse, K.; del Pino Aleman, T.; Feller, A.; Froment,
   C.; Harrison, R.; Janvier, M.; Matthews, S.; Parenti, S.; Przybylski,
   D.; Solanki, S. K.; Stepan, J.; Teriaca, L.; Trujillo Bueno, J.
2021arXiv210101566P    Altcode:
  The magnetic activity of the Sun directly impacts the Earth and human
  life. Likewise, other stars will have an impact on the habitability
  of planets orbiting these host stars. The lack of information on the
  magnetic field in the higher atmospheric layers hampers our progress in
  understanding solar magnetic activity. Overcoming this limitation would
  allow us to address four paramount long-standing questions: (1) How
  does the magnetic field couple the different layers of the atmosphere,
  and how does it transport energy? (2) How does the magnetic field
  structure, drive and interact with the plasma in the chromosphere and
  upper atmosphere? (3) How does the magnetic field destabilise the outer
  solar atmosphere and thus affect the interplanetary environment? (4)
  How do magnetic processes accelerate particles to high energies? New
  ground-breaking observations are needed to address these science
  questions. We suggest a suite of three instruments that far exceed
  current capabilities in terms of spatial resolution, light-gathering
  power, and polarimetric performance: (a) A large-aperture UV-to-IR
  telescope of the 1-3 m class aimed mainly to measure the magnetic
  field in the chromosphere by combining high spatial resolution and high
  sensitivity. (b) An extreme-UV-to-IR coronagraph that is designed to
  measure the large-scale magnetic field in the corona with an aperture
  of about 40 cm. (c) An extreme-UV imaging polarimeter based on a 30
  cm telescope that combines high throughput in the extreme UV with
  polarimetry to connect the magnetic measurements of the other two
  instruments. This mission to measure the magnetic field will unlock
  the driver of the dynamics in the outer solar atmosphere and thereby
  greatly advance our understanding of the Sun and the heliosphere.

---------------------------------------------------------
Title: Stereoscopic Measurements of Coronal Doppler Velocities aboard
    Solar Orbiter
Authors: Podladchikova, Olena; Harra, Louise K.; Mandrini, Cristina
   H.; Rodriguez, Luciano; Parenti, Susanna; Dolla, Laurent; Buchlin,
   Eric; Auchere, Frederic; Mierla, Marilena; Barczynski, Krzysztof
2021cosp...43E.957P    Altcode:
  The Solar Orbiter mission, whose orbit is outside the Sun-Earth
  line, opens up novel opportunities for the combined analysis of
  measurements by solar imagers and spectrometers. For the first time
  different spectrometers will be located at wide angles with each
  other allowing 3D spectroscopy in the solar atmosphere. In order
  to develop a methodology for these opportunities we make use of the
  Hinode EUV Imaging Spectrometer (EIS) and Atmospheric Imaging Assembly
  (AIA) on the Solar Dynamics Observatory (SDO) and by employing solar
  rotation we simulate the measurements of spectrometers that have
  different views of solar corona. The resulting data allows us to apply
  stereoscopic tie-pointing and triangulation techniques designed for
  SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation)
  imaging suite on the STEREO (Solar Terrestrial Relations Observatory)
  spacecraft pair and perform three-dimensional analysis of Doppler shifts
  of quasi-stationary active region.We present a technique that allows
  the accurate reconstruction of the 3D velocity vector in plasma flows
  along open and closed magnetic loops. This technique will be applied
  to the real situation of two spacecraft at different separations with
  spectrometers onboard. This will include the Solar Orbiter Spectral
  Imaging of the Coronal Environment (SPICE), the Solar Orbiter Extreme
  Ultraviolet Imager (EUI), the Interface Region Imaging Spectrograph
  (IRIS) and Hinode EIS spectrometers and we summarise how these can be
  coordinated. This 3D spectroscopy is a new research domain that will
  aid the understanding of the complex flows that take place throughout
  the solar atmosphere.

---------------------------------------------------------
Title: The MDOR/PDOR on-line module for MISO, the planning software
    of Solar Orbiter instruments
Authors: Volpicelli, Cosimo; Landini, Federico; Pancrazzi, Maurizio;
   Straus, Thomas; Susino, Roberto; Nicolini, Gianalfredo; Sasso,
   Clementina; Fabi, Michele; De Leo, Yara; Casini, Chiara; Naletto,
   Giampiero; Nicolosi, Piergiorgio; Spadaro, Daniele; Andretta, Vincenzo;
   Antonucci, Ester; Fineschi, Silvano; Da Deppo, Vania; Zuppella, Paola;
   Frassetto, Fabio; Slemer, Alessandra; Mercier, Claude; Kouliche,
   Dimitri; Caminade, Stephane; Picard, David; Buchlin, Eric; Auchère,
   Frédéric; Romoli, Marco
2020SPIE11452E..0SV    Altcode:
  Solar Orbiter is a solar mission that will approach the Sun down to a
  minimum perihelion of 0.28 AU and will increase its orbit inclination
  with respect to the ecliptic up to a maximum angle of 34 deg. For
  imagers aboard Solar Orbiter there will be three 10-days remote sensing
  windows per orbit. Observations shall be carefully planned at least 6
  months in advance. The Multi Instrument Sequence Organizer (MISO) is
  a web based platform developed by the SPICE group and made available
  to support Solar Orbiter instruments teams in planning observations
  by assembling Mission Database sequences. Metis is the UV and visible
  light coronagraph aboard Solar Orbiter. Metis is a complex instrument
  characterized by a rich variety of observing modes, which required a
  careful commissioning activity and will need support for potential
  maintenance operations throughout the mission. In order to support
  commissioning and maintenance activities, the Metis team developed
  a PDOR (Payload Direct Operation Request) and MDOR (Memory Direct
  Operation Request) module integrated in MISO and made available to all
  Solar Orbiter instruments. An effort was made in order to interpret
  the coding philosophy of the main project and to make the additional
  module as homogeneous as possible both to the web interface and to the
  algorithm logic, while integrating characteristics which are peculiar
  to PDORs and MDORs. An user friendly web based interface allows the
  operator to build the operation request and to successively modify or
  integrate it with further or alternative information. In the present
  work we describe the PDOR/MDOR module for MISO by addressing its logic
  and main characteristics.

---------------------------------------------------------
Title: Relative coronal abundance diagnostics with Solar Orbiter/SPICE
Authors: Zambrana Prado, N.; Buchlin, E.; Peter, H.; Young, P. R.;
   Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Aznar Cuadrado,
   R.; Caminade, S.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra,
   L.; Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller,
   D.; Parenti, S.; Schmutz, W. K.; Schühle, U.; Sidher, S.; Teriaca,
   L.; Thompson, W. T.; Williams, D.
2020AGUFMSH038..09Z    Altcode:
  Linking solar activity on the surface and in the corona to the inner
  heliosphere is one of Solar Orbiter's main goals. Its UV spectrometer
  SPICE (SPectral Imaging of the Coronal Environment) will provide
  relative abundance measurements which will be key in this quest
  as different structures on the Sun have different abundances as a
  consequence of the FIP (First Ionization Potential) effect. Solar
  Orbiter's unique combination of remote sensing and in-situ instruments
  coupled with observation from other missions such as Parker Solar
  Probe will allow us to compare in-situ and remote sensing composition
  data. With the addition of modeling, these new results will allow us
  to trace back the source of heliospheric plasma. As high telemetry
  will not always be available with SPICE, we have developed a method
  for measuring relative abundances that is both telemetry efficient
  and reliable. Unlike methods based on Differential Emission Measure
  (DEM) inversion, the Linear Combination Ratio (LCR) method does not
  require a large number of spectral lines. This new method is based
  on linear combinations of UV spectral lines. The coefficients of
  the combinations are optimized such that the ratio of two linear
  combinations of radiances would yield the relative abundance of two
  elements. We present some abundance diagnostics tested on different
  combinations of spectral lines observable by SPICE.

---------------------------------------------------------
Title: Dynamics and thermal structure in the quiet Sun seen by SPICE
Authors: Peter, H.; Aznar Cuadrado, R.; Schühle, U.; Teriaca, L.;
   Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Buchlin, E.;
   Caminade, S.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L. K.;
   Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.;
   Parenti, S.; Schmutz, W. K.; Sidher, S.; Thompson, W. T.; Williams,
   D.; Young, P. R.
2020AGUFMSH038..03P    Altcode:
  We will present some of the early data of the Spectral Imaging of the
  Coronal Environment (SPICE) instrument on Solar Orbiter. One of the
  unique features of SPICE is its capability to record a wide range of
  wavelengths in the extreme UV with the possibility to record spectral
  lines giving access to a continuous plasma temperature range from 10.000
  K to well above 1 MK. The data taken so far were for commissioning
  purposes and they can be used for a preliminary evaluation of the
  science performance of the instrument. Here we will concentrate on
  sample spectra covering the whole wavelength region and on the early
  raster maps acquired in bright lines in the quiet Sun close to disk
  center. Looking at different quiet Sun features we investigate the
  thermal structure of the atmosphere and flow structures. For this
  we apply fits to the spectral profiles and check the performance in
  terms of Doppler shifts and line widths to retrieve the structure of
  the network in terms of dynamics. While the amount of data available
  so far is limited, we will have a first look on how quiet Sun plasma
  responds to heating events. For this, we will compare spectral lines
  forming at different temperatures recorded at strictly the same time.

---------------------------------------------------------
Title: First Results From SPICE EUV Spectrometer on Solar Orbiter
Authors: Fludra, A.; Caldwell, M.; Giunta, A. S.; Grundy, T.; Guest,
   S.; Sidher, S.; Auchere, F.; Carlsson, M.; Hassler, D.; Peter, H.;
   Aznar Cuadrado, R.; Buchlin, E.; Caminade, S.; DeForest, C.; Fredvik,
   T.; Harra, L. K.; Janvier, M.; Kucera, T. A.; Leeks, S.; Mueller,
   D.; Parenti, S.; Schmutz, W. K.; Schühle, U.; Teriaca, L.; Thompson,
   W. T.; Tustain, S.; Williams, D.; Young, P. R.
2020AGUFMSH038..02F    Altcode:
  SPICE (Spectral Imaging of Coronal Environment) is one of the remote
  sensing instruments onboard Solar Orbiter. It is an EUV imaging
  spectrometer observing the Sun in two wavelength bands: 69.6-79.4 nm
  and 96.6-105.1 nm. SPICE is capable of recording full spectra in these
  bands with exposures as short as 1s. SPICE is the only Solar Orbiter
  instrument that can measure EUV spectra from the disk and low corona
  of the Sun and record all spectral lines simultaneously. SPICE uses
  one of three narrow slits, 2"x11', 4”x11', 6”x11', or a wide slit
  30”x14'. The primary mirror can be scanned in a direction perpendicular
  to the slit, allowing raster images of up to 16' in size. <P />We
  present an overview of the first SPICE data taken on several days
  during the instrument commissioning carried out by the RAL Space team
  between 2020 April 21 and 2020 June 14. We also include results from
  SPICE observations at the first Solar Orbiter perihelion at 0.52AU,
  taken between June 16-21<SUP>st</SUP>. We give examples of full spectra
  from the quiet Sun near disk centre and provide a list of key spectral
  lines emitted in a range of temperatures between 10,000 K and over 1
  million K, from neutral hydrogen and ions of carbon, oxygen, nitrogen,
  neon, sulphur and magnesium. We show examples of first raster images
  in several strong lines, obtained with different slits and a range
  of exposure times between 5s and 180s. We describe the temperature
  coverage and density diagnostics, determination of plasma flows, and
  discuss possible applications to studies of the elemental abundances
  in the corona. We also show the first off-limb measurements with SPICE,
  as obtained when the spacecraft pointed at the limb.

---------------------------------------------------------
Title: The Solar-C (EUVST) mission: the latest status
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko; Suematsu,
   Yoshinori; Hara, Hirohisa; Tsuzuki, Toshihiro; Katsukawa, Yukio; Kubo,
   Masahito; Ishikawa, Ryoko; Watanabe, Tetsuya; Toriumi, Shin; Ichimoto,
   Kiyoshi; Nagata, Shin'ichi; Hasegawa, Takahiro; Yokoyama, Takaaki;
   Watanabe, Kyoko; Tsuno, Katsuhiko; Korendyke, Clarence M.; Warren,
   Harry; De Pontieu, Bart; Boerner, Paul; Solanki, Sami K.; Teriaca,
   Luca; Schuehle, Udo; Matthews, Sarah; Long, David; Thomas, William;
   Hancock, Barry; Reid, Hamish; Fludra, Andrzej; Auchère, Frederic;
   Andretta, Vincenzo; Naletto, Giampiero; Poletto, Luca; Harra, Louise
2020SPIE11444E..0NS    Altcode:
  Solar-C (EUVST) is the next Japanese solar physics mission to
  be developed with significant contributions from US and European
  countries. The mission carries an EUV imaging spectrometer with
  slit-jaw imaging system called EUVST (EUV High-Throughput Spectroscopic
  Telescope) as the mission payload, to take a fundamental step towards
  answering how the plasma universe is created and evolves and how the
  Sun influences the Earth and other planets in our solar system. In
  April 2020, ISAS (Institute of Space and Astronautical Science) of JAXA
  (Japan Aerospace Exploration Agency) has made the final down-selection
  for this mission as the 4th in the series of competitively chosen
  M-class mission to be launched with an Epsilon launch vehicle in mid
  2020s. NASA (National Aeronautics and Space Administration) has selected
  this mission concept for Phase A concept study in September 2019 and
  is in the process leading to final selection. For European countries,
  the team has (or is in the process of confirming) confirmed endorsement
  for hardware contributions to the EUVST from the national agencies. A
  recent update to the mission instrumentation is to add a UV spectral
  irradiance monitor capability for EUVST calibration and scientific
  purpose. This presentation provides the latest status of the mission
  with an overall description of the mission concept emphasizing on key
  roles of the mission in heliophysics research from mid 2020s.

---------------------------------------------------------
Title: Observation of Smallest Ever Detected Brightening Events with
    the Solar Orbiter EUI HRI-EUV Imager
Authors: Parenti, S.; Berghmans, D.; Buchlin, E.; Teriaca, L.; Auchere,
   F.; Harra, L.; Long, D.; Rochus, P. L.; Schühle, U.; Aznar Cuadrado,
   R.; Gissot, S.; Kraaikamp, E.; Smith, P.; Stegen, K.; Verbeeck, C.
2020AGUFMSH038..01P    Altcode:
  The Extreme Ultraviolet Imager (EUI) suite on board Solar Orbiter
  acquired its first images in May 2020. The passband of the 17.4 nm
  High Resolution Imager (HRI-EUV) is dominated by emission lines of
  Fe IX and Fe X, that is the 1 million degree solar corona. The solar
  atmosphere at this temperature is dynamic at all scales, down to the
  highest spatial resolution available from instruments priori to Solar
  Orbiter. During the Commissioning phase, HRI-EUV acquired several high
  temporal resolution (a few seconds) sequences at quiet Sun regions at
  disk center. The instrument revealed a multitude of brightenings at
  the smallest-ever detectable spatial scales which, at that time, was
  about 400 km (two pixels). These events appear to be present everywhere
  all the time. We present the first results of the analysis of these
  sequences with the aim of understanding the role of these small scale
  events in the heating of the solar corona.

---------------------------------------------------------
Title: Stereoscopic Measurements of Coronal Doppler Velocities
Authors: Podladchikova, O.; Harra, L. K.; Barczynski, K.; Mandrini,
   C. H.; Auchere, F.; Buchlin, E.; Dolla, L.; Mierla, M.; Rodriguez, L.
2020AGUFMSH038..07P    Altcode:
  The Solar Orbiter mission, whose orbit is outside the Sun-Earth
  line, opens up novel opportunities for the combined analysis of
  measurements by solar imagers and spectrometers. For the first time
  different spectrometers will be located at wide angles with each
  other allowing 3D spectroscopy in the solar atmosphere. In order
  to develop a methodology for these opportunities we make use of the
  Hinode EUV Imaging Spectrometer (EIS) and Atmospheric Imaging Assembly
  (AIA) on the Solar Dynamics Observatory (SDO) and by employing solar
  rotation we simulate the measurements of two spectrometers that have
  different views of solar corona. The resulting data allows us to apply
  stereoscopic tie-pointing and triangulation techniques designed for
  SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation)
  imaging suite on the STEREO (Solar Terrestrial Relations Observatory)
  spacecraft pair and perform three-dimensional analysis of Doppler shifts
  of quasi-stationary active region. We present a technique that allows
  the accurate reconstruction of the 3D velocity vector in plasma flows
  along open and closed magnetic loops. This technique will be applied
  to the real situation of two spacecraft at different separations with
  spectrometers onboard. This will include the Solar Orbiter Spectral
  Imaging of the Coronal Environment (SPICE), the Solar Orbiter Extreme
  Ultraviolet Imager (EUI),the Interface Region Imaging Spectrograph
  (IRIS) and Hinode EIS spectrometers and we summarise how these can be
  coordinated. This 3D spectroscopy is a new research domain that will
  aid the understanding of the complex flows that take place throughout
  the solar atmosphere.

---------------------------------------------------------
Title: Optical design of the Chromospheric LAyer Spectro-Polarimeter
    (CLASP2)
Authors: Tsuzuki, Toshihiro; Ishikawa, Ryohko; Kano, Ryouhei; Narukage,
   Noriyuki; Song, Donguk; Yoshida, Masaki; Uraguchi, Fumihiro; Okamoto,
   Takenori J.; McKenzie, David; Kobayashi, Ken; Rachmeler, Laurel;
   Auchere, Frederic; Trujillo Bueno, Javier
2020SPIE11444E..6WT    Altcode:
  Chromospheric LAyer Spectro-Polarimeter (CLASP2) was a sounding
  rocket experiment, which is a follow-up mission to the Chromospheric
  Lyman-Alpha Spectro-Polarimeter (CLASP1) in 2015. To measure the
  magnetic fields in the upper solar atmosphere in a highly quantitative
  manner, CLASP2 changes the target wavelengths from the hydrogen Ly-α
  line (121.567 nm) to Mg II lines near 280 nm. We reused the main
  structure and most of the optical components in the CLASP1 instrument,
  which reduced the turnaround time and cost. We added a magnifying
  optical system to maintain the wavelength resolution, even at the
  longer wavelength of CLASP2. Here, we describe the optical design and
  performance of the CLASP2 instrument.

---------------------------------------------------------
Title: Calibrating optical distortions in the Solar Orbiter SPICE
    spectrograph
Authors: Thompson, W. T.; Schühle, U.; Young, P. R.; Auchere, F.;
   Carlsson, M.; Fludra, A.; Hassler, D.; Peter, H.; Aznar Cuadrado, R.;
   Buchlin, E.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L. K.;
   Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.;
   Parenti, S.; Caminade, S.; Schmutz, W. K.; Teriaca, L.; Williams,
   D.; Sidher, S.
2020AGUFMSH0360029T    Altcode:
  The Spectral Imaging of the Coronal Environment (SPICE) instrument on
  Solar Orbiter is a high-resolution imaging spectrometer operating
  at extreme ultraviolet (EUV) wavelengths from 70.4-79.0 nm and
  97.3-104.9 nm. A single-mirror off-axis paraboloid focuses the solar
  image onto the entrance slit of the spectrometer section. A Toroidal
  Variable Line Space (TVLS) grating images the entrance slit onto a
  pair of MCP-intensified APS detectors. Ray-tracing analysis prior
  to launch showed that the instrument was subject to a number of
  small image distortions which need to be corrected in the final data
  product. We compare the ray tracing results with measurements made in
  flight. Co-alignment with other telescopes on Solar Orbiter will also
  be examined.

---------------------------------------------------------
Title: First results from the EUI and SPICE observations of Alpha
    Leo near Solar Orbiter first perihelion
Authors: Buchlin, E.; Teriaca, L.; Giunta, A. S.; Grundy, T.; Andretta,
   V.; Auchere, F.; Peter, H.; Berghmans, D.; Carlsson, M.; Fludra, A.;
   Harra, L.; Hassler, D.; Long, D.; Rochus, P. L.; Schühle, U.; Aznar
   Cuadrado, R.; Caldwell, M.; Caminade, S.; DeForest, C.; Fredvik, T.;
   Gissot, S.; Heerlein, K.; Janvier, M.; Kraaikamp, E.; Kucera, T. A.;
   Müller, D.; Parenti, S.; Schmutz, W. K.; Sidher, S.; Smith, P.;
   Stegen, K.; Thompson, W. T.; Verbeeck, C.; Williams, D.; Young, P. R.
2020AGUFMSH0360024B    Altcode:
  On June 16th 2020 Solar Orbiter made a dedicated observing campaign
  where the spacecraft pointed to the solar limb to allow some of the
  high resolution instruments to observe the ingress (at the east limb)
  and later the egress (west limb) of the occultation of the star Alpha
  Leonis by the solar disk. The star was chosen because its luminosity and
  early spectral type ensure high and stable flux at wavelengths between
  100 and 122 nanometers, a range observed by the High Resolution EUI
  Lyman alpha telescope (HRI-LYA) and by the long wavelength channel
  of the SPICE spectrograph. Star observations, when feasible, allow
  to gather a great deal of information on the instrument performances,
  such as the radiometric performance and the instrument optical point
  spread function (PSF). <P />We report here the first results from the
  above campaign for the two instruments.

---------------------------------------------------------
Title: Solar Orbiter: connecting remote sensing and in situ
    measurements
Authors: Horbury, T. S.; Auchere, F.; Antonucci, E.; Berghmans, D.;
   Bruno, R.; Carlsson, M.; del Toro Iniesta, J. C.; Fludra, A.; Harra,
   L.; Hassler, D.; Heinzel, P.; Howard, R. A.; Krucker, S.; Livi, S. A.;
   Long, D.; Louarn, P.; Maksimovic, M.; Mueller, D.; Owen, C. J.; Peter,
   H.; Rochus, P. L.; Rodriguez-Pacheco, J.; Romoli, M.; Schühle, U.;
   Solanki, S. K.; Teriaca, L.; Wimmer-Schweingruber, R. F.; Zouganelis,
   Y.; Laker, R.
2020AGUFMSH038..10H    Altcode:
  A key science goal of the Solar Orbiter mission is to make connections
  between phenomena on the Sun and their manifestations in interplanetary
  space. To that end, the spacecraft carries a carefully tailored
  payload of six remote sensing instruments and four making in situ
  measurements. During June 2020, while the spacecraft was around 0.5
  AU from the Sun, the remote sensing instruments operated for several
  days. While this was primarily an engineering activity, the resulting
  observations provided outstanding measurements and represent the ideal
  first opportunity to investigate the potential for making connections
  between the remote sensing and in situ payloads on Solar Orbiter. <P
  />We present a preliminary analysis of the available remote sensing and
  in situ observations, showing how connections can be made, and discuss
  the potential for further, more precise mapping to be performed as
  the mission progresses.

---------------------------------------------------------
Title: First Images and Initial In-Flight Performance of the Extreme
    Ultraviolet Imager On-Board Solar Orbiter.
Authors: Auchere, F.; Gissot, S.; Teriaca, L.; Berghmans, D.; Harra,
   L.; Long, D.; Rochus, P. L.; Smith, P.; Schühle, U.; Stegen, K.;
   Aznar Cuadrado, R.; Heerlein, K.; Kraaikamp, E.; Verbeeck, C.
2020AGUFMSH0360025A    Altcode:
  The Extreme Ultraviolet Imager (EUI) on board Solar Orbiter is
  composed of two High Resolution Imagers working at 121.6 (HRI-LYA,
  H I, chromosphere) and 17.4 nm (HRI-EUV, Fe IX/X, corona) and one
  dual-band Full Sun Imager (FSI) working at 30.4 nm (He II, transition
  region) and 17.4 nm (Fe IX/X, corona). During the commissioning period
  following the launch of Solar Orbiter and two and a half months of
  outgassing, EUI acquired its first solar images on May 12th, 2020 at
  about 0.67 AU. Most of the capabilities of the instrument have been
  tested during the following weeks, which revealed excellent overall
  performance. HRI-EUV already provided images with an angular resolution
  equivalent to ~0.6" (2 pixels) at 1 A.U. HRI-LYA will routinely provide
  images of the Sun at Lyman alpha, which have been otherwise relatively
  rare, with sub-second cadence capability. FSI will provide context for
  connection science but it will also explore regions of the corona never
  imaged before at EUV wavelengths, owing to its 3.8° field of view. EUI
  uses a complex on-board image processing system including advanced
  image compression and event detection algorithms. In particular,
  commissioning tests confirm the good performance of the compression,
  which is critical given the limited total telemetry volume imposed by
  the mission profile. In this paper, we present the main characteristics
  of the first images taken in each channel and we provide an initial
  assessment of the in-flight performance.

---------------------------------------------------------
Title: First results from combined EUI and SPICE observations of
    Lyman lines of Hydrogen and He II
Authors: Teriaca, L.; Aznar Cuadrado, R.; Giunta, A. S.; Grundy, T.;
   Parenti, S.; Auchere, F.; Vial, J. C.; Fludra, A.; Berghmans, D.;
   Carlsson, M.; Harra, L.; Hassler, D.; Long, D.; Peter, H.; Rochus,
   P. L.; Schühle, U.; Buchlin, E.; Caldwell, M.; Caminade, S.; DeForest,
   C.; Fredvik, T.; Gissot, S.; Heerlein, K.; Janvier, M.; Kraaikamp,
   E.; Kucera, T. A.; Mueller, D.; Schmutz, W. K.; Sidher, S.; Smith, P.;
   Stegen, K.; Thompson, W. T.; Verbeeck, C.; Williams, D.; Young, P. R.
2020AGUFMSH0360003T    Altcode:
  The Solar Orbiter spacecraft carries a powerful set of remote
  sensing instruments that allow studying the solar atmosphere with
  unprecedented diagnostic capabilities. Many such diagnostics require
  the simultaneous usage of more than one instrument. One example of that
  is the capability, for the first time, to obtain (near) simultaneous
  spatially resolved observations of the emission from the first three
  lines of the Lyman series of hydrogen and of He II Lyman alpha. In fact,
  the SPectral Imaging of the Coronal Environment (SPICE) spectrometer
  can observe the Lyman beta and gamma lines in its long wavelength
  (SPICE-LW) channel, the High Resolution Lyman Alpha (HRI-LYA) telescope
  of the Extreme Ultraviolet Imager (EUI) acquires narrow band images in
  the Lyman alpha line while the Full Disk Imager (FSI) of EUI can take
  images dominated by the Lyman alpha line of ionized Helium at 30.4 nm
  (FSI-304). Being hydrogen and helium the main components of our star,
  these very bright transitions play an important role in the energy
  budget of the outer atmosphere via radiative losses and the measurement
  of their profiles and radiance ratios is a fundamental constraint to
  any comprehensive modelization effort of the upper solar chromosphere
  and transition region. Additionally, monitoring their average ratios
  can serve as a check out for the relative radiometric performance of
  the two instruments throughout the mission. Although the engineering
  data acquired so far are far from ideal in terms of time simultaneity
  (often only within about 1 h) and line coverage (often only Lyman beta
  was acquired by SPICE and not always near simultaneous images from all
  three telescopes are available) the analysis we present here still
  offers a great opportunity to have a first look at the potential of
  this diagnostic from the two instruments. In fact, we have identified
  a series of datasets obtained at disk center and at various positions
  at the solar limb that allow studying the Lyman alpha to beta radiance
  ratio and their relation to He II 30.4 as a function of the position
  on the Sun (disk center versus limb and quiet Sun versus coronal holes).

---------------------------------------------------------
Title: Very high-resolution observations of the solar atmosphere
    in H I Lyman alpha and Fe IX-X at 17.4 nm as seen by EUI aboard
    Solar Orbiter
Authors: Aznar Cuadrado, R.; Berghmans, D.; Teriaca, L.; Gissot,
   S.; Schühle, U.; Auchere, F.; Harra, L.; Long, D.; Rochus, P. L.;
   Heerlein, K.; Kraaikamp, E.; Smith, P.; Stegen, K.; Verbeeck, C.
2020AGUFMSH0360026A    Altcode:
  The Extreme Ultraviolet Imager (EUI) aboard Solar Orbiter consists of
  three telescopes, the Full Sun Imager (FSI) and two High Resolution
  Imagers (HRIs). The two HRI telescopes provide images of the base
  of the corona, near to the chromosphere, and of the 1 million K
  corona. In fact, the HRI-EUV telescope operates around 17.4 nm to
  obtain images dominated by emission from lines generated from Fe-IX
  and X ions, formed at about 1 MK, while the HRI-LYA telescope provides
  narrow band images dominated by the H I Lyman alpha line at 121.6 nm,
  formed in the upper chromosphere/lower transition region of the solar
  atmosphere around 20,000 K. Thus, the two imagers provide a powerful
  diagnostics of the solar structural organization, in terms of loop
  hierarchies and connectivity. Here we present an analysis of the first
  two near-simultaneous (within 15s) high-resolution images of the solar
  quiet atmosphere obtained near disk center by the two high-resolution
  telescopes on May 30th 2020, during the commissioning phase of the
  mission , when Solar Orbiter was at about 0.56 AU from the Sun.

---------------------------------------------------------
Title: A sensitivity analysis of the updated optical design for
    EUVST on the Solar-C mission
Authors: Kawate, Tomoko; Tsuzuki, Toshihiro; Shimizu, Toshifumi;
   Imada, Shinsuke; Katsukawa, Yukio; Hara, Hirohisa; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Hattori, Tomoya; Narasaki, Shota; Warren, Harry P.;
   Teriaca, Luca; Korendyke, Clarence M.; Brown, Charles M.; Auchere,
   Frederic
2020SPIE11444E..3JK    Altcode:
  The EUV high-throughput spectroscopic telescope (EUVST) onboard the
  Solar-C mission has the high spatial (0.4”) resolution over a wide
  wavelength range in the vacuum ultraviolet. To achieve high spatial
  resolution under a design constraint given by the JAXA Epsilon launch
  vehicle, we further update the optical design to secure margins
  needed to realize 0.4” spatial resolution over a field of view of
  100”×100”. To estimate the error budgets of spatial and spectral
  resolutions due to installation and fabrication errors, we perform a
  sensitivity analysis for the position and orientation of each optical
  element and for the grating parameters by ray tracing with the Zemax
  software. We obtain point spread functions (PSF) for rays from 9
  fields and at 9 wavelengths on each detector by changing each parameter
  slightly. A full width at half maximum (FWHM) of the PSF is derived at
  each field and wavelength position as a function of the perturbation
  of each optical parameter. Assuming a mount system of each optical
  element and an error of each optical parameter, we estimate spatial
  and spectral resolutions by taking installation and fabrication errors
  into account. The results of the sensitivity analysis suggest that
  budgets of the total of optical design and the assembly errors account
  for 15% and 5.8% of our budgets of the spatial resolution in the long
  wavelength and short wavelength bands, respectively. On the other hand,
  the grating fabrication errors give a large degradation of spatial and
  spectral resolutions, and investigations of compensators are needed
  to relax the fabrication tolerance of the grating surface parameters.

---------------------------------------------------------
Title: 20 Years of ACE Data: How Superposed Epoch Analyses Reveal
    Generic Features in Interplanetary CME Profiles
Authors: Regnault, F.; Janvier, M.; Démoulin, P.; Auchère, F.;
   Strugarek, A.; Dasso, S.; Noûs, C.
2020JGRA..12528150R    Altcode: 2020arXiv201105050R
  Interplanetary coronal mass ejections (ICMEs) are magnetic structures
  propagating from the Sun's corona to the interplanetary medium. With
  over 20 years of observations at the L1 libration point, ACE offers
  hundreds of ICMEs detected at different times during several solar
  cycles and with different features such as the propagation speed. We
  investigate a revisited catalog of more than 400 ICMEs using the
  superposed epoch method on the mean, median, and the most probable
  values of the distribution of magnetic and plasma parameters. We also
  investigate the effects of the speed of ICMEs relative to the solar
  wind, the solar cycle, and the existence of a magnetic cloud on the
  generic ICME profile. We find that fast-propagating ICMEs (relatively
  to the solar wind in front) still show signs of compression at 1 au, as
  seen by the compressed sheath and the asymmetric profile of the magnetic
  field. While the solar cycle evolution does not impact the generic
  features of ICMEs, there are more extreme events during the active part
  of the cycle, widening the distributions of all parameters. Finally, we
  find that ICMEs with or without a detected magnetic cloud show similar
  profiles, which confirms the hypothesis that ICMEs with no detected
  magnetic clouds are crossed further away from the flux rope core. Such
  a study provides a generic understanding of processes that shape the
  overall features of ICMEs in the solar wind and can be extended with
  future missions at different locations in the solar system.

---------------------------------------------------------
Title: Coordination within the remote sensing payload on the Solar
    Orbiter mission
Authors: Auchère, F.; Andretta, V.; Antonucci, E.; Bach, N.;
   Battaglia, M.; Bemporad, A.; Berghmans, D.; Buchlin, E.; Caminade,
   S.; Carlsson, M.; Carlyle, J.; Cerullo, J. J.; Chamberlin, P. C.;
   Colaninno, R. C.; Davila, J. M.; De Groof, A.; Etesi, L.; Fahmy,
   S.; Fineschi, S.; Fludra, A.; Gilbert, H. R.; Giunta, A.; Grundy,
   T.; Haberreiter, M.; Harra, L. K.; Hassler, D. M.; Hirzberger, J.;
   Howard, R. A.; Hurford, G.; Kleint, L.; Kolleck, M.; Krucker, S.;
   Lagg, A.; Landini, F.; Long, D. M.; Lefort, J.; Lodiot, S.; Mampaey,
   B.; Maloney, S.; Marliani, F.; Martinez-Pillet, V.; McMullin, D. R.;
   Müller, D.; Nicolini, G.; Orozco Suarez, D.; Pacros, A.; Pancrazzi,
   M.; Parenti, S.; Peter, H.; Philippon, A.; Plunkett, S.; Rich, N.;
   Rochus, P.; Rouillard, A.; Romoli, M.; Sanchez, L.; Schühle, U.;
   Sidher, S.; Solanki, S. K.; Spadaro, D.; St Cyr, O. C.; Straus, T.;
   Tanco, I.; Teriaca, L.; Thompson, W. T.; del Toro Iniesta, J. C.;
   Verbeeck, C.; Vourlidas, A.; Watson, C.; Wiegelmann, T.; Williams,
   D.; Woch, J.; Zhukov, A. N.; Zouganelis, I.
2020A&A...642A...6A    Altcode:
  Context. To meet the scientific objectives of the mission, the Solar
  Orbiter spacecraft carries a suite of in-situ (IS) and remote sensing
  (RS) instruments designed for joint operations with inter-instrument
  communication capabilities. Indeed, previous missions have shown that
  the Sun (imaged by the RS instruments) and the heliosphere (mainly
  sampled by the IS instruments) should be considered as an integrated
  system rather than separate entities. Many of the advances expected
  from Solar Orbiter rely on this synergistic approach between IS and
  RS measurements. <BR /> Aims: Many aspects of hardware development,
  integration, testing, and operations are common to two or more
  RS instruments. In this paper, we describe the coordination effort
  initiated from the early mission phases by the Remote Sensing Working
  Group. We review the scientific goals and challenges, and give an
  overview of the technical solutions devised to successfully operate
  these instruments together. <BR /> Methods: A major constraint for the
  RS instruments is the limited telemetry (TM) bandwidth of the Solar
  Orbiter deep-space mission compared to missions in Earth orbit. Hence,
  many of the strategies developed to maximise the scientific return from
  these instruments revolve around the optimisation of TM usage, relying
  for example on onboard autonomy for data processing, compression,
  and selection for downlink. The planning process itself has been
  optimised to alleviate the dynamic nature of the targets, and an
  inter-instrument communication scheme has been implemented which can
  be used to autonomously alter the observing modes. We also outline the
  plans for in-flight cross-calibration, which will be essential to the
  joint data reduction and analysis. <BR /> Results: The RS instrument
  package on Solar Orbiter will carry out comprehensive measurements
  from the solar interior to the inner heliosphere. Thanks to the close
  coordination between the instrument teams and the European Space
  Agency, several challenges specific to the RS suite were identified
  and addressed in a timely manner.

---------------------------------------------------------
Title: The Solar Orbiter Science Activity Plan. Translating solar
    and heliospheric physics questions into action
Authors: Zouganelis, I.; De Groof, A.; Walsh, A. P.; Williams, D. R.;
   Müller, D.; St Cyr, O. C.; Auchère, F.; Berghmans, D.; Fludra,
   A.; Horbury, T. S.; Howard, R. A.; Krucker, S.; Maksimovic, M.;
   Owen, C. J.; Rodríguez-Pacheco, J.; Romoli, M.; Solanki, S. K.;
   Watson, C.; Sanchez, L.; Lefort, J.; Osuna, P.; Gilbert, H. R.;
   Nieves-Chinchilla, T.; Abbo, L.; Alexandrova, O.; Anastasiadis, A.;
   Andretta, V.; Antonucci, E.; Appourchaux, T.; Aran, A.; Arge, C. N.;
   Aulanier, G.; Baker, D.; Bale, S. D.; Battaglia, M.; Bellot Rubio,
   L.; Bemporad, A.; Berthomier, M.; Bocchialini, K.; Bonnin, X.; Brun,
   A. S.; Bruno, R.; Buchlin, E.; Büchner, J.; Bucik, R.; Carcaboso,
   F.; Carr, R.; Carrasco-Blázquez, I.; Cecconi, B.; Cernuda Cangas, I.;
   Chen, C. H. K.; Chitta, L. P.; Chust, T.; Dalmasse, K.; D'Amicis, R.;
   Da Deppo, V.; De Marco, R.; Dolei, S.; Dolla, L.; Dudok de Wit, T.;
   van Driel-Gesztelyi, L.; Eastwood, J. P.; Espinosa Lara, F.; Etesi,
   L.; Fedorov, A.; Félix-Redondo, F.; Fineschi, S.; Fleck, B.; Fontaine,
   D.; Fox, N. J.; Gandorfer, A.; Génot, V.; Georgoulis, M. K.; Gissot,
   S.; Giunta, A.; Gizon, L.; Gómez-Herrero, R.; Gontikakis, C.; Graham,
   G.; Green, L.; Grundy, T.; Haberreiter, M.; Harra, L. K.; Hassler,
   D. M.; Hirzberger, J.; Ho, G. C.; Hurford, G.; Innes, D.; Issautier,
   K.; James, A. W.; Janitzek, N.; Janvier, M.; Jeffrey, N.; Jenkins,
   J.; Khotyaintsev, Y.; Klein, K. -L.; Kontar, E. P.; Kontogiannis,
   I.; Krafft, C.; Krasnoselskikh, V.; Kretzschmar, M.; Labrosse, N.;
   Lagg, A.; Landini, F.; Lavraud, B.; Leon, I.; Lepri, S. T.; Lewis,
   G. R.; Liewer, P.; Linker, J.; Livi, S.; Long, D. M.; Louarn, P.;
   Malandraki, O.; Maloney, S.; Martinez-Pillet, V.; Martinovic, M.;
   Masson, A.; Matthews, S.; Matteini, L.; Meyer-Vernet, N.; Moraitis,
   K.; Morton, R. J.; Musset, S.; Nicolaou, G.; Nindos, A.; O'Brien,
   H.; Orozco Suarez, D.; Owens, M.; Pancrazzi, M.; Papaioannou, A.;
   Parenti, S.; Pariat, E.; Patsourakos, S.; Perrone, D.; Peter, H.;
   Pinto, R. F.; Plainaki, C.; Plettemeier, D.; Plunkett, S. P.; Raines,
   J. M.; Raouafi, N.; Reid, H.; Retino, A.; Rezeau, L.; Rochus, P.;
   Rodriguez, L.; Rodriguez-Garcia, L.; Roth, M.; Rouillard, A. P.;
   Sahraoui, F.; Sasso, C.; Schou, J.; Schühle, U.; Sorriso-Valvo, L.;
   Soucek, J.; Spadaro, D.; Stangalini, M.; Stansby, D.; Steller, M.;
   Strugarek, A.; Štverák, Š.; Susino, R.; Telloni, D.; Terasa, C.;
   Teriaca, L.; Toledo-Redondo, S.; del Toro Iniesta, J. C.; Tsiropoula,
   G.; Tsounis, A.; Tziotziou, K.; Valentini, F.; Vaivads, A.; Vecchio,
   A.; Velli, M.; Verbeeck, C.; Verdini, A.; Verscharen, D.; Vilmer, N.;
   Vourlidas, A.; Wicks, R.; Wimmer-Schweingruber, R. F.; Wiegelmann,
   T.; Young, P. R.; Zhukov, A. N.
2020A&A...642A...3Z    Altcode: 2020arXiv200910772Z
  Solar Orbiter is the first space mission observing the solar plasma
  both in situ and remotely, from a close distance, in and out of the
  ecliptic. The ultimate goal is to understand how the Sun produces
  and controls the heliosphere, filling the Solar System and driving
  the planetary environments. With six remote-sensing and four in-situ
  instrument suites, the coordination and planning of the operations are
  essential to address the following four top-level science questions:
  (1) What drives the solar wind and where does the coronal magnetic field
  originate?; (2) How do solar transients drive heliospheric variability?;
  (3) How do solar eruptions produce energetic particle radiation that
  fills the heliosphere?; (4) How does the solar dynamo work and drive
  connections between the Sun and the heliosphere? Maximising the
  mission's science return requires considering the characteristics
  of each orbit, including the relative position of the spacecraft
  to Earth (affecting downlink rates), trajectory events (such
  as gravitational assist manoeuvres), and the phase of the solar
  activity cycle. Furthermore, since each orbit's science telemetry
  will be downloaded over the course of the following orbit, science
  operations must be planned at mission level, rather than at the level
  of individual orbits. It is important to explore the way in which those
  science questions are translated into an actual plan of observations
  that fits into the mission, thus ensuring that no opportunities are
  missed. First, the overarching goals are broken down into specific,
  answerable questions along with the required observations and the
  so-called Science Activity Plan (SAP) is developed to achieve this. The
  SAP groups objectives that require similar observations into Solar
  Orbiter Observing Plans, resulting in a strategic, top-level view of
  the optimal opportunities for science observations during the mission
  lifetime. This allows for all four mission goals to be addressed. In
  this paper, we introduce Solar Orbiter's SAP through a series of
  examples and the strategy being followed.

---------------------------------------------------------
Title: Models and data analysis tools for the Solar Orbiter mission
Authors: Rouillard, A. P.; Pinto, R. F.; Vourlidas, A.; De Groof, A.;
   Thompson, W. T.; Bemporad, A.; Dolei, S.; Indurain, M.; Buchlin, E.;
   Sasso, C.; Spadaro, D.; Dalmasse, K.; Hirzberger, J.; Zouganelis, I.;
   Strugarek, A.; Brun, A. S.; Alexandre, M.; Berghmans, D.; Raouafi,
   N. E.; Wiegelmann, T.; Pagano, P.; Arge, C. N.; Nieves-Chinchilla,
   T.; Lavarra, M.; Poirier, N.; Amari, T.; Aran, A.; Andretta, V.;
   Antonucci, E.; Anastasiadis, A.; Auchère, F.; Bellot Rubio, L.;
   Nicula, B.; Bonnin, X.; Bouchemit, M.; Budnik, E.; Caminade, S.;
   Cecconi, B.; Carlyle, J.; Cernuda, I.; Davila, J. M.; Etesi, L.;
   Espinosa Lara, F.; Fedorov, A.; Fineschi, S.; Fludra, A.; Génot,
   V.; Georgoulis, M. K.; Gilbert, H. R.; Giunta, A.; Gomez-Herrero, R.;
   Guest, S.; Haberreiter, M.; Hassler, D.; Henney, C. J.; Howard, R. A.;
   Horbury, T. S.; Janvier, M.; Jones, S. I.; Kozarev, K.; Kraaikamp,
   E.; Kouloumvakos, A.; Krucker, S.; Lagg, A.; Linker, J.; Lavraud,
   B.; Louarn, P.; Maksimovic, M.; Maloney, S.; Mann, G.; Masson, A.;
   Müller, D.; Önel, H.; Osuna, P.; Orozco Suarez, D.; Owen, C. J.;
   Papaioannou, A.; Pérez-Suárez, D.; Rodriguez-Pacheco, J.; Parenti,
   S.; Pariat, E.; Peter, H.; Plunkett, S.; Pomoell, J.; Raines, J. M.;
   Riethmüller, T. L.; Rich, N.; Rodriguez, L.; Romoli, M.; Sanchez,
   L.; Solanki, S. K.; St Cyr, O. C.; Straus, T.; Susino, R.; Teriaca,
   L.; del Toro Iniesta, J. C.; Ventura, R.; Verbeeck, C.; Vilmer, N.;
   Warmuth, A.; Walsh, A. P.; Watson, C.; Williams, D.; Wu, Y.; Zhukov,
   A. N.
2020A&A...642A...2R    Altcode:
  Context. The Solar Orbiter spacecraft will be equipped with a wide
  range of remote-sensing (RS) and in situ (IS) instruments to record
  novel and unprecedented measurements of the solar atmosphere and
  the inner heliosphere. To take full advantage of these new datasets,
  tools and techniques must be developed to ease multi-instrument and
  multi-spacecraft studies. In particular the currently inaccessible
  low solar corona below two solar radii can only be observed
  remotely. Furthermore techniques must be used to retrieve coronal
  plasma properties in time and in three dimensional (3D) space. Solar
  Orbiter will run complex observation campaigns that provide interesting
  opportunities to maximise the likelihood of linking IS data to their
  source region near the Sun. Several RS instruments can be directed
  to specific targets situated on the solar disk just days before
  data acquisition. To compare IS and RS, data we must improve our
  understanding of how heliospheric probes magnetically connect to the
  solar disk. <BR /> Aims: The aim of the present paper is to briefly
  review how the current modelling of the Sun and its atmosphere
  can support Solar Orbiter science. We describe the results of a
  community-led effort by European Space Agency's Modelling and Data
  Analysis Working Group (MADAWG) to develop different models, tools,
  and techniques deemed necessary to test different theories for the
  physical processes that may occur in the solar plasma. The focus here
  is on the large scales and little is described with regards to kinetic
  processes. To exploit future IS and RS data fully, many techniques have
  been adapted to model the evolving 3D solar magneto-plasma from the
  solar interior to the solar wind. A particular focus in the paper is
  placed on techniques that can estimate how Solar Orbiter will connect
  magnetically through the complex coronal magnetic fields to various
  photospheric and coronal features in support of spacecraft operations
  and future scientific studies. <BR /> Methods: Recent missions such as
  STEREO, provided great opportunities for RS, IS, and multi-spacecraft
  studies. We summarise the achievements and highlight the challenges
  faced during these investigations, many of which motivated the Solar
  Orbiter mission. We present the new tools and techniques developed
  by the MADAWG to support the science operations and the analysis of
  the data from the many instruments on Solar Orbiter. <BR /> Results:
  This article reviews current modelling and tool developments that ease
  the comparison of model results with RS and IS data made available
  by current and upcoming missions. It also describes the modelling
  strategy to support the science operations and subsequent exploitation
  of Solar Orbiter data in order to maximise the scientific output
  of the mission. <BR /> Conclusions: The on-going community effort
  presented in this paper has provided new models and tools necessary
  to support mission operations as well as the science exploitation of
  the Solar Orbiter data. The tools and techniques will no doubt evolve
  significantly as we refine our procedure and methodology during the
  first year of operations of this highly promising mission.

---------------------------------------------------------
Title: Understanding the origins of the heliosphere: integrating
    observations and measurements from Parker Solar Probe, Solar Orbiter,
    and other space- and ground-based observatories
Authors: Velli, M.; Harra, L. K.; Vourlidas, A.; Schwadron,
   N.; Panasenco, O.; Liewer, P. C.; Müller, D.; Zouganelis, I.;
   St Cyr, O. C.; Gilbert, H.; Nieves-Chinchilla, T.; Auchère, F.;
   Berghmans, D.; Fludra, A.; Horbury, T. S.; Howard, R. A.; Krucker,
   S.; Maksimovic, M.; Owen, C. J.; Rodríguez-Pacheco, J.; Romoli,
   M.; Solanki, S. K.; Wimmer-Schweingruber, R. F.; Bale, S.; Kasper,
   J.; McComas, D. J.; Raouafi, N.; Martinez-Pillet, V.; Walsh, A. P.;
   De Groof, A.; Williams, D.
2020A&A...642A...4V    Altcode:
  Context. The launch of Parker Solar Probe (PSP) in 2018, followed
  by Solar Orbiter (SO) in February 2020, has opened a new window in
  the exploration of solar magnetic activity and the origin of the
  heliosphere. These missions, together with other space observatories
  dedicated to solar observations, such as the Solar Dynamics Observatory,
  Hinode, IRIS, STEREO, and SOHO, with complementary in situ observations
  from WIND and ACE, and ground based multi-wavelength observations
  including the DKIST observatory that has just seen first light,
  promise to revolutionize our understanding of the solar atmosphere
  and of solar activity, from the generation and emergence of the Sun's
  magnetic field to the creation of the solar wind and the acceleration of
  solar energetic particles. <BR /> Aims: Here we describe the scientific
  objectives of the PSP and SO missions, and highlight the potential for
  discovery arising from synergistic observations. Here we put particular
  emphasis on how the combined remote sensing and in situ observations of
  SO, that bracket the outer coronal and inner heliospheric observations
  by PSP, may provide a reconstruction of the solar wind and magnetic
  field expansion from the Sun out to beyond the orbit of Mercury in the
  first phases of the mission. In the later, out-of-ecliptic portions of
  the SO mission, the solar surface magnetic field measurements from SO
  and the multi-point white-light observations from both PSP and SO will
  shed light on the dynamic, intermittent solar wind escaping from helmet
  streamers, pseudo-streamers, and the confined coronal plasma, and on
  solar energetic particle transport. <BR /> Methods: Joint measurements
  during PSP-SO alignments, and magnetic connections along the same
  flux tube complemented by alignments with Earth, dual PSP-Earth,
  and SO-Earth, as well as with STEREO-A, SOHO, and BepiColumbo will
  allow a better understanding of the in situ evolution of solar-wind
  plasma flows and the full three-dimensional distribution of the
  solar wind from a purely observational point of view. Spectroscopic
  observations of the corona, and optical and radio observations,
  combined with direct in situ observations of the accelerating solar
  wind will provide a new foundation for understanding the fundamental
  physical processes leading to the energy transformations from solar
  photospheric flows and magnetic fields into the hot coronal plasma
  and magnetic fields and finally into the bulk kinetic energy of the
  solar wind and solar energetic particles. <BR /> Results: We discuss
  the initial PSP observations, which already provide a compelling
  rationale for new measurement campaigns by SO, along with ground-
  and space-based assets within the synergistic context described above.

---------------------------------------------------------
Title: The Solar Orbiter SPICE instrument. An extreme UV imaging
    spectrometer
Authors: SPICE Consortium; Anderson, M.; Appourchaux, T.; Auchère, F.;
   Aznar Cuadrado, R.; Barbay, J.; Baudin, F.; Beardsley, S.; Bocchialini,
   K.; Borgo, B.; Bruzzi, D.; Buchlin, E.; Burton, G.; Büchel, V.;
   Caldwell, M.; Caminade, S.; Carlsson, M.; Curdt, W.; Davenne, J.;
   Davila, J.; Deforest, C. E.; Del Zanna, G.; Drummond, D.; Dubau,
   J.; Dumesnil, C.; Dunn, G.; Eccleston, P.; Fludra, A.; Fredvik, T.;
   Gabriel, A.; Giunta, A.; Gottwald, A.; Griffin, D.; Grundy, T.; Guest,
   S.; Gyo, M.; Haberreiter, M.; Hansteen, V.; Harrison, R.; Hassler,
   D. M.; Haugan, S. V. H.; Howe, C.; Janvier, M.; Klein, R.; Koller,
   S.; Kucera, T. A.; Kouliche, D.; Marsch, E.; Marshall, A.; Marshall,
   G.; Matthews, S. A.; McQuirk, C.; Meining, S.; Mercier, C.; Morris,
   N.; Morse, T.; Munro, G.; Parenti, S.; Pastor-Santos, C.; Peter, H.;
   Pfiffner, D.; Phelan, P.; Philippon, A.; Richards, A.; Rogers, K.;
   Sawyer, C.; Schlatter, P.; Schmutz, W.; Schühle, U.; Shaughnessy,
   B.; Sidher, S.; Solanki, S. K.; Speight, R.; Spescha, M.; Szwec, N.;
   Tamiatto, C.; Teriaca, L.; Thompson, W.; Tosh, I.; Tustain, S.; Vial,
   J. -C.; Walls, B.; Waltham, N.; Wimmer-Schweingruber, R.; Woodward,
   S.; Young, P.; de Groof, A.; Pacros, A.; Williams, D.; Müller, D.
2020A&A...642A..14S    Altcode: 2019arXiv190901183A; 2019arXiv190901183S
  <BR /> Aims: The Spectral Imaging of the Coronal Environment (SPICE)
  instrument is a high-resolution imaging spectrometer operating at
  extreme ultraviolet wavelengths. In this paper, we present the concept,
  design, and pre-launch performance of this facility instrument on the
  ESA/NASA Solar Orbiter mission. <BR /> Methods: The goal of this paper
  is to give prospective users a better understanding of the possible
  types of observations, the data acquisition, and the sources that
  contribute to the instrument's signal. <BR /> Results: The paper
  discusses the science objectives, with a focus on the SPICE-specific
  aspects, before presenting the instrument's design, including optical,
  mechanical, thermal, and electronics aspects. This is followed by a
  characterisation and calibration of the instrument's performance. The
  paper concludes with descriptions of the operations concept and data
  processing. <BR /> Conclusions: The performance measurements of the
  various instrument parameters meet the requirements derived from the
  mission's science objectives. The SPICE instrument is ready to perform
  measurements that will provide vital contributions to the scientific
  success of the Solar Orbiter mission.

---------------------------------------------------------
Title: The Solar Orbiter Heliospheric Imager (SoloHI)
Authors: Howard, R. A.; Vourlidas, A.; Colaninno, R. C.; Korendyke,
   C. M.; Plunkett, S. P.; Carter, M. T.; Wang, D.; Rich, N.; Lynch,
   S.; Thurn, A.; Socker, D. G.; Thernisien, A. F.; Chua, D.; Linton,
   M. G.; Koss, S.; Tun-Beltran, S.; Dennison, H.; Stenborg, G.; McMullin,
   D. R.; Hunt, T.; Baugh, R.; Clifford, G.; Keller, D.; Janesick, J. R.;
   Tower, J.; Grygon, M.; Farkas, R.; Hagood, R.; Eisenhauer, K.; Uhl,
   A.; Yerushalmi, S.; Smith, L.; Liewer, P. C.; Velli, M. C.; Linker,
   J.; Bothmer, V.; Rochus, P.; Halain, J. -P.; Lamy, P. L.; Auchère,
   F.; Harrison, R. A.; Rouillard, A.; Patsourakos, S.; St. Cyr, O. C.;
   Gilbert, H.; Maldonado, H.; Mariano, C.; Cerullo, J.
2020A&A...642A..13H    Altcode:
  <BR /> Aims: We present the design and pre-launch performance of
  the Solar Orbiter Heliospheric Imager (SoloHI) which is an instrument
  prepared for inclusion in the ESA/NASA Solar Orbiter mission, currently
  scheduled for launch in 2020. <BR /> Methods: The goal of this paper
  is to provide details of the SoloHI instrument concept, design, and
  pre-flight performance to give the potential user of the data a better
  understanding of how the observations are collected and the sources
  that contribute to the signal. <BR /> Results: The paper discusses
  the science objectives, including the SoloHI-specific aspects, before
  presenting the design concepts, which include the optics, mechanical,
  thermal, electrical, and ground processing. Finally, a list of planned
  data products is also presented. <BR /> Conclusions: The performance
  measurements of the various instrument parameters meet or exceed the
  requirements derived from the mission science objectives. SoloHI is
  poised to take its place as a vital contributor to the science success
  of the Solar Orbiter mission.

---------------------------------------------------------
Title: The Solar Orbiter mission. Science overview
Authors: Müller, D.; St. Cyr, O. C.; Zouganelis, I.; Gilbert, H. R.;
   Marsden, R.; Nieves-Chinchilla, T.; Antonucci, E.; Auchère, F.;
   Berghmans, D.; Horbury, T. S.; Howard, R. A.; Krucker, S.; Maksimovic,
   M.; Owen, C. J.; Rochus, P.; Rodriguez-Pacheco, J.; Romoli, M.;
   Solanki, S. K.; Bruno, R.; Carlsson, M.; Fludra, A.; Harra, L.;
   Hassler, D. M.; Livi, S.; Louarn, P.; Peter, H.; Schühle, U.;
   Teriaca, L.; del Toro Iniesta, J. C.; Wimmer-Schweingruber, R. F.;
   Marsch, E.; Velli, M.; De Groof, A.; Walsh, A.; Williams, D.
2020A&A...642A...1M    Altcode: 2020arXiv200900861M
  <BR /> Aims: Solar Orbiter, the first mission of ESA's Cosmic Vision
  2015-2025 programme and a mission of international collaboration between
  ESA and NASA, will explore the Sun and heliosphere from close up and
  out of the ecliptic plane. It was launched on 10 February 2020 04:03
  UTC from Cape Canaveral and aims to address key questions of solar and
  heliospheric physics pertaining to how the Sun creates and controls
  the Heliosphere, and why solar activity changes with time. To answer
  these, the mission carries six remote-sensing instruments to observe
  the Sun and the solar corona, and four in-situ instruments to measure
  the solar wind, energetic particles, and electromagnetic fields. In
  this paper, we describe the science objectives of the mission, and how
  these will be addressed by the joint observations of the instruments
  onboard. <BR /> Methods: The paper first summarises the mission-level
  science objectives, followed by an overview of the spacecraft and
  payload. We report the observables and performance figures of each
  instrument, as well as the trajectory design. This is followed by a
  summary of the science operations concept. The paper concludes with a
  more detailed description of the science objectives. <BR /> Results:
  Solar Orbiter will combine in-situ measurements in the heliosphere
  with high-resolution remote-sensing observations of the Sun to address
  fundamental questions of solar and heliospheric physics. The performance
  of the Solar Orbiter payload meets the requirements derived from the
  mission's science objectives. Its science return will be augmented
  further by coordinated observations with other space missions and
  ground-based observatories. <P />ARRAY(0x207ce98)

---------------------------------------------------------
Title: The Solar Orbiter EUI instrument: The Extreme Ultraviolet
    Imager
Authors: Rochus, P.; Auchère, F.; Berghmans, D.; Harra, L.; Schmutz,
   W.; Schühle, U.; Addison, P.; Appourchaux, T.; Aznar Cuadrado,
   R.; Baker, D.; Barbay, J.; Bates, D.; BenMoussa, A.; Bergmann, M.;
   Beurthe, C.; Borgo, B.; Bonte, K.; Bouzit, M.; Bradley, L.; Büchel,
   V.; Buchlin, E.; Büchner, J.; Cabé, F.; Cadiergues, L.; Chaigneau,
   M.; Chares, B.; Choque Cortez, C.; Coker, P.; Condamin, M.; Coumar,
   S.; Curdt, W.; Cutler, J.; Davies, D.; Davison, G.; Defise, J. -M.;
   Del Zanna, G.; Delmotte, F.; Delouille, V.; Dolla, L.; Dumesnil, C.;
   Dürig, F.; Enge, R.; François, S.; Fourmond, J. -J.; Gillis, J. -M.;
   Giordanengo, B.; Gissot, S.; Green, L. M.; Guerreiro, N.; Guilbaud,
   A.; Gyo, M.; Haberreiter, M.; Hafiz, A.; Hailey, M.; Halain, J. -P.;
   Hansotte, J.; Hecquet, C.; Heerlein, K.; Hellin, M. -L.; Hemsley, S.;
   Hermans, A.; Hervier, V.; Hochedez, J. -F.; Houbrechts, Y.; Ihsan,
   K.; Jacques, L.; Jérôme, A.; Jones, J.; Kahle, M.; Kennedy, T.;
   Klaproth, M.; Kolleck, M.; Koller, S.; Kotsialos, E.; Kraaikamp, E.;
   Langer, P.; Lawrenson, A.; Le Clech', J. -C.; Lenaerts, C.; Liebecq,
   S.; Linder, D.; Long, D. M.; Mampaey, B.; Markiewicz-Innes, D.;
   Marquet, B.; Marsch, E.; Matthews, S.; Mazy, E.; Mazzoli, A.; Meining,
   S.; Meltchakov, E.; Mercier, R.; Meyer, S.; Monecke, M.; Monfort,
   F.; Morinaud, G.; Moron, F.; Mountney, L.; Müller, R.; Nicula, B.;
   Parenti, S.; Peter, H.; Pfiffner, D.; Philippon, A.; Phillips, I.;
   Plesseria, J. -Y.; Pylyser, E.; Rabecki, F.; Ravet-Krill, M. -F.;
   Rebellato, J.; Renotte, E.; Rodriguez, L.; Roose, S.; Rosin, J.;
   Rossi, L.; Roth, P.; Rouesnel, F.; Roulliay, M.; Rousseau, A.; Ruane,
   K.; Scanlan, J.; Schlatter, P.; Seaton, D. B.; Silliman, K.; Smit,
   S.; Smith, P. J.; Solanki, S. K.; Spescha, M.; Spencer, A.; Stegen,
   K.; Stockman, Y.; Szwec, N.; Tamiatto, C.; Tandy, J.; Teriaca, L.;
   Theobald, C.; Tychon, I.; van Driel-Gesztelyi, L.; Verbeeck, C.;
   Vial, J. -C.; Werner, S.; West, M. J.; Westwood, D.; Wiegelmann, T.;
   Willis, G.; Winter, B.; Zerr, A.; Zhang, X.; Zhukov, A. N.
2020A&A...642A...8R    Altcode:
  Context. The Extreme Ultraviolet Imager (EUI) is part of the remote
  sensing instrument package of the ESA/NASA Solar Orbiter mission
  that will explore the inner heliosphere and observe the Sun from
  vantage points close to the Sun and out of the ecliptic. Solar Orbiter
  will advance the "connection science" between solar activity and the
  heliosphere. <BR /> Aims: With EUI we aim to improve our understanding
  of the structure and dynamics of the solar atmosphere, globally as well
  as at high resolution, and from high solar latitude perspectives. <BR />
  Methods: The EUI consists of three telescopes, the Full Sun Imager and
  two High Resolution Imagers, which are optimised to image in Lyman-α
  and EUV (17.4 nm, 30.4 nm) to provide a coverage from chromosphere
  up to corona. The EUI is designed to cope with the strong constraints
  imposed by the Solar Orbiter mission characteristics. Limited telemetry
  availability is compensated by state-of-the-art image compression,
  onboard image processing, and event selection. The imposed power
  limitations and potentially harsh radiation environment necessitate
  the use of novel CMOS sensors. As the unobstructed field of view of
  the telescopes needs to protrude through the spacecraft's heat shield,
  the apertures have been kept as small as possible, without compromising
  optical performance. This led to a systematic effort to optimise the
  throughput of every optical element and the reduction of noise levels
  in the sensor. <BR /> Results: In this paper we review the design
  of the two elements of the EUI instrument: the Optical Bench System
  and the Common Electronic Box. Particular attention is also given to
  the onboard software, the intended operations, the ground software,
  and the foreseen data products. <BR /> Conclusions: The EUI will
  bring unique science opportunities thanks to its specific design,
  its viewpoint, and to the planned synergies with the other Solar
  Orbiter instruments. In particular, we highlight science opportunities
  brought by the out-of-ecliptic vantage point of the solar poles,
  the high-resolution imaging of the high chromosphere and corona,
  and the connection to the outer corona as observed by coronagraphs.

---------------------------------------------------------
Title: Metis: the Solar Orbiter visible light and ultraviolet
    coronal imager
Authors: Antonucci, Ester; Romoli, Marco; Andretta, Vincenzo; Fineschi,
   Silvano; Heinzel, Petr; Moses, J. Daniel; Naletto, Giampiero; Nicolini,
   Gianalfredo; Spadaro, Daniele; Teriaca, Luca; Berlicki, Arkadiusz;
   Capobianco, Gerardo; Crescenzio, Giuseppe; Da Deppo, Vania; Focardi,
   Mauro; Frassetto, Fabio; Heerlein, Klaus; Landini, Federico; Magli,
   Enrico; Marco Malvezzi, Andrea; Massone, Giuseppe; Melich, Radek;
   Nicolosi, Piergiorgio; Noci, Giancarlo; Pancrazzi, Maurizio; Pelizzo,
   Maria G.; Poletto, Luca; Sasso, Clementina; Schühle, Udo; Solanki,
   Sami K.; Strachan, Leonard; Susino, Roberto; Tondello, Giuseppe;
   Uslenghi, Michela; Woch, Joachim; Abbo, Lucia; Bemporad, Alessandro;
   Casti, Marta; Dolei, Sergio; Grimani, Catia; Messerotti, Mauro;
   Ricci, Marco; Straus, Thomas; Telloni, Daniele; Zuppella, Paola;
   Auchère, Frederic; Bruno, Roberto; Ciaravella, Angela; Corso,
   Alain J.; Alvarez Copano, Miguel; Aznar Cuadrado, Regina; D'Amicis,
   Raffaella; Enge, Reiner; Gravina, Alessio; Jejčič, Sonja; Lamy,
   Philippe; Lanzafame, Alessandro; Meierdierks, Thimo; Papagiannaki,
   Ioanna; Peter, Hardi; Fernandez Rico, German; Giday Sertsu, Mewael;
   Staub, Jan; Tsinganos, Kanaris; Velli, Marco; Ventura, Rita; Verroi,
   Enrico; Vial, Jean-Claude; Vives, Sebastien; Volpicelli, Antonio;
   Werner, Stephan; Zerr, Andreas; Negri, Barbara; Castronuovo, Marco;
   Gabrielli, Alessandro; Bertacin, Roberto; Carpentiero, Rita; Natalucci,
   Silvia; Marliani, Filippo; Cesa, Marco; Laget, Philippe; Morea, Danilo;
   Pieraccini, Stefano; Radaelli, Paolo; Sandri, Paolo; Sarra, Paolo;
   Cesare, Stefano; Del Forno, Felice; Massa, Ernesto; Montabone, Mauro;
   Mottini, Sergio; Quattropani, Daniele; Schillaci, Tiziano; Boccardo,
   Roberto; Brando, Rosario; Pandi, Arianna; Baietto, Cristian; Bertone,
   Riccardo; Alvarez-Herrero, Alberto; García Parejo, Pilar; Cebollero,
   María; Amoruso, Mauro; Centonze, Vito
2020A&A...642A..10A    Altcode: 2019arXiv191108462A
  <BR /> Aims: Metis is the first solar coronagraph designed for a
  space mission and is capable of performing simultaneous imaging of the
  off-limb solar corona in both visible and UV light. The observations
  obtained with Metis aboard the Solar Orbiter ESA-NASA observatory
  will enable us to diagnose, with unprecedented temporal coverage and
  spatial resolution, the structures and dynamics of the full corona
  in a square field of view (FoV) of ±2.9° in width, with an inner
  circular FoV at 1.6°, thus spanning the solar atmosphere from 1.7
  R<SUB>⊙</SUB> to about 9 R<SUB>⊙</SUB>, owing to the eccentricity
  of the spacecraft orbit. Due to the uniqueness of the Solar Orbiter
  mission profile, Metis will be able to observe the solar corona
  from a close (0.28 AU, at the closest perihelion) vantage point,
  achieving increasing out-of-ecliptic views with the increase of the
  orbit inclination over time. Moreover, observations near perihelion,
  during the phase of lower rotational velocity of the solar surface
  relative to the spacecraft, allow longer-term studies of the off-limb
  coronal features, thus finally disentangling their intrinsic evolution
  from effects due to solar rotation. <BR /> Methods: Thanks to a novel
  occultation design and a combination of a UV interference coating of
  the mirrors and a spectral bandpass filter, Metis images the solar
  corona simultaneously in the visible light band, between 580 and 640
  nm, and in the UV H I Lyman-α line at 121.6 nm. The visible light
  channel also includes a broadband polarimeter able to observe the
  linearly polarised component of the K corona. The coronal images in
  both the UV H I Lyman-α and polarised visible light are obtained at
  high spatial resolution with a spatial scale down to about 2000 km
  and 15 000 km at perihelion, in the cases of the visible and UV light,
  respectively. A temporal resolution down to 1 s can be achieved when
  observing coronal fluctuations in visible light. <BR /> Results: The
  Metis measurements, obtained from different latitudes, will allow for
  complete characterisation of the main physical parameters and dynamics
  of the electron and neutral hydrogen/proton plasma components of the
  corona in the region where the solar wind undergoes the acceleration
  process and where the onset and initial propagation of coronal mass
  ejections (CMEs) take place. The near-Sun multi-wavelength coronal
  imaging performed with Metis, combined with the unique opportunities
  offered by the Solar Orbiter mission, can effectively address crucial
  issues of solar physics such as: the origin and heating/acceleration
  of the fast and slow solar wind streams; the origin, acceleration,
  and transport of the solar energetic particles; and the transient
  ejection of coronal mass and its evolution in the inner heliosphere,
  thus significantly improving our understanding of the region connecting
  the Sun to the heliosphere and of the processes generating and driving
  the solar wind and coronal mass ejections. <BR /> Conclusions: This
  paper presents the scientific objectives and requirements, the overall
  optical design of the Metis instrument, the thermo-mechanical design,
  and the processing and power unit; reports on the results of the
  campaigns dedicated to integration, alignment, and tests, and to
  the characterisation of the instrument performance; describes the
  operation concept, data handling, and software tools; and, finally,
  the diagnostic techniques to be applied to the data, as well as a brief
  description of the expected scientific products. The performance of the
  instrument measured during calibrations ensures that the scientific
  objectives of Metis can be pursued with success. <P />Metis website:
  <A href="http://metis.oato.inaf.it">http://metis.oato.inaf.it</A>

---------------------------------------------------------
Title: The Solaris Solar Polar Mission
Authors: Hassler, Donald M.; Newmark, Jeff; Gibson, Sarah; Harra,
   Louise; Appourchaux, Thierry; Auchere, Frederic; Berghmans, David;
   Colaninno, Robin; Fineschi, Silvano; Gizon, Laurent; Gosain, Sanjay;
   Hoeksema, Todd; Kintziger, Christian; Linker, John; Rochus, Pierre;
   Schou, Jesper; Viall, Nicholeen; West, Matt; Woods, Tom; Wuelser,
   Jean-Pierre
2020EGUGA..2217703H    Altcode:
  The solar poles are one of the last unexplored regions of the solar
  system. Although Ulysses flew over the poles in the 1990s, it did
  not have remote sensing instruments onboard to probe the Sun's polar
  magnetic field or surface/sub-surface flows.We will discuss Solaris,
  a proposed Solar Polar MIDEX mission to revolutionize our understanding
  of the Sun by addressing fundamental questions that can only be answered
  from a polar vantage point. Solaris uses a Jupiter gravity assist to
  escape the ecliptic plane and fly over both poles of the Sun to &gt;75
  deg. inclination, obtaining the first high-latitude, multi-month-long,
  continuous remote-sensing solar observations. Solaris will address key
  outstanding, breakthrough problems in solar physics and fill holes in
  our scientific understanding that will not be addressed by current
  missions.With focused science and a simple, elegant mission design,
  Solaris will also provide enabling observations for space weather
  research (e.g. polar view of CMEs), and stimulate future research
  through new unanticipated discoveries.

---------------------------------------------------------
Title: Spectroscopic detection of coronal plasma flows in loops
    undergoing thermal non-equilibrium cycles
Authors: Pelouze, Gabriel; Auchère, Frédéric; Bocchialini, Karine;
   Froment, Clara; Parenti, Susanna; Soubrié, Elie
2020A&A...634A..54P    Altcode: 2019arXiv191202538P
  Context. Long-period intensity pulsations were recently detected in
  the EUV emission of coronal loops and attributed to cycles of plasma
  evaporation and condensation driven by thermal non-equilibrium
  (TNE). Numerical simulations that reproduce this phenomenon
  also predict the formation of periodic flows of plasma at coronal
  temperatures along some of the pulsating loops. <BR /> Aims: We aim
  to detect these predicted flows of coronal-temperature plasma in
  pulsating loops. <BR /> Methods: We used time series of spatially
  resolved spectra from the EUV imaging spectrometer (EIS) onboard
  Hinode and tracked the evolution of the Doppler velocity in loops in
  which intensity pulsations have previously been detected in images
  of SDO/AIA. <BR /> Results: We measured signatures of flows that are
  compatible with the simulations but only for a fraction of the observed
  events. We demonstrate that this low detection rate can be explained
  by line of sight ambiguities combined with instrumental limitations,
  such as low signal-to-noise ratio or insufficient cadence. <P
  />Movies associated to Figs. 1, 4, 7, 10 are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/201935872/olm">https://www.aanda.org</A>

---------------------------------------------------------
Title: Global helium abundance measurements in the solar corona
Authors: Moses, John D.; Antonucci, Ester; Newmark, Jeffrey; Auchère,
   Frédéric; Fineschi, Silvano; Romoli, Marco; Telloni, Daniele;
   Massone, Giuseppe; Zangrilli, Luca; Focardi, Mauro; Landini, Federico;
   Pancrazzi, Maurizio; Rossi, Guglielmo; Malvezzi, Andrea M.; Wang,
   Dennis; Leclec'h, Jean-Christophe; Moalic, Jean-Pierre; Rouesnel,
   Frédéric; Abbo, Lucia; Canou, Aurélien; Barbey, Nicolas; Guennou,
   Chloé; Laming, John M.; Lemen, James; Wuelser, Jean-Pierre; Kohl,
   John L.; Gardner, Lawrence D.
2020NatAs...4.1134M    Altcode: 2020NatAs.tmp..152M
  Solar abundances have been historically assumed to be representative
  of cosmic abundances. However, our knowledge of the solar abundance
  of helium, the second most abundant element, relies mainly on
  models<SUP>1</SUP> and indirect measurements through helioseismic
  observations<SUP>2</SUP>, because actual measurements of helium in the
  solar atmosphere are very scarce. Helium cannot be directly measured
  in the photosphere because of its high first ionization potential,
  and measurements of its abundance in the inner corona have been
  sporadic<SUP>3,4</SUP>. In this Letter, we present simultaneous global
  images of the helium (out to a heliocentric distance of 3R<SUB>⊙</SUB>
  (solar radii)) and hydrogen emission in the solar corona during
  the minimum of solar activity of cycle 23 and directly derive the
  helium abundance in the streamer region and surrounding corona
  (out to 2.2R<SUB>⊙</SUB>). The morphology of the He<SUP>+</SUP>
  corona is markedly different from that of the H corona, owing to
  significant spatial variations in helium abundance. The observations
  show that the helium abundance is shaped according to and modulated
  by the structure of the large-scale coronal magnetic field and that
  helium is almost completely depleted in the equatorial regions during
  the quiet Sun. This measurement provides a trace back to the coronal
  source of the anomalously slow solar wind observed in the heliosphere
  at the Sun-Earth Lagrangian point L1 in 2009, during the exceptionally
  long-lasting minimum of solar activity cycle 23.

---------------------------------------------------------
Title: The SPICE (Spectral Imaging of the Coronal Environment)
    Ultraviolet Imaging Spectrograph Investigation
Authors: Hassler, D.; Auchere, F.; Carlsson, M.; Fludra, A.; Giunta,
   A. S.; Mueller, D.; Peter, H.; Parenti, S.; Teriaca, L.; Fredvik, T.
2019AGUFMSH24A..02H    Altcode:
  One of the primary objectives of the Solar Orbiter mission is to link
  remote sensing observations of the solar surface structures with in-situ
  observations of solar wind streams. The SPICE (Spectral Imaging of the
  Coronal Environment) instrument will characterize the plasma properties
  of regions near the Sun to directly compare with in-situ measurements
  from both Solar Orbiter &amp; Parker Solar Probe. Specifically, SPICE
  will map outflow velocities of surface features to solar wind structures
  with similar composition (FIP, M/q) measured in-situ by the SWA/HIS
  instrument on Solar Orbiter. These observations will help discriminate
  models of solar wind origin by matching composition signatures in
  solar wind streams to surface feature composition, and discriminate
  physical processes that inject material from closed structures into
  solar wind streams. <P />This presentation will provide an overview of
  the SPICE investigation, including science &amp; measurement objective,
  instrument design, capabilities and performance as measured during
  calibration prior to delivery to the Solar Orbiter spacecraft. The
  presentation will also provide a description of the operations concept
  and data processing during the mission.

---------------------------------------------------------
Title: The Solar Orbiter EUI instrument: The Extreme Ultraviolet
    Imager
Authors: Rochus, P. L.; Auchere, F.; Berghmans, D.; Harra, L.; Schmutz,
   W. K.; Schühle, U.
2019AGUFMSH21D3291R    Altcode:
  The Extreme Ultraviolet Imager (EUI) is part of the remote sensing
  instrument package of the ESA/NASA Solar Orbiter mission that will
  explore the inner heliosphere and observe the Sun from vantage points
  close to the Sun and out-of-the-ecliptic. <P />EUI aims at improving our
  understanding of the structure and dynamics of the solar atmosphere. EUI
  will take images of the solar atmosphere, globally as well as at high
  resolution, and from high solar latitude perspectives. <P />EUI consists
  of 3 telescopes that are optimized to image in Lyman-a and EUV 17.4nm
  and 30.4 nm to provide a coverage from chromosphere up to corona. EUI
  is designed to cope with the strong constraints that Solar Orbiter has
  as a deep space mission. Limited telemetry availability is compensated
  by state-of-the-art image compression, on board image processing and
  event selection. The imposed power limitations and potentially harsh
  radiation environment lead to the usage of novel CMOS sensors. As
  the unobstructed field of view of the telescopes needs to protrude
  through the spacecraft heat shield, the apertures were kept as small as
  possible. This lead to a systematic effort to optimize the throughput
  of every optical element and the reduction of noise levels in the
  sensor. <P />In this paper we review the design of the two elements of
  the EUI instrument: the Optical Bench System and the Common Electronic
  Box. Particular attention is also given to the on board software,
  the intended operations, the ground software and the foreseen data
  products. <P />EUI will bring unique science opportunities thanks to its
  specific design, its viewpoint and thanks to the planned synergies with
  the other Solar Orbiter instruments. We highlight in particular science
  opportunities brought by the out-of-ecliptic vantage point of the solar
  poles, the high resolution imaging of the high chromosphere and corona,
  and the connection to the outer corona as observed by coronagraphs.

---------------------------------------------------------
Title: The Chromospheric Layer Spectro-Polarimeter (CLASP2) Sounding
Rocket Mission: First Results
Authors: McKenzie, D. E.; Ishikawa, R.; Trujillo Bueno, J.; Auchere,
   F.; Rachmeler, L.; Kano, R.; Song, D.; Okamoto, J.; Kobayashi, K.;
   Yoshida, M.
2019AGUFMSH44A..06M    Altcode:
  A major challenge for heliophysics is to decipher the magnetic structure
  of the chromosphere, because of its vital role in the transport of
  energy into the corona and solar wind. Routine satellite measurements
  of the chromospheric magnetic field will dramatically improve our
  understanding of the chromosphere and its connection to the rest of
  the solar atmosphere. Before such a satellite can be considered for
  flight, we must refine the measurement techniques by exploring emission
  lines with a range of magnetic sensitivities. In 2015, CLASP achieved
  the first measurement of linear polarization produced by scattering
  processes in a far UV resonance line (hydrogen Lyman­-α), and the
  first exploration of the magnetic field (via the Hanle effect) and
  geometrical complexity in quiet regions of the chromosphere/­corona
  transition region. These measurements are a first step towards
  routine quantitative characterization of the local thermal and magnetic
  conditions in this key layer of the solar atmosphere. <P />Nonetheless,
  Lyman­-α is only one of the magnetically sensitive spectral lines in
  the UV spectrum. CLASP2 extends the capability of UV spectropolarimetry
  by acquiring ground­breaking measurements in the Mg II h and k spectral
  lines near 280 nm, whose cores form about 100 km below the Lyman-­α
  core. These lines are sensitive to a larger range of field strengths
  than Lyman­-α, through both the Hanle and Zeeman effects. CLASP2
  captures measurements of linear and circular polarization to enable
  the first determination of all 4 Stokes parameters in chromospheric
  UV radiation. Coupled with numerical modeling of the observed spectral
  line polarization (anisotropic radiation pumping with Hanle, Zeeman and
  magneto-­optical effects), CLASP2 is a pathfinder for determination
  of the magnetic field's strength and direction, as well as of the
  geometry of the plasma in the upper solar chromosphere. <P />CLASP2
  was launched from White Sands Missile Range in April 2019. In this
  presentation, we will summarize the characteristics of the CLASP2
  flight, the performance of the UV telescope and spectropolarimeter,
  and our preliminary findings.

---------------------------------------------------------
Title: From PROBA2/SWAP to Solar Orbiter/EUI: exploring the outer
    edge of the EUV corona.
Authors: Berghmans, D.; D'Huys, E.; Zhukov, A.; Auchere, F.
2019AGUFMSH13A..01B    Altcode:
  SWAP is a small coronal EUV imager onboard the ESA microsatellite
  PROBA2. Thanks to its large field of view (54 arcmin), spacecraft
  offpoints and applied image processing, SWAP has been able to show the
  structures of the EUV corona more than 1 Rsun above the limb. This
  "middle corona" is in between the classical off limb EUV corona
  as seen by e.g. SDO/AIA and the much further white light corona as
  seen by e.g. the LASCO coronagraphs and is thus a poorly observed
  region. The Middle Corona harbours interesting physics, as it is
  here where the solar wind accelerates and the topology of streamers
  and pseudo-streamers fade in the solar wind. SWAP imagery has shown
  how 'coronal fan' structures in the middle corona survive many solar
  rotations and how the extended corona above the solar poles reverses
  polarity. The Full Sun Imager (FSI, part of Extreme Ultraviolet Imager
  EUI onboard Solar Orbiter) will take this further with a field of view
  of 228 arcmin. Furthermore, as embarked on the Solar Orbiter mission
  (launch 2020) FSI will be the first to image all this from out of the
  ecliptic. In this paper we will review the Middle Corona results of
  SWAP and provide an outlook on what to expect from EUI/FSI.

---------------------------------------------------------
Title: Center-to-Limb Variation of the polarization of Mg II h &amp;
    k lines as measured by CLASP2
Authors: Rachmeler, L.; McKenzie, D. E.; Ishikawa, R.; Kano, R.;
   Trujillo Bueno, J.; Kobayashi, K.; Song, D.; Yoshida, M.; Auchere,
   F.; Okamoto, J.
2019AGUFMSH11D3380R    Altcode:
  The Chromospheric LAyer SpectroPolarimeter 2 (CLASP2) is a sounding
  rocket that was launched from White Sands Missile Range in April
  2019. CLASP2 is a reflight of the CLASP instrument, and has been
  modified to observe the polarization of the Magnesium II h &amp; k
  lines in the solar chromosphere. The instrument contains a slit-jaw
  context imager at Lyman Alpha (~121.6nm) and two spectropolarimetric
  cameras that capture Mg II h &amp; k near 280nm. A rotating polarization
  modulation unit allows us to capture the full polarization state of
  Mg II h &amp; k; the measured polarization signals are sensitive
  to the Hanle and the Zeeman magnetic effects, and magneto-optical
  effects. The center-to-limb variations (CLV) of the intensity of
  these lines has been measured, but the CLV of the polarization signals
  has only been investigated theoretically. The first flight of CLASP,
  which measured the linear polarization of the Lyman alpha line, found
  a surprising lack of CLV in the line core (Kano et al. 2017), which
  has important implications for the magnetic strength and geometrical
  complexity of the chromosphere-corona transition region (Trujillo Bueno
  et al. 2018). We present here initial results on the CLV of the Mg II
  polarization signals.

---------------------------------------------------------
Title: High-frequency Wave Propagation Along a Spicule Observed
    by CLASP
Authors: Yoshida, Masaki; Suematsu, Yoshinori; Ishikawa, Ryohko;
   Okamoto, Takenori J.; Kubo, Masahito; Kano, Ryouhei; Narukage,
   Noriyuki; Bando, Takamasa; Winebarger, Amy R.; Kobayashi, Ken;
   Trujillo Bueno, Javier; Auchère, Frédéric
2019ApJ...887....2Y    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) sounding
  rocket experiment, launched in 2015 September, observed the hydrogen
  Lyα line (121.6 nm) in an unprecedented high temporal cadence of
  0.3 s. CLASP performed sit-and-stare observations of the quiet Sun
  near the limb for 5 minutes with a slit perpendicular to the limb
  and successfully captured an off-limb spicule evolving along the
  slit. The Lyα line is well suited for investigating how spicules
  affect the corona because it is sensitive to higher temperatures than
  other chromospheric lines, owing to its large optical thickness. We
  found high-frequency oscillations of the Doppler velocity with periods
  of 20-50 s and low-frequency oscillation of periods of ∼240 s on
  the spicule. From a wavelet analysis of the time sequence data of
  the Doppler velocity, in the early phase of the spicule evolution,
  we found that waves with a period of ∼30 s and a velocity amplitude
  of 2-3 km s<SUP>-1</SUP> propagated upward along the spicule with a
  phase velocity of ∼470 km s<SUP>-1</SUP>. In contrast, in the later
  phase, possible downward and standing waves with smaller velocity
  amplitudes were also observed. The high-frequency waves observed in
  the early phase of the spicule evolution would be related with the
  dynamics and the formation of the spicules. Our analysis enabled us to
  identify the upward, downward, and standing waves along the spicule
  and to obtain the velocity amplitude of each wave directly from the
  Doppler velocity for the first time. We evaluated the energy flux
  by the upward-propagating waves along the spicule, and discussed the
  impact to the coronal heating.

---------------------------------------------------------
Title: Pointing the NTT at the Sun: Studying the Solar Corona During
    the Total Eclipse
Authors: Dennefeld, M.; Koutchmy, S.; Sèvre, F.; Fathivavsari,
   H.; Auchère, F.; Baudin, F.; Abdi, S.; Sinclaire, P.; Saviane, I.;
   Labraña, F.; Schmidtobreick, L.
2019Msngr.177...54D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The Solar-C_EUVST mission
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko;
   Ichimoto, Kiyoshi; Suematsu, Yoshinori; Hara, Hirohisa; Katsukawa,
   Yukio; Kubo, Masahito; Toriumi, Shin; Watanabe, Tetsuya; Yokoyama,
   Takaaki; Korendyke, Clarence M.; Warren, Harry P.; Tarbell, Ted; De
   Pontieu, Bart; Teriaca, Luca; Schühle, Udo H.; Solanki, Sami; Harra,
   Louise K.; Matthews, Sarah; Fludra, A.; Auchère, F.; Andretta, V.;
   Naletto, G.; Zhukov, A.
2019SPIE11118E..07S    Altcode:
  Solar-C EUVST (EUV High-Throughput Spectroscopic Telescope) is a
  solar physics mission concept that was selected as a candidate for
  JAXA competitive M-class missions in July 2018. The onboard science
  instrument, EUVST, is an EUV spectrometer with slit-jaw imaging
  system that will simultaneously observe the solar atmosphere from the
  photosphere/chromosphere up to the corona with seamless temperature
  coverage, high spatial resolution, and high throughput for the first
  time. The mission is designed to provide a conclusive answer to the
  most fundamental questions in solar physics: how fundamental processes
  lead to the formation of the solar atmosphere and the solar wind, and
  how the solar atmosphere becomes unstable, releasing the energy that
  drives solar flares and eruptions. The entire instrument structure
  and the primary mirror assembly with scanning and tip-tilt fine
  pointing capability for the EUVST are being developed in Japan, with
  spectrograph and slit-jaw imaging hardware and science contributions
  from US and European countries. The mission will be launched and
  installed in a sun-synchronous polar orbit by a JAXA Epsilon vehicle in
  2025. ISAS/JAXA coordinates the conceptual study activities during the
  current mission definition phase in collaboration with NAOJ and other
  universities. The team is currently working towards the JAXA final
  down-selection expected at the end of 2019, with strong support from
  US and European colleagues. The paper provides an overall description
  of the mission concept, key technologies, and the latest status.

---------------------------------------------------------
Title: Optical alignment of the Solar Orbiter EUI flight instrument
Authors: Mazzoli, A.; Halain, J. -P.; Auchère, F.; Barbay, J.;
   Meining, S.; Philippon, A.; Morinaud, G.; Roose, S.; Hellin, M. -L.;
   Jacques, L.; Schühle, U.; Dumesnil, C.; Mercier, R.; Renotte, E.;
   Rochus, P.
2019SPIE11180E..1OM    Altcode:
  The Extreme Ultraviolet Imager (EUI) instrument for the Solar Orbiter
  mission will image the solar corona in the extreme ultraviolet
  (17.1 nm and 30.4 nm) and in the vacuum ultraviolet (121.6 nm). It
  is composed of three channels, each one containing a telescope. Two
  of these channels are high resolution imagers (HRI) at respectively
  17.1 nm (HRI-EUV) and 121.6 nm (HRI-Ly ), each one composed of two
  off-axis aspherical mirrors. The third channel is a full sun imager
  (FSI) composed of one single off-axis aspherical mirror and working
  at 17.1 nm and 30.4 nm alternatively. This paper presents the optical
  alignment of each telescope. The alignment process involved a set of
  Optical Ground Support Equipment (OGSE) such as theodolites, laser
  tracker, visible-light interferometer as well as a 3D Coordinates
  Measuring Machine (CMM). The mirrors orientation have been measured
  with respect to reference alignment cubes using theodolites. Their
  positions with respect to reference pins on the instrument optical
  bench have been measured using the 3D CMM. The mirrors orientations and
  positions have been adjusted by shimming of the mirrors mount during
  the alignment process. After this mechanical alignment, the quality
  of the wavefront has been checked by interferometric measurements,
  in an iterative process with the orientation and position adjustment
  to achieve the required image quality.

---------------------------------------------------------
Title: The Chromospheric Layer Spectro-Polarimeter (CLASP2) Sounding
Rocket Mission: First Results
Authors: McKenzie, David Eugene; Ishikawa, Ryohko; Kano, Ryouhei;
   Rachmeler, Laurel; Trujillo Bueno, Javier; Kobayashi, Ken; Song,
   Donguk; Yoshida, Masaki; Auchere, Frederic; Okamoto, Takenori
2019AAS...23412601M    Altcode:
  A major challenge for heliophysics is to decipher the magnetic structure
  of the chromosphere, because of its vital role in the transport of
  energy into the corona and solar wind. Routine satellite measurements
  of the chromospheric magnetic field will dramatically improve our
  understanding of the chromosphere and its connection to the rest of
  the solar atmosphere. Before such a satellite can be considered for
  flight, we must refine the measurement techniques by exploring emission
  lines with a range of magnetic sensitivities. In 2015, CLASP achieved
  the first measurement of linear polarization produced by scattering
  processes in a far UV resonance line (hydrogen Lyman-α), and the
  first exploration of the magnetic field (via the Hanle effect) and
  geometrical complexity in quiet regions of the chromosphere-corona
  transition region. These measurements are a first step towards
  routine quantitative characterization of the local thermal and magnetic
  conditions in this key layer of the solar atmosphere. <P />Nonetheless,
  Lyman-α is only one of the magnetically sensitive spectral lines in the
  UV spectrum. CLASP2 extends the capability of UV spectropolarimetry by
  acquiring ground-breaking measurements in the Mg II h and k spectral
  lines near 280 nm, whose cores form about 100 km below the Lyman-α
  core. These lines are sensitive to a larger range of field strengths
  than Lyman-α, through both the Hanle and Zeeman effects. CLASP2 will
  capture measurements of linear and circular polarization to enable the
  first determination of all 4 Stokes parameters in chromospheric UV
  radiation. Coupled with numerical modeling of the observed spectral
  line polarization (anisotropic radiation pumping with Hanle, Zeeman
  and magneto-optical effects), CLASP2 is a pathfinder for determination
  of the magnetic field's strength and direction, as well as of the
  geometry of the plasma in the upper solar chromosphere. <P />CLASP2
  will launch from White Sands Missile Range in April 2019. In this
  presentation, we will summarize the characteristics of the CLASP2
  flight, the performance of the UV telescope and spectropolarimeter,
  and our preliminary findings.

---------------------------------------------------------
Title: Lyman-α imaging polarimetry with the CLASP2 sounding rocket
    mission
Authors: Kano, Ryouhei; Ishikawa, Ryohko; McKenzie, David Eugene;
   Trujillo Bueno, Javier; Song, Donguk; Yoshida, Masaki; Okamoto,
   Takenori; Rachmeler, Laurel; Kobayashi, Ken; Auchere, Frederic
2019AAS...23430216K    Altcode:
  Ultraviolet polarimetry offers a unique opportunity to explore the upper
  solar chromosphere and the transition region (TR) to the million-degree
  corona. These outer atmospheric regions play a key role in the transfer
  of mass and energy from the solar photosphere to the corona. With
  a sounding rocket experiment called the Chromospheric Lyman-Alpha
  Spectro-Polarimeter (CLASP), in September 2015 we succeeded in obtaining
  the first measurement of the linear polarization produced by scattering
  processes in the hydrogen Lyman-α line of the solar disk radiation. The
  analysis and interpretation of such spectro-polarimetric observation
  allowed us to obtain information on the geometrical complexity of
  the corrugated surface that delineates the TR, as well as on the
  magnetic field strength via the Hanle effect. At the same time, the
  CLASP slit-jaw (SJ) optics system, which is a Lyman-α filter imager
  characterized by a FWHM= 7 nm, allowed us to obtain broad-band Stokes-I
  and Q/I images over a large field of view. The obtained broad-band
  Q/I images are dominated by the scattering polarization signals of the
  Lyman-α wings, and not by the much weaker line-center signals where
  the Hanle effect operates. Recently, Alsina Ballester et al. (2019,
  ApJ, in press) showed that the scattering polarization signals of the
  Lyman-α wings are sensitive to chromospheric magnetic fields via the
  magneto-optical effects. Therefore, Lyman-α imaging polarimetry is of
  scientific interest also for magnetic-field investigations. On April
  11, 2019, we performed another sounding rocket experiment, called
  the Chromospheric LAyer Spectro-Polarimeter (CLASP2). We used the
  same instrument after significant modifications in order to obtain
  spectro-polarimetric observations of a plage and a quiet region in
  the ionized magnesium lines around 280 nm (i.e., the Mg II h &amp;
  k lines). At the same time, the CLASP2 SJ optics system allowed us to
  obtain broad-band Q/I and U/I images at the Lyman-α wavelength, in
  addition to the well-known SJ intensity images. In this presentation,
  we provide a first overview of the CLASP2 SJ data.

---------------------------------------------------------
Title: Modeling the Scattering Polarization of the Hydrogen Lyα
    Line Observed by CLASP in a Filament Channel
Authors: Štěpán, J.; Trujillo Bueno, J.; Gunár, S.; Heinzel, P.;
   del Pino Alemán, T.; Kano, R.; Ishikawa, R.; Narukage, N.; Bando,
   T.; Winebarger, A.; Kobayashi, K.; Auchère, F.
2019ASPC..526..165S    Altcode:
  The 400 arcsec spectrograph slit of CLASP crossed mainly quiet
  regions of the solar chromosphere, from the limb towards the solar
  disk center. Interestingly, in the CLASP slit-jaw images and in the
  SDO images of the He II line at 304 Å, we can identify a filament
  channel (FC) extending over more than 60 arcsec crossing the slit of
  the spectrograph. In order to interpret the peculiar spatial variation
  of the Q/I and U/I signals observed by CLASP in the hydrogen Lyα line
  (1216 Å), we perform multi-dimensional radiative transfer modeling
  in given filament models. In this contribution, we show the first
  results of the two-dimensional calculations we have carried out, with
  the aim of determining the filament thermal and magnetic structure by
  comparing the theoretical and the observed polarization signals. Our
  results suggest that the temperature gradients in the filament observed
  by CLASP are significantly larger than previously thought.

---------------------------------------------------------
Title: Comprehensive Determination of the Hinode/EIS Roll Angle
Authors: Pelouze, Gabriel; Auchère, Frédéric; Bocchialini, Karine;
   Harra, Louise; Baker, Deborah; Warren, Harry P.; Brooks, David H.;
   Mariska, John T.
2019SoPh..294...59P    Altcode: 2019arXiv190311923P
  We present a new coalignment method for the EUV Imaging Spectrometer
  (EIS) on board the Hinode spacecraft. In addition to the pointing
  offset and spacecraft jitter, this method determines the roll angle
  of the instrument, which has never been systematically measured, and
  which is therefore usually not corrected. The optimal pointing for EIS
  is computed by maximizing the cross-correlations of the Fe XII 195.119
  Å line with images from the 193 Å band of the Atmospheric Imaging
  Assembly (AIA) on board the Solar Dynamics Observatory (SDO). By
  coaligning 3336 rasters with high signal-to-noise ratio, we estimate
  the rotation angle between EIS and AIA and explore the distribution
  of its values. We report an average value of (−0.387<SUP>±0.007 )
  ∘</SUP>. We also provide a software implementation of this method
  that can be used to coalign any EIS raster.

---------------------------------------------------------
Title: Comparison of Scattering Polarization Signals Observed by
CLASP: Possible Indication of the Hanle Effect
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
   Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
   Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
   Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
   Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
   Sainz, R.; De Pomtieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
2019ASPC..526..305I    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP; Kano et
  al. 2012; Kobayashi et al. 2012; Kubo et al. 2014) observed, for the
  first time, the linear polarization produced by scattering processes
  in the hydrogen Lyman-α (121.57 nm) and Si III (120.56 nm) lines of
  the solar disk radiation. The complexity of the observed scattering
  polarization (i.e., conspicuous spatial variations in Q/I and U/I
  at spatial scales of 10″-20″ and the absence of center-to- limb
  variation at the Lyman-α center; see Kano et al. 2017) motivated us
  to search for possible hints of the operation of the Hanle effect by
  comparing: (a) the Lyman-α line center signal, for which the critical
  field strength (B<SUB>H</SUB>) for the onset of the Hanle effect is
  53 G, (b) the Lyman-α wing, which is insensitive to the Hanle effect,
  and (c) the Si III line, whose B<SUB>H</SUB> = 290 G. We focus on four
  regions with different total unsigned photospheric magnetic fluxes
  (estimated from SDO/HMI observations), and compare the corresponding
  U/I spatial variations in the Lyman-α wing, Lyman-α center, and Si III
  line. The U/I signal in the Lyman-α wing shows an antisymmetric spatial
  distribution, which is caused by the presence of a bright structure in
  all the selected regions, regardless of the total unsigned photospheric
  magnetic flux. In an internetwork region, the Lyman-α center shows an
  antisymmetric spatial variation across the selected bright structure,
  but it does not show it in other more magnetized regions. In the Si III
  line, the spatial variation of U/I deviates from the above-mentioned
  antisymmetric shape as the total unsigned photospheric magnetic flux
  increases. We argue that a plausible explanation of this differential
  behavior is the operation of the Hanle effect. <P />This work, presented
  in an oral contribution at this Workshop, has been published on The
  Astrophysical Journal (Ishikawa et al. 2017).

---------------------------------------------------------
Title: Solar data, dataproducts, and tools at MEDOC
Authors: Buchlin, Eric; Caminade, Stéphane; Dufourg, Nicolas;
   Auchère, Frédéric; Baudin, Frédéric; Bocchialini, Karine;
   Boumier, Patrick; Janvier, Miho; Parenti, Susanna; Alingery, Pablo;
   Ballans, Hervé; Chane-Yook, Martine; Dexet, Marc; Mercier, Claude;
   Poulleau, Gilles
2019EGUGA..2117362B    Altcode:
  MEDOC (Multi-Experiment Data and Operation Centre), initially created
  as a European data and operation centre for the SOHO mission, has
  grown with data from other solar physics space missions, from STEREO
  to SDO. Derived data products such as DEM maps from SDO/AIA, synoptic
  EUV intensity maps from SOHO/EIT, and catalogues of solar structures
  are also automatically produced and redistributed. Both the data and
  the derived data products are publicly available from web interfaces
  and from programmatic interfaces (with clients for IDL and Python),
  allowing classical data analysis as well as automatic queries, data
  download, and processing to be made on large datasets.

---------------------------------------------------------
Title: Groupe de Travail Soleil Heliosphere-Magnetospheres (SHM)
Authors: Auchère, F.; Astafyeva, E.; Baudin, F.; Bourdarie, S.;
   Briand, C.; Brun, S.; Célestin, S.; Génot, V.; Kretzschmar, M.;
   Leblanc, F.; Rouillard, A.; Sahraoui, F.
2019shm..rept....1A    Altcode:
  Les grandes questions scientifiques abordées dans le cadre de la
  thématique Soleil Héliosphère et Magnétosphères (SHM) couvrent
  l'ensemble des problématiques liées aux relations entre notre
  étoile et le système solaire. Cela commence par l'étude de la
  structure interne du Soleil à travers l'observation multi-spectrales,
  l'hélio-sismologie et la modélisation ; par l'étude de l'origine
  de la couronne solaire, son chauffage et l'accélération du vent
  solaire et des particules énergétiques solaires lors d'événements
  énergétiques solaires ; et enfin par l'étude de la propagation
  du vent solaire et des mécanismes de chauffage de celui-ci par
  dissipation turbulente.

---------------------------------------------------------
Title: The EUI instrument onboard Solar Orbiter: the EUV corona
    imaged differently
Authors: Berghmans, David; Rochus, Pierre; Auchère, Frédéric;
   Harra, Louise; Schmutz, Werner; Schühle, Udo
2018csc..confE..73B    Altcode:
  The ESA Solar Orbiter mission is designed to determine how the Sun
  creates and controls the heliosphere. The spacecraft will bring
  a combination of in situ and remote sensing instruments out of the
  ecliptic (&gt;30°) and close to the sun (0.3 solar-radii). The launch
  of Solar Orbiter is expected (not earlier than) Feb 2019. The Extreme
  Ultraviolet Imager is part of the remote-sensing package of Solar
  Orbiter, to be operating during 3 ten-day periods of each orbit around
  the Sun, which last roughly half a year. These 3 periods will correspond
  to perihelion and maximal solar latitude north and south. The Extreme
  Ultraviolet Imager is itself a suite of three UV and EUV telescopes
  that observe the solar atmosphere both globally as well as at very
  high resolution. The two high-resolution imagers (HRIs) will image the
  solar atmosphere in the chromospheric Lyman alpha line and the coronal
  17nm pass band with a resolution of 0.5 arcsec. From perihelion, this
  will correspond to a pixel footprint on the solar disc of (110km)^2
  . The Full Sun Imager (FSI), working at the 17.4 nm and 30.4 nm EUV
  passbands, will provide a global view of the solar atmosphere and is
  therefore an essential building block for the "connection science"
  of the Solar Orbiter mission. The FSI field of view is large enough
  (228arcmin) that, even at perihelion and at maximal off-points by Solar
  Orbiter, the full solar disk remains in the field of view. This large
  FOV and the FSI's high sensitivity will allow to image the "transition
  corona" where the topology of streamers and pseudo-streamers fades in
  the solar wind. Furthermore, FSI will be the first to image all this
  from out of the ecliptic. In this talk we will give an overview of the
  EUI instrument. We will focus on the novel aspects of EUI that will
  allow it to image beyond what previous EUV imagers could show us: EUV
  imaging from the highest solar latitude, with the widest field-of-view
  and at highest spatial resolution.

---------------------------------------------------------
Title: The Coronal Monsoon: Thermal Nonequilibrium Revealed by
    Periodic Coronal Rain
Authors: Auchère, Frédéric; Froment, Clara; Soubrié, Elie; Antolin,
   Patrick; Oliver, Ramon; Pelouze, Gabriel; Voyeux, Alfred
2018csc..confE.114A    Altcode:
  We report on the discovery of periodic coronal rain in an off-limb
  sequence of SDO/AIA images. The showers are co-spatial and in phase
  with periodic (6.6 hr) intensity pulsations of coronal loops of the
  sort described by Auchère et al. (2014) and Froment et al. (2015,
  2017. These new observations make possible a unified description of
  both phenomena. Coronal rain and periodic intensity pulsations of loops
  are two manifestations of the same physical process: evaporation /
  condensation cycles resulting from a state of thermal nonequilibrium
  (TNE). The fluctuations around coronal temperatures produce the
  intensity pulsations of loops, and rain falls along their legs
  if thermal runaway cools the periodic condensations down and below
  transition-region (TR)temperatures. This scenario is in line with the
  predictions of numerical models of quasi-steadily and footpoint heated
  loops. This event of periodic coronal rain is compared with a similar
  event showing only pulsations at coronal temperatures but no significant
  cool rain fall. For both events we have stereoscopic observations from
  the SDO and STEREO spacecraft which allows reconstruction of the 3D loop
  geometries. Comparison with numerical simulations suggest that these two
  events correspond to two regimes of TNE: one with "full condensations"
  (coronal rain) and another in which "incomplete condensations" start
  to develop but are pushed down one loop leg before they can reach
  chromospheric temperatures. These new observations impose severe
  constrains on the spatio-temporal distribution of coronal heating.

---------------------------------------------------------
Title: CLASP Constraints on the Magnetization and Geometrical
    Complexity of the Chromosphere-Corona Transition Region
Authors: Trujillo Bueno, J.; Štěpán, J.; Belluzzi, L.; Asensio
   Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Ishikawa,
   R.; Kano, R.; Winebarger, A.; Auchère, F.; Narukage, N.; Kobayashi,
   K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
   H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
   Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
2018ApJ...866L..15T    Altcode: 2018arXiv180908865T
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  suborbital rocket experiment that on 2015 September 3 measured
  the linear polarization produced by scattering processes in the
  hydrogen Lyα line of the solar disk radiation. The line-center
  photons of this spectral line radiation mostly stem from the
  chromosphere-corona transition region (TR). These unprecedented
  spectropolarimetric observations revealed an interesting surprise,
  namely that there is practically no center-to-limb variation (CLV) in
  the Q/I line-center signals. Using an analytical model, we first show
  that the geometric complexity of the corrugated surface that delineates
  the TR has a crucial impact on the CLV of the Q/I and U/I line-center
  signals. Second, we introduce a statistical description of the solar
  atmosphere based on a 3D model derived from a state-of-the-art radiation
  magnetohydrodynamic simulation. Each realization of the statistical
  ensemble is a 3D model characterized by a given degree of magnetization
  and corrugation of the TR, and for each such realization we solve the
  full 3D radiative transfer problem taking into account the impact
  of the CLASP instrument degradation on the calculated polarization
  signals. Finally, we apply the statistical inference method presented
  in a previous paper to show that the TR of the 3D model that produces
  the best agreement with the CLASP observations has a relatively weak
  magnetic field and a relatively high degree of corrugation. We emphasize
  that a suitable way to validate or refute numerical models of the upper
  solar chromosphere is by confronting calculations and observations
  of the scattering polarization in ultraviolet lines sensitive to the
  Hanle effect.

---------------------------------------------------------
Title: A Statistical Inference Method for Interpreting the CLASP
    Observations
Authors: Štěpán, J.; Trujillo Bueno, J.; Belluzzi, L.; Asensio
   Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Kano, R.;
   Winebarger, A.; Auchère, F.; Ishikawa, R.; Narukage, N.; Kobayashi,
   K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
   H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
   Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
2018ApJ...865...48S    Altcode: 2018arXiv180802725S
  On 2015 September 3, the Chromospheric Lyman-Alpha SpectroPolarimeter
  (CLASP) successfully measured the linear polarization produced by
  scattering processes in the hydrogen Lyα line of the solar disk
  radiation, revealing conspicuous spatial variations in the Q/I and U/I
  signals. Via the Hanle effect, the line-center Q/I and U/I amplitudes
  encode information on the magnetic field of the chromosphere-corona
  transition region, but they are also sensitive to the three-dimensional
  structure of this corrugated interface region. With the help of a simple
  line-formation model, here we propose a statistical inference method
  for interpreting the Lyα line-center polarization observed by CLASP.

---------------------------------------------------------
Title: Current State of UV Spectro-Polarimetry and its Future
    Direction
Authors: Ishikawa, Ryohko; Sakao, Taro; Katsukawa, Yukio; Hara,
   Hirohisa; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Kubo, Masahito;
   Auchere, Frederic; De Pontieu, Bart; Winebarger, Amy; Kobayashi,
   . Ken; Kano, Ryouhei; Narukage, Noriyuki; Trujillo Bueno, Javier;
   Song, Dong-uk; Manso Sainz, Rafael; Asensio Ramos, Andres; Leenaarts,
   Jorritt; Carlsson, Mats; Bando, Takamasa; Ishikawa, Shin-nosuke;
   Tsuneta, Saku; Belluzzi, Luca; Suematsu, Yoshinori; Giono, Gabriel;
   Yoshida, Masaki; Goto, Motoshi; Del Pino Aleman, Tanausu; Stepan,
   Jiri; Okamoto, Joten; Tsuzuki, Toshihiro; Uraguchi, Fumihiro; Champey,
   Patrick; Alsina Ballester, Ernest; Casini, Roberto; McKenzie, David;
   Rachmeler, Laurel; Bethge, Christian
2018cosp...42E1564I    Altcode:
  To obtain quantitative information on the magnetic field in low beta
  regions (i.e., upper chromosphere and above) has been increasingly
  important to understand the energetic phenomena of the outer
  solar atmosphere such as flare, coronal heating, and the solar wind
  acceleration. In the UV range, there are abundant spectral lines that
  originate in the upper chromosphere and transition region. However,
  the Zeeman effect in these spectral lines does not give rise to easily
  measurable polarization signals because of the weak magnetic field
  strength and the larger Doppler broadening compared with the Zeeman
  effect. Instead, the Hanle effect in UV lines is expected to be a
  suitable diagnostic tool of the magnetic field in the upper atmospheric
  layers. To investigate the validity of UV spectro-polarimetry and
  the Hanle effect, the Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP), which is a NASA sounding- rocket experiment, was launched at
  White Sands in US on September 3, 2015. During its 5 minutes ballistic
  flight, it successfully performed spectro-polarimetric observations
  of the hydrogen Lyman-alpha line (121.57 nm) with an unprecedentedly
  high polarization sensitivity of 0.1% in this wavelength range. CLASP
  observed the linear polarization produced by scattering process in VUV
  lines for the first time and detected the polarization signals which
  indicate the operation of the Hanle effect. Following the success
  of CLASP, we are confident that UV spectro-polarimetry is the way
  to proceed, and we are planning the second flight of CLASP (CLASP2:
  Chromospheric LAyer SpectroPolarimeter 2). For this second flight we
  will carry out spectro-polarimetry in the Mg II h and k lines around
  280 nm, with minimum modifications of the CLASP1 instrument. The linear
  polarization in the Mg II k line is induced by scattering processes and
  the Hanle effect, being sensitive to magnetic field strengths of 5 to 50
  G. In addition, the circular polarizations in the Mg II h and k lines
  induced by the Zeeman effect can be measurable in at least plage and
  active regions. The combination of the Hanle and Zeeman effects could
  help us to more reliably infer the magnetic fields of the upper solar
  chromosphere. CLASP2 was selected for flight and is being developed for
  launch in the spring of 2019.Based on these sounding rocket experiments
  (CLASP1 and 2), we aim at establishing the strategy and refining the
  instrument concept for future space missions to explore the enigmatic
  atmospheric layers via UV spectro-polarimetry.

---------------------------------------------------------
Title: Wavefront error measurements and alignment of CLASP2 telescope
    with a dual-band pass cold mirror coated primary mirror
Authors: Yoshida, Masaki; Song, Donguk; Ishikawa, Ryoko; Kano, Ryouhei;
   Katsukawa, Yukio; Suematsu, Yoshinori; Narukage, Noriyuki; Kubo,
   Masahito; Shinoda, Kazuya; Okamoto, Takenori J.; McKenzie, David E.;
   Rachmeler, Laurel A.; Auchère, Frédéric; Trujillo Bueno, Javier
2018SPIE10699E..30Y    Altcode:
  "Chromospheric LAyer Spectro-Polarimeter (CLASP2)" is the next sounding
  rocket experiment of the "Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP)" that succeeded in observing for the first time the linear
  polarization spectra in the hydrogen Lyman-α line (121.6 nm) and is
  scheduled to be launched in 2019. In CLASP2, we will carry out full
  Stokes-vector spectropolarimetric observations in the Mg ii h and k
  lines near 280 nm with the spectro-polarimeter (SP), while imaging
  observations in the Lyman-α line will be conducted with the slitjaw
  optics (SJ). For the wavelength selection of CLASP2, the primary
  mirror of the telescope uses a new dual-band pass cold mirror coating
  targeting both at 121.6 nm and 280 nm. Therefore, we have to perform
  again the alignment of the telescope after the installation of the
  recoated primary mirror. Before unmounting the primary mirror from
  the telescope structure, we measured the wave-front error (WFE) of the
  telescope. The measured WFE map was consistent with what we had before
  the CLASP flight, clearly indicating that the telescope alignment has
  been maintained even after the flight. After the re-coated primary
  mirror was installed the WFE was measured, and coma aberration was
  found to be larger. Finally, the secondary mirror shim adjustments
  were carried out based on the WFE measurements. In CLASP2 telescope,
  we improved a fitting method of WFE map (applying 8th terms circular
  Zernike polynomial fitting instead of 37th terms circular Zernike
  fitting) and the improved method enables to achieve better performance
  than CLASP telescope. Indeed, WFE map obtained after the final shim
  adjustment indicated that the required specification (&lt; 5.5 μm
  RMS spot radius) that is more stringent than CLASP telescope was met.

---------------------------------------------------------
Title: Optical alignment of the high-precision UV spectro-polarimeter
    (CLASP2)
Authors: Song, Donguk; Ishikawa, Ryohko; Kano, Ryouhei; Yoshida,
   Masaki; Tsuzuki, Toshihiro; Uraguchi, Fumihiro; Shinoda, Kazuya;
   Hara, Hirohisa; Okamoto, Takenori J.; Auchère, Frédéric; McKenzie,
   David E.; Rachmeler, Laurel A.; Trujillo Bueno, Javier
2018SPIE10699E..2WS    Altcode:
  Chromospheric LAyer Spectro-Polarimeter (CLASP2) is our next sounding
  rocket experiment after the success of Chromospheric Lyman-Alpha
  Spectro-Polarimeter (CLASP1). CLASP2 is scheduled to launch in 2019,
  and aims to achieve high precision measurements (&lt; 0.1 %) of the
  linear and circular polarizations in the Mg ii h and k lines near the
  280 nm, whose line cores originate in the upper solar chromosphere. The
  CLASP2 spectro-polarimeter follows very successful design concept of
  the CLASP1 instrument with the minimal modification. A new grating was
  fabricated with the same radius of curvature as the CLASP1 grating, but
  with a different ruling density. This allows us to essentially reuse
  the CLASP1 mechanical structures and layout of the optics. However,
  because the observing wavelength of CLASP2 is twice longer than that
  of CLASP1, a magnifier optical system was newly added in front of the
  cameras to double the focal length of CLASP2 and to maintain the same
  wavelength resolution as CLASP1 (0.01 nm). Meanwhile, a careful optical
  alignment of the spectro-polarimeter is required to reach the 0.01 nm
  wavelength resolution. Therefore, we established an efficient alignment
  procedure for the CLASP2 spectro-polarimeter based on an experience
  of CLASP1. Here, we explain in detail the methods for achieving the
  optical alignment of the CLASP2 spectro-polarimeter and discuss our
  results by comparing with the performance requirements.

---------------------------------------------------------
Title: The Coronal Monsoon: Thermal Nonequilibrium Revealed by
    Periodic Coronal Rain
Authors: Auchere, Frederic; Soubrie, Elie; Antolin, Patrick; Froment,
   Clara; Oliver, Ramon; Pelouze, Gabriel
2018cosp...42E.144A    Altcode:
  We report on the discovery of periodic coronal rain in an off-limb
  sequence of SDO/AIA images. The showers are co-spatial and in phase
  with periodic (6.6 hr) intensity pulsations of coronal loops of the
  sort described by Auchère et al. (2014) and Froment et al. (2015,
  2017}. These new observations make possible a unified description of
  both phenomena. Coronal rain and periodic intensity pulsations of loops
  are two manifestations of the same physical process: evaporation /
  condensation cycles resulting from a state of thermal nonequilibrium
  (TNE). The fluctuations around coronal temperatures produce the
  intensity pulsations of loops, and rain falls along their legs
  if thermal runaway cools the periodic condensations down and below
  transition-region (TR) temperatures. This scenario is in line with the
  predictions of numerical models of quasi-steadily and footpoint heated
  loops.This event of periodic coronal rain is compared with a similar
  event showing only pulsations at coronal temperatures but no significant
  cool rain fall. For both events we have stereoscopic observations from
  the SDO and STEREO spacecraft which allows reconstruction of the 3D loop
  geometries. Comparison with numerical simulations suggest that these two
  events correspond to two regimes of TNE: one with "full condensations"
  (coronal rain) and another in which "incomplete condensations" start
  to develop but are pushed down one loop leg before they can reach
  chromospheric temperatures.These new observations impose severe
  constrains on the spatio-temporal distribution of coronal heating.

---------------------------------------------------------
Title: Prospects for coronal magnetic field measurements from space
Authors: Auchere, Frederic
2018cosp...42E.143A    Altcode:
  Despite its fundamental importance as a driver for the physics
  of the Sun and of the helio-sphere, the magnetic field of our
  star's outer atmosphere remains poorly understood. This is due in
  large part to the fact that the magnetic field is a very dfficult
  quantity to measure. Our knowledge of its strength and orientation
  is largely based on extrapolations from photospheric observations,
  not from direct measurements. These extrapolations require strong
  assumptions on critical but unobserved quantities and thus fail
  to accurately reproduce the complex topologies inferred from
  remote-sensing observations of coronal structures in white light,
  EUV, and X-rays. Direct measurements of the coronal magnetic field are
  clearly identified by the international heliophysics community as a key
  element in the understanding of our star.In the past ten years, reliable
  ground based coronal magnetic field measurements have emerged. However,
  these measurements wil always be limited by the difficulty to observe
  the corona from the ground. Much like routine coronagraphic observations
  from space by SOHO/LASCO haverevolutionized our knowledge of the solar
  corona, space based polarimetric observations are expected to lead
  to major breakthroughs. In this perspective, we will review the past
  and future projects of space missions designed to measure the coronal
  magnetic field from space.

---------------------------------------------------------
Title: Search for predicted periodic flows in loops undergoing
    thermal non-equilibrium
Authors: Pelouze, Gabriel; Parenti, Susanna; Bocchialini, Karine;
   Soubrie, Elie; Auchere, Frederic; Froment, Clara
2018cosp...42E2623P    Altcode:
  Long-period intensity pulsations have been recently detected in
  coronal loopswith EUV images of both SoHO/EIT (Auchère et al.,
  2014) and SDO/AIA (Froment etal., 2015). These pulsations have
  been interpreted as resulting from thermalnon-equilibrium (TNE),
  thus providing a signature of a highly-stratified andquasi-constant
  heating at the loops footpoints (Froment et al., 2017; Auchèreet al.,
  2016). Depending on the adequacy between the geometry of the loop
  andthe characteristics of the heating, this can result in either
  complete (atchromospheric temperatures) or incomplete (&gt; 1 MK)
  condensation and evaporationcycles, that are responsible for the
  observed intensity pulsations. Using 1Dhydrodynamic simulations,
  Froment et al. (2017) were able to reproduce theobserved pulsations,
  with incomplete condensation for the active region studiedin their
  previous paper. The simulations also predict periodic plasma flowsalong
  the loops footpoints, with velocities up to 40 km/s. We try to detect
  these flows by using time series of spatially resolved spectrafrom
  the EUV spectrometer Hinode/EIS. We systematically search for EIS
  datasetsthat correspond to the observation of pulsation events among
  the 3000+ thatwere detected in AIA data, between 2010 and 2016. For the
  9 datasets that arefound, we derive series of Doppler velocity maps,
  which allows us to track theevolution of the plasma velocity in the
  loop over several pulsation periods. Wethen compare these data to the
  results of previous simulations andobservations. However the expected
  pulsations in velocity cannot be identifiedin any of the datasets that
  we analysed. We demonstrate that line of sightambiguities, combined
  with low signal to noise ratio or lack of time cadence,can explain
  this non-detection.

---------------------------------------------------------
Title: The EUI flight instrument of Solar Orbiter: from optical
    alignment to end-to-end calibration
Authors: Halain, J. -P.; Renotte, E.; Auchère, F.; Berghmans, D.;
   Delmotte, F.; Harra, L.; Schmutz, W.; Schühle, U.; Aznar Cuadrado,
   R.; Dumesnil, C.; Gyo, M.; Kennedy, T.; Verbeeck, C.; Barbay, J.;
   Giordanengo, B.; Gissot, S.; Gottwald, A.; Heerlein, K.; Hellin,
   M. -L.; Hermans, A.; Hervier, V.; Jacques, L.; Laubis, C.; Mazzoli,
   A.; Meining, S.; Mercier, R.; Philippon, A.; Roose, S.; Rossi, L.;
   Scholze, F.; Smith, P.; Teriaca, L.; Zhang, X.; Rochus, P.
2018SPIE10699E..0HH    Altcode:
  The Extreme Ultraviolet Imager (EUI) instrument for the Solar Orbiter
  mission will image the solar corona in the extreme ultraviolet (17.1
  nm and 30.4 nm) and in the vacuum ultraviolet (121.6 nm) spectral
  ranges. The development of the EUI instrument has been successfully
  completed with the optical alignment of its three channels' telescope,
  the thermal and mechanical environmental verification, the electrical
  and software validations, and an end-toend on-ground calibration of
  the two-units' flight instrument at the operating wavelengths. The
  instrument has been delivered and installed on the Solar Orbiter
  spacecraft, which is now undergoing all preparatory activities before
  launch.

---------------------------------------------------------
Title: On the Occurrence of Thermal Nonequilibrium in Coronal Loops
Authors: Froment, C.; Auchère, F.; Mikić, Z.; Aulanier, G.;
   Bocchialini, K.; Buchlin, E.; Solomon, J.; Soubrié, E.
2018ApJ...855...52F    Altcode: 2018arXiv180204010F
  Long-period EUV pulsations, recently discovered to be common in active
  regions, are understood to be the coronal manifestation of thermal
  nonequilibrium (TNE). The active regions previously studied with
  EIT/Solar and Heliospheric Observatory and AIA/SDO indicated that
  long-period intensity pulsations are localized in only one or two
  loop bundles. The basic idea of this study is to understand why. For
  this purpose, we tested the response of different loop systems, using
  different magnetic configurations, to different stratifications and
  strengths of the heating. We present an extensive parameter-space study
  using 1D hydrodynamic simulations (1020 in total) and conclude that the
  occurrence of TNE requires specific combinations of parameters. Our
  study shows that the TNE cycles are confined to specific ranges in
  parameter space. This naturally explains why only some loops undergo
  constant periodic pulsations over several days: since the loop geometry
  and the heating properties generally vary from one loop to another in
  an active region, only the ones in which these parameters are compatible
  exhibit TNE cycles. Furthermore, these parameters (heating and geometry)
  are likely to vary significantly over the duration of a cycle, which
  potentially limits the possibilities of periodic behavior. This study
  also confirms that long-period intensity pulsations and coronal rain are
  two aspects of the same phenomenon: both phenomena can occur for similar
  heating conditions and can appear simultaneously in the simulations.

---------------------------------------------------------
Title: The Coronal Monsoon: Thermal Nonequilibrium Revealed by
    Periodic Coronal Rain
Authors: Auchère, Frédéric; Froment, Clara; Soubrié, Elie; Antolin,
   Patrick; Oliver, Ramon; Pelouze, Gabriel
2018ApJ...853..176A    Altcode: 2018arXiv180201852A
  We report on the discovery of periodic coronal rain in an off-limb
  sequence of Solar Dynamics Observatory/Atmospheric Imaging Assembly
  images. The showers are co-spatial and in phase with periodic (6.6 hr)
  intensity pulsations of coronal loops of the sort described by Auchère
  et al. and Froment et al. These new observations make possible a unified
  description of both phenomena. Coronal rain and periodic intensity
  pulsations of loops are two manifestations of the same physical
  process: evaporation/condensation cycles resulting from a state of
  thermal nonequilibrium. The fluctuations around coronal temperatures
  produce the intensity pulsations of loops, and rain falls along their
  legs if thermal runaway cools the periodic condensations down and
  below transition-region temperatures. This scenario is in line with
  the predictions of numerical models of quasi-steadily and footpoint
  heated loops. The presence of coronal rain—albeit non-periodic—in
  several other structures within the studied field of view implies that
  this type of heating is at play on a large scale.

---------------------------------------------------------
Title: EUV high resolution imager on-board solar orbiter: optical
    design and detector performances
Authors: Halain, J. P.; Mazzoli, A.; Rochus, P.; Renotte, E.; Stockman,
   Y.; Berghmans, D.; BenMoussa, A.; Auchère, F.
2017SPIE10564E..3VH    Altcode:
  The EUV high resolution imager (HRI) channel of the Extreme Ultraviolet
  Imager (EUI) on-board Solar Orbiter will observe the solar atmospheric
  layers at 17.4 nm wavelength with a 200 km resolution. The HRI channel
  is based on a compact two mirrors off-axis design. The spectral
  selection is obtained by a multilayer coating deposited on the mirrors
  and by redundant Aluminum filters rejecting the visible and infrared
  light. The detector is a 2k x 2k array back-thinned silicon CMOS-APS
  with 10 μm pixel pitch, sensitive in the EUV wavelength range. Due to
  the instrument compactness and the constraints on the optical design,
  the channel performance is very sensitive to the manufacturing,
  alignments and settling errors. A trade-off between two optical
  layouts was therefore performed to select the final optical design
  and to improve the mirror mounts. The effect of diffraction by the
  filter mesh support and by the mirror diffusion has been included
  in the overall error budget. Manufacturing of mirror and mounts has
  started and will result in thermo-mechanical validation on the EUI
  instrument structural and thermal model (STM). Because of the limited
  channel entrance aperture and consequently the low input flux, the
  channel performance also relies on the detector EUV sensitivity,
  readout noise and dynamic range. Based on the characterization of
  a CMOS-APS back-side detector prototype, showing promising results,
  the EUI detector has been specified and is under development. These
  detectors will undergo a qualification program before being tested
  and integrated on the EUI instrument.

---------------------------------------------------------
Title: Comparison of Solar Fine Structure Observed Simultaneously
    in Lyα and Mg II h
Authors: Schmit, D.; Sukhorukov, A. V.; De Pontieu, B.; Leenaarts,
   J.; Bethge, C.; Winebarger, A.; Auchère, F.; Bando, T.; Ishikawa,
   R.; Kano, R.; Kobayashi, K.; Narukage, N.; Trujillo Bueno, J.
2017ApJ...847..141S    Altcode: 2017arXiv170900035S
  The Chromospheric Lyman Alpha Spectropolarimeter (CLASP) observed the
  Sun in H I Lyα during a suborbital rocket flight on 2015 September
  3. The Interface Region Imaging Telescope (IRIS) coordinated with the
  CLASP observations and recorded nearly simultaneous and co-spatial
  observations in the Mg II h and k lines. The Mg II h and Lyα lines
  are important transitions, energetically and diagnostically, in the
  chromosphere. The canonical solar atmosphere model predicts that these
  lines form in close proximity to each other and so we expect that the
  line profiles will exhibit similar variability. In this analysis, we
  present these coordinated observations and discuss how the two profiles
  compare over a region of quiet Sun at viewing angles that approach the
  limb. In addition to the observations, we synthesize both line profiles
  using a 3D radiation-MHD simulation. In the observations, we find that
  the peak width and the peak intensities are well correlated between the
  lines. For the simulation, we do not find the same relationship. We
  have attempted to mitigate the instrumental differences between IRIS
  and CLASP and to reproduce the instrumental factors in the synthetic
  profiles. The model indicates that formation heights of the lines
  differ in a somewhat regular fashion related to magnetic geometry. This
  variation explains to some degree the lack of correlation, observed
  and synthesized, between Mg II and Lyα. Our analysis will aid in the
  definition of future observatories that aim to link dynamics in the
  chromosphere and transition region.

---------------------------------------------------------
Title: CLASP/SJ Observations of Rapid Time Variations in the Lyα
    Emission in a Solar Active Region
Authors: Ishikawa, Shin-nosuke; Kubo, Masahito; Katsukawa, Yukio;
   Kano, Ryouhei; Narukage, Noriyuki; Ishikawa, Ryohko; Bando, Takamasa;
   Winebarger, Amy; Kobayashi, Ken; Trujillo Bueno, Javier; Auchère,
   Frédéric
2017ApJ...846..127I    Altcode:
  The Chromospheric Lyα SpectroPolarimeter (CLASP) is a sounding
  rocket experiment launched on 2015 September 3 to investigate the
  solar chromosphere and transition region. The slit-jaw (SJ) optical
  system captured Lyα images with a high time cadence of 0.6 s. From
  the CLASP/SJ observations, many variations in the solar chromosphere
  and transition region emission with a timescale of &lt;1 minute
  were discovered. In this paper, we focus on the active region within
  the SJ field of view and investigate the relationship between short
  (&lt;30 s) temporal variations in the Lyα emission and the coronal
  structures observed by Solar Dynamics Observatory/Atmospheric Imaging
  Assembly (AIA). We compare the Lyα temporal variations at the coronal
  loop footpoints observed in the AIA 211 Å (≈2 MK) and AIA 171 Å
  (≈0.6 MK) channels with those in the regions with bright Lyα features
  without a clear association with the coronal loop footpoints. We find
  more short (&lt;30 s) temporal variations in the Lyα intensity in the
  footpoint regions. Those variations did not depend on the temperature
  of the coronal loops. Therefore, the temporal variations in the Lyα
  intensity at this timescale range could be related to the heating of
  the coronal structures up to temperatures around the sensitivity peak
  of 171 Å. No signature was found to support the scenario that these
  Lyα intensity variations were related to the nanoflares. Waves or
  jets from the lower layers (lower chromosphere or photosphere) are
  possible causes for this phenomenon.

---------------------------------------------------------
Title: The VUV instrument SPICE for Solar Orbiter: performance
    ground testing
Authors: Caldwell, Martin E.; Morris, Nigel; Griffin, Douglas K.;
   Eccleston, Paul; Anderson, Mark; Pastor Santos, Carmen; Bruzzi,
   Davide; Tustain, Samuel; Howe, Chris; Davenne, Jenny; Grundy, Timothy;
   Speight, Roisin; Sidher, Sunil D.; Giunta, Alessandra; Fludra, Andrzej;
   Philippon, Anne; Auchere, Frederic; Hassler, Don; Davila, Joseph M.;
   Thompson, William T.; Schuehle, Udo H.; Meining, Stefan; Walls, Buddy;
   Phelan, P.; Dunn, Greg; Klein, Roman M.; Reichel, Thomas; Gyo, Manfred;
   Munro, Grant J.; Holmes, William; Doyle, Peter
2017SPIE10397E..08C    Altcode:
  SPICE is an imaging spectrometer operating at vacuum ultraviolet
  (VUV) wavelengths, 70.4 - 79.0 nm and 97.3 - 104.9 nm. It is a
  facility instrument on the Solar Orbiter mission, which carries
  10 science instruments in all, to make observations of the Sun's
  atmosphere and heliosphere, at close proximity to the Sun, i.e to
  0.28 A.U. at perihelion. SPICE's role is to make VUV measurements
  of plasma in the solar atmosphere. SPICE is designed to achieve
  spectral imaging at spectral resolution &gt;1500, spatial resolution
  of several arcsec, and two-dimensional FOV of 11 x16arcmins. The many
  strong constraints on the instrument design imposed by the mission
  requirements prevent the imaging performance from exceeding those of
  previous instruments, but by being closer to the sun there is a gain in
  spatial resolution. The price which is paid is the harsher environment,
  particularly thermal. This leads to some novel features in the design,
  which needed to be proven by ground test programs. These include a
  dichroic solar-transmitting primary mirror to dump the solar heat, a
  high in-flight temperature (60deg.C) and gradients in the optics box,
  and a bespoke variable-line-spacing grating to minimise the number of
  reflective components used. The tests culminate in the systemlevel test
  of VUV imaging performance and pointing stability. We will describe how
  our dedicated facility with heritage from previous solar instruments,
  is used to make these tests, and show the results, firstly on the
  Engineering Model of the optics unit, and more recently on the Flight
  Model. For the keywords, select up to 8 key terms for a search on your
  manuscript's subject.

---------------------------------------------------------
Title: CLASP2: The Chromospheric LAyer Spectro-Polarimeter
Authors: Rachmeler, Laurel; E McKenzie, David; Ishikawa, Ryohko;
   Trujillo Bueno, Javier; Auchère, Frédéric; Kobayashi, Ken;
   Winebarger, Amy; Bethge, Christian; Kano, Ryouhei; Kubo, Masahito;
   Song, Donguk; Narukage, Noriyuki; Ishikawa, Shin-nosuke; De Pontieu,
   Bart; Carlsson, Mats; Yoshida, Masaki; Belluzzi, Luca; Stepan, Jiri;
   del Pino Alemná, Tanausú; Ballester, Ernest Alsina; Asensio Ramos,
   Andres
2017SPD....4811010R    Altcode:
  We present the instrument, science case, and timeline of the CLASP2
  sounding rocket mission. The successful CLASP (Chromospheric Lyman-Alpha
  Spectro-Polarimeter) sounding rocket flight in 2015 resulted in
  the first-ever linear polarization measurements of solar hydrogen
  Lyman-alpha line, which is sensitive to the Hanle effect and can be used
  to constrain the magnetic field and geometric complexity of the upper
  chromosphere. Ly-alpha is one of several upper chromospheric lines that
  contain magnetic information. In the spring of 2019, we will re-fly
  the modified CLASP telescope to measure the full Stokes profile of Mg
  II h &amp; k near 280 nm. This set of lines is sensitive to the upper
  chromospheric magnetic field via both the Hanle and the Zeeman effects.

---------------------------------------------------------
Title: CLASP2: The Chromospheric LAyer Spectro-Polarimeter
Authors: Rachmeler, Laurel A.; McKenzie, D. E.; Ishikawa, R.;
   Trujillo-Bueno, J.; Auchere, F.; Kobayashi, K.; Winebarger, A.;
   Bethge, C.; Kano, R.; Kubo, M.; Song, D.; Narukage, N.; Ishikawa, S.;
   De Pontieu, B.; Carlsson, M.; Yoshida, M.; Belluzzi, L.; Stepan, J.;
   del Pino Alemán, T.; Alsina Ballester, E.; Asensio Ramos, A.
2017shin.confE..79R    Altcode:
  We present the instrument, science case, and timeline of the CLASP2
  sounding rocket mission. The successful CLASP (Chromospheric Lyman-Alpha
  Spectro-Polarimeter) sounding rocket flight in 2015 resulted in
  the first-ever linear polarization measurements of solar hydrogen
  Lyman-alpha line, which is sensitive to the Hanle effect and can be used
  to constrain the magnetic field and geometric complexity of the upper
  chromosphere. Ly-alpha is one of several upper chromospheric lines that
  contain magnetic information. In the spring of 2019, we will re-fly
  the modified CLASP telescope to measure the full Stokes profile of Mg
  II h &amp; k near 280 nm. This set of lines is sensitive to the upper
  chromospheric magnetic field via both the Hanle and the Zeeman effects.

---------------------------------------------------------
Title: SOLARIS: Solar Sail Investigation of the Sun
Authors: Appourchaux, Thierry; Auchère, Frédéric; Antonucci, Ester;
   Gizon, Laurent; MacDonald, Malcolm; Hara, Hirohisa; Sekii, Takashi;
   Moses, Daniel; Vourlidas, Angelos
2017arXiv170708193A    Altcode:
  In this paper, we detail the scientific objectives and outline
  a strawman payload of the SOLAR sail Investigation of the Sun
  (SOLARIS). The science objectives are to study the 3D structure
  of the solar magnetic and velocity field, the variation of total
  solar irradiance with latitude, and the structure of the corona. We
  show how we can meet these science objective using solar-sail
  technologies currently under development. We provide a tentative
  mission profile considering several trade-off approaches. We also
  provide a tentative mass budget breakdown and a perspective for a
  programmatic implementation.

---------------------------------------------------------
Title: Indication of the Hanle Effect by Comparing the Scattering
    Polarization Observed by CLASP in the Lyα and Si III 120.65 nm Lines
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
   Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
   Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
   Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
   Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
   Sainz, R.; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
2017ApJ...841...31I    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding
  rocket experiment that has provided the first successful measurement
  of the linear polarization produced by scattering processes in
  the hydrogen Lyα line (121.57 nm) radiation of the solar disk. In
  this paper, we report that the Si III line at 120.65 nm also shows
  scattering polarization and we compare the scattering polarization
  signals observed in the Lyα and Si III lines in order to search for
  observational signatures of the Hanle effect. We focus on four selected
  bright structures and investigate how the U/I spatial variations vary
  between the Lyα wing, the Lyα core, and the Si III line as a function
  of the total unsigned photospheric magnetic flux estimated from Solar
  Dynamics Observatory/Helioseismic and Magnetic Imager observations. In
  an internetwork region, the Lyα core shows an antisymmetric spatial
  variation across the selected bright structure, but it does not show
  it in other more magnetized regions. In the Si III line, the spatial
  variation of U/I deviates from the above-mentioned antisymmetric
  shape as the total unsigned photospheric magnetic flux increases. A
  plausible explanation of this difference is the operation of the Hanle
  effect. We argue that diagnostic techniques based on the scattering
  polarization observed simultaneously in two spectral lines with very
  different sensitivities to the Hanle effect, like Lyα and Si III,
  are of great potential interest for exploring the magnetism of the
  upper solar chromosphere and transition region.

---------------------------------------------------------
Title: Erratum: “On the Fourier and Wavelet Analysis of Coronal Time
Series” (<A href="https://doi.org/10.3847/0004-637x/825/2/110">2016,
    ApJ, 825, 110</A>)
Authors: Auchère, F.; Froment, C.; Bocchialini, K.; Buchlin, E.;
   Solomon, J.
2017ApJ...838..166A    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Polarization Calibration of the Chromospheric Lyman-Alpha
    SpectroPolarimeter for a 0.1% Polarization Sensitivity in the VUV
Range. Part II: In-Flight Calibration
Authors: Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa,
   Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.;
   Tsuneta, S.; Shimizu, T.; Sakao, T.; Cirtain, J.; Champey, P.; Asensio
   Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
   B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
2017SoPh..292...57G    Altcode:
  The Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding
  rocket instrument designed to measure for the first time the linear
  polarization of the hydrogen Lyman-α line (121.6 nm). The instrument
  was successfully launched on 3 September 2015 and observations were
  conducted at the solar disc center and close to the limb during the
  five-minutes flight. In this article, the disc center observations are
  used to provide an in-flight calibration of the instrument spurious
  polarization. The derived in-flight spurious polarization is consistent
  with the spurious polarization levels determined during the pre-flight
  calibration and a statistical analysis of the polarization fluctuations
  from solar origin is conducted to ensure a 0.014% precision on the
  spurious polarization. The combination of the pre-flight and the
  in-flight polarization calibrations provides a complete picture of
  the instrument response matrix, and a proper error transfer method
  is used to confirm the achieved polarization accuracy. As a result,
  the unprecedented 0.1% polarization accuracy of the instrument in the
  vacuum ultraviolet is ensured by the polarization calibration.

---------------------------------------------------------
Title: Discovery of Scattering Polarization in the Hydrogen Lyα
    Line of the Solar Disk Radiation
Authors: Kano, R.; Trujillo Bueno, J.; Winebarger, A.; Auchère, F.;
   Narukage, N.; Ishikawa, R.; Kobayashi, K.; Bando, T.; Katsukawa, Y.;
   Kubo, M.; Ishikawa, S.; Giono, G.; Hara, H.; Suematsu, Y.; Shimizu,
   T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.; Goto, M.; Belluzzi, L.;
   Štěpán, J.; Asensio Ramos, A.; Manso Sainz, R.; Champey, P.;
   Cirtain, J.; De Pontieu, B.; Casini, R.; Carlsson, M.
2017ApJ...839L..10K    Altcode: 2017arXiv170403228K
  There is a thin transition region (TR) in the solar atmosphere where
  the temperature rises from 10,000 K in the chromosphere to millions
  of degrees in the corona. Little is known about the mechanisms that
  dominate this enigmatic region other than the magnetic field plays a
  key role. The magnetism of the TR can only be detected by polarimetric
  measurements of a few ultraviolet (UV) spectral lines, the Lyα line
  of neutral hydrogen at 121.6 nm (the strongest line of the solar UV
  spectrum) being of particular interest given its sensitivity to the
  Hanle effect (the magnetic-field-induced modification of the scattering
  line polarization). We report the discovery of linear polarization
  produced by scattering processes in the Lyα line, obtained with
  the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) rocket
  experiment. The Stokes profiles observed by CLASP in quiet regions of
  the solar disk show that the Q/I and U/I linear polarization signals are
  of the order of 0.1% in the line core and up to a few percent in the
  nearby wings, and that both have conspicuous spatial variations with
  scales of ∼10 arcsec. These observations help constrain theoretical
  models of the chromosphere-corona TR and extrapolations of the
  magnetic field from photospheric magnetograms. In fact, the observed
  spatial variation from disk to limb of polarization at the line core
  and wings already challenge the predictions from three-dimensional
  magnetohydrodynamical models of the upper solar chromosphere.

---------------------------------------------------------
Title: High-Reflectivity Coatings for a Vacuum Ultraviolet
    Spectropolarimeter
Authors: Narukage, Noriyuki; Kubo, Masahito; Ishikawa, Ryohko;
   Ishikawa, Shin-nosuke; Katsukawa, Yukio; Kobiki, Toshihiko; Giono,
   Gabriel; Kano, Ryouhei; Bando, Takamasa; Tsuneta, Saku; Auchère,
   Frédéric; Kobayashi, Ken; Winebarger, Amy; McCandless, Jim; Chen,
   Jianrong; Choi, Joanne
2017SoPh..292...40N    Altcode:
  Precise polarization measurements in the vacuum ultraviolet (VUV)
  region are expected to be a new tool for inferring the magnetic fields
  in the upper atmosphere of the Sun. High-reflectivity coatings are key
  elements to achieving high-throughput optics for precise polarization
  measurements. We fabricated three types of high-reflectivity coatings
  for a solar spectropolarimeter in the hydrogen Lyman-α (Lyα ; 121.567
  nm) region and evaluated their performance. The first high-reflectivity
  mirror coating offers a reflectivity of more than 80 % in Lyα
  optics. The second is a reflective narrow-band filter coating that has
  a peak reflectivity of 57 % in Lyα , whereas its reflectivity in the
  visible light range is lower than 1/10 of the peak reflectivity (∼5
  % on average). This coating can be used to easily realize a visible
  light rejection system, which is indispensable for a solar telescope,
  while maintaining high throughput in the Lyα line. The third is a
  high-efficiency reflective polarizing coating that almost exclusively
  reflects an s-polarized beam at its Brewster angle of 68° with a
  reflectivity of 55 %. This coating achieves both high polarizing power
  and high throughput. These coatings contributed to the high-throughput
  solar VUV spectropolarimeter called the Chromospheric Lyman-Alpha
  SpectroPolarimeter (CLASP), which was launched on 3 September, 2015.

---------------------------------------------------------
Title: Long-period Intensity Pulsations in Coronal Loops Explained
    by Thermal Non-equilibrium Cycles
Authors: Froment, C.; Auchère, F.; Aulanier, G.; Mikić, Z.;
   Bocchialini, K.; Buchlin, E.; Solomon, J.
2017ApJ...835..272F    Altcode: 2017arXiv170101309F
  In solar coronal loops, thermal non-equilibrium (TNE) is a phenomenon
  that can occur when the heating is both highly stratified and
  quasi-constant. Unambiguous observational identification of TNE
  would thus permit us to strongly constrain heating scenarios. While
  TNE is currently the standard interpretation of coronal rain, the
  long-term periodic evolution predicted by simulations has never been
  observed. However, the detection of long-period intensity pulsations
  (periods of several hours) has been recently reported with the Solar
  and Heliospheric Observatory/EIT, and this phenomenon appears to be very
  common in loops. Moreover, the three intensity-pulsation events that we
  recently studied with the Solar Dynamics Observatory/Atmospheric Imaging
  Assembly (AIA) show strong evidence for TNE in warm loops. In this
  paper, a realistic loop geometry from linear force-free field (LFFF)
  extrapolations is used as input to 1D hydrodynamic simulations. Our
  simulations show that, for the present loop geometry, the heating has
  to be asymmetrical to produce TNE. We analyze in detail one particular
  simulation that reproduces the average thermal behavior of one of the
  pulsating loop bundle observed with AIA. We compare the properties of
  this simulation with those deduced from the observations. The magnetic
  topology of the LFFF extrapolations points to the presence of sites
  of preferred reconnection at one footpoint, supporting the presence
  of asymmetric heating. In addition, we can reproduce the temporal
  large-scale intensity properties of the pulsating loops. This simulation
  further strengthens the interpretation of the observed pulsations as
  signatures of TNE. This consequently provides important information
  on the heating localization and timescale for these loops.

---------------------------------------------------------
Title: Polarization Calibration of the Chromospheric Lyman-Alpha
    SpectroPolarimeter for a 0.1 % Polarization Sensitivity in the VUV
Range. Part I: Pre-flight Calibration
Authors: Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa,
   Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.
2016SoPh..291.3831G    Altcode: 2016SoPh..tmp..177G
  The Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) is a sounding
  rocket experiment designed to measure for the first time the linear
  polarization of the hydrogen Lyman-α line (121.6 nm) and requires
  a 0.1 % polarization sensitivity, which is unprecedented for a
  spectropolarimeter in the vacuum UV (VUV) spectral range.

---------------------------------------------------------
Title: Discovery of Ubiquitous Fast-Propagating Intensity Disturbances
    by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)
Authors: Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando,
   T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.;
   Ishikawa, S.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.;
   Cirtain, J.; Champey, P.; Auchère, F.; Trujillo Bueno, J.; Asensio
   Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
   B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
2016ApJ...832..141K    Altcode:
  High-cadence observations by the slit-jaw (SJ) optics system of the
  sounding rocket experiment known as the Chromospheric Lyman Alpha
  Spectropolarimeter (CLASP) reveal ubiquitous intensity disturbances
  that recurrently propagate in either the chromosphere or the transition
  region or both at a speed much higher than the speed of sound. The
  CLASP/SJ instrument provides a time series of two-dimensional images
  taken with broadband filters centered on the Lyα line at a 0.6 s
  cadence. The multiple fast-propagating intensity disturbances appear in
  the quiet Sun and in an active region, and they are clearly detected in
  at least 20 areas in a field of view of 527″ × 527″ during the 5
  minute observing time. The apparent speeds of the intensity disturbances
  range from 150 to 350 km s<SUP>-1</SUP>, and they are comparable
  to the local Alfvén speed in the transition region. The intensity
  disturbances tend to propagate along bright elongated structures away
  from areas with strong photospheric magnetic fields. This suggests
  that the observed fast-propagating intensity disturbances are related
  to the magnetic canopy structures. The maximum distance traveled by
  the intensity disturbances is about 10″, and the widths are a few
  arcseconds, which are almost determined by a pixel size of 1.″03. The
  timescale of each intensity pulse is shorter than 30 s. One possible
  explanation for the fast-propagating intensity disturbances observed
  by CLASP is magnetohydrodynamic fast-mode waves.

---------------------------------------------------------
Title: Thermal Non-Equilibrium Revealed by Periodic Pulses of Random
    Amplitudes in Solar Coronal Loops
Authors: Auchère, F.; Froment, C.; Bocchialini, K.; Buchlin, E.;
   Solomon, J.
2016usc..confE.131A    Altcode:
  We recently detected variations in extreme ultraviolet intensity in
  coronal loops repeating with periods of several hours. Models of loops
  including stratified and quasi-steady heating predict the development
  of a state of thermal non-equilibrium (TNE): cycles of evaporative
  upflows at the footpoints followed by falling condensations at the
  apex. Based on Fourier and wavelet analysis, we demonstrate that the
  observed periodic signals are indeed not signatures of vibrational
  modes. Instead, superimposed on the power law expected from the
  stochastic background emission, the power spectra of the time series
  exhibit the discrete harmonics and continua expected from periodic
  trains of pulses of random amplitudes. These characteristics reinforce
  our earlier interpretation of these pulsations as being aborted
  TNE cycles.

---------------------------------------------------------
Title: Fourier and Wavelet Analysis of Coronal Time Series
Authors: Auchère, F.; Froment, C.; Bocchialini, K.; Buchlin, E.;
   Solomon, J.
2016usc..confE.130A    Altcode:
  Using Fourier and wavelet analysis, we critically re-assess the
  significance of our detection of periodic pulsations in coronal
  loops. We show that the proper identification of the frequency
  dependence and statistical properties of the different components of
  the power spectra provies a strong argument against the common practice
  of data detrending, which tends to produce spurious detections around
  the cut-off frequency of the filter. In addition, the white and red
  noise models built into the widely used wavelet code of Torrence &amp;
  Compo cannot, in most cases, adequately represent the power spectra of
  coronal time series, thus also possibly causing false positives. Both
  effects suggest that several reports of periodic phenomena should
  be re-examined. The Torrence &amp; Compo code nonetheless effectively
  computes rigorous confidence levels if provided with pertinent models of
  mean power spectra, and we describe the appropriate manner in which to
  call its core routines. We recall the meaning of the default confidence
  levels output from the code, and we propose new Monte-Carlo-derived
  levels that take into account the total number of degrees of freedom
  in the wavelet spectra. These improvements allow us to confirm that
  the power peaks that we detected have a very low probability of being
  caused by noise.

---------------------------------------------------------
Title: Long-period Intensity Pulsations as the Manifestation of the
    Heating Stratification and Timescale in Coronal Loops
Authors: Froment, Clara; Auchère, Frédéric; Aulanier, Guillaume;
   Mikić, Zoran; Bocchialini, Karine; Buchlin, Eric; Solomon, Jacques
2016usc..confE..47F    Altcode:
  In solar coronal loops, thermal non-equilibrium (TNE) is a phenomenon
  that can occur when the heating is both highly-stratified and
  quasi-constant. Unambiguous observational identification of TNE
  would thus permit to strongly constrain heating scenarios. Up to
  now, while TNE is the standard interpretation of coronal rain, it
  was not believed to happen commonly in warm coronal loops. Recently,
  the detection of long-period intensity pulsations (periods of several
  hours) has been reported with SoHO/EIT. This phenomenon appears to be
  very common in loops (Auchère et al. 2014). In Froment et al. 2015,
  three intensity-pulsation events studied with SDO/AIA, show strong
  evidence for TNE in warm loops. We use realistic loop geometries
  from LFFF extrapolations for one of these events are used as input
  to a 1D hydrodynamic simulation of TNE. A highly-stratified heating
  function is chosen to reproduce the observed period of pulsation and
  temperature of the loops. With these conditions, the heating function
  has to be asymmetric. The magnetic topology of the LFFF extrapolations
  points to the presence of sites of preferred reconnection at one
  footpoint, supporting the presence of asymmetric heating. We compared
  the properties of the simulated loop with the properties deduced
  from observations. We found that the 1D hydrodynamic simulation
  can reproduce the large temporal scale intensity properties of the
  pulsating loops (Froment et al. 2016, submitted). This simulation
  further strengthen the interpretation of the observed pulsations as
  signatures of TNE. This implies that the heating for these loops is
  highly-stratified and that the frequency of the heating events must
  be high compared to the typical cooling time.

---------------------------------------------------------
Title: GAIA-DEM: a database providing AIA/SDO DEM maps
Authors: Guennou, C.; Auchère, F.; Bocchialini, F.; Soubrié, E.;
   Mercier, C.; Parenti, S.; Alingery, P.
2016usc..confE.108G    Altcode:
  The Gaussian AIA DEm Maps (GAIA-DEM) database at MEDOC (IAS) provides
  through a simple and intuitive web interface DEM inversions of the
  SDO/AIA data, computed every 30min. The Gaussian approximation is used
  to describe the main features of the true DEM(log T) by its first
  moments. For each date, maps of the three Gaussian fit parameters
  (central temperature, total emission measure and Gaussian width) and
  of the chi^2 are available in FITS format. Users can preview the maps
  before downloading them. In addition, users can display the initial
  SDO/AIA images using Helioviewer, and query the database through
  webservices accessible from IDL and Python clients. This presentation
  is for the "Thermal Diagnostics with SDO/AIA" mini-workshop.

---------------------------------------------------------
Title: A small mission concept to the Sun-Earth Lagrangian L5 point
    for innovative solar, heliospheric and space weather science
Authors: Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer,
   M.; Vial, J. -C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.; Pinto,
   R.; Auchère, F.; Harrison, R. A.; Eyles, C.; Gan, W.; Lamy, P.;
   Xia, L.; Eastwood, J. P.; Kong, L.; Wang, J.; Wimmer-Schweingruber,
   R. F.; Zhang, S.; Zong, Q.; Soucek, J.; An, J.; Prech, L.; Zhang,
   A.; Rochus, P.; Bothmer, V.; Janvier, M.; Maksimovic, M.; Escoubet,
   C. P.; Kilpua, E. K. J.; Tappin, J.; Vainio, R.; Poedts, S.; Dunlop,
   M. W.; Savani, N.; Gopalswamy, N.; Bale, S. D.; Li, G.; Howard, T.;
   DeForest, C.; Webb, D.; Lugaz, N.; Fuselier, S. A.; Dalmasse, K.;
   Tallineau, J.; Vranken, D.; Fernández, J. G.
2016JASTP.146..171L    Altcode:
  We present a concept for a small mission to the Sun-Earth Lagrangian L5
  point for innovative solar, heliospheric and space weather science. The
  proposed INvestigation of Solar-Terrestrial Activity aNd Transients
  (INSTANT) mission is designed to identify how solar coronal magnetic
  fields drive eruptions, mass transport and particle acceleration that
  impact the Earth and the heliosphere. INSTANT is the first mission
  designed to (1) obtain measurements of coronal magnetic fields from
  space and (2) determine coronal mass ejection (CME) kinematics with
  unparalleled accuracy. Thanks to innovative instrumentation at a vantage
  point that provides the most suitable perspective view of the Sun-Earth
  system, INSTANT would uniquely track the whole chain of fundamental
  processes driving space weather at Earth. We present the science
  requirements, payload and mission profile that fulfill ambitious science
  objectives within small mission programmatic boundary conditions.

---------------------------------------------------------
Title: Thermal Non-equilibrium Revealed by Periodic Pulses of Random
    Amplitudes in Solar Coronal Loops
Authors: Auchère, F.; Froment, C.; Bocchialini, K.; Buchlin, E.;
   Solomon, J.
2016ApJ...827..152A    Altcode: 2016arXiv160803789A
  We recently detected variations in extreme ultraviolet intensity in
  coronal loops repeating with periods of several hours. Models of loops
  including stratified and quasi-steady heating predict the development
  of a state of thermal non-equilibrium (TNE): cycles of evaporative
  upflows at the footpoints followed by falling condensations at the
  apex. Based on Fourier and wavelet analysis, we demonstrate that the
  observed periodic signals are indeed not signatures of vibrational
  modes. Instead, superimposed on the power law expected from the
  stochastic background emission, the power spectra of the time series
  exhibit the discrete harmonics and continua expected from periodic
  trains of pulses of random amplitudes. These characteristics reinforce
  our earlier interpretation of these pulsations as being aborted
  TNE cycles.

---------------------------------------------------------
Title: The qualification campaign of the EUI instrument of Solar
    Orbiter
Authors: Halain, J. -P.; Rochus, P.; Renotte, E.; Hermans, A.; Jacques,
   L.; Mazzoli, A.; Auchère, F.; Berghmans, D.; Harra, L.; Schühle,
   U.; Schmutz, W.; Aznar Cuadrado, R.; Dumesnil, C.; Gyo, M.; Kennedy,
   T.; Verbeeck, C.; Smith, P.
2016SPIE.9905E..2XH    Altcode:
  The Extreme Ultraviolet Imager (EUI) instrument is one of the ten
  scientific instruments on board the Solar Orbiter mission to be launched
  in October 2018. It will provide full-sun and high-resolution images of
  the solar corona in the extreme ultraviolet (17.1 nm and 30.4 nm) and in
  the vacuum ultraviolet (121.6 nm). The validation of the EUI instrument
  design has been completed with the Assembly, Integration and Test
  (AIT) of the instrument two-units Qualification Model (QM). Optical,
  electrical, electro-magnetic compatibility, thermal and mechanical
  environmental verifications were conducted and are summarized here. The
  integration and test procedures for the Flight Model (FM) instrument
  and sub-systems were also verified. Following the Qualification Review,
  the flight instrument activities were started with the assembly of
  the flight units. The mechanical and thermal acceptance tests and an
  end-to-end final calibration in the (E)UV will then be conducted before
  delivery for integration on the Solar Orbiter Spacecraft by end of 2016.

---------------------------------------------------------
Title: The SPICE Spectral Imager on Solar Orbiter: Linking the Sun
    to the Heliosphere
Authors: Fludra, Andrzej; Haberreiter, Margit; Peter, Hardi; Vial,
   Jean-Claude; Harrison, Richard; Parenti, Susanna; Innes, Davina;
   Schmutz, Werner; Buchlin, Eric; Chamberlin, Phillip; Thompson,
   William; Gabriel, Alan; Morris, Nigel; Caldwell, Martin; Auchere,
   Frederic; Curdt, Werner; Teriaca, Luca; Hassler, Donald M.; DeForest,
   Craig; Hansteen, Viggo; Carlsson, Mats; Philippon, Anne; Janvier, Miho;
   Wimmer-Schweingruber, Robert; Griffin, Douglas; Davila, Joseph; Giunta,
   Alessandra; Waltham, Nick; Eccleston, Paul; Gottwald, Alexander;
   Klein, Roman; Hanley, John; Walls, Buddy; Howe, Chris; Schuehle, Udo
2016cosp...41E.607F    Altcode:
  The SPICE (Spectral Imaging of the Coronal Environment) instrument is
  one of the key remote sensing instruments onboard the upcoming Solar
  Orbiter Mission. SPICE has been designed to contribute to the science
  goals of the mission by investigating the source regions of outflows
  and ejection processes which link the solar surface and corona to the
  heliosphere. In particular, SPICE will provide quantitative information
  on the physical state and composition of the solar atmosphere
  plasma. For example, SPICE will access relative abundances of ions to
  study the origin and the spatial/temporal variations of the 'First
  Ionization Potential effect', which are key signatures to trace the
  solar wind and plasma ejections paths within the heliosphere. Here we
  will present the instrument and its performance capability to attain the
  scientific requirements. We will also discuss how different observation
  modes can be chosen to obtain the best science results during the
  different orbits of the mission. To maximize the scientific return of
  the instrument, the SPICE team is working to optimize the instrument
  operations, and to facilitate the data access and their exploitation.

---------------------------------------------------------
Title: Optical alignment of the Chromospheric Lyman-Alpha
    Spectro-Polarimeter using sophisticated methods to minimize activities
    under vacuum
Authors: Giono, G.; Katsukawa, Y.; Ishikawa, R.; Narukage, N.;
   Kano, R.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.
2016SPIE.9905E..3DG    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  sounding-rocket instrument developed at the National Astronomical
  Observatory of Japan (NAOJ) as a part of an international
  collaboration. The instrument main scientific goal is to achieve
  polarization measurement of the Lyman-α line at 121.56 nm emitted from
  the solar upper-chromosphere and transition region with an unprecedented
  0.1% accuracy. The optics are composed of a Cassegrain telescope
  coated with a "cold mirror" coating optimized for UV reflection and
  a dual-channel spectrograph allowing for simultaneous observation of
  the two orthogonal states of polarization. Although the polarization
  sensitivity is the most important aspect of the instrument, the spatial
  and spectral resolutions of the instrument are also crucial to observe
  the chromospheric features and resolve the Ly-α profiles. A precise
  alignment of the optics is required to ensure the resolutions, but
  experiments under vacuum conditions are needed since Ly-α is absorbed
  by air, making the alignment experiments difficult. To bypass this
  issue, we developed methods to align the telescope and the spectrograph
  separately in visible light. We explain these methods and present
  the results for the optical alignment of the CLASP telescope and
  spectrograph. We then discuss the combined performances of both parts
  to derive the expected resolutions of the instrument, and compare them
  with the flight observations performed on September 3<SUP>rd</SUP> 2015.

---------------------------------------------------------
Title: Solar abundances with the SPICE spectral imager on Solar
    Orbiter
Authors: Giunta, Alessandra; Haberreiter, Margit; Peter, Hardi;
   Vial, Jean-Claude; Harrison, Richard; Parenti, Susanna; Innes, Davina;
   Schmutz, Werner; Buchlin, Eric; Chamberlin, Phillip; Thompson, William;
   Bocchialini, Karine; Gabriel, Alan; Morris, Nigel; Caldwell, Martin;
   Auchere, Frederic; Curdt, Werner; Teriaca, Luca; Hassler, Donald M.;
   DeForest, Craig; Hansteen, Viggo; Carlsson, Mats; Philippon, Anne;
   Janvier, Miho; Wimmer-Schweingruber, Robert; Griffin, Douglas; Baudin,
   Frederic; Davila, Joseph; Fludra, Andrzej; Waltham, Nick; Eccleston,
   Paul; Gottwald, Alexander; Klein, Roman; Hanley, John; Walls, Buddy;
   Howe, Chris; Schuehle, Udo; Gyo, Manfred; Pfiffner, Dany
2016cosp...41E.681G    Altcode:
  Elemental composition of the solar atmosphere and in particular
  abundance bias of low and high First Ionization Potential (FIP)
  elements are a key tracer of the source regions of the solar wind. These
  abundances and their spatio-temporal variations, as well as the other
  plasma parameters , will be derived by the SPICE (Spectral Imaging
  of the Coronal Environment) EUV spectral imager on the upcoming
  Solar Orbiter mission. SPICE is designed to provide spectroheliograms
  (spectral images) using a core set of emission lines arising from ions
  of both low-FIP and high-FIP elements. These lines are formed over
  a wide range of temperatures, enabling the analysis of the different
  layers of the solar atmosphere. SPICE will use these spectroheliograms
  to produce dynamic composition maps of the solar atmosphere to be
  compared to in-situ measurements of the solar wind composition of
  the same elements (i.e. O, Ne, Mg, Fe). This will provide a tool to
  study the connectivity between the spacecraft (the Heliosphere) and
  the Sun. We will discuss the SPICE capabilities for such composition
  measurements.

---------------------------------------------------------
Title: On the Fourier and Wavelet Analysis of Coronal Time Series
Authors: Auchère, F.; Froment, C.; Bocchialini, K.; Buchlin, E.;
   Solomon, J.
2016ApJ...825..110A    Altcode: 2016arXiv160605251A
  Using Fourier and wavelet analysis, we critically re-assess the
  significance of our detection of periodic pulsations in coronal
  loops. We show that the proper identification of the frequency
  dependence and statistical properties of the different components of the
  power spectra provides a strong argument against the common practice
  of data detrending, which tends to produce spurious detections around
  the cut-off frequency of the filter. In addition, the white and red
  noise models built into the widely used wavelet code of Torrence &amp;
  Compo cannot, in most cases, adequately represent the power spectra of
  coronal time series, thus also possibly causing false positives. Both
  effects suggest that several reports of periodic phenomena should
  be re-examined. The Torrence &amp; Compo code nonetheless effectively
  computes rigorous confidence levels if provided with pertinent models of
  mean power spectra, and we describe the appropriate manner in which to
  call its core routines. We recall the meaning of the default confidence
  levels output from the code, and we propose new Monte-Carlo-derived
  levels that take into account the total number of degrees of freedom
  in the wavelet spectra. These improvements allow us to confirm that
  the power peaks that we detected have a very low probability of being
  caused by noise.

---------------------------------------------------------
Title: Chromospheric LAyer SpectroPolarimeter (CLASP2)
Authors: Narukage, Noriyuki; McKenzie, David E.; Ishikawa, Ryoko;
   Trujillo-Bueno, Javier; De Pontieu, Bart; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Kano, Ryouhei; Suematsu, Yoshinori; Yoshida, Masaki;
   Rachmeler, Laurel A.; Kobayashi, Ken; Cirtain, Jonathan W.; Winebarger,
   Amy R.; Asensio Ramos, Andres; del Pino Aleman, Tanausu; Štępán,
   Jiri; Belluzzi, Luca; Larruquert, Juan Ignacio; Auchère, Frédéric;
   Leenaarts, Jorrit; Carlsson, Mattias J. L.
2016SPIE.9905E..08N    Altcode:
  The sounding rocket Chromospheric Lyman-Alpha SpectroPolarimeter
  (CLASP) was launched on September 3rd, 2015, and successfully detected
  (with a polarization accuracy of 0.1 %) the linear polarization signals
  (Stokes Q and U) that scattering processes were predicted to produce
  in the hydrogen Lyman-alpha line (Lyα 121.567 nm). Via the Hanle
  effect, this unique data set may provide novel information about the
  magnetic structure and energetics in the upper solar chromosphere. The
  CLASP instrument was safely recovered without any damage and we have
  recently proposed to dedicate its second flight to observe the four
  Stokes profiles in the spectral region of the Mg II h and k lines
  around 280 nm; in these lines the polarization signals result from
  scattering processes and the Hanle and Zeeman effects. Here we describe
  the modifications needed to develop this new instrument called the
  "Chromospheric LAyer SpectroPolarimeter" (CLASP2).

---------------------------------------------------------
Title: Lifecycle of a large-scale polar coronal pseudostreamer/cavity
    system
Authors: Guennou, Chloé; Auchere, Frederic; Seaton, Daniel; Rachmeler,
   Laurel
2016cosp...41E.749G    Altcode:
  Coronal cavities, tunnel-like areas of rarefied density, provide
  important information about the magnetic structures that support
  prominences. The magnetic energy is stored through the twisted or shared
  magnetic field, ultimately released through Coronal Mass Ejections
  (CME). To be able to forecast these energetic releases of material
  and prevent potential terrestrial consequences, the understanding
  of the cavity 3D morphology, magnetic and thermal properties are
  essential. The prominences embedded in the cavity only trace a small
  part of the magnetic field, whereas the much larger cavity provides more
  information about the magnetic field morphology. As a result, a clear
  understanding of the coronal volume of the cavity significantly advances
  our understanding of both the pre-eruption equilibrium and the triggers
  of such eruptions. Determining both morphological and thermodynamical
  coronal structures is difficult due to the optically thin nature of the
  plasma. Observations are subject to integration along the line-of-sight
  (LOS). This effect can strongly complicate both the derivation and the
  interpretation of important physical quantities. One way to deduce
  the 3D structure is with Solar Rotational Tomography (SRT). The 3D
  plasma emissivity is estimated from EUV/white light images taken
  from different viewpoints. Physical properties can be then derived
  using Differential Emission Measure analysis from multi-wavelength 3D
  reconstructions. We applied this technique to an exceptional large-scale
  coronal pseudostreamer/cavity system in the southern polar region of
  the solar corona that was visible for approximately a year starting
  in February 2014. It is unusual to see such a large closed-field
  structure embedded within the open polar coronal hole. We investigate
  this structure to document its formation, evolution and eventually its
  shrinking process using data from both the PROBA2/SWAP and SDO/AIA EUV
  imagers. We found that the cavity temperature is extremely stable with
  time and is essentially at a similar or slightly hotter temperature
  than the surrounding pseudostreamer. Two regimes in cavity thermal
  properties were observed: during the first 5 months of observation,
  we found lower density depletion and highly multi-thermal plasma,
  while after the pseudostreamer became stable and slowly shrank, the
  depletion was more pronounced and the plasma was less multithermal. As
  the thermodynamic properties are strongly correlated with the magnetic
  structure, these results provide constraints on both the trigger of
  CMEs and the processes that maintain cavities stability for such a
  long lifetime.

---------------------------------------------------------
Title: Tracking a large pseudostreamer to pinpoint the southern
    polar magnetic field reversal
Authors: Rachmeler, Laurel; Guennou, Chloé; Seaton, Daniel B.;
   Gibson, Sarah; Auchère, Frédéric
2016SPD....4740104R    Altcode:
  The reversal of the solar polar magnetic field is notoriously hard
  to pin down due to the extreme viewing angle of the pole. In Cycle
  24, the southern polar field reversal can be pinpointed with high
  accuracy due to a large-scale pseudostreamer that formed over the
  pole and persisted for approximately a year. We tracked the size
  and shape of this structure with multiple observations and analysis
  techniques including PROBA2/SWAP EUV images, AIA EUV images, CoMP data,
  and 3D tomographic reconstructions. We find that the heliospheric field
  reversed polarity in February 2014, whereas in the photosphere the last
  vestiges of the previous polar field polarity remained until March 2015.

---------------------------------------------------------
Title: Lifecycle of a large-scale polar coronal pseudostreamer/cavity
    system
Authors: Guennou, Chloé; Rachmeler, Laurel; Seaton, Daniel; Auchère,
   Frédéric
2016FrASS...3...14G    Altcode:
  We report on an exceptional large-scale coronal pseudostreamer/cavity
  system in the southern polar region of the solar corona that was
  visible for approximately a year starting in February 2014. It is
  unusual to see such a large closed-field structure embedded within the
  open polar coronal hole. We investigate this structure to document its
  formation, evolution and eventually its shrinking process using data
  from both the PROBA2/SWAP and SDO/AIA EUV imagers. In particular, we
  used EUV tomography to find the overall shape and internal structure
  of the pseudostreamer and to determine its 3D temperature and density
  structure using DEM analysis. We found that the cavity temperature
  is extremely stable with time and is essentially at a similar or
  slightly hotter temperature than the surrounding pseudostreamer. Two
  regimes in cavity thermal properties were observed: during the first
  5 months of observation, we found lower density depletion and highly
  multi-thermal plasma, while after the pseudostreamer became stable and
  slowly shrank, the depletion was more pronounced and the plasma was less
  multithermal. As the thermodynamic properties are strongly correlated
  with the magnetic structure, these results provide constraints on both
  the trigger of CMEs and the processes that maintain cavities stability
  for such a long lifetime.

---------------------------------------------------------
Title: Spectro-polarimetric observation in UV with CLASP to probe
    the chromosphere and transition region
Authors: Kano, Ryouhei; Ishikawa, Ryohko; Winebarger, Amy R.; Auchère,
   Frédéric; Trujillo Bueno, Javier; Narukage, Noriyuki; Kobayashi,
   Ken; Bando, Takamasa; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-Nosuke; Giono, Gabriel; Hara, Hirohisa; Suematsu, Yoshinori;
   Shimizu, Toshifumi; Sakao, Taro; Tsuneta, Saku; Ichimoto, Kiyoshi;
   Goto, Motoshi; Cirtain, Jonathan W.; De Pontieu, Bart; Casini, Roberto;
   Manso Sainz, Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi,
   Luca; Carlsson, Mats
2016SPD....4710107K    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a NASA
  sounding-rocket experiment that was performed in White Sands in
  the US on September 3, 2015. During its 5-minute ballistic flight,
  CLASP successfully made the first spectro-polarimetric observation in
  the Lyman-alpha line (121.57 nm) originating in the chromosphere and
  transition region. Since the Lyman-alpha polarization is sensitive
  to magnetic field of 10-100 G by the Hanle effect, we aim to infer
  the magnetic field information in such upper solar atmosphere with
  this experiment.The obtained CLASP data showed that the Lyman-alpha
  scattering polarization is about a few percent in the wings and
  the order of 0.1% in the core near the solar limb, as it had been
  theoretically predicted, and that both polarization signals have a
  conspicuous spatio-temporal variability. CLASP also observed another
  upper-chromospheric line, Si III (120.65 nm), whose critical field
  strength for the Hanle effect is 290 G, and showed a measurable
  scattering polarization of a few % in this line. The polarization
  properties of the Si III line could facilitate the interpretation of
  the scattering polarization observed in the Lyman-alpha line.In this
  presentation, we would like to show how the upper chromosphere and
  transition region are seen in the polarization of these UV lines and
  discuss the possible source of these complicated polarization signals.

---------------------------------------------------------
Title: Waves and Magnetism in the Solar Atmosphere (WAMIS)
Authors: Ko, Yuan-Kuen; Moses, John; Laming, John; Strachan, Leonard;
   Tun Beltran, Samuel; Tomczyk, Steven; Gibson, Sarah; Auchere, Frederic;
   Casini, Roberto; Fineschi, Silvano; Knoelker, Michael; Korendyke,
   Clarence; McIntosh, Scott; Romoli, Marco; Rybak, Jan; Socker, Dennis;
   Vourlidas, Angelos; Wu, Qian
2016FrASS...3....1K    Altcode:
  Comprehensive measurements of magnetic fields in the solar corona have
  a long history as an important scientific goal. Besides being crucial
  to understanding coronal structures and the Sun’s generation of space
  weather, direct measurements of their strength and direction are also
  crucial steps in understanding observed wave motions. In this regard,
  the remote sensing instrumentation used to make coronal magnetic field
  measurements is well suited to measuring the Doppler signature of waves
  in the solar structures. In this paper, we describe the design and
  scientific values of the Waves and Magnetism in the Solar Atmosphere
  (WAMIS) investigation. WAMIS, taking advantage of greatly improved
  infrared filters and detectors, forward models, advanced diagnostic
  tools and inversion codes, is a long-duration high-altitude balloon
  payload designed to obtain a breakthrough in the measurement of
  coronal magnetic fields and in advancing the understanding of the
  interaction of these fields with space plasmas. It consists of a 20 cm
  aperture coronagraph with a visible-IR spectro-polarimeter focal plane
  assembly. The balloon altitude would provide minimum sky background and
  atmospheric scattering at the wavelengths in which these observations
  are made. It would also enable continuous measurements of the strength
  and direction of coronal magnetic fields without interruptions from
  the day-night cycle and weather. These measurements will be made
  over a large field-of-view allowing one to distinguish the magnetic
  signatures of different coronal structures, and at the spatial and
  temporal resolutions required to address outstanding problems in
  coronal physics. Additionally, WAMIS could obtain near simultaneous
  observations of the electron scattered K-corona for context and to
  obtain the electron density. These comprehensive observations are not
  provided by any current single ground-based or space observatory. The
  fundamental advancements achieved by the near-space observations of
  WAMIS on coronal field would point the way for future ground based
  and orbital instrumentation.

---------------------------------------------------------
Title: Waves and Magnetism in the Solar Atmosphere (WAMIS)
Authors: Strachan, L.; Ko, Y. -K.; Moses, J. D.; Laming, J. M.;
   Auchere, F.; Casini, R.; Fineschi, S.; Gibson, S.; Knoelker, M.;
   Korendyke, C.; Mcintosh, S.; Romoli, M.; Rybak, J.; Socker, D.;
   Tomczyk, S.; Vourlidas, A.; Wu, Q.
2015IAUS..305..121S    Altcode:
  Magnetic fields in the solar atmosphere provide the energy for most
  varieties of solar activity, including high-energy electromagnetic
  radiation, solar energetic particles, flares, and coronal mass
  ejections, as well as powering the solar wind. Despite the fundamental
  role of magnetic fields in solar and heliospheric physics, there
  exist only very limited measurements of the field above the base of
  the corona. What is needed are direct measurements of not only the
  strength and orientation of the magnetic field but also the signatures
  of wave motions in order to better understand coronal structure, solar
  activity, and the role of MHD waves in heating and accelerating the
  solar wind. Fortunately, the remote sensing instrumentation used to make
  magnetic field measurements is also well suited to measure the Doppler
  signature of waves in the solar structures. We present here a mission
  concept for the Waves And Magnetism In the Solar Atmosphere (WAMIS)
  experiment which is proposed for a NASA long-duration balloon flight.

---------------------------------------------------------
Title: The extreme ultraviolet imager of solar orbiter: optical
    design and alignment scheme
Authors: Halain, J. -P.; Mazzoli, A.; Meining, S.; Rochus, P.; Renotte,
   E.; Auchère, F.; Schühle, U.; Delmotte, F.; Dumesnil, C.; Philippon,
   A.; Mercier, R.; Hermans, A.
2015SPIE.9604E..0HH    Altcode:
  The Extreme Ultraviolet Imager (EUI) is one of the remote sensing
  instruments on-board the Solar Orbiter mission. It will provide
  dual-band full-Sun images of the solar corona in the extreme ultraviolet
  (17.1 nm and 30.4 nm), and high resolution images of the solar disk in
  both extreme ultraviolet (17.1 nm) and vacuum ultraviolet (Lyman-alpha
  121.6 nm). The EUI optical design takes heritage of previous similar
  instruments. The Full Sun Imager (FSI) channel is a single mirror
  Herschel design telescope. The two High Resolution Imager (HRI)
  channels are based on a two-mirror optical refractive scheme, one
  Ritchey-Chretien and one Gregory optical design for the EUV and the
  Lyman-alpha channels, respectively. The spectral performances of the
  EUI channels are obtained thanks to dedicated mirror multilayer coatings
  and specific band-pass filters. The FSI channel uses a dual-band mirror
  coating combined with aluminum and zirconium band-pass filters. The HRI
  channels use optimized band-pass selection mirror coatings combined
  with aluminum band-pass filters and narrow band interference filters
  for Lyman-alpha. The optical performances result from accurate mirror
  manufacturing tolerances and from a two-step alignment procedure. The
  primary mirrors are first co-aligned. The HRI secondary mirrors
  and focal planes positions are then adjusted to have an optimum
  interferometric cavity in each of these two channels. For that purpose
  a dedicated alignment test setup has been prepared, composed of a dummy
  focal plane assembly representing the detector position. Before the
  alignment on the flight optical bench, the overall alignment method
  has been validated on the Structural and Thermal Model, on a dummy
  bench using flight spare optics, then on the Qualification Model to
  be used for the system verification test and qualifications.

---------------------------------------------------------
Title: The extreme UV imager telescope on-board the Solar Orbiter
mission: overview of phase C and D
Authors: Halain, J. -P.; Rochus, P.; Renotte, E.; Hermans, A.; Jacques,
   L.; Auchère, F.; Berghmans, D.; Harra, L.; Schühle, U.; Schmutz,
   W.; Zhukov, A.; Aznar Cuadrado, R.; Delmotte, F.; Dumesnil, C.; Gyo,
   M.; Kennedy, T.; Smith, P.; Tandy, J.; Mercier, R.; Verbeeck, C.
2015SPIE.9604E..0GH    Altcode:
  The Solar Orbiter mission is composed of ten scientific instruments
  dedicated to the observation of the Sun's atmosphere and its
  heliosphere, taking advantage of an out-of ecliptic orbit and at
  perihelion reaching a proximity close to 0.28 A.U. On board Solar
  Orbiter, the Extreme Ultraviolet Imager (EUI) will provide full-Sun
  image sequences of the solar corona in the extreme ultraviolet (17.1
  nm and 30.4 nm), and high-resolution image sequences of the solar disk
  in the extreme ultraviolet (17.1 nm) and in the vacuum ultraviolet
  (121.6 nm). The EUI concept uses heritage from previous similar extreme
  ultraviolet instrument. Additional constraints from the specific orbit
  (thermal and radiation environment, limited telemetry download) however
  required dedicated technologies to achieve the scientific objectives
  of the mission. The development phase C of the instrument and its
  sub-systems has been successfully completed, including thermomechanical
  and electrical design validations with the Structural Thermal Model
  (STM) and the Engineering Model (EM). The instrument STM and EM units
  have been integrated on the respective spacecraft models and will
  undergo the system level tests. In parallel, the Phase D has been
  started with the sub-system qualifications and the flight parts
  manufacturing. The next steps of the EUI development will be the
  instrument Qualification Model (QM) integration and qualification
  tests. The Flight Model (FM) instrument activities will then follow
  with the acceptance tests and calibration campaigns.

---------------------------------------------------------
Title: CLASP: A UV Spectropolarimeter on a Sounding Rocket for
    Probing theChromosphere-Corona Transition Regio
Authors: Ishikawa, Ryohko; Kano, Ryouhei; Winebarger, Amy; Auchere,
   Frederic; Trujillo Bueno, Javier; Bando, Takamasa; Narukage,
   Noriyuki; Kobayashi, Ken; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Giono, Gabriel; Tsuneta, Saku; Hara, Hirohisa; Suematsu,
   Yoshinori; Shimizu, Toshifumi; Sakao, Taro; Ichimoto, Kiyoshi;
   Cirtain, Jonathan; De Pontieu, Bart; Casini, Roberto; Manso Sainz,
   Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi, Luca
2015IAUGA..2254536I    Altcode:
  The wish to understand the energetic phenomena of the outer solar
  atmosphere makes it increasingly important to achieve quantitative
  information on the magnetic field in the chromosphere-corona
  transition region. To this end, we need to measure and model the
  linear polarization produced by scattering processes and the Hanle
  effect in strong UV resonance lines, such as the hydrogen Lyman-alpha
  line. A team consisting of Japan, USA, Spain, France, and Norway has
  been developing a sounding rocket experiment called the Chromospheric
  Lyman-alpha Spectro-Polarimeter (CLASP). The aim is to detect the
  scattering polarization produced by anisotropic radiation pumping in
  the hydrogen Lyman-alpha line (121.6 nm), and via the Hanle effect to
  try to constrain the magnetic field vector in the upper chromosphere
  and transition region. In this talk, we will present an overview
  of our CLASP mission, its scientific objectives, ground tests made,
  and the latest information on the launch planned for the Summer of 2015.

---------------------------------------------------------
Title: Probing Solar Cycle 24's southern polar field reversal with
    a pseudostreamer
Authors: Rachmeler, Laurel A.; Guennou, Chloe; Seaton, Daniel;
   Auchère, Frédéric
2015shin.confE..65R    Altcode:
  In Solar Cycle 24 the northern hemisphere reached activity maximum
  around late 2011, while the south has trailed by at least two years. The
  northern hemispheric polar field reversal has been fragmented and
  complicated by poleward surges of both polarities. The southern polar
  field, on the other hand, has progressed in a straightforward manner:
  the boundary between the old cycle's positive field and the new cycle's
  negative field has moved progressively southward. Determining when the
  polar field flips sign is a difficult task because the photospheric
  magnetic field at the poles is either poorly, or not at all, observed
  depending on the solar B-angle. Here, we report on a pseudostreamer
  that we observed at the southern pole for a year beginning in February
  2014, and we use this feature to determine the southern polar field
  reversal. We tracked the formation, evolution, and disappearance of
  the pseudostreamer using limb identification and tomography with SWAP
  17.4 nm EUV images. The pseudostreamer overlayed a roughly circular
  polarity inversion line at the photosphere; both the pseudostreamer
  and the inversion line gradually shrank as the new cycle's negative
  field moved poleward. Using the morphology of the pseudostreamer, we
  determined that the southern polar coronal field completely reversed in
  approximately March 2015. All of the field inside the pseudostreamer is
  closed field, including the former cycle's positive polar field. Thus
  the heliospheric field, which is composed of open structures, reversed
  polarity a year earlier, when the pseudostreamer first formed.

---------------------------------------------------------
Title: Evidence for Evaporation-incomplete Condensation Cycles in
    Warm Solar Coronal Loops
Authors: Froment, C.; Auchère, F.; Bocchialini, K.; Buchlin, E.;
   Guennou, C.; Solomon, J.
2015ApJ...807..158F    Altcode: 2015arXiv150408129F
  Quasi-constant heating at the footpoints of loops leads to evaporation
  and condensation cycles of the plasma: thermal non-equilibrium
  (TNE). This phenomenon is believed to play a role in the formation
  of prominences and coronal rain. However, it is often discounted
  as being involved in the heating of warm loops because the
  models do not reproduce observations. Recent simulations have
  shown that these inconsistencies with observations may be due to
  oversimplifications of the geometries of the models. In addition,
  our recent observations reveal that long-period intensity pulsations
  (several hours) are common in solar coronal loops. These periods are
  consistent with those expected from TNE. The aim of this paper is to
  derive characteristic physical properties of the plasma for some of
  these events to test the potential role of TNE in loop heating. We
  analyzed three events in detail using the six EUV coronal channels
  of the Solar Dynamics Observatory/Atmospheric Imaging Assembly. We
  performed both a differential emission measure (DEM) and a time-lag
  analysis, including a new method to isolate the relevant signal from
  the foreground and background emission. For the three events, the DEM
  undergoes long-period pulsations, which is a signature of periodic
  heating even though the loops are captured in their cooling phase,
  as is the bulk of the active regions. We link long-period intensity
  pulsations to new signatures of loop heating with strong evidence for
  evaporation and condensation cycles. We thus simultaneously witness
  widespread cooling and TNE. Finally, we discuss the implications of
  our new observations for both static and impulsive heating models.

---------------------------------------------------------
Title: Instant: An Innovative L5 Small Mission Concept for Coordinated
    Science with Solar Orbiter and Solar Probe Plus
Authors: Lavraud, B.; Liu, Y. D.; Harrison, R. A.; Liu, W.;
   Auchere, F.; Gan, W.; Lamy, P. L.; Xia, L.; Eastwood, J. P.;
   Wimmer-Schweingruber, R. F.; Zong, Q.; Rochus, P.; Maksimovic, M.;
   Temmer, M.; Escoubet, C. P.; Kilpua, E.; Rouillard, A. P.; Davies,
   J. A.; Vial, J. C.; Gopalswamy, N.; Bale, S. D.; Li, G.; Howard,
   T. A.; DeForest, C. E.
2014AGUFMSH21B4109L    Altcode:
  We will present both the science objectives and related instrumentation
  of a small solar and heliospheric mission concept, INSTANT:
  INvestigation of Solar-Terrestrial Activity aNd Transients. It will be
  submitted as an opportunity to the upcoming ESA-China S-class mission
  call later this year. This concept was conceived to allow innovative
  measurements and unprecedented, early determination of key properties
  of Earthbound CMEs from the L5 vantage point. Innovative measurements
  will include magnetic field determination in the corona thanks to
  Hanle measurement in Lyman-α and polarized heliospheric imaging
  for accurate determination of CME trajectories. With complementary
  in situ measurements, it will uniquely permit solar storm science,
  solar storm surveillance, and synergy with Solar Orbiter and Solar
  Probe Plus (the ESA-China S2 mission launch is planned in 2021).

---------------------------------------------------------
Title: Waves and Magnetism in the Solar Atmosphere (WAMIS)
Authors: Ko, Y. K.; Auchere, F.; Casini, R.; Fineschi, S.; Gibson,
   S. E.; Knoelker, M.; Korendyke, C.; Laming, J. M.; Mcintosh, S. W.;
   Moses, J. D.; Romoli, M.; Rybak, J.; Socker, D. G.; Strachan, L.;
   Tomczyk, S.; Vourlidas, A.; Wu, Q.
2014AGUFMSH53B4221K    Altcode:
  Magnetic fields in the solar atmosphere provide the energy for most
  varieties of solar activity, including high-energy electromagnetic
  radiation, solar energetic particles, flares, and coronal mass
  ejections, as well as powering the solar wind. Despite the fundamental
  role of magnetic fields in solar and heliospheric physics, there
  exists only very limited measurements of the field above the base of
  the corona. What is needed are direct measurements of not only the
  strength and orientation of the magnetic field but also the signatures
  of wave motions in order to better understand coronal structure,
  solar activity and the role of MHD waves in heating and accelerating
  the solar wind. Fortunately, the remote sensing instrumentation used
  to make magnetic field measurements is also well suited for measuring
  the Doppler signature of waves in the solar structures. With this
  in mind, we are proposing the WAMIS (Waves and Magnetism in the
  Solar Atmosphere) investigation. WAMIS will take advantage of greatly
  improved infrared (IR) detectors, forward models, advanced diagnostic
  tools and inversion codes to obtain a breakthrough in the measurement
  of coronal magnetic fields and in the understanding of the interaction
  of these fields with space plasmas. This will be achieved with a high
  altitude balloon borne payload consisting of a coronagraph with an IR
  spectro-polarimeter focal plane assembly. The balloon platform provides
  minimum atmospheric absorption and scattering at the IR wavelengths in
  which these observations are made. Additionally, a NASA long duration
  balloon flight mission from the Antarctic can achieve continuous
  observations over most of a solar rotation, covering all of the key
  time scales for the evolution of coronal magnetic fields. With these
  improvements in key technologies along with experience gained from
  current ground-based instrumentation, WAMIS will provide a low-cost
  mission with a high technology readiness leve.

---------------------------------------------------------
Title: Precision VUV Spectro-Polarimetry for Solar Chromospheric
    Magnetic Field Measurements
Authors: Ishikawa, R.; Bando, T.; Hara, H.; Ishikawa, S.; Kano, R.;
   Kubo, M.; Katsukawa, Y.; Kobiki, T.; Narukage, N.; Suematsu, Y.;
   Tsuneta, S.; Aoki, K.; Miyagawa, K.; Ichimoto, K.; Kobayashi, K.;
   Auchère, F.; Clasp Team
2014ASPC..489..319I    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a VUV
  spectro-polarimeter optimized for measuring the linear polarization
  of the Lyman-α line (121.6 nm) to be launched in 2015 with NASA's
  sounding rocket (Ishikawa et al. 2011; Narukage et al. 2011; Kano et
  al. 2012; Kobayashi et al. 2012). With this experiment, we aim to (1)
  observe the scattering polarization in the Lyman-α line, (2) detect
  the Hanle effect, and (3) assess the magnetic fields in the upper
  chromosphere and transition region for the first time. The polarization
  measurement error consists of scale error δ a (error in amplitude
  of linear polarization), azimuth error Δφ (error in the direction
  of linear polarization), and spurious polarization ɛ (false linear
  polarization signals). The error ɛ should be suppressed below 0.1%
  in the Lyman-α core (121.567 nm ±0.02 nm), and 0.5% in the Lyman-α
  wing (121.567 nm ±0.05 nm), based on our scientific requirements shown
  in Table 2 of Kubo et al. (2014). From scientific justification, we
  adopt Δ φ&lt;2° and δ a&lt;10% as the instrument requirements. The
  spectro-polarimeter features a continuously rotating MgF<SUB>2</SUB>
  waveplate (Ishikawa et al. 2013), a dual-beam spectrograph with a
  spherical grating working also as a beam splitter, and two polarization
  analyzers (Bridou et al. 2011), which are mounted at 90 degree from
  each other to measure two orthogonal polarization simultaneously. For
  the optical layout of the CLASP instrument, see Figure 3 in Kubo et
  al. (2014). Considering the continuous rotation of the half-waveplate,
  the modulation efficiency is 0.64 both for Stokes Q and U. All the raw
  data are returned and demodulation (successive addition or subtraction
  of images) is done on the ground. <P />We control the CLASP polarization
  performance in the following three steps. First, we evaluate the
  throughput and polarization properties of each optical component in
  the Lyman-α line, using the Ultraviolet Synchrotron ORbital Radiation
  Facility (UVSOR) at the Institute for Molecular Science. The second
  step is polarization calibration of the spectro-polarimeter after
  alignment. Since the spurious polarization caused by the axisymmetric
  telescope is estimated to be negligibly small because of the symmetry
  (Ishikawa et al. 2014), we do not perform end-to-end polarization
  calibration. As the final step, before the scientific observation near
  the limb, we make a short observation at the Sun center and verify
  the polarization sensitivity, because the scattering polarization
  is expected to be close to zero at the Sun center due to symmetric
  geometry. In order to clarify whether we will be able to achieve the
  required polarization sensitivity and accuracy via these steps, we
  exercise polarization error budget, by investigating all the possible
  causes and their magnitudes of polarization errors, all of which are not
  necessarily verified by the polarization calibration. Based on these
  error budgets, we conclude that a polarization sensitivity of 0.1% in
  the line core, δ a&lt;10% and Δ φ&lt;2° can be achieved combined
  with the polarization calibration of the spectro-polarimeter and the
  onboard calibration at the Sun center(refer to Ishikawa et al. 2014,
  for the detail). <P />We are currently conducting verification tests
  of the flight components and development of the UV light source for
  the polarization calibration. From 2014 spring, we will begin the
  integration, alignment, and calibration. We will update the error
  budgets throughout the course of these tests.

---------------------------------------------------------
Title: A Sounding Rocket Experiment for the Chromospheric Lyman-Alpha
    Spectro-Polarimeter (CLASP)
Authors: Kubo, M.; Kano, R.; Kobayashi, K.; Bando, T.; Narukage, N.;
   Ishikawa, R.; Tsuneta, S.; Katsukawa, Y.; Ishikawa, S.; Suematsu, Y.;
   Hara, H.; Shimizu, T.; Sakao, T.; Ichimoto, K.; Goto, M.; Holloway,
   T.; Winebarger, A.; Cirtain, J.; De Pontieu, B.; Casini, R.; Auchère,
   F.; Trujillo Bueno, J.; Manso Sainz, R.; Belluzzi, L.; Asensio Ramos,
   A.; Štěpán, J.; Carlsson, M.
2014ASPC..489..307K    Altcode:
  A sounding-rocket experiment called the Chromospheric Lyman-Alpha
  Spectro-Polarimeter (CLASP) is presently under development to measure
  the linear polarization profiles in the hydrogen Lyman-alpha (Lyα)
  line at 121.567 nm. CLASP is a vacuum-UV (VUV) spectropolarimeter to aim
  for first detection of the linear polarizations caused by scattering
  processes and the Hanle effect in the Lyα line with high accuracy
  (0.1%). This is a fist step for exploration of magnetic fields in
  the upper chromosphere and transition region of the Sun. Accurate
  measurements of the linear polarization signals caused by scattering
  processes and the Hanle effect in strong UV lines like Lyα are
  essential to explore with future solar telescopes the strength
  and structures of the magnetic field in the upper chromosphere and
  transition region of the Sun. The CLASP proposal has been accepted by
  NASA in 2012, and the flight is planned in 2015.

---------------------------------------------------------
Title: Current progress of optical alignment procedure of CLASP's
    Lyman-alpha polarimetry instrument
Authors: Giono, G.; Ishikawa, R.; Katsukawa, Y.; Bando, T.; Kano, R.;
   Suematsu, Y.; Narukage, N.; Sakao, Taro; Kobayashi, K.; Auchère, F.
2014SPIE.9144E..3EG    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  sounding-rocket instrument currently under development at the
  National Astronomical Observatory of Japan (NAOJ) as a part of an
  international collaboration. CLASP's optics are composed of a Cassegrain
  telescope and a spectro-polarimeter which are designed to achieve an
  unprecedentedly accurate polarization measurement of the Ly-α line
  at 121.6nm emitted from the solar upper-chromosphere and transition
  region. CLASP's first flight is scheduled for August 2015. Reaching
  such accuracy requires a careful alignment of the optical elements
  to optimize the image quality at 121.6 nm. However Ly-α is absorbed
  by air and therefore the optics alignment has to be done under vacuum
  condition which makes any experiment difficult. To bypass this issue,
  we proposed to align the telescope and the spectrograph separately
  in visible light. Hence we present our alignment procedure for both
  telescope and spectro-polarimeter. We will explain details about the
  telescope preliminary alignment before mirrors coating, which was done
  in April 2014, present the telescope combined optical performance
  and compare them to CLASP tolerance. Then we will present details
  about an experiment designed to confirm our alignment procedure for
  the CLASP spectro-polarimeter. We will discuss the resulting image
  quality achieved during this experiment and the lessons learned.

---------------------------------------------------------
Title: The extreme UV imager of solar orbiter: from detailed design
    to flight model
Authors: Halain, J. -P.; Rochus, P.; Renotte, E.; Auchère, F.;
   Berghmans, D.; Harra, L.; Schühle, U.; Schmutz, W.; Zhukov, A.;
   Aznar Cuadrado, R.; Delmotte, F.; Dumesnil, C.; Gyo, M.; Kennedy,
   T.; Mercier, R.; Verbeeck, F.; Thome, M.; Heerlein, K.; Hermans, A.;
   Jacques, L.; Mazzoli, A.; Meining, S.; Rossi, L.; Tandy, J.; Smith,
   P.; Winter, B.
2014SPIE.9144E..08H    Altcode:
  The Extreme Ultraviolet Imager (EUI) on-board the Solar Orbiter mission
  will provide full-sun and high-resolution image sequences of the solar
  atmosphere at selected spectral emission lines in the extreme and vacuum
  ultraviolet. After the breadboarding and prototyping activities that
  focused on key technologies, the EUI project has completed the design
  phase and has started the final manufacturing of the instrument and its
  validation. The EUI instrument has successfully passed its Critical
  Design Review (CDR). The process validated the detailed design of
  the Optical Bench unit and of its sub-units (entrance baffles, doors,
  mirrors, camera, and filter wheel mechanisms), and of the Electronic
  Box unit. In the same timeframe, the Structural and Thermal Model
  (STM) test campaign of the two units have been achieved, and allowed
  to correlate the associated mathematical models. The lessons learned
  from STM and the detailed design served as input to release the
  manufacturing of the Qualification Model (QM) and of the Flight Model
  (FM). The QM will serve to qualify the instrument units and sub-units,
  in advance of the FM acceptance tests and final on-ground calibration.

---------------------------------------------------------
Title: Long-period intensity pulsations in the solar corona during
    activity cycle 23
Authors: Auchère, F.; Bocchialini, K.; Solomon, J.; Tison, E.
2014A&A...563A...8A    Altcode: 2013arXiv1312.3792A
  We report on the detection (10σ) of 917 events of long-period (3 to
  16 h) intensity pulsations in the 19.5 nm passband of the SOHO Extreme
  ultraviolet Imaging Telescope. The data set spans from January 1997
  to July 2010, i.e. the entire solar cycle 23 and the beginning of
  cycle 24. The events can last for up to six days and have relative
  amplitudes up to 100%. About half of the events (54%) are found
  to happen in active regions, and 50% of these have been visually
  associated with coronal loops. The remaining 46% are localized in
  the quiet Sun. We performed a comprehensive analysis of the possible
  instrumental artefacts and we conclude that the observed signal is
  of solar origin. We discuss several scenarios that could explain the
  main characteristics of the active region events. The long periods
  and the amplitudes observed rule out any explanation in terms of
  magnetohydrodynamic waves. Thermal non-equilibrium could produce the
  right periods, but it fails to explain all the observed properties
  of coronal loops and the spatial coherence of the events. We propose
  that moderate temporal variations of the heating term in the energy
  equation, so as to avoid a thermal non-equilibrium state, could be
  sufficient to explain those long-period intensity pulsations. The
  large number of detections suggests that these pulsations are common
  in active regions. This would imply that the measurement of their
  properties could provide new constraints on the heating mechanisms
  of coronal loops. <P />Movies are available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201322572/olm">http://www.aanda.org</A>

---------------------------------------------------------
Title: INSTANT: INvestigation of Solar-Terrestrial Associated
    Natural Threats
Authors: Lavraud, Benoit; Vial, Jean-Claude; Harrison, Richard; Davies,
   Jackie; Escoubet, C. Philippe; Zong, Qiugang; Auchere, Frederic; Liu,
   Ying; Bale, Stuart; Gopalswamy, Nat; Li, Gang; Maksimovic, Milan;
   Liu, William; Rouillard, Alexis
2014cosp...40E1758L    Altcode:
  The INSTANT mission will tackle both compelling solar and heliospheric
  science objectives and novel space weather capabilities. This is
  allowed by combining innovative and state-of-the-art instrumentation
  at an appropriate off-Sun-Earth line location on an orbit lagging
  the Earth around the Sun, near the L5 Lagrangian point. It is an
  affordable mission that tackles major objectives of the European and
  Chinese communities in terms of space physics and space weather. The
  science objectives are: 1. What is the magnetic field magnitude and
  topology in the corona? 2. How does the magnetic field reconfigure
  itself during CME eruptions? 3. What are the sources and links between
  the slow and fast winds? 4. How do CMEs accelerate and interact in the
  interplanetary medium? The mission will further allow the following
  crucial space weather capabilities: 5. Three-days advance knowledge
  of CIR properties that reach Earth. 6. Twelve hours to 2 days advance
  warning of Earth-directed CMEs. 7. Thanks to Lyman-α observations,
  first-ever capability of determining the magnetic field magnitude and
  orientation of Earth-directed CMEs. The mission will be proposed in
  the context of the upcoming ESA-China S-class call for mission.

---------------------------------------------------------
Title: Chromospheric Lyman-alpha spectro-polarimeter (CLASP)
Authors: Kano, Ryouhei; Katsukawa, Yukio; Kubo, Masahito; Auchere,
   Frederic; Ishikawa, Ryohko; Kobayashi, Ken; Narukage, Noriyuki;
   Trujillo Bueno, Javier; Bando, Takamasa; Ishikawa, Shin-nosuke
2014cosp...40E1383K    Altcode:
  In the solar chromosphere, magneto-hydrodynamic waves and super-sonic
  jets ubiquitously happen as revealed by the Japanese solar satellite
  Hinode. Now, we understand that the solar chromosphere is not a simple
  intermediate layer smoothly connecting the photosphere and corona,
  but a site where those dynamics may play an important role in the
  chromospheric and coronal heating. Such discoveries imply that the
  next frontier in solar physics lies in simultaneous observations
  between the dynamics and magnetic structures in the chromosphere and
  transition region, where the gas-dominant photosphere changes to the
  magnetic-dominant corona. Therefore, we promote the Chromospheric
  Lyman-Alpha SpectroPolarimeter (CLASP), which is a NASA's sounding
  rocket experiment scheduled in 2015 for aiming to infer the magnetic
  field information in the solar chromosphere and transition region. CLASP
  makes precise measurement (0.1%) of the polarization profile of the
  Lyman-alpha line, and aims to make the first ever measurement of the
  Hanle effect polarization caused by magnetic fields in the upper solar
  atmosphere. It is also a pathfinder to establish a new measurement
  tool for chromospheric and transition-region magnetic fields, and to
  make progress on chromospheric studies in future missions.

---------------------------------------------------------
Title: MASC: Magnetic Activity of the Solar Corona
Authors: Auchere, Frederic; Fineschi, Silvano; Gan, Weiqun; Peter,
   Hardi; Vial, Jean-Claude; Zhukov, Andrei; Parenti, Susanna; Li, Hui;
   Romoli, Marco
2014cosp...40E.149A    Altcode:
  We present MASC, an innovative payload designed to explore the magnetic
  activity of the solar corona. It is composed of three complementary
  instruments: a Hard-X-ray spectrometer, a UV / EUV imager, and a Visible
  Light / UV polarimetric coronagraph able to measure the coronal magnetic
  field. The solar corona is structured in magnetically closed and
  open structures from which slow and fast solar winds are respectively
  released. In spite of much progress brought by two decades of almost
  uninterrupted observations from several space missions, the sources and
  acceleration mechanisms of both types are still not understood. This
  continuous expansion of the solar atmosphere is disturbed by sporadic
  but frequent and violent events. Coronal mass ejections (CMEs) are
  large-scale massive eruptions of magnetic structures out of the corona,
  while solar flares trace the sudden heating of coronal plasma and the
  acceleration of electrons and ions to high, sometimes relativistic,
  energies. Both phenomena are most probably driven by instabilities
  of the magnetic field in the corona. The relations between flares
  and CMEs are still not understood in terms of initiation and energy
  partition between large-scale motions, small-scale heating and
  particle acceleration. The initiation is probably related to magnetic
  reconnection which itself results magnetic topological changes due to
  e.g. flux emergence, footpoints motions, etc. Acceleration and heating
  are also strongly coupled since the atmospheric heating is thought to
  result from the impact of accelerated particles. The measurement of
  both physical processes and their outputs is consequently of major
  importance. However, despite its fundamental importance as a driver
  for the physics of the Sun and of the heliosphere, the magnetic field
  of our star’s outer atmosphere remains poorly understood. This
  is due in large part to the fact that the magnetic field is a very
  difficult quantity to measure. Our knowledge of its strength and
  orientation is primarily based on extrapolations from photospheric
  observations, not from direct measurements. These extrapolations
  require strong assumptions on critical but unobserved quantities and
  thus fail to accurately reproduce the complex topologies inferred
  from remote-sensing observations of coronal structures in white
  light, EUV, and X-rays. Direct measurements of the coronal magnetic
  field are also clearly identified by the international heliophysics
  community as a key element susceptible to lead to major breakthroughs
  in the understanding of our star. MASC is thus designed to answer
  the following top-level scientific questions: 1. What is the global
  magnetic field configuration in the corona? 2. What is the role of
  the magnetic field in the triggering of flares and CMEs? 3. What is
  the role of the magnetic field in the acceleration mechanisms of the
  solar winds? 4. What is the energy spectrum and in particular what are
  the highest energies to which charged particles can be accelerated in
  the solar corona? MASC will address these fundamental questions with
  a suite of instruments composed of an X-ray spectrometer, a UV / EUV
  imager, and a coronagraph working in the visible and at Lyman alpha. The
  spectrometer will provide information on the energetics of solar flares,
  in particular at very high energies of accelerated particles. The
  UV / EUV imager will provide constraints on the temperature of the
  flaring and non-flaring corona. The coronagraph will provide the number
  density of free electrons in the corona, maps of the outflow velocity
  of neutral hydrogen, and measurements of the coronal magnetic field,
  via the Hanle effect. These measurements will be performed at all
  steps of the flare-CME processes, thus providing a detailed picture
  of the solar coronal dynamics in the quiet and eruptive periods.

---------------------------------------------------------
Title: The Solar EUV flux in the 3D Heliosphere
Authors: Auchere, Frederic; Von Steiger, Rudolf; McMullin, Donald;
   Newmark, Jeffrey
2014cosp...40E.150A    Altcode:
  The absolute measurement of solar EUV flux and its time dependence
  provide critical data on the solar driven photo chemistry which results
  in solar system objects. For example, the Solar HeII 30.4 nm emission
  is a major contributor to photo-ionization in the heliosphere, and thus
  30.4 nm measurements provide the data required to determine the absolute
  photoionization rate of neutral interstellar helium flowing into our
  solar system. However, because of the orbit characteristics of the vast
  majority of spacecraft, the solar irradiance has mostly been measured at
  Earth or at least in the plane of the ecliptic. Therefore, the existing
  data ignore the fact that the angular distribution of the solar flux
  is largely anisotropic. Indeed, in the far and extreme ultraviolet,
  the chromosphere and the corona display very contrasted structures. At
  solar minimum, the polar regions are darkened by large coronal holes,
  and in the most active part of the solar cycle, bright active regions
  are scattered around the solar globe at low heliocentric latitudes. To
  date, due to the small number of off- ecliptic measurements, very
  few attempts have been made to investigate these variations. The
  implications of the anisotropy of the solar irradiance are diverse. For
  example, in the case of the 121.6 nm line of H I, the latitudinal
  anisotropy must be taken into account when modeling the Lyman alpha
  resonantly backscattered sky background. Identically, the anisotropy
  must be included in the modeling of the intensity of the HI 121.6 nm
  and He II 30.4 nm resonantly scattered coronal lines. We present here
  a generalization of an earlier work on the anisotropy of the 30.4
  nm EUV flux. Our empirical model, is now able to synthethize solar
  spectra as seen from any point in the heliosphere in the 10 to 50 nm
  wavelength range. The model is based on a Differential Emission Measure
  resonstruction of the spectrum from reprojected EUV Carrington maps of
  the Sun. We present the results obtained on the 3D distribution of the
  Solar EUV flux during solar cycle 23. We discuss their consequences
  on the GAS/Ulysses measurements of the Helium abundance in the Local
  Interstellar Medium.

---------------------------------------------------------
Title: Observations and possible interpretations of very long period
    intensity pulsations in solar coronal loops
Authors: Froment, Clara; Solomon, Jacques; Buchlin, Eric; Bocchialini,
   Karine; Auchere, Frederic; Guennou, Chloe
2014cosp...40E.903F    Altcode:
  We discovered that intensity pulsations with periods ranging from 3
  to 16 hours are common in solar coronal loops. Initially developed
  for EIT/SOHO 195 nm images, the automatic detection algorithm is now
  running on AIA/SDO data and allows detection of pulsation events in
  six coronal bands simultaneously. From may 2010 to december 2013, we
  detected more than 2000 events in the 6 EUV bands. We focus our study
  on pulsations in active regions and in particular in solar coronal
  loops where most of events are detected. A multi-wavelength analysis
  of some characteristic events is presented to help understand their
  physical nature. We perform a Differential Emission Measure analysis
  on AIA time series in order to determine the temporal variations of the
  thermal structure of the pulsating loops. This analysis gives important
  clues to investigate possible physical interpretations in particular in
  term of small perturbations of loops in static equilibrium and to study
  how this can constraint coronal heating models. We will also compare
  our observations to the results of a MHD turbulence and heating model
  of coronal loops.

---------------------------------------------------------
Title: Future L5 Missions for Solar Physics and Space Weather
Authors: Auchere, Frederic; Gopalswamy, Nat
2014cosp...40E.148A    Altcode:
  Coronal mass ejections (CMEs) and corotating interaction regions (CIR)
  are the sources of intense space weather in the heliosphere. Most of
  the current knowledge on CMEs accumulated over the past few decades
  has been derived from observations made from the Sun-Earth line,
  which is not the ideal vantage point to observe Earth-affecting
  CMEs (Gopalswamy et al., 2011a,b). In this paper, the advantages of
  remote-sensing and in-situ observations from the Sun-Earth L5 point
  are discussed. Locating a mission at Sun-Earth L5 has several key
  benefits for solar physics and space weather: (1) off the Sun-Earth
  line view is critical in observing Earth-arriving parts of CMEs,
  (2) L5 coronagraphic observations can also provide near-Sun space
  speed of CMEs, which is an important input to models that forecast
  Earth-arrival time of CMEs, (3) backside and frontside CMEs can be
  readily distinguished even without inner coronal imagers, (4) preceding
  CMEs in the path of Earth-affecting CMEs can be identified for a better
  estimate of the travel time, (5) CIRs reach the L5 point a few days
  before they arrive at Earth, and hence provide significant lead time
  before CIR arrival, (6) L5 observations can provide advance knowledge
  of CME and CIR source regions (coronal holes) rotating to Earth view,
  and (7) magnetograms obtained from L5 can improve the surface magnetic
  field distribution used as input to MHD models that predict the
  background solar wind. The paper also discusses L5 mission concepts
  that can be achieved in the near future. References Gopalswamy, N.,
  Davila, J. M., St. Cyr, O. C., Sittler, E. C., Auchère, F., Duvall,
  T. L., Hoeksema, J. T., Maksimovic, M., MacDowall, R. J., Szabo,
  A., Collier, M. R. (2011a), Earth-Affecting Solar Causes Observatory
  (EASCO): A potential International Living with a Star Mission from
  Sun-Earth L5 JASTP 73, 658-663, DOI: 10.1016/j.jastp.2011.01.013
  Gopalswamy, N., Davila, J. M., Auchère, F., Schou, J., Korendyke,
  C. M. Shih, A., Johnston, J. C., MacDowall, R. J., Maksimovic, M.,
  Sittler, E., et al. (2011b), Earth-Affecting Solar Causes Observatory
  (EASCO): a mission at the Sun-Earth L5, Solar Physics and Space Weather
  Instrumentation IV. Ed. Fineschi, S. &amp; Fennelly, J., Proceedings
  of the SPIE, Volume 8148, article id. 81480Z, DOI: 10.1117/12.901538

---------------------------------------------------------
Title: Innovative multilayer coated optics for Solar Physics
Authors: Meltchakov, Evgueni; Auchere, Frederic; Delmotte, Franck;
   De Rossi, Sebastien; Mercier, Raymond; Zhang, Xueyan
2014cosp...40E2069M    Altcode:
  Development of multilayer coated optics with specific spectral
  characteristics and enhanced temporal, thermal and radiation
  stability requires an innovative approach to the design of reflecting
  multilayers and optimization of the coating process. Here we report
  on the progress in design, calculations and fabrication of reflecting
  multilayer coatings for solar imaging in the extreme ultra-violet
  (EUV) range. We will present recent results of characterization of
  new tri-component periodic multilayer structures containing aluminum
  as a low absorbing material within the spectral range from 17 to
  40 nm. The EUV peak reflectance of these coatings (for instance,
  the Al/Mo/SiC multilayers) reaches 56% at 17.4 nm and 42% at 30 nm,
  highest reported up to now for these wavelengths. We have studied the
  temporal and thermal stability of structural and optical parameters
  of Al-based multilayer coatings as well as the resistivity of the
  coatings to high-energy and high-dose proton irradiation. A special
  attention will be drawn to specific bi-periodic systems with enhanced
  selectivity, which possess two efficient reflection bands and attenuate
  some unwanted emission lines in the EUV range. Experimental results
  show that such multilayer coatings are good candidates for the EUV
  imaging telescopes of Solar Orbiter and future solar missions.

---------------------------------------------------------
Title: UV spectropolarimeter design for precise polarization
    measurement and its application to the CLASP for exploration of
    magnetic fields in solar atmosphere
Authors: Narukage, Noriyuki; Katsukawa, Yukio; Hara, Hirohisa; Kubo,
   Masahito; Auchere, Frederic; Ishikawa, Ryohko; Kano, Ryouhei; Bando,
   Takamasa; Ishikawa, Shin-nosuke; Suematsu, Yoshinori; Tsuneta, Saku
2014cosp...40E2232N    Altcode:
  In order to measure the magnetic field in the region where the
  hot plasma from 10 (4) K to 10 (6) K is occupied, e.g., for solar
  atmosphere, the polarimetric measurements in ultra violet (UV)
  with 0.1% accuracy are required. In this paper, we propose a new
  UV spectropolarimeter design with 0.1% sensitivity in polarization
  measurement. This spectropolarimeter has two devices for the 0.1%
  accuracy. First, all optical components except the waveplate are the
  reflective type ones that can be equipped with the high reflectivity
  coating for the high throughput. Secondly, it equips the optically
  symmetric dual channels to measure the orthogonal linear polarization
  state simultaneously, using a concave diffraction grating as both the
  spectral dispersion element and the beam splitter. These two devices
  make the spurious polarizations caused by the photon noise, by the
  intensity variation of the observation target, and, by the instrument
  itself, enough small to achieve the 0.1% accuracy in polarization
  measurement. The spectropolarimeter thus designed is currently under
  fabrication for the sounding rocket project of Chromospheric Lyman-Alpha
  SpectroPolarimeter (CLASP) that aims at the direct measurement of the
  magnetic fields in solar atmosphere with Lyman-alpha line (121.6 nm)
  for the first time.

---------------------------------------------------------
Title: On-Orbit Degradation of Solar Instruments
Authors: BenMoussa, A.; Gissot, S.; Schühle, U.; Del Zanna, G.;
   Auchère, F.; Mekaoui, S.; Jones, A. R.; Walton, D.; Eyles, C. J.;
   Thuillier, G.; Seaton, D.; Dammasch, I. E.; Cessateur, G.; Meftah,
   M.; Andretta, V.; Berghmans, D.; Bewsher, D.; Bolsée, D.; Bradley,
   L.; Brown, D. S.; Chamberlin, P. C.; Dewitte, S.; Didkovsky, L. V.;
   Dominique, M.; Eparvier, F. G.; Foujols, T.; Gillotay, D.; Giordanengo,
   B.; Halain, J. P.; Hock, R. A.; Irbah, A.; Jeppesen, C.; Judge,
   D. L.; Kretzschmar, M.; McMullin, D. R.; Nicula, B.; Schmutz, W.;
   Ucker, G.; Wieman, S.; Woodraska, D.; Woods, T. N.
2013SoPh..288..389B    Altcode: 2013arXiv1304.5488B
  We present the lessons learned about the degradation observed in
  several space solar missions, based on contributions at the Workshop
  about On-Orbit Degradation of Solar and Space Weather Instruments
  that took place at the Solar Terrestrial Centre of Excellence (Royal
  Observatory of Belgium) in Brussels on 3 May 2012. The aim of this
  workshop was to open discussions related to the degradation observed
  in Sun-observing instruments exposed to the effects of the space
  environment. This article summarizes the various lessons learned
  and offers recommendations to reduce or correct expected degradation
  with the goal of increasing the useful lifespan of future and ongoing
  space missions.

---------------------------------------------------------
Title: Can the Differential Emission Measure Constrain the Timescale
    of Energy Deposition in the Corona?
Authors: Guennou, C.; Auchère, F.; Klimchuk, J. A.; Bocchialini,
   K.; Parenti, S.
2013ApJ...774...31G    Altcode: 2013arXiv1306.3114G
  In this paper, the ability of the Hinode/EIS instrument to detect
  radiative signatures of coronal heating is investigated. Recent
  observational studies of active region cores suggest that both
  the low and high frequency heating mechanisms are consistent with
  observations. Distinguishing between these possibilities is important
  for identifying the physical mechanism(s) of the heating. The
  differential emission measure (DEM) tool is one diagnostic that
  allows us to make this distinction, through the amplitude of the
  DEM slope coolward of the coronal peak. It is therefore crucial to
  understand the uncertainties associated with these measurements. Using
  proper estimations of the uncertainties involved in the problem
  of DEM inversion, we derive confidence levels on the observed DEM
  slope. Results show that the uncertainty in the slope reconstruction
  strongly depends on the number of lines constraining the slope. Typical
  uncertainty is estimated to be about ±1.0 in the more favorable cases.

---------------------------------------------------------
Title: The SWAP EUV Imaging Telescope Part I: Instrument Overview
    and Pre-Flight Testing
Authors: Seaton, D. B.; Berghmans, D.; Nicula, B.; Halain, J. -P.; De
   Groof, A.; Thibert, T.; Bloomfield, D. S.; Raftery, C. L.; Gallagher,
   P. T.; Auchère, F.; Defise, J. -M.; D'Huys, E.; Lecat, J. -H.; Mazy,
   E.; Rochus, P.; Rossi, L.; Schühle, U.; Slemzin, V.; Yalim, M. S.;
   Zender, J.
2013SoPh..286...43S    Altcode: 2012SoPh..tmp..217S; 2012arXiv1208.4631S
  The Sun Watcher with Active Pixels and Image Processing (SWAP) is
  an EUV solar telescope onboard ESA's Project for Onboard Autonomy 2
  (PROBA2) mission launched on 2 November 2009. SWAP has a spectral
  bandpass centered on 17.4 nm and provides images of the low solar
  corona over a 54×54 arcmin field-of-view with 3.2 arcsec pixels and
  an imaging cadence of about two minutes. SWAP is designed to monitor
  all space-weather-relevant events and features in the low solar
  corona. Given the limited resources of the PROBA2 microsatellite,
  the SWAP telescope is designed with various innovative technologies,
  including an off-axis optical design and a CMOS-APS detector. This
  article provides reference documentation for users of the SWAP image
  data.

---------------------------------------------------------
Title: Chromospheric Lyman Alpha SpectroPolarimeter: CLASP
Authors: Kobayashi, Ken; Kano, R.; Trujillo Bueno, J.; Winebarger,
   A. R.; Cirtain, J. W.; Bando, T.; De Pontieu, B.; Ishikawa, R.;
   Katsukawa, Y.; Kubo, M.; Narukage, N.; Sakao, T.; Tsuneta, S.;
   Auchère, F.; Asensio Ramos, A.; Belluzzi, L.; Carlsson, M.; Casini,
   R.; Hara, H.; Ichimoto, K.; Manso Sainz, R.; Shimizu, T.; Stepan,
   J.; Suematsu, Y.; Holloway, T.
2013SPD....44..142K    Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a VUV
  spectropolarimeter optimized for measuring the linear polarization of
  the Lyman-alpha line (121.6 nm). The Lyman-alpha line is predicted to
  show linear polarization caused by atomic scattering in the chromosphere
  and modified by the magnetic field through the Hanle effect. The
  Hanle effect is sensitive to weaker magnetic fields than Zeeman
  effect, and is not canceled by opposing fields, making it sensitive
  to tangled or unresolved magnetic field structures. These factors make
  the Hanle effect a valuable tool for probing the magnetic field in the
  chromosphere above the quiet sun. To meet this goal, CLASP is designed
  to measure linear polarization with 0.1% polarization sensitivity
  at 0.01 nm spectral resolution and 10" spatial resolution. CLASP is
  scheduled to be launched in 2015.

---------------------------------------------------------
Title: The LYOT+ UV/EUV instrumentation for measuring the magnetic
    field in the corona
Authors: Auchère, Frederic; Vial, Jean Claude
2013EGUGA..1513788A    Altcode:
  The solar corona is the seat of a variability which involves basic
  processes of plasma-magnetic field interaction in the universe,
  while also being a source of disturbances for spacecraft, technology,
  and possibly for human beings. Of special interest are coronal mass
  ejections (CMEs) with their associated Eruptive Prominences (EPs). Since
  they are basically driven by instabilities of the magnetic field in the
  corona, the measurement of the magnetic field before, after (and during)
  the event is critical in the corona. Also of interest for these studies
  and the source of the solar wind, the radial velocity of the plasma is a
  critical parameter to be determined. We present a new proposal to CNES
  called LYOT+ which meets the above-mentioned objectives: measurement
  of the coronal magnetic field up to 2 solar radii, of the electron
  density and the radial velocity. These measurements are complemented
  by EUV images of the underlying corona providing plasma diagnostic and
  magnetic field morphology. We describe the proposed combination of EUV
  imager and VUV and visible coronagraph. A main feature of the proposed
  instrumentation is the extended overlap of the fields-of-view of both
  instruments. In our presentation, we focus on the polarimetric concept
  which leads to the determination of the magnetic field through the
  Hanle effect. We also mention the extensive studies already performed
  in designing the instrumentation and testing parts of it. In summary,
  science, instrumentation and constraints on missions on which LYOT+
  could be implemented, are presented.

---------------------------------------------------------
Title: Tomographic reconstructions of large scale coronal structures
Authors: Guennou, C.; Auchère, F.; Seaton, D.; Canou, A.; Barbey,
   N.; Bocchialini, K.
2013enss.confE..83G    Altcode:
  Classical plasma diagnostic techniques suffer from the line of sight
  (LOS) integration problem, which can confuse structures to the point
  that measurements crucial to the understanding of coronal physics are
  difficult to interpret. Tomography provides one way of understanding the
  LOS content, giving important insights on the morphology and physical
  properties of the coronal structures. Large scale, long-lived, arch-like
  structures are observed in the field of view of EUV telescopes at
  mid-latitudes, most notably in the 174 nm passband. In the present work,
  we use tomographic inversions of the solar corona the 3D morphology of
  these structures. We focus on a 28 days period of data from July/August
  2012 during which some of these features were observed up to 1.7 Rsol by
  the SWAP/PROBA2 telescope. Additional multi-wavelength observations in
  the 6 bands of AIA/SDO are used to derive the corresponding 3-D maps
  of electron density and temperature. The results are then compared
  with global magnetic field extrapolations. We conclude by proposing
  an interpretation of the morphology of these structures as seen in
  EUV images.

---------------------------------------------------------
Title: TomograPy: A Fast, Instrument-Independent, Solar Tomography
    Software
Authors: Barbey, N.; Guennou, C.; Auchère, F.
2013SoPh..283..227B    Altcode: 2011SoPh..tmp..181B; 2011SoPh..tmp..250B; 2011arXiv1103.5904B;
   2011SoPh..tmp..126B
  Solar tomography has progressed rapidly in recent years thanks to the
  development of robust algorithms and the availability of more powerful
  computers. It can today provide crucial insights in solving issues
  related to the line-of-sight integration present in the data of solar
  imagers and coronagraphs. However, there remain challenges such as the
  increase of the available volume of data, the handling of the temporal
  evolution of the observed structures, and the heterogeneity of the data
  in multi-spacecraft studies. We present a generic software package that
  can perform fast tomographic inversions that scales linearly with the
  number of measurements, linearly with the length of the reconstruction
  cube (and not the number of voxels), and linearly with the number of
  cores and can use data from different sources and with a variety of
  physical models: TomograPy (http://nbarbey.github.com/TomograPy/), an
  open-source software freely available on the Python Package Index. For
  performance, TomograPy uses a parallelized-projection algorithm. It
  relies on the World Coordinate System standard to manage various data
  sources. A variety of inversion algorithms are provided to perform
  the tomographic-map estimation. A test suite is provided along with
  the code to ensure software quality. Since it makes use of the Siddon
  algorithm it is restricted to rectangular parallelepiped voxels but
  the spherical geometry of the corona can be handled through proper
  use of priors. We describe the main features of the code and show
  three practical examples of multi-spacecraft tomographic inversions
  using STEREO/EUVI and STEREO/COR1 data. Static and smoothly varying
  temporal evolution models are presented.

---------------------------------------------------------
Title: Coronal Temperature Maps from Solar EUV Images: A Blind Source
    Separation Approach
Authors: Dudok de Wit, T.; Moussaoui, S.; Guennou, C.; Auchère, F.;
   Cessateur, G.; Kretzschmar, M.; Vieira, L. A.; Goryaev, F. F.
2013SoPh..283...31D    Altcode: 2012SoPh..tmp..258D; 2012arXiv1203.0116D; 2012SoPh..tmp..276D
  Multi-wavelength solar images in the extreme ultraviolet (EUV) are
  routinely used for analysing solar features such as coronal holes,
  filaments, and flares. However, images taken in different bands often
  look remarkably similar, as each band receives contributions coming from
  regions with a range of different temperatures. This has motivated the
  search for empirical techniques that may unmix these contributions and
  concentrate salient morphological features of the corona in a smaller
  set of less redundant source images. Blind Source Separation (BSS)
  does precisely this. Here we show how this novel concept also provides
  new insight into the physics of the solar corona, using observations
  made by SDO/AIA. The source images are extracted using a Bayesian
  positive source-separation technique. We show how observations made
  in six spectral bands, corresponding to optically thin emissions,
  can be reconstructed by a linear combination of three sources. These
  sources have a narrower temperature response and allow for considerable
  data reduction, since the pertinent information from all six bands can
  be condensed into a single composite picture. In addition, they give
  access to empirical temperature maps of the corona. The limitations
  of the BSS technique and some applications are briefly discussed.

---------------------------------------------------------
Title: GAIA-DEM : The Gaussian AIA DEm Maps database
Authors: Guennou, C.; Auchère, F.; Soubrié, E.; Bocchialini, K.
2013enss.confE...7G    Altcode:
  Providing the amount of emitting material as a function of the
  temperature along the line-of-sight, the Differential Emisssion Measure
  (DEM) analysis is a widespread diagnostic tool, used for most types of
  coronal structures. With six available coronal bands, the AIA instrument
  on board the SDO satellite provides new possibilities to more reliably
  estimate the DEM than previous UV imagers, and over a large FOV. The
  purpose of this database is to provide synoptic Gaussian DEM inversions
  of the AIA data. Using our recent results (Guennou et al. 2012a and
  2012b), these maps can be then interpreted, taking advantage of our new
  tools developed to facilitate the DEM interpretation. The GAIA database
  provides the best Gaussian DEM fit matching the observations. A Gaussian
  form is a good first order approximation to determine the main thermal
  characteristics of the coronal plasma. With generally four inversions
  per day, at a 6 hours cadence, this database enables the user to
  quickly examine the global evolution of the thermal structure of the
  solar corona. DEM maps are available at http://medoc-dem.ias.u-psud.fr/.

---------------------------------------------------------
Title: FESTIVAL 5.0 - AIA and more !
Authors: Auchère, F.; Soubrié, E.
2013enss.confE.141A    Altcode:
  FESTIVAL is an open source IDL-based browser designed for simultaneous
  and dynamic compositing of multi-instrument imaging data. FESTIVAL
  is very flexible and works with FITS files, which allows advanced
  processing. It is distributed as a Solar Software package. Initially
  developed for SECCHI, FESTIVAL now supports most space imaging
  telescopes, the latest additions being AIA /SDO and SWAP / Proba2. Its
  native zoom/pan mouse navigation mode makes it well suited to the large
  format of AIA images. In additio, version 5.0 brings a variety of new
  features making FESTIVAL even more powerful: enhanced search options,
  base and N-x running differences, solar rotation compensation, remote
  access to the MEDOC data archive, etc.

---------------------------------------------------------
Title: Can the Differential Emission Measure diagnostic be used to
    constrain the timescale of energy deposition in the corona?
Authors: Guennou, C.; Auchère, F.; Klimchuk, J. A.; Bocchialini,
   K.; Parenti, S.
2013enss.confE..34G    Altcode:
  Differential emission measure (DEM) analysis is a widespread tool used
  to diagnose the thermal properties of coronal plasmas. The slope of
  the DEM distribution coolward of the coronal peak (near 3-4MK in active
  regions) can be used to diagnose the timescale for the energy deposition
  repeating on a given magnetic strand. Recent AR studies suggest that
  some active region cores are consistent with low frequency heating
  mechanisms, where the plasma cools completely before being reheated,
  while other show consistency with high frequency energy deposition,
  where rapid reheating causes the temperature to fluctuate about
  a particular value. Distinguishing between these possibilities is
  important for identifying the physical mechanism of the heating. It is
  therefore crucial to understand the uncertainties in measurements of
  observed DEM slopes. In this work, based on a probabilistic approach
  and Monte Carlo simulations, we carefully assess the errors in the
  slopes determined from EIS data. We consider both the random errors due
  to photon counting statistics, and the systematic errors associated
  with uncertainties in atomic physics and instrument calibration. The
  technique developed provides all the solutions consistent with the data
  and their associated probabilities. We demonstrate how the quality
  and the accuracy of the inversion are affected by the presence of
  noises and systematic errors, and we characterise the quality of the
  DEM inversion and its statistical properties. From these results,
  estimation of the uncertainties in the reconstructed slopes can be
  derived, thereby allowing a proper interpretation of the degree of
  agreement between observations and heating model predictions.

---------------------------------------------------------
Title: MEDIA : MEDoc Interface for AIA
Authors: Alingery, P.; Soubrié, E.; Auchère, F.; Bocchialini, K.;
   Boignard, J. P.; Buchlin, E.; Malappert, J. C.; Parenti, S.
2013enss.confE..88A    Altcode:
  MEDOC, the space solar data center at Orsay
  (http://www.ias.u-psud.fr/medoc) is now providing a new web access
  to the AIA/SDO level 1 images. This interface has the advantage of
  being simple, intuitive, very stable and fast. The full resolution
  4k x 4k AIA level 1 images archived at MEDOC are downloaded from
  upstream DRMS nodes with a 1 minute cadence at all wavelengths. The
  dataset will be kept online on a redundant archive for the whole SDO
  mission duration. The FITS files are accessible via an user friendly
  web interface (http://medoc-sdo.ias.u-psud.fr) that allows users
  to request data by selecting a date range, the desired wavelengths
  and a sampling rate (choosing a cadence from 1 minute to 1 day). For
  each file, users can preview the image (using the Helioviewer tool)
  or display the header information before downloading the FITS files
  (with or without Rice-compression). This web interface was built
  using Sitools2, a tool developed by CNES, the French space agency, and
  supports most browsers. For more advanced users, a Search/Get Python
  module is also available at http://sdo.ias.u-psud.fr/python. The users
  can use it to build more complex yet more powerful queries. We encourage
  everyone in Europe and beyond to use these new services!

---------------------------------------------------------
Title: On the Accuracy of the Differential Emission Measure
    Diagnostics of Solar Plasmas. Application to SDO/AIA. II. Multithermal
    Plasmas
Authors: Guennou, C.; Auchère, F.; Soubrié, E.; Bocchialini, K.;
   Parenti, S.; Barbey, N.
2012ApJS..203...26G    Altcode: 2012arXiv1210.2302G
  Differential emission measure (DEM) analysis is one of the most
  used diagnostic tools for solar and stellar coronae. Being an inverse
  problem, it has limitations due to the presence of random and systematic
  errors. We present in this series of papers an analysis of the
  robustness of the inversion in the case of SDO/AIA observations. We
  completely characterize the DEM inversion and its statistical
  properties, providing all the solutions consistent with the data along
  with their associated probabilities, and a test of the suitability of
  the assumed DEM model. While Paper I focused on isothermal conditions,
  we now consider multithermal plasmas and investigate both isothermal and
  multithermal solutions. We demonstrate how the ambiguity between noises
  and multithermality fundamentally limits the temperature resolution
  of the inversion. We show that if the observed plasma is multithermal,
  isothermal solutions tend to cluster on a constant temperature whatever
  the number of passbands or spectral lines. The multithermal solutions
  are also found to be biased toward near-isothermal solutions around 1
  MK. This is true even if the residuals support the chosen DEM model,
  possibly leading to erroneous conclusions on the observed plasma. We
  propose tools for identifying and quantifying the possible degeneracy
  of solutions, thus helping the interpretation of DEM inversion.

---------------------------------------------------------
Title: On the Accuracy of the Differential Emission Measure
    Diagnostics of Solar Plasmas. Application to SDO/AIA. I. Isothermal
    Plasmas
Authors: Guennou, C.; Auchère, F.; Soubrié, E.; Bocchialini, K.;
   Parenti, S.; Barbey, N.
2012ApJS..203...25G    Altcode: 2012arXiv1210.2304G
  Differential emission measure (DEM) analysis is a major diagnostic
  tool for stellar atmospheres. However, both its derivation and its
  interpretation are notably difficult because of random and systematic
  errors, and the inverse nature of the problem. We use simulations with
  simple thermal distributions to investigate the inversion properties
  of SDO/AIA observations of the solar corona. This allows a systematic
  exploration of the parameter space, and using a statistical approach
  the respective probabilities of all the DEMs compatible with the
  uncertainties can be computed. Following this methodology, several
  important properties of the DEM inversion, including new limitations,
  can be derived and presented in a very synthetic fashion. In this first
  paper, we describe the formalism and we focus on isothermal plasmas
  as building blocks to understand the more complex DEMs studied in the
  second paper. The behavior of the inversion of AIA data being thus
  quantified, and we provide new tools to properly interpret the DEM. We
  quantify the improvement of the isothermal inversion with six AIA bands
  compared to previous EUV imagers. The maximum temperature resolution
  of AIA is found to be 0.03 log T<SUB>e</SUB> , and we derive a rigorous
  test to quantify the compatibility of observations with the isothermal
  hypothesis. However, we demonstrate limitations in the ability of AIA
  alone to distinguish different physical conditions.

---------------------------------------------------------
Title: Measurements and Modeling of Heliospheric EUV Spectral
    Irradiance and Luminosity
Authors: Floyd, L. E.; McMullin, D. R.; Auchere, F.
2012AGUFMSH11B2212F    Altcode:
  For more than 15 years, The EIT and the later EUVI instruments aboard
  SoHO and STEREO, respectively, have provided a time series of images
  of the solar radiance in the HeII 30.4 nm transition region and
  three coronal emission lines (FeIX/X, FeXII, and FeXV) of differing
  temperatures. While the EIT measurements were gathered from a position
  very near to the Earth-Sun axis, the EUVI measurements were gathered at
  angles ranging up to and in excess of ±90 degrees in solar longitude
  from the Earth-Sun axis. Using a Differential Emission Measure (DEM)
  model, these measurements provide the basis for estimates of the
  spectral irradiance for the entire solar spectrum up to about 50 nm at
  any position in the heliosphere. These spectra are utilized in this
  work for two purposes. First, the photoionization rate of neutral He
  at each position is calculated. Neutral He is of interest because it
  traverses the heliopause relatively undisturbed and therefore provides a
  measure of isotopic parameters beyond the heliosphere. Second, we use
  these generate a time series of estimates of the solar EUV spectral
  luminosity extending from the recent post Solar Cycle 23 minimum
  into the current unusually weak rise of Solar Cycle 24. Because this
  EUV spectral luminosity is the sum of all solar radiation at each
  wavelength in every direction, their time series should not contain
  any systematic 27-day solar rotation periodicities as do typical solar
  activity indices and its presence would be an indication of time series
  reliability. This EUV luminosity time series is compared with other
  solar indices such as SSN and the F10.7 radio flux.

---------------------------------------------------------
Title: LEMUR: Large European module for solar Ultraviolet
    Research. European contribution to JAXA's Solar-C mission
Authors: Teriaca, Luca; Andretta, Vincenzo; Auchère, Frédéric;
   Brown, Charles M.; Buchlin, Eric; Cauzzi, Gianna; Culhane, J. Len;
   Curdt, Werner; Davila, Joseph M.; Del Zanna, Giulio; Doschek, George
   A.; Fineschi, Silvano; Fludra, Andrzej; Gallagher, Peter T.; Green,
   Lucie; Harra, Louise K.; Imada, Shinsuke; Innes, Davina; Kliem,
   Bernhard; Korendyke, Clarence; Mariska, John T.; Martínez-Pillet,
   Valentin; Parenti, Susanna; Patsourakos, Spiros; Peter, Hardi; Poletto,
   Luca; Rutten, Robert J.; Schühle, Udo; Siemer, Martin; Shimizu,
   Toshifumi; Socas-Navarro, Hector; Solanki, Sami K.; Spadaro, Daniele;
   Trujillo-Bueno, Javier; Tsuneta, Saku; Dominguez, Santiago Vargas;
   Vial, Jean-Claude; Walsh, Robert; Warren, Harry P.; Wiegelmann,
   Thomas; Winter, Berend; Young, Peter
2012ExA....34..273T    Altcode: 2011ExA...tmp..135T; 2011arXiv1109.4301T
  The solar outer atmosphere is an extremely dynamic environment
  characterized by the continuous interplay between the plasma and the
  magnetic field that generates and permeates it. Such interactions play a
  fundamental role in hugely diverse astrophysical systems, but occur at
  scales that cannot be studied outside the solar system. Understanding
  this complex system requires concerted, simultaneous solar observations
  from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at
  high spatial resolution (between 0.1” and 0.3”), at high temporal
  resolution (on the order of 10 s, i.e., the time scale of chromospheric
  dynamics), with a wide temperature coverage (0.01 MK to 20 MK,
  from the chromosphere to the flaring corona), and the capability of
  measuring magnetic fields through spectropolarimetry at visible and
  near-infrared wavelengths. Simultaneous spectroscopic measurements
  sampling the entire temperature range are particularly important. These
  requirements are fulfilled by the Japanese Solar-C mission (Plan B),
  composed of a spacecraft in a geosynchronous orbit with a payload
  providing a significant improvement of imaging and spectropolarimetric
  capabilities in the UV, visible, and near-infrared with respect to
  what is available today and foreseen in the near future. The Large
  European Module for solar Ultraviolet Research (LEMUR), described
  in this paper, is a large VUV telescope feeding a scientific payload
  of high-resolution imaging spectrographs and cameras. LEMUR consists
  of two major components: a VUV solar telescope with a 30 cm diameter
  mirror and a focal length of 3.6 m, and a focal-plane package composed
  of VUV spectrometers covering six carefully chosen wavelength ranges
  between 170 Å and 1270 Å. The LEMUR slit covers 280” on the Sun with
  0.14” per pixel sampling. In addition, LEMUR is capable of measuring
  mass flows velocities (line shifts) down to 2 km s<SUP> - 1</SUP> or
  better. LEMUR has been proposed to ESA as the European contribution
  to the Solar C mission.

---------------------------------------------------------
Title: Chromospheric Lyman-alpha spectro-polarimeter (CLASP)
Authors: Kano, Ryouhei; Bando, Takamasa; Narukage, Noriyuki; Ishikawa,
   Ryoko; Tsuneta, Saku; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Hara, Hirohisa; Shimizu, Toshifumi; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Sakao, Taro; Goto, Motoshi; Kato, Yoshiaki; Imada,
   Shinsuke; Kobayashi, Ken; Holloway, Todd; Winebarger, Amy; Cirtain,
   Jonathan; De Pontieu, Bart; Casini, Roberto; Trujillo Bueno, Javier;
   Štepán, Jiří; Manso Sainz, Rafael; Belluzzi, Luca; Asensio Ramos,
   Andres; Auchère, Frédéric; Carlsson, Mats
2012SPIE.8443E..4FK    Altcode:
  One of the biggest challenges in heliophysics is to decipher the
  magnetic structure of the solar chromosphere. The importance of
  measuring the chromospheric magnetic field is due to both the key role
  the chromosphere plays in energizing and structuring the outer solar
  atmosphere and the inability of extrapolation of photospheric fields to
  adequately describe this key boundary region. Over the last few years,
  significant progress has been made in the spectral line formation
  of UV lines as well as the MHD modeling of the solar atmosphere. It
  is found that the Hanle effect in the Lyman-alpha line (121.567 nm)
  is a most promising diagnostic tool for weaker magnetic fields in
  the chromosphere and transition region. Based on this groundbreaking
  research, we propose the Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP) to NASA as a sounding rocket experiment, for making the first
  measurement of the linear polarization produced by scattering processes
  and the Hanle effect in the Lyman-alpha line (121.567 nm), and making
  the first exploration of the magnetic field in the upper chromosphere
  and transition region of the Sun. The CLASP instrument consists
  of a Cassegrain telescope, a rotating 1/2-wave plate, a dual-beam
  spectrograph assembly with a grating working as a beam splitter, and
  an identical pair of reflective polarization analyzers each equipped
  with a CCD camera. We propose to launch CLASP in December 2014.

---------------------------------------------------------
Title: Multi Element Telescope for Imaging and Spectroscopy (METIS)
    coronagraph for the Solar Orbiter mission
Authors: Antonucci, Ester; Fineschi, Silvano; Naletto, Giampiero;
   Romoli, Marco; Spadaro, Daniele; Nicolini, Gianalfredo; Nicolosi,
   Piergiorgio; Abbo, Lucia; Andretta, Vincenzo; Bemporad, Alessandro;
   Auchère, Frédéric; Berlicki, Arkadiusz; Bruno, Roberto; Capobianco,
   Gerardo; Ciaravella, Angela; Crescenzio, Giuseppe; Da Deppo, Vania;
   D'Amicis, Raffaella; Focardi, Mauro; Frassetto, Fabio; Heinzel,
   Peter; Lamy, Philippe L.; Landini, Federico; Massone, Giuseppe;
   Malvezzi, Marco A.; Moses, J. Dan; Pancrazzi, Maurizio; Pelizzo,
   Maria-Guglielmina; Poletto, Luca; Schühle, Udo H.; Solanki, Sami K.;
   Telloni, Daniele; Teriaca, Luca; Uslenghi, Michela
2012SPIE.8443E..09A    Altcode:
  METIS, the “Multi Element Telescope for Imaging and Spectroscopy”,
  is a coronagraph selected by the European Space Agency to be part of
  the payload of the Solar Orbiter mission to be launched in 2017. The
  unique profile of this mission will allow 1) a close approach to the
  Sun (up to 0.28 A.U.) thus leading to a significant improvement in
  spatial resolution; 2) quasi co-rotation with the Sun, resulting in
  observations that nearly freeze for several days the large-scale outer
  corona in the plane of the sky and 3) unprecedented out-of-ecliptic
  view of the solar corona. This paper describes the experiment concept
  and the observational tools required to achieve the science drivers
  of METIS. METIS will be capable of obtaining for the first time: •
  simultaneous imaging of the full corona in polarized visible-light
  (590-650 nm) and narrow-band ultraviolet HI Lyman α (121.6 nm); •
  monochromatic imaging of the full corona in the extreme ultraviolet
  He II Lyman α (30.4 nm); • spectrographic observations of the HI
  and He II Ly α in corona. These measurements will allow a complete
  characterization of the three most important plasma components of
  the corona and the solar wind, that is, electrons, hydrogen, and
  helium. This presentation gives an overview of the METIS imaging and
  spectroscopic observational capabilities to carry out such measurements.

---------------------------------------------------------
Title: The EUI instrument on board the Solar Orbiter mission: from
    breadboard and prototypes to instrument model validation
Authors: Halain, J. -P.; Rochus, P.; Renotte, E.; Appourchaux, T.;
   Berghmans, D.; Harra, L.; Schühle, U.; Schmutz, W.; Auchère, F.;
   Zhukov, A.; Dumesnil, C.; Delmotte, F.; Kennedy, T.; Mercier, R.;
   Pfiffner, D.; Rossi, L.; Tandy, J.; BenMoussa, A.; Smith, P.
2012SPIE.8443E..07H    Altcode:
  The Solar Orbiter mission will explore the connection between the Sun
  and its heliosphere, taking advantage of an orbit approaching the Sun at
  0.28 AU. As part of this mission, the Extreme Ultraviolet Imager (EUI)
  will provide full-sun and high-resolution image sequences of the solar
  atmosphere at selected spectral emission lines in the extreme and vacuum
  ultraviolet. To achieve the required scientific performances under the
  challenging constraints of the Solar Orbiter mission it was required
  to further develop existing technologies. As part of this development,
  and of its maturation of technology readiness, a set of breadboard and
  prototypes of critical subsystems have thus been realized to improve
  the overall instrument design. The EUI instrument architecture, its
  major components and sub-systems are described with their driving
  constraints and the expected performances based on the breadboard and
  prototype results. The instrument verification and qualification plan
  will also be discussed. We present the thermal and mechanical model
  validation, the instrument test campaign with the structural-thermal
  model (STM), followed by the other instrument models in advance of
  the flight instrument manufacturing and AIT campaign.

---------------------------------------------------------
Title: On the Thermal diagnostics of Coronal Loops with SDO/AIA
Authors: Guennou, Chloe; Parenti, Susanna; Bocchialini, Karine;
   Soubrie, Elie; Auchere, Frederic; Barbey, Nicolas
2012cosp...39..675G    Altcode: 2012cosp.meet..675G
  With simultaneous observations in 6 coronal bands, AIA has the
  capability to provide spectral diagnostics over an extended field of
  view at high resolution and high cadence. Therefore, DEM diagnostics of
  coronal loops can in principle be performed routinely for statistical
  studies. We investigate here the pertinence of the DEM analysis with
  AIA. The inevitable presence of noises and uncertainties, incompleteness
  of the atomic physics databases lead to notable difficulties in the
  inversion process. The complications involved in the derivation of
  the DEM are one of the reasons of the controversial results regarding
  the thermal structure and thus the heating scenario of the coronal
  loops. The purpose of this work, based on a probabilistic approach, is
  precisely to investigate the properties of the solutions, providing a
  quantification of the DEM inversion problem robustness. The technique
  relies on Monte Carlo simulations of observed intensities in the six
  AIA coronal bands. The comparison between the known inputs and the
  inversion results allows us to determine the degree of robustness. This
  approach provides all the solutions consistent with the data along with
  their associated probabilities, as well as a test of the validity of
  the assumptions made on the DEM shape. Applications to SDO/AIA coronal
  loops data are presented.

---------------------------------------------------------
Title: Tomographic reconstruction of polar plumes
Authors: Auchère, F.; Guennou, C.; Barbey, N.
2012EAS....55..207A    Altcode:
  We present a tomographic reconstruction of polar plumes as observed in
  the Extreme Ultraviolet in January 2010. Plumes are elusive structures
  visible in polar coronal holes that may play an important role in the
  acceleration of the solar wind. However, despite numerous observations,
  little is irrefutably known about them. Because of line of sight
  effects, even their geometry is subject to debate. Are they genuine
  cylindrical features of the corona or are they only chance alignments
  along the line of sight? Tomography provides a means to reconstruct
  the volume of an optically thin object from a set of observations
  taken from different vantage points. In the case of the Sun, these are
  typically obtained by using a solar rotation worth of images, which
  limits the ability to reconstruct short lived structures. We present
  here a tomographic inversion of the solar corona obtained using only
  6 days of data. This is achieved by using simultaneously three space
  telescopes (EUVI/STEREO and SWAP/PROBA2) in a very specific orbital
  configuration. The result is the shortest possible tomographic snapshot
  of polar plumes. The 3D reconstruction shows both quasi-cylindrical
  plumes and a network pattern that can mimic them by line of sight
  superimpositions. This suggests that the controversy on plume geometry
  is due to the coexistence of both types of structures.

---------------------------------------------------------
Title: Solar magnetism eXplorer (SolmeX). Exploring the magnetic
    field in the upper atmosphere of our closest star
Authors: Peter, Hardi; Abbo, L.; Andretta, V.; Auchère, F.; Bemporad,
   A.; Berrilli, F.; Bommier, V.; Braukhane, A.; Casini, R.; Curdt,
   W.; Davila, J.; Dittus, H.; Fineschi, S.; Fludra, A.; Gandorfer, A.;
   Griffin, D.; Inhester, B.; Lagg, A.; Landi Degl'Innocenti, E.; Maiwald,
   V.; Sainz, R. Manso; Martínez Pillet, V; Matthews, S.; Moses, D.;
   Parenti, S.; Pietarila, A.; Quantius, D.; Raouafi, N. -E.; Raymond, J.;
   Rochus, P.; Romberg, O.; Schlotterer, M.; Schühle, U.; Solanki, S.;
   Spadaro, D.; Teriaca, L.; Tomczyk, S.; Trujillo Bueno, J.; Vial, J. -C.
2012ExA....33..271P    Altcode: 2011arXiv1108.5304P; 2011ExA...tmp..134P
  The magnetic field plays a pivotal role in many fields of
  Astrophysics. This is especially true for the physics of the solar
  atmosphere. Measuring the magnetic field in the upper solar atmosphere
  is crucial to understand the nature of the underlying physical
  processes that drive the violent dynamics of the solar corona—that
  can also affect life on Earth. SolmeX, a fully equipped solar space
  observatory for remote-sensing observations, will provide the first
  comprehensive measurements of the strength and direction of the
  magnetic field in the upper solar atmosphere. The mission consists
  of two spacecraft, one carrying the instruments, and another one in
  formation flight at a distance of about 200 m carrying the occulter to
  provide an artificial total solar eclipse. This will ensure high-quality
  coronagraphic observations above the solar limb. SolmeX integrates two
  spectro-polarimetric coronagraphs for off-limb observations, one in
  the EUV and one in the IR, and three instruments for observations on
  the disk. The latter comprises one imaging polarimeter in the EUV for
  coronal studies, a spectro-polarimeter in the EUV to investigate the low
  corona, and an imaging spectro-polarimeter in the UV for chromospheric
  studies. SOHO and other existing missions have investigated the emission
  of the upper atmosphere in detail (not considering polarization),
  and as this will be the case also for missions planned for the near
  future. Therefore it is timely that SolmeX provides the final piece of
  the observational quest by measuring the magnetic field in the upper
  atmosphere through polarimetric observations.

---------------------------------------------------------
Title: Earth-Affecting Solar Causes Observatory (EASCO): a mission
    at the Sun-Earth L5
Authors: Gopalswamy, Nat; Davila, Joseph M.; Auchère, Frédéric;
   Schou, Jesper; Korendyke, Clarence M.; Shih, Albert; Johnston, Janet
   C.; MacDowall, Robert J.; Maksimovic, Milan; Sittler, Edward; Szabo,
   Adam; Wesenberg, Richard; Vennerstrom, Suzanne; Heber, Bernd
2011SPIE.8148E..0ZG    Altcode: 2011SPIE.8148E..30G; 2011arXiv1109.2929G
  Coronal mass ejections (CMEs) and corotating interaction regions
  (CIRs) as well as their source regions are important because of
  their space weather consequences. The current understanding of CMEs
  primarily comes from the Solar and Heliospheric Observatory (SOHO)
  and the Solar Terrestrial Relations Observatory (STEREO) missions,
  but these missions lacked some key measurements: STEREO did not have a
  magnetograph; SOHO did not have in-situ magnetometer. SOHO and other
  imagers such as the Solar Mass Ejection Imager (SMEI) located on the
  Sun-Earth line are also not well-suited to measure Earth-directed
  CMEs. The Earth-Affecting Solar Causes Observatory (EASCO) is a
  proposed mission to be located at the Sun-Earth L5 that overcomes
  these deficiencies. The mission concept was recently studied at the
  Mission Design Laboratory (MDL), NASA Goddard Space Flight Center,
  to see how the mission can be implemented. The study found that the
  scientific payload (seven remote-sensing and three in-situ instruments)
  can be readily accommodated and can be launched using an intermediate
  size vehicle; a hybrid propulsion system consisting of a Xenon ion
  thruster and hydrazine has been found to be adequate to place the
  payload at L5. Following a 2-year transfer time, a 4-year operation
  is considered around the next solar maximum in 2025.

---------------------------------------------------------
Title: The coronal suprathermal particle explorer (C-SPEX)
Authors: Moses, J. Daniel; Brown, Charles; Doschek, George; Ko,
   Yuan-Kuen; Korendyke, Clarence; Laming, J. Martin; Socker, Dennis;
   Tylka, Allen; McMullin, Donald; Ng, Chee; Wassom, Steven; Lee, Martin;
   Auchère, Frédéric; Fineschi, Silvano; Carter, Tim
2011SPIE.8148E..0JM    Altcode: 2011SPIE.8148E..18M
  The primary science objective of the Coronal Suprathermal Particle
  Explorer (C-SPEX) is to investigate the spatial and temporal
  variations of coronal suprathermal particle populations that are
  seeds for acceleration to solar energetic particles (SEPs). It is
  understood that such seed particle populations vary with coronal
  structures and can change responding to solar flare and coronal mass
  ejection (CME) events. Models have shown that higher densities of
  suprathermal protons can result in higher rates of acceleration to
  high energies. Understanding the variations in the suprathermal seed
  particle population is thus crucial for understanding the variations
  in SEPs. However, direct measurements are still lacking. C-SPEX
  will measure the variation in the suprathermal protons across
  various coronal magnetic structures, before/after the passage of CME
  shocks, in the post-CME current sheets, and before/after major solar
  flares. Understanding the causes for variation in the suprathermal
  seed particle population and its effect on the variation in SEPs
  will also help build the predictive capability of SEPs that reach
  Earth. The CSPEX measurements will be obtained from instrumentation
  on the International Space Station (ISS) employing well-established
  UV coronal spectroscopy techniques.

---------------------------------------------------------
Title: Development of multilayer thin film filters for the full-sun
    imager on Solar Orbiter
Authors: Auchère, Frédéric; Zhang, Xueyan; Delmotte, Franck;
   Meltchakov, Evgueni; BenMoussa, Ali
2011SPIE.8148E..0NA    Altcode: 2011SPIE.8148E..21A
  Membranes a few hundred nanometers thick are used in EUV optics to
  make, for example, beams splitters or passband filters. Despite their
  necessity in numerous applications these components are, because of
  their thinness, extremely fragile and their implementation in space
  instruments is always difficult. The authors are developing thin film
  filters for the Full Sun Imager, one of the EUV telescopes on board
  the Solar Orbiter mission with objectives of high optical efficiency
  and mechanical strength. These filters are specifically designed
  to isolate one or the other of the two passbands (17.4 and 30.4 nm)
  reflected by the telescope's dual band mirror coating. In this paper
  we present the optical properties of the prototype components.

---------------------------------------------------------
Title: Morphology, dynamics and plasma parameters of plumes and
    inter-plume regions in solar coronal holes
Authors: Wilhelm, K.; Abbo, L.; Auchère, F.; Barbey, N.; Feng, L.;
   Gabriel, A. H.; Giordano, S.; Imada, S.; Llebaria, A.; Matthaeus,
   W. H.; Poletto, G.; Raouafi, N. -E.; Suess, S. T.; Teriaca, L.; Wang,
   Y. -M.
2011A&ARv..19...35W    Altcode: 2011arXiv1103.4481W
  Coronal plumes, which extend from solar coronal holes (CH) into the high
  corona and—possibly—into the solar wind (SW), can now continuously
  be studied with modern telescopes and spectrometers on spacecraft,
  in addition to investigations from the ground, in particular, during
  total eclipses. Despite the large amount of data available on these
  prominent features and related phenomena, many questions remained
  unanswered as to their generation and relative contributions to
  the high-speed streams emanating from CHs. An understanding of the
  processes of plume formation and evolution requires a better knowledge
  of the physical conditions at the base of CHs, in plumes and in the
  surrounding inter-plume regions. More specifically, information is
  needed on the magnetic field configuration, the electron densities
  and temperatures, effective ion temperatures, non-thermal motions,
  plume cross sections relative to the size of a CH, the plasma bulk
  speeds, as well as any plume signatures in the SW. In spring 2007, the
  authors proposed a study on `Structure and dynamics of coronal plumes
  and inter-plume regions in solar coronal holes' to the International
  Space Science Institute (ISSI) in Bern to clarify some of these aspects
  by considering relevant observations and the extensive literature. This
  review summarizes the results and conclusions of the study. Stereoscopic
  observations allowed us to include three-dimensional reconstructions
  of plumes. Multi-instrument investigations carried out during several
  campaigns led to progress in some areas, such as plasma densities,
  temperatures, plume structure and the relation to other solar phenomena,
  but not all questions could be answered concerning the details of
  plume generation process(es) and interaction with the SW.

---------------------------------------------------------
Title: AIA Observations of Sunspot Waves
Authors: Leibacher, John W.; Soubrié, E.; Auchère, F.; Baudin, F.
2011SPD....42.2115L    Altcode: 2011BAAS..43S.2115L
  Waves in the low solar atmosphere above sunspots i) present an
  interesting phenomenon in their own right, ii) are potentially a probe
  of magnetic structures (e.g. "plumes") in the sunspot atmosphere and a
  source of excitation of higher, coronal loop waves, and iii) are coupled
  to umbral flashes and sub-surface, helioseismic waves in a manner that
  is not fully understood. We present an analysis of AIA observations
  of waves in AR 11092, showing their propagation, temporal coherence,
  and angular symmetry; characterizing them in terms of frequency,
  amplitude, and propagation speed.

---------------------------------------------------------
Title: The Coronal Suprathermal Particle Explorer (C-SPEX)
Authors: Moses, John Daniel; Brown, C. M.; Doschek, G. A.; -. Ko,
   Y.; Korendyke, C. M.; Laming, J. M.; Rakowski, C. E.; Socker, D. G.;
   Tylka, A.; Ng, C. K.; Wassom, S. R.; McMullin, D. R.; Lee, M. A.;
   Auchere, F.; Fineschi, S.
2011SPD....42.1519M    Altcode: 2011BAAS..43S.1519M
  The primary science objective of the Coronal Suprathermal Particle
  Explorer (C-SPEX) is to investigate the spatial and temporal
  variations of coronal suprathermal particle populations that are
  seeds for acceleration to solar energetic particles (SEPs). It is
  understood that such seed particle populations vary with coronal
  structures and can change responding to solar flare and coronal mass
  ejection (CME) events. Models have shown that higher densities of
  suprathermal protons can result in higher rates of acceleration to
  high energies. Understanding the variations in the suprathermal seed
  particle population is thus crucial for understanding the variations
  in SEPs. However, direct measurements are still lacking. <P />C-SPEX
  will measure the variation in the suprathermal protons across various
  coronal magnetic structures, before/after the passage of CME shocks, in
  the post-CME current sheets, and before/after major solar flares. The
  measurements will not only constrain models of SEP acceleration but
  also constrain models of the production of suprathermal particles from
  processes such as magnetic reconnection at the Sun. Understanding the
  causes for variation in the suprathermal seed particle population and
  its effect on the variation in SEPs will also help build the predictive
  capability of SEPs that reach Earth. <P />The C-SPEX measurements will
  be obtained from instrumentation on the International Space Station
  (ISS) employing well-established UV coronal spectroscopy techniques. The
  unique aspect of C-SPEX is a &gt;100-fold increase of light gathering
  power over any previous UV coronal spectrometer. It is demonstrated
  C-SPEX will thus overcome the limitations in signal to noise that have
  thwarted prior attempts to observe suprathermals in the corona. <P />The
  present lack of a means to predict the variability of SEP intensities
  and the likelihood C-SPEX will help develop such predictions makes the
  proposed investigation directly relevant to each of the three strategic
  objectives of the NASA Heliophysics Research Strategic Objectives.

---------------------------------------------------------
Title: TomograPy: A Fast, Instrument-Independent, Solar Tomography
    Software
Authors: Barbey, Nicolas; Guennou, Chloé; Auchère, Frédéric
2011ascl.soft04001B    Altcode:
  TomograPy is an open-source software freely available on the Python
  Package Index that can perform fast tomographic inversions that scale
  linearly with the number of measurements, linearly with the length of
  the reconstruction cube (and not the number of voxels) and linearly
  with the number of cores and can use data from different sources
  and with a variety of physical models. For performance, TomograPy
  uses a parallelized-projection algorithm. It relies on the World
  Coordinate System standard to manage various data sources. A variety
  of inversion algorithms are provided to perform the tomographic-map
  estimation. A test suite is provided along with the code to ensure
  software quality. Since it makes use of the Siddon algorithm it is
  restricted to rectangular parallelepiped voxels but the spherical
  geometry of the corona can be handled through proper use of priors.

---------------------------------------------------------
Title: Earth-Affecting Solar Causes Observatory (EASCO): A potential
    International Living with a Star Mission from Sun-Earth L5
Authors: Gopalswamy, N.; Davila, J. M.; St. Cyr, O. C.; Sittler,
   E. C.; Auchère, F.; Duvall, T. L.; Hoeksema, J. T.; Maksimovic, M.;
   MacDowall, R. J.; Szabo, A.; Collier, M. R.
2011JASTP..73..658G    Altcode:
  This paper describes the scientific rationale for an L5 mission
  and a partial list of key scientific instruments the mission should
  carry. The L5 vantage point provides an unprecedented view of the
  solar disturbances and their solar sources that can greatly advance
  the science behind space weather. A coronagraph and a heliospheric
  imager at L5 will be able to view CMEs broadsided, so space speed
  of the Earth-directed CMEs can be measured accurately and their
  radial structure discerned. In addition, an inner coronal imager
  and a magnetograph from L5 can give advance information on active
  regions and coronal holes that will soon rotate on to the solar
  disk. Radio remote sensing at low frequencies can provide information
  on shock-driving CMEs, the most dangerous of all CMEs. Coordinated
  helioseismic measurements from the Sun-Earth line and L5 provide
  information on the physical conditions at the base of the convection
  zone, where solar magnetism originates. Finally, in situ measurements
  at L5 can provide information on the large-scale solar wind structures
  (corotating interaction regions (CIRs)) heading towards Earth that
  potentially result in adverse space weather.

---------------------------------------------------------
Title: Initiation and Early Development of the 2008 April 26 Coronal
    Mass Ejection
Authors: Huang, J.; Démoulin, P.; Pick, M.; Auchère, F.; Yan, Y. H.;
   Bouteille, A.
2011ApJ...729..107H    Altcode:
  We present a detailed study of a coronal mass ejection (CME) with
  high temporal cadence observations in radio and extreme-ultraviolet
  (EUV). The radio observations combine imaging of the low corona with
  radio spectra in the outer corona and interplanetary space. The EUV
  observations combine the three points of view of the STEREO and SOHO
  spacecraft. The beginning of the CME initiation phase is characterized
  by emissions that are signatures of the reconnection of the outer part
  of the erupting configuration with surrounding magnetic fields. Later
  on, a main source of emission is located in the core of the active
  region. It is an indirect signature of the magnetic reconnection
  occurring behind the erupting flux rope. Energetic particles are also
  injected in the flux rope and the corresponding radio sources are
  detected. Other radio sources, located in front of the EUV bright
  front, trace the interaction of the flux rope with the surrounding
  fields. Hence, the observed radio sources enable us to detect the main
  physical steps of the CME launch. We find that imaging radio emissions
  in the metric range permits us to trace the extent and orientation of
  the flux rope which is later detected in interplanetary space. Moreover,
  combining the radio images at various frequencies with fast EUV imaging
  permits us to characterize in space and time the processes involved
  in the CME launch.

---------------------------------------------------------
Title: Minimization of the shadow patterns produced by periodic mesh
    grids in extreme ultraviolet telescopes
Authors: Auchère, Frédéric; Rizzi, Julien; Philippon, Anne;
   Rochus, Pierre
2011JOSAA..28...40A    Altcode:
  Thin metallic films are used as passband filters in space telescopes
  operating in the extreme ultraviolet (EUV). Because of their thinness,
  typically 100 to 200nm, they are very sensitive to static pressure
  differentials and to mechanic and acoustic vibrations. Therefore,
  they are difficult to manage in all phases of a space program, from
  manufacturing to vacuum testing to launch. A common solution to this
  problem is to reinforce them with fine mesh grids with pitches ranging
  from a few hundred micrometers to a few millimeters. Depending on their
  location in the optical path, the main effect of these periodic grids
  is either to diffract light or to cast penumbral shadows on the focal
  plane. In this paper, we analyze the formation of the shadow modulation
  patterns and derive design rules to minimize their amplitude. The
  minimization principle is illustrated by an application to a solar
  EUV telescope.

---------------------------------------------------------
Title: Center-to-Limb Variation in the Solar HeII 30.4 nm Emission
    Line from STEREO EUVI
Authors: Floyd, L. E.; McMullin, D. R.; Auchere, F.
2010AGUFMSH31C1803F    Altcode:
  The variation of radiant energy that emerges from the each portion of
  the solar surface depends on the temperature and density structure
  of the solar atmosphere in those emitting regions. For wavelengths
  where the opacity is sufficiently large, some of the emissions are
  blocked by overlying plasma. HeII 30.4 nm (optically thick) solar
  emissions fall into this category. Accordingly, the center-to-limb
  (C2L) brightness variation across the solar disk will differ from that
  of optically thin emissions. Knowledge of the C2L variation provides
  important constraints on solar radiative transfer models in the lower
  transition region where these emissions are formed. Images from the
  EUVI instruments aboard the two STEREO spacecraft for the first time
  provide direct measurements of the C2L variation, especially in the
  channel centered on the strong HeII 30.4 nm emission. In general,
  comparisons of simultaneous images taken from different viewing angles
  in the ecliptic plane where the same regions of the Sun are measured
  provide the basis for C2L estimates. After 4 years of the STEREO
  mission, the increasing satellite separation provides the baseline
  dataset for sampling at nearly all angles. Simultaneous images are
  corrected for instrumental responsivity degradation and converted to
  purely HeII 30.4 nm radiation using a DEM model (ref needed). The C2L is
  expressed as parameterized models whose specific values are determined
  via iteration with the initial estimate based on pre-DEM images. Solar
  surface region types are segregated into different parameter sets by
  the implied intensity at disk center. Validation of the responsivity
  model is provided by measurements along the meridian halfway between
  the two satellites and through intercomparisons with simultaneous
  images from similar EIT instrument aboard SOHO. Validation of the
  model and approach are provided through similar calculations obtained
  for optically thin coronal lines such as FeXV.

---------------------------------------------------------
Title: The technical challenges of the Solar-Orbiter EUI instrument
Authors: Halain, Jean-Philippe; Rochus, Pierre; Appourchaux, Thierry;
   Berghmans, David; Harra, Louise; Schühle, Udo; Auchère, Frédéric;
   Zhukov, Andrei; Renotte, Etienne; Defise, Jean-Marc; Rossi, Laurence;
   Fleury-Frenette, Karl; Jacques, Lionel; Hochedez, Jean-François;
   Ben Moussa, Ali
2010SPIE.7732E..0RH    Altcode: 2010SPIE.7732E..20H
  The Extreme Ultraviolet Imager (EUI) onboard Solar Orbiter consists of
  a suite of two high-resolution imagers (HRI) and one dual-band full
  Sun imager (FSI) that will provide EUV and Lyman-α images of the
  solar atmospheric layers above the photosphere. The EUI instrument is
  based on a set of challenging new technologies allowing to reach the
  scientific objectives and to cope with the hard space environment of
  the Solar Orbiter mission. The mechanical concept of the EUI instrument
  is based on a common structure supporting the HRI and FSI channels,
  and a separated electronic box. A heat rejection baffle system is
  used to reduce the Sun heat load and provide a first protection level
  against the solar disk straylight. The spectral bands are selected by
  thin filters and multilayer mirror coatings. The detectors are 10μm
  pitch back illuminated CMOS Active Pixel Sensors (APS), best suited
  for the EUI science requirements and radiation hardness. This paper
  presents the EUI instrument concept and its major sub-systems. The
  current developments of the instrument technologies are also summarized.

---------------------------------------------------------
Title: Definition of an imaging spectrometer meeting the needs of
    UV solar physics
Authors: Ruiz de Galarreta Fanjul, C.; Philippon, A.; Vial, J. -C.;
   Lemaire, P.; Maillard, J. -P.; Buisset, C.; Appourchaux, T.;
   Auchère, F.
2010SPIE.7732E..36R    Altcode: 2010SPIE.7732E..99R
  The study of the outer solar atmosphere requires combining imaging
  and spectroscopy in the UV lines formed in the high chromosphere,
  the transition region and the corona. We start from the science
  requirements and we define the instrumental specifications in terms
  of field-of-view (FOV), spatial, temporal and spectral resolution and
  bandpass. We propose two different all-reflection optical architectures
  based on interferometric techniques: Spatial Heterodyne Spectroscopy
  (SHS); and Imaging Transform Spectrometer (IFTS). We describe the
  different set-ups and compare the potential performances of the two
  types of solutions, and discuss their feasibility. We conclude that
  IFTS appears to be the best solution, meeting the needs of UV solar
  physics. However, we point out the many difficulties to be encountered,
  especially as far as metrology is concerned.

---------------------------------------------------------
Title: HERSCHEL Sounding Rocket Mission Observations of the Helium
    Corona
Authors: Newmark, Jeffrey; Moses, J.; Antonucci, E.; Fineschi, S.;
   Abbo, L.; Telloni, D.; Auchere, F.; Barbey, N.; Romoli, M.
2010AAS...21640721N    Altcode:
  The HERSCHEL (Helium Resonant Scattering in the Corona and Heliosphere)
  investigation successfully obtained unprecedented images of the helium
  and hydrogen components of the solar corona out to 3 solar radii
  during a suborbital flight on 14 September 2009. Preliminary analysis
  of these observations indicates the spatial distribution of the helium
  abundance and outflow velocity provides powerful diagnostics for the
  source and dynamics of the slow solar wind during the time of solar
  minimum activity. An analysis of co-temporal STEREO EUVI data to derive
  the temperature of low coronal structures associated with the regions
  of enhanced helium abundance observed by HERSCHEL provides evidence the
  relative first ionization potential (FIP) of helium and hydrogen may
  play an important role in the observed abundance distribution. <P />NRL
  was supported by the Office of Naval Research and NASA under NDPRS6598G.

---------------------------------------------------------
Title: Hanle signatures of the coronal magnetic field in the linear
    polarization of the hydrogen Lα line
Authors: Derouich, M.; Auchère, F.; Vial, J. C.; Zhang, M.
2010A&A...511A...7D    Altcode: 2009arXiv0912.5068D
  <BR /> Aims: This paper is dedicated to the assessment of the validity
  of future coronal spectro-polarimetric observations and to prepare their
  interpretation in terms of the magnetic field vector. <BR /> Methods:
  We assume that the polarization of the hydrogen coronal Lα line is
  due to anisotropic scattering of an incident chromospheric radiation
  field. The anisotropy is due to geometrical effects but also to the
  inhomogeneities of the chromospheric regions which we model by using
  Carrington maps of the Lα. Because the corona is optically thin, we
  fully consider the effects of the integration over the line-of-sight
  (LOS). As a modeling case, we include a dipolar magnetic topology
  perturbed by a non-dipolar magnetic structure arising from a prominence
  current sheet in the corona. The spatial variation of the hydrogen
  density and the temperature is taken into account. We determine the
  incident radiation field developed on the tensorial basis at each
  point along the LOS. Then, we calculate the local emissivity vector
  to obtain integrated Stokes parameters with and without coronal
  magnetic field. <BR /> Results: We show that the Hanle effect is an
  interesting technique for interpreting the scattering polarization of
  the Lαλ1216 line in order to diagnose the coronal magnetic field. The
  difference between the calculated polarization and the zero magnetic
  field polarization gives us an estimation of the needed polarimetric
  sensitivity in future polarization observations. We also obtain
  useful indications about the optimal observational strategy. <BR />
  Conclusions: Quantitative interpretation of the Hanle effect on the
  scattering linear polarization of Lα line can be a crucial source
  of information about the coronal magnetic field at a height over the
  limb h &lt; 0.7 R<SUB>⊙</SUB>. Therefore, one needs the development
  of spatial instrumentation to observe this line. <P />Present address:
  Colorado Research Associates Division, NorthWest Research Associates,
  Inc., 3380 Mitchell Ln., Boulder, CO 80301, USA.

---------------------------------------------------------
Title: The SDO data centre at IDOC/MEDOC in France
Authors: Parenti, Susanna; Bocchialini, Karine; Soubrie, Elie;
   Auchere, Frederic; Ballans, Herv; Buchlin, Eric; Gabriel, Alan;
   Mercier, Claude; Poulleau, Gilles; Vial, Jean-Claude
2010cosp...38.2888P    Altcode: 2010cosp.meet.2888P
  The IDOC/MEDOC centre at the Institut d'Astrophysique Spatiale (IAS,
  Université Paris 11/CNRS) has a long experience in solar data archiving
  and distribution, including almost 15 years of data from SOHO, STEREO
  and TRACE. The center is now expanding its activity and becoming a
  Pˆle Thématique Solaire of the CNES and INSU/CNRS. Part of the new
  activities of the centre will be linked to the arrival of the enormous
  volume of the new SDO data. The center will be one of the three European
  centers to receive and redistribute the data to the community. It will
  also be the only European site to permanently store about 10% of the
  data (mainly from AIA). In continuity with its previous activities,
  SDO data will be included in the data visualization tool FESTIVAL
  and it will provide new services, like tools for the solar feature
  identification (filaments, EUV intensity fluctuations). We will present
  an overview of the facilities and activities of the centre in relation
  to the SDO data.

---------------------------------------------------------
Title: On the observations and possible interpretations of very long
    period intensity oscillations of solar coronal loops
Authors: Solomon, Jacques; Auchere, Frederic; Bocchialini, Karine;
   Gabriel, Alan; Tison, Emmanuelle
2010cosp...38.2853S    Altcode: 2010cosp.meet.2853S
  A comprehensive analysis of intensity oscillations in the Fe XII
  line (19.5 nm) observed with EIT/SoHO in solar coronal loops during
  solar cycle 23 (january 1997-september 2008) was performed. About
  450 occurences of oscillations were obtained with periods ranging
  between 3.4 and 13.6 hours and with durations up to about a
  hundred hours. Interpratations in term of slow waves or of thermal
  nonequilibrium were examined. However numerous inconsistencies arise
  between current theories (in fact mostly expressed in terms of various
  numerical simulations) and observations. Presently the lack of a direct
  link between those very long oscillation periods and the characteristic
  physical parameters of the loops (density, temperature, loop geometry)
  hampers making progress in this major issue. This situation requires
  an effort in a specific time analysis of the classical system of
  equations of the problem: the question is examined from different
  angles in relation to the data.

---------------------------------------------------------
Title: Large-scale Extreme-Ultraviolet Disturbances Associated with
    a Limb Coronal Mass Ejection
Authors: Dai, Y.; Auchère, F.; Vial, J. -C.; Tang, Y. H.; Zong, W. G.
2010ApJ...708..913D    Altcode:
  We present composite observations of a coronal mass ejection (CME)
  and the associated large-scale extreme-ultraviolet (EUV) disturbances
  on 2007 December 31 by the Extreme-ultraviolet Imager (EUVI) and COR1
  coronagraph on board the recent Solar Terrestrial Relations Observatory
  mission. For this limb event, the EUV disturbances exhibit some typical
  characteristics of EUV Imaging Telescope waves: (1) in the 195 Å
  bandpass, diffuse brightenings are observed propagating oppositely
  away from the flare site with a velocity of ~260 km s<SUP>-1</SUP>,
  leaving dimmings behind; (2) when the brightenings encounter the
  boundary of a polar coronal hole, they stop there to form a stationary
  front. Multi-temperature analysis of the propagating EUV disturbances
  favors a heating process over a density enhancement in the disturbance
  region. Furthermore, the EUVI-COR1 composite display shows unambiguously
  that the propagation of the diffuse brightenings coincides with a
  large lateral expansion of the CME, which consequently results in a
  double-loop-structured CME leading edge. Based on these observational
  facts, we suggest that the wave-like EUV disturbances are a result of
  magnetic reconfiguration related to the CME liftoff rather than true
  waves in the corona. Reconnections between the expanding CME magnetic
  field lines and surrounding quiet-Sun magnetic loops account for the
  propagating diffuse brightenings; dimmings appear behind them as a
  consequence of volume expansion. X-ray and radio data provide us with
  complementary evidence.

---------------------------------------------------------
Title: Modeling and forecasting the 3D solar EUV flux
Authors: Auchere, Frederic; McMullin, Donald
2010cosp...38.1097A    Altcode: 2010cosp.meet.1097A
  The UV/EUV solar flux drives many physical processes in the
  heliosphere. One of its most important effects are the complex
  photochemistry reactions produced in the Planet's atmospheres. It is
  thus a key parameter in space weather, and there is today a clear
  need for reliable modeling and forecasting of the UV/EUV flux. The
  STEREO mission offers un unprecedented opportunity to improve and
  validate irradiance models and the associated pre-dictions. Indeed,
  the separation angle of the two probes allow or a better coverage of
  the solar surface, and the B probe monitors the upcoming hemisphere of
  the Sun a few days before it is visible from Earth. The authors have
  developped an empirical model of the three-dimensional EUV solar flux
  based on EIT/SOHO data. Taking into account the flux anisotropies,
  it can be used to compute and predict the irradiance at any position
  in the heliosphere. We present in this paper the generalization of
  this model to EUVI/STEREO data, and present the improved forecasting
  performances compared to those of the previous version.

---------------------------------------------------------
Title: Automatic detection and statistical analysis of intensity
    oscillations in the solar corona with SDO
Authors: Auchere, Frederic; Bocchialini, Karine; Solomon, Jacques;
   Gabriel, Alan; Tison, Emmanuelle
2010cosp...38.2863A    Altcode: 2010cosp.meet.2863A
  We present the generalization to SDO data of our automatic oscillation
  detection algorithm. This technique was successfully tested using EIT
  data on board SOHO at 19.5 nm from January 1997 to September 2008,
  i.e almost the entire solar cycle 23. In the EIT data set we detected
  400 oscillations whose periods range between 3.4 and 13.6 h with a
  maximum around 6-7 hours. Most of the oscillations are localized in
  coronal structures associated with active regions and last several
  tens of hours. The AIA data will allow the detection of similar events
  in several coronal temperature bands simultaneously, which will help
  understand their physical nature.

---------------------------------------------------------
Title: Polarimetry of the Lα Line for Coronal Magnetic Field
    Diagnostic
Authors: Derouich, M.; Auchère, F.; Vial, J. C.; Millard, A. A.
2009ASPC..405..389D    Altcode:
  Measurement and physical interpretation of the scattering polarization
  of the Extreme-ultraviolet (EUV) and Far-UV (FUV) spectral lines
  provide a largely unexplored diagnostic of coronal magnetic field. In
  this context, we present the LYOT (LYman Orbiting Telescope) project
  that makes it possible to observe the Lα λ1216 line polarization
  in the solar corona. Because the corona is optically thin, it
  is necessary to consider the effects of the integration over the
  line-of-sight (LOS). The LOS effects have been usually addressed for
  non polarimetric studies where the unknown is a scalar quantity (the
  intensity) but not a Stokes vector. Previous studies investigating the
  coronal polarization are generally concerned with a local position of
  the scattering center and a deterministic magnetic field (see Raouafi
  et al.~2002 for a measurement and interpretation of the O VI λ 1032
  line polarization). Here, we perform computations that test whether
  a LOS integrated Hanle effect can be detected in order to access to
  the magnetic field topology.

---------------------------------------------------------
Title: Coronal and Interplanetary Structures Associated with Type
    III Bursts
Authors: Pick, M.; Kerdraon, A.; Auchère, F.; Stenborg, G.; Bouteille,
   A.; Soubrié, E.
2009SoPh..256..101P    Altcode:
  This paper pursues former studies of the coronal structures that
  are associated with radio type III bursts by taking advantage of
  the new capabilities of STEREO/SECCHI. The data analysis has been
  performed for 02 and 03 June 2007. During these two days several
  type III bursts, which were detected in the corona and in the
  interplanetary medium, occurred during the observing time of the
  Nançay radioheliograph. Electron beams accelerated in the same active
  region and producing type III emissions almost at the same time,
  can propagate in different well defined coronal structures below 15
  R<SUB>⊙</SUB>. Then, these structures become imbedded in the same
  plasma sheet which can be tracked up to 0.25 AU. Inhomogeneities travel
  along these structures; their velocities measured between 15 and 35
  R<SUB>⊙</SUB> are typical of those of a slow solar wind. Comparison
  with PFSS magnetic field extrapolation shows that its connection
  with the IP magnetic field is different from what is suggested by the
  present observations.

---------------------------------------------------------
Title: Design and performance of two-channel EUV multilayer mirrors
    with enhanced spectral selectivity
Authors: Hecquet, Christophe; Delmotte, Franck; Ravet-Krill,
   Marie-Françoise; de Rossi, Sébastien; Jérome, Arnaud; Bridou,
   Françoise; Varnière, Françoise; Meltchakov, Evgueni; Auchère,
   Frédéric; Giglia, Angelo; Mahne, Nicola; Nanaronne, Stefano
2009ApPhA..95..401H    Altcode: 2009ApPhA.tmp...37H
  In this paper, we present a study on two-channel multilayer mirrors
  which can operate at two wavelengths in Extreme Ultraviolet (EUV)
  spectral range. We propose a new method to design two-channel EUV
  multilayer mirrors with enhanced spectral selectivity. The mirror
  structure is a stack of two periodic multilayers separated by a buffer
  layer. We have defined the main parameters which allow adjustment of
  the distance between different order Bragg’s peak and of wavelength
  positions of reflectivity minima. Two mirrors have been designed and
  deposited for solar EUV telescope applications by using this method. The
  first mirror reflects Fe IX-X line (17.1 nm) and Fe XVI (33.5 nm) lines
  with attenuation of the He II line (30.4 nm). The second mirror reflects
  Fe IX-X and He II lines with attenuation of Fe XV (28.4 nm) and Fe XVI
  lines. Measurements with synchrotron radiation source confirm that,
  in both cases, for these mirrors, we are able to adjust reflectivity
  maxima (Bragg peak position) and minima. Such multilayers offer new
  possibilities for compact design of multi-wavelength EUV telescopes
  and/or for high spectral selectivity.

---------------------------------------------------------
Title: Stellar and galactic environment survey (SAGE)
Authors: Barstow, M. A.; Burleigh, M. R.; Bannister, N. J.; Lapington,
   J. S.; Kowalski, M. P.; Cruddace, R. G.; Wood, K. S.; Auchere,
   F.; Bode, M. F.; Bromage, G. E.; Gibson, B.; Collier Cameron, A.;
   Cassatella, A.; Delmotte, F.; Ravet, M. -F.; Doyle, J. G.; Jeffery,
   C. S.; Gaensicke, B.; Jordan, C.; Kappelmann, N.; Werner, K.;
   Lallement, R.; de Martino, D.; Matthews, S. A.; Phillips, K. J. H.;
   Del Zanna, G.; Orio, M.; Pace, E.; Pagano, I.; Schmitt, J. H. M. M.;
   Welsh, B. Y.
2009Ap&SS.320..231B    Altcode: 2008Ap&SS.tmp..161B
  This paper describes a proposed high resolution soft X-ray and
  Extreme Ultraviolet (EUV) spectroscopy mission to carry out a survey
  of Stellar and Galactic Environments (SAGE). The payload is based on
  novel diffraction grating technology which has already been proven in
  a sub-orbital space mission and which is ready to fly on a satellite
  platform with minimal development. Much of the technical detail of
  the instrumentation has been reported elsewhere and we concentrate
  our discussion here on the scientific goals of a SAGE base-line
  mission, demonstrating the scientific importance of high resolution
  spectroscopy in the Extreme Ultraviolet for the study of stars and
  the local interstellar medium.

---------------------------------------------------------
Title: Solar EUV/FUV irradiance variations: analysis and observational
    strategy
Authors: Kretzschmar, Matthieu; Dudok de Wit, Thierry; Lilensten, Jean;
   Hochedez, Jean-Francois; Aboudarham, Jean; Amblard, Pierre-Olivier;
   Auchère, Frederic; Moussaoui, Said
2009AcGeo..57...42K    Altcode: 2008AcGeo..57...42K; 2008AcGeo.tmp...50K
  The knowledge of solar extreme and far ultraviolet (EUV) irradiance
  variations is essential for the characterization of the Earth’s
  upper atmosphere. For a long time, this knowledge has been based
  on empirical models, which are themselves based on proxies of the
  solar activity. However, the accurate modeling and prediction of the
  Earth’s upper atmosphere necessitate to improve the precision on the
  irradiance and its variations below about 200 nm. Here, we present a
  review of recent works made by the authors that aim at quantifying the
  irradiance variability at these wavelengths, and that lead to new way
  of monitoring the solar EUV/FUV irradiance spectrum. In more details,
  it is shown that the quantification of the high level of redundancy in
  the solar spectrum variability allows to envisage measuring only a small
  portion of the spectrum without losing essential knowledge. Finally,
  we discuss what should and could be measured in order to retrieve the
  solar extreme and far ultraviolet spectrum.

---------------------------------------------------------
Title: POLAR investigation of the Sun—POLARIS
Authors: Appourchaux, T.; Liewer, P.; Watt, M.; Alexander, D.;
   Andretta, V.; Auchère, F.; D'Arrigo, P.; Ayon, J.; Corbard, T.;
   Fineschi, S.; Finsterle, W.; Floyd, L.; Garbe, G.; Gizon, L.; Hassler,
   D.; Harra, L.; Kosovichev, A.; Leibacher, J.; Leipold, M.; Murphy,
   N.; Maksimovic, M.; Martinez-Pillet, V.; Matthews, B. S. A.; Mewaldt,
   R.; Moses, D.; Newmark, J.; Régnier, S.; Schmutz, W.; Socker, D.;
   Spadaro, D.; Stuttard, M.; Trosseille, C.; Ulrich, R.; Velli, M.;
   Vourlidas, A.; Wimmer-Schweingruber, C. R.; Zurbuchen, T.
2009ExA....23.1079A    Altcode: 2008ExA...tmp...40A; 2008arXiv0805.4389A
  The POLAR Investigation of the Sun (POLARIS) mission uses a combination
  of a gravity assist and solar sail propulsion to place a spacecraft
  in a 0.48 AU circular orbit around the Sun with an inclination of 75°
  with respect to solar equator. This challenging orbit is made possible
  by the challenging development of solar sail propulsion. This first
  extended view of the high-latitude regions of the Sun will enable
  crucial observations not possible from the ecliptic viewpoint or from
  Solar Orbiter. While Solar Orbiter would give the first glimpse of
  the high latitude magnetic field and flows to probe the solar dynamo,
  it does not have sufficient viewing of the polar regions to achieve
  POLARIS’s primary objective: determining the relation between the
  magnetism and dynamics of the Sun’s polar regions and the solar cycle.

---------------------------------------------------------
Title: Stellar And Galactic Environment survey (SAGE)
Authors: Barstow, M. A.; Kowalski, M. P.; Cruddace, R. G.; Wood, K. S.;
   Auchere, F.; Bannister, N. J.; Bode, M. F.; Bromage, G. E.; Burleigh,
   M. R.; Collier Cameron, A.; Cassatella, A.; Delmotte, F.; Doyle, J. G.;
   Gaensicke, B.; Gibson, B.; Jeffery, C. S.; Jordan, C.; Kappelmann,
   N.; Lallement, R.; Lapington, J. S.; de Martino, D.; Matthews, S. A.;
   Orio, M.; Pace, E.; Pagano, I.; Phillips, K. J. H.; Ravet, M. -F.;
   Schmitt, J. H. M. M.; Welsh, B. Y.; Werner, K.; Del Zanna, G.
2009ExA....23..169B    Altcode: 2008ExA...tmp...25B
  This paper describes a proposed high resolution soft X-ray and Extreme
  Ultraviolet spectroscopy mission to carry out a survey of Stellar
  and Galactic Environments (SAGE). The payload is based on novel
  diffraction grating technology which has already been proven in a
  sub-orbital space mission and which is ready to fly on a satellite
  platform with minimal development. We discuss the goals of a SAGE
  base-line mission and demonstrate the scientific importance of high
  resolution spectroscopy in the Extreme Ultraviolet for the study of
  stars and the local interstellar medium.

---------------------------------------------------------
Title: Solar EUV Spectral Irradiance Throughout The 3-Dimensional
    Heliosphere
Authors: McMullin, D. R.; Auchere, F.; Cook, J. W.; Newmark, J. S.;
   Quemerais, E.; von Steiger, R.; Witte, M.
2008AGUFMSH13B1522M    Altcode:
  When Ulysses moved from 30 to 80 degrees in solar latitude (July
  2001), the Ulysses GAS instrument measured an apparent increase
  in the neutral He density. This is more naturally interpreted as
  a latitudinal dependence (decrease) of the loss rate due to solar
  photoionization rather than a true increase of the neutral He
  density. This concept has been tested through the development of a
  3-Dimensional solar EUV model for the Heliosphere. The model concept
  has been presented earlier, and we are now presenting results and
  applications of the new model. Using daily SOHO EIT observations,
  over successive Carrington rotations, we have developed a three-
  dimensional model for solar EUV fluxes observed at any heliospheric
  position, projected to any heliospheric position. The combined
  effects of solar rotational and latitude-dependent flux variability
  are explicitly treated in this model. The flux model will be compared
  with other direct spectral irradiance observations in the ecliptic
  plane, such as those available from the TIMED SEE instrument as well
  as broadband measurements available from the SOHO/SEM irradiance time
  series. These comparisons will be used in part to validate the current
  results. We then use this flux to compute the photoionization rate of
  the in-flowing neutral Helium, and compare the modeled change with that
  observed along the spacecraft trajectory with the direct measurements
  from the out-of-ecliptic Ulysses GAS observations. The unique GAS
  comparisons will provide validation of the original hypothesis as to
  the latitudinal dependence (decrease) of the loss rate due to solar
  photoionization rather than an increase of the neutral He density.

---------------------------------------------------------
Title: Which solar EUV indices are best for reconstructing the solar
    EUV irradiance?
Authors: Dudok de Wit, T.; Kretzschmar, M.; Aboudarham, J.; Amblard,
   P. -O.; Auchère, F.; Lilensten, J.
2008AdSpR..42..903D    Altcode: 2007astro.ph..2053D
  The solar EUV irradiance is of key importance for space weather. Most
  of the time, however, surrogate quantities such as EUV indices have to
  be used by lack of continuous and spectrally resolved measurements of
  the irradiance. The ability of such proxies to reproduce the irradiance
  from different solar atmospheric layers is usually investigated by
  comparing patterns of temporal correlations. We consider instead
  a statistical approach. The TIMED/SEE experiment, which has been
  continuously operating since February 2002, allows for the first time
  to compare in a statistical manner the EUV spectral irradiance to five
  EUV proxies: the sunspot number, the f10.7, Ca K, and Mg II indices,
  and the He I equivalent width. Using multivariate statistical methods,
  we represent in a single graph the measure of relatedness between these
  indices and various strong spectral lines. The ability of each index
  to reproduce the EUV irradiance is discussed; it is shown why so few
  lines can be effectively reconstructed from them. All indices exhibit
  comparable performance, apart from the sunspot number, which is the
  least appropriate. No single index can satisfactorily describe both
  the level of variability on time scales beyond 27 days, and relative
  changes of irradiance on shorter time scales.

---------------------------------------------------------
Title: The EUV Sun as the superposition of elementary Suns
Authors: Amblard, P. -O.; Moussaoui, S.; Dudok de Wit, T.; Aboudarham,
   J.; Kretzschmar, M.; Lilensten, J.; Auchère, F.
2008A&A...487L..13A    Altcode: 2008arXiv0809.0566A
  Aims: Many studies assume that the solar irradiance in the EUV can be
  decomposed into different contributions, which makes modelling the
  spectral variability considerably easier. We consider a different
  approach in which these contributions are not imposed a priori
  but effectively and robustly inferred from spectral irradiance
  measurements. <BR />Methods: This is a source separation problem with
  a positivity constraint, for which we use a Bayesian solution. <BR
  />Results: Using five years of daily EUV spectra recorded by the
  TIMED/SEE satellite, we show that the spectral irradiance can be
  decomposed into three elementary spectra. Our results suggest that they
  describe different layers of the solar atmosphere rather than specific
  regions. The temporal variability of these spectra is discussed.

---------------------------------------------------------
Title: Two channel multilayer mirrors for astrophysics
Authors: Gautier, Julien; Delmotte, Franck; Françoise Ravet, Marie;
   Jérome, Arnaud; Bridou, Françoise; Varnière, Francoise; Auchère,
   Frédéric
2008OptCo.281.3032G    Altcode:
  A two-channel mirror reflecting both Fe-IX/X (λ = 17.1 nm) and He-II
  (30.4 nm) resonance lines at near normal incidence has been designed,
  fabricated and characterized. These two passbands are often chosen in
  space instruments designed for the observation of the solar corona. The
  mirror structure used for optimization is a superposition of two
  periodic multilayers with three components per period. It has been
  designed by using optimization software with an appropriate merit
  function. The theoretical reflectivity for both resonance lines can
  reach 0.25. It is shown that, by using a set of filters, one can select
  either the Fe-IX/X or the He-II channel. The spectral response of the
  two-channel mirror has been measured on synchrotron radiation source on
  a large wavelength range, from 12 nm to 35 nm. Experimental reflectivity
  reaches 0.32 for the Fe-IX/X line and 0.19 for the He-II line.

---------------------------------------------------------
Title: FESTIVAL: A Multiscale Visualization Tool for Solar Imaging
    Data
Authors: Auchère, F.; Soubrié, E.; Bocchialini, K.; LeGall, F.
2008SoPh..248..213A    Altcode: 2008SoPh..tmp...59A
  Since 4 December 2006, the SECCHI instrument suites onboard the
  two STEREO A and B probes have been imaging the solar corona and the
  heliosphere on a wide range of angular scales. The EUVI telescopes have
  a plate scale of 1.7 arcseconds pixel<SUP>−1</SUP>, while that of the
  HI2 wide-angle cameras is 2.15 arcminutes pixel<SUP>−1</SUP>, i.e. 75
  times larger, with the COR1 and COR2 coronagraphs having intermediate
  plate scales. These very different instruments, aimed at studying
  Coronal Mass Ejections and their propagation in the heliosphere,
  create a data visualization challenge. This paper presents FESTIVAL,
  a SolarSoftware package originally developed to be able to map the
  SECCHI data into dynamic composite images of the sky as seen by the
  STEREO and SOHO probes. Data from other imaging instruments can also
  be displayed. Using the mouse, the user can quickly and easily zoom in
  and out and pan through these composite images to explore all spatial
  scales from EUVI to HI2 while keeping the native resolution of the
  original data. A large variety of numerical filters can be applied,
  and additional data (i.e. coordinate grids, stars catalogs, etc.) can
  be overlaid on the images. The architecture of FESTIVAL is such that
  it is easy to add support for other instruments and these new data
  immediately benefit from the already existing capabilities. Also,
  because its mapping engine is fully 3D, FESTIVAL provides a convenient
  environment to display images from future out-of-the-Ecliptic solar
  missions, such as Solar Orbiter or Solar Probe.

---------------------------------------------------------
Title: A Time-Evolving 3D Method Dedicated to the Reconstruction of
    Solar Plumes and Results Using Extreme Ultraviolet Data
Authors: Barbey, Nicolas; Auchère, Frédéric; Rodet, Thomas; Vial,
   Jean-Claude
2008SoPh..248..409B    Altcode: 2008SoPh..tmp...65B; 2008arXiv0802.0113B
  An important issue in the tomographic reconstruction of the solar poles
  is the relatively rapid evolution of the polar plumes. We demonstrate
  that it is possible to take into account this temporal evolution in
  the reconstruction. The difficulty of this problem comes from the fact
  that we want a four-dimensional reconstruction (three spatial dimensions
  plus time) whereas we only have three-dimensional data (two-dimensional
  images plus time). To overcome this difficulty, we introduce a model
  that describes polar plumes as stationary objects whose intensity varies
  homogeneously with time. This assumption can be physically justified
  if one accepts the stability of the magnetic structure. This model
  leads to a bilinear inverse problem. We describe how to extend linear
  inversion methods to these kinds of problems. Studies of simulations
  show the reliability of our method. Results for SOHO/EIT data show
  that we can estimate the temporal evolution of polar plumes to improve
  the reconstruction of the solar poles from only one point of view. We
  expect further improvements from STEREO/EUVI data when the two probes
  will be separated by about 60°.

---------------------------------------------------------
Title: Sun Earth Connection Coronal and Heliospheric Investigation
    (SECCHI)
Authors: Howard, R. A.; Moses, J. D.; Vourlidas, A.; Newmark, J. S.;
   Socker, D. G.; Plunkett, S. P.; Korendyke, C. M.; Cook, J. W.; Hurley,
   A.; Davila, J. M.; Thompson, W. T.; St Cyr, O. C.; Mentzell, E.;
   Mehalick, K.; Lemen, J. R.; Wuelser, J. P.; Duncan, D. W.; Tarbell,
   T. D.; Wolfson, C. J.; Moore, A.; Harrison, R. A.; Waltham, N. R.;
   Lang, J.; Davis, C. J.; Eyles, C. J.; Mapson-Menard, H.; Simnett,
   G. M.; Halain, J. P.; Defise, J. M.; Mazy, E.; Rochus, P.; Mercier,
   R.; Ravet, M. F.; Delmotte, F.; Auchere, F.; Delaboudiniere, J. P.;
   Bothmer, V.; Deutsch, W.; Wang, D.; Rich, N.; Cooper, S.; Stephens,
   V.; Maahs, G.; Baugh, R.; McMullin, D.; Carter, T.
2008SSRv..136...67H    Altcode: 2008SSRv..tmp...64H
  The Sun Earth Connection Coronal and Heliospheric Investigation
  (SECCHI) is a five telescope package, which has been developed for
  the Solar Terrestrial Relation Observatory (STEREO) mission by the
  Naval Research Laboratory (USA), the Lockheed Solar and Astrophysics
  Laboratory (USA), the Goddard Space Flight Center (USA), the University
  of Birmingham (UK), the Rutherford Appleton Laboratory (UK), the
  Max Planck Institute for Solar System Research (Germany), the Centre
  Spatiale de Leige (Belgium), the Institut d’Optique (France) and the
  Institut d’Astrophysique Spatiale (France). SECCHI comprises five
  telescopes, which together image the solar corona from the solar disk to
  beyond 1 AU. These telescopes are: an extreme ultraviolet imager (EUVI:
  1 1.7 R<SUB>⊙</SUB>), two traditional Lyot coronagraphs (COR1: 1.5 4
  R<SUB>⊙</SUB> and COR2: 2.5 15 R<SUB>⊙</SUB>) and two new designs
  of heliospheric imagers (HI-1: 15 84 R<SUB>⊙</SUB> and HI-2: 66 318
  R<SUB>⊙</SUB>). All the instruments use 2048×2048 pixel CCD arrays
  in a backside-in mode. The EUVI backside surface has been specially
  processed for EUV sensitivity, while the others have an anti-reflection
  coating applied. A multi-tasking operating system, running on a PowerPC
  CPU, receives commands from the spacecraft, controls the instrument
  operations, acquires the images and compresses them for downlink
  through the main science channel (at compression factors typically
  up to 20×) and also through a low bandwidth channel to be used for
  space weather forecasting (at compression factors up to 200×). An
  image compression factor of about 10× enable the collection of images
  at the rate of about one every 2 3 minutes. Identical instruments,
  except for different sizes of occulters, are included on the STEREO-A
  and STEREO-B spacecraft.

---------------------------------------------------------
Title: Review on the solar spectral variability in the EUV for space
    weather purposes
Authors: Lilensten, J.; Dudok de Wit, T.; Kretzschmar, M.; Amblard,
   P. -O.; Moussaoui, S.; Aboudarham, J.; Auchère, F.
2008AnGeo..26..269L    Altcode:
  The solar XUV-EUV flux is the main energy source in the terrestrial
  diurnal thermosphere: it produces ionization, dissociation, excitation
  and heating. Accurate knowledge of this flux is of prime importance
  for space weather. We first list the space weather applications that
  require nowcasting and forecasting of the solar XUV-EUV flux. We
  then review present models and discuss how they account for the
  variability of the solar spectrum. We show why the measurement of the
  full spectrum is difficult, and why it is illusory to retrieve it from
  its atmospheric effects. We then address the problem of determining
  a set of observations that are adapted for space weather purposes,
  in the frame of ionospheric studies. Finally, we review the existing
  and future space experiments that are devoted to the observation of
  the solar XUV-EUV spectrum.

---------------------------------------------------------
Title: Polarisation and magnetic depolarization of the Lyman-alpha
line in the corona : the line-of-sight effects
Authors: Vial, Jean-Claude; Derouich, Moncef; Auchere, Frederic;
   Zhang, Mei
2008cosp...37.3340V    Altcode: 2008cosp.meet.3340V
  In view of the importance of measuring coronal magnetic field and of
  the capability of measuring linear polarization in the Lyman α line
  with the LYOT coronagraph on board the SMESE mission, we carried out
  some calculations of the degrees of depolarization resulting from the
  presence of a magnetic field. Our calculation is based on a simple
  magnetic field model where a current sheet in the field represents
  a solar prominence. We focus in this study on the effect of the
  line-of-sight integration at various locations in the corona on the
  polarizing/depolarizing properties. Other magnetic configurations are
  also considered and are under the study.

---------------------------------------------------------
Title: The EUV Sun as a superposition of 3 elementary Suns
Authors: Dudok de Wit, Thierry; Kretzschmar, Matthieu; Moussaoui,
   Saïd; Amblard, Pierre-Olivier; Lilensten, Jean; Auchere, Frederic;
   Aboudarham, Jean
2008cosp...37..763D    Altcode: 2008cosp.meet..763D
  Many studies assume that the solar irradiance in the EUV can be
  decomposed into different contributions, which considerably eases
  the modelling of the spectral variability for thermosphere/ionosphere
  models. We consider a different approach, in which these contributions
  are not imposed a priori but inferred from the spectral irradiance
  measurements. This problem can be considered as a source separation
  problem with positivity constraint, for which we use a recent Bayesian
  method. Using five years of daily EUV spectra recorded by the SEE
  instrument onboard TIMED, we show that the spectral irradiance can be
  decomposed into three elementary spectra. The first one is associated
  with the quiet Sun, the second one with active regions, whereas the
  third one captures the cold contribution from the chromosphere.

---------------------------------------------------------
Title: SMESE (SMall Explorer for Solar Eruptions): A microsatellite
    mission with combined solar payload
Authors: Vial, J. -C.; Auchère, F.; Chang, J.; Fang, C.; Gan, W. Q.;
   Klein, K. -L.; Prado, J. -Y.; Rouesnel, F.; Sémery, A.; Trottet,
   G.; Wang, C.
2008AdSpR..41..183V    Altcode:
  The SMESE (SMall Explorer for Solar Eruptions) mission is a
  microsatellite proposed by France and China. The payload of SMESE
  consists of three packages: LYOT (a Lyman α imager and a Lyman α
  coronagraph), DESIR (an Infra-red Telescope working at 35 80 and
  100 250 μm), and HEBS (a High Energy Burst Spectrometer working
  in X- and gamma-rays). The scientific objectives of the mission are
  shortly presented. We describe the three instrumental packages and the
  profile of the mission which accommodates them. With a launch around
  2012 2013, the SMESE microsatellite mission will provide a unique
  tool for detecting and understanding eruptions (flares and coronal
  mass ejections). Observations should start around solar maximum, and
  continue in the declining phase of activity, at a time when the Solar
  Dynamics Observatory (SDO) should still be operating.

---------------------------------------------------------
Title: The SECCHI Experiment on the STEREO Mission
Authors: Howard, R. A.; Moses, J. D.; Vourlidas, A.; Newmark, J. S.;
   Socker, D. G.; Wang, D.; Plunkett, S. P.; Baugh, R.; McMullin, D. R.;
   Davila, J. M.; Thompson, W. T.; Lemen, J. R.; Wuelser, J.; Harrison,
   R. A.; Waltham, N. R.; Davis, C. J.; Eyles, C. J.; Defise, J.; Halain,
   J.; Bothmer, V.; Delaboudiniere, J.; Auchere, F.; Mercier, R.; Ravet,
   M. F.
2007AGUSMSH33A..01H    Altcode:
  The Sun Earth Connection Coronal and Heliospheric Investigation
  (SECCHI) on the NASA Solar Terrestrial Relations Observatory (STEREO)
  mission is a suite of remote sensing instruments consisting of an
  extreme ultraviolet (EUV) imager, two white light coronagraphs, and
  two telescopes that comprise the heliospheric imager. SECCHI will
  observe coronal mass ejections (CMEs) from their birth at the sun,
  through the corona and into the heliosphere. A complete instrument
  suite is being carried on each of the two STEREO spacecraft, which
  will provide the first sampling of a CME from two vantage points. The
  spacecraft, launched 25 October 2006, are orbiting the Sun, one Ahead
  of the Earth and the other Behind, each separating from Earth at about
  22 degrees per year. The varying separation means that we will have
  different observational capabilities as the spacecraft separate and
  therefore differing science goals. The primary science objectives
  all are focused on understanding the physics of the CME process
  their initiation, 3D morphology, propagation, interaction with the
  interplanetary medium and space weather effects. By observing the CME
  from multiple viewpoints with UV and coronagraphic telescopes and by
  combining these observations with radio and in-situ observations from
  the other instruments on STEREO as well as from other satellites and
  ground based observatories operating at the same time, answers to some
  of the outstanding questions will be obtained. We will show some of
  the initial results.

---------------------------------------------------------
Title: Stereo Observations Of The Solar Corona Using The Secchi
    Experiment
Authors: Plunkett, Simon P.; Howard, R. A.; Moses, J. D.; Vourlidas,
   A.; Socker, D.; Newmark, J.; Wang, D.; Baugh, R.; Davila, J.;
   Thompson, W.; St. Cyr, O. C.; Lemen, J.; Wuelser, J. P.; Harrison,
   R. A.; Waltham, N.; Davis, C. J.; Eyles, C. J.; Defise, J. M.; Halain,
   J. P.; Bothmer, V.; Delaboudiniere, J. P.; Auchere, F.; Mercier, R.;
   Ravet, M. F.
2007AAS...21011901P    Altcode: 2007BAAS...39..243P
  The Sun Earth Connection Coronal and Heliospheric Investigation
  (SECCHI) on the NASA Solar Terrestrial Relations Observatory (STEREO)
  mission is a suite of remote sensing instruments consisting of an
  extreme ultraviolet (EUV) imager, two white light coronagraphs,
  and two telescopes that comprise the heliospheric imager. The main
  objective of SECCHI is to observe coronal mass ejections (CMEs) from
  their birth at the sun, through the corona and into the heliosphere. A
  complete instrument suite is being carried on each of the two STEREO
  spacecraft, which will provide the first sampling of a CME from two
  vantage points as the spacecraft separate from each other at the rate
  of about 45 degrees per year. We will show examples of some of the
  data and some of the initial stereo results.

---------------------------------------------------------
Title: Multispectral analysis of solar EUV images: linking temperature
    to morphology
Authors: Dudok de Wit, T.; Auchère, F.
2007A&A...466..347D    Altcode: 2007astro.ph..2052D
  Context: Solar images taken simultaneously at different wavelengths in
  the EUV are widely used for understanding structures such as flares,
  coronal holes, loops, etc. The line-of-sight integration and the finite
  spectral resolution of EUV telescopes, however, hinders interpretation
  of these individual images in terms of temperature bands. Traditional
  approaches involve simple visualisation or explicit modelling. We take
  a more empirical approach, using statistical methods. <BR />Aims:
  The morphology of solar structures changes with the wavelength of
  observation and, therefore, with temperature. We explore the possibility
  of separating the different solar structures from a linear combination
  of images. <BR />Methods: Using a blind source separation approach,
  we build a new set of statistically independent "source" images from
  the original EUV images. Two techniques are compared: the singular
  value decomposition and independent component analysis. <BR />Results:
  The source images show more contrast than the original ones, thereby
  easing the characterisation of morphological structures. A comparison
  with the differential emission measure shows that each source image
  also isolates structures with specific emission temperatures.

---------------------------------------------------------
Title: SMESE: A SMall Explorer for Solar Eruptions
Authors: Vial, J. -C.; Auchère, F.; Chang, J.; Fang, C.; Gan, W. Q.;
   Klein, K. -L.; Prado, J. -Y.; Trottet, G.; Wang, C.; Yan, Y. H.
2007AdSpR..40.1787V    Altcode:
  The SMall Explorer for Solar Eruptions (SMESE) mission is a
  microsatellite proposed by France and China. The payload of SMESE
  consists of three packages: LYOT (a Lyman α imager and a Lyman α
  coronagraph), DESIR (an Infra-Red Telescope working at 35-80 and
  100-250 μm), and HEBS (a High-Energy Burst Spectrometer working in
  X- and γ-rays). The status of research on flares and coronal mass
  ejections is briefly reviewed in the context of on-going missions such
  as SOHO, TRACE and RHESSI. The scientific objectives and the profile of
  the mission are described. With a launch around 2012-2013, SMESE will
  provide a unique tool for detecting and understanding eruptions (flares
  and coronal mass ejections) close to the maximum phase of activity.

---------------------------------------------------------
Title: EUI, The Ultraviolet Imaging Telescopes Of Solar Orbiter
Authors: Hochedez, J. -F.; Appourchaux, T.; Defise, J. -M.; Harra,
   L. K.; Schühle, U.; Auchère, F.; Curdt, W.; Hancock, B.; Kretzschmar,
   M.; Lawrence, G.; Leclec'h, J. -C.; Marsch, E.; Mercier, R.; Parenti,
   S.; Podladchikova, E.; Ravet, M. -F.; Rochus, P.; Rodriguez, L.;
   Rouesnel, F.; Solanki, S.; Teriaca, L.; Van Driel, L.; Vial, J. -C.;
   Winter, B.; Zhukov, A.
2007ESASP.641E..33H    Altcode:
  The scientific objectives of Solar Orbiter rely ubiquitously on EUI,
  its suite of solar atmosphere imaging telescopes. In the configuration
  discussed here, EUI includes three co-aligned High Resolution Imagers
  (HRI) and one Full Sun Imager (FSI). FSI and two HRIs observe in extreme
  ultraviolet passbands, dominated by coronal emission. Another HRI is
  designed for the hydrogen Lyman α radiation in the far UV, imaging the
  Chromosphere and the lower Transition Region. The current EUI design
  and some of its development challenges are highlighted. EUI profits from
  co-rotation phases, solar proximity and departure from the ecliptic. In
  synergy with the other S.O. payload, EUI probes the dynamics of the
  solar atmosphere, provides context data for all investigations and helps
  to link in-situ and remote-sensing observations. In short, it serves all
  four top-level goals of the mission. For these reasons, the EUI suite
  is keenly anticipated in the European scientific community and beyond.

---------------------------------------------------------
Title: The SECCHI Experiment on the STEREO Mission
Authors: Howard, R. A.; Moses, D.; Vourlidas, A.; Newmark, J.; Socker,
   D. G.; Plunkett, S.; Wang, D.; Baugh, R.; McMullin, D.; Davila, J.;
   St. Cyr, C.; Thompson, W. T.; Lemen, J.; Wuelser, J.; Harrison, R. A.;
   Waltham, N. R.; Davis, C.; Eyles, C. J.; Defise, J.; Halain, J.;
   Bothmer, V.; Delaboudiniere, J.; Auchere, F.; Mercier, R.; Ravet, M.
2006AGUFMSM12A..02H    Altcode:
  The Sun Earth Connection Coronal and Heliospheric Investigation
  (SECCHI) on the NASA Solar Terrestrial Relations Observatory (STEREO)
  mission is a suite of remote sensing instruments consisting of an
  extreme ultraviolet (EUV) imager, two white light coronagraphs, and
  two telescopes that comprise the heliospheric imager. SECCHI will
  observe coronal mass ejections (CMEs) from their birth at the sun,
  through the corona and into the heliosphere. A complete instrument
  suite is being carried on each of the two STEREO spacecraft, which
  will provide the first sampling of a CME from two vantage points. The
  spacecraft will orbit the Sun, one Ahead of the Earth and the other
  Behind, each separating from Earth at about 22 degrees per year. The
  varying separation means that we will have different observational
  capabilities as the spacecraft separate and therefore differing science
  goals. The primary science objectives all are focused on understanding
  the physics of the CME process their initiation, 3D morphology,
  propagation, interaction with the interplanetary medium and space
  weather effects. By observing the CME from multiple viewpoints with UV
  and coronagraphic telescopes and by combining these observations with
  radio and in-situ observations from the other instruments on STEREO as
  well as from other satellites and ground based observatories operating
  at the same time, answers to some of the outstanding questions will
  be obtained. STEREO follows the very successful SOHO mission. SOHO's
  success was primarily due to the highly complementary nature of the
  instruments, but it was partly due to the very stable platform. The
  L1 orbit enables an extremely stable thermal environment and thus
  very stable pointing, as well as uninterrupted solar viewing. The
  STEREO will have both of these characteristics, but in addition will
  have multi-viewpoint viewing of CMEs, which will greatly enhance the
  many discoveries that SOHO data have produced. We have been developing
  techniques to interpret the observations from multiple viewpoints and
  to perform 3-dimensional deconvolution of the CME observations using
  forward modeling and inversion techniques. A continuous downlink of
  STEREO data will provide a low-resolution, real- time view from all
  of the instruments. The full data are downlinked once a day and will
  be available about 24 hours later. We will present some preliminary
  results from the instrument, which is expected to be launched in
  October/November, 2006

---------------------------------------------------------
Title: Rotational Tomography of the Solar Corona-Calculation of the
    Electron Density and Temperature
Authors: Barbey, Nicolas; Auchère, Frédéric; Rodet, Thomas;
   Bocchialini, Karine; Vial, Jean-Claude
2006ESASP.617E..82B    Altcode: 2006soho...17E..82B
  No abstract at ADS

---------------------------------------------------------
Title: Helium/Hydrogen Fractionation in the Solar Wind-How Much is
    Due to Inefficient Coulomb Drag?
Authors: Bochsler, P.; Auchère, F.; Skoug, R. M.
2006ESASP.617E..28B    Altcode: 2006soho...17E..28B
  No abstract at ADS

---------------------------------------------------------
Title: SMESE: a combined UV-IR-X-gamma solar mission
Authors: Millard, Anne A.; Auchere, Frederic; Fang, Cheng; Gan,
   Weiqun; Molodij, Guillaume; Prado, Jean-Yves; Rouesnel, Frederic;
   Semery, Alain; Trottet, Gerard; Vial, Jean-Claude; Yan, Yihua; Wu, Ji
2006SPIE.6266E..0JM    Altcode: 2006SPIE.6266E..15M
  SMESE (SMall Explorer For the study of Solar Eruptions) is a
  Franco-Chinese microsatellite mission. The scientific objectives of
  SMESE are the study of coronal mass ejections and flares. Its payload
  consists of three instrument packages : LYOT, DESIR and HEBS. LYOT is
  composed of a Lyman α (121.6 nm) coronagraph, a Lyman α disk imager
  and a far UV disk imager. DESIR is an infrared telescope working at 35
  μm and 150 μm. HEBS is a high energy burst spectrometer working in
  X rays and γ rays covering the 10 keV to 600 MeV range. SMESE will
  be launched around 2011, providing a unique opportunity of detecting
  and understanding eruptions at the maximum activity phase of the solar
  cycle in a wide range of energies. The instrumentation on board SMESE
  is described in this paper.

---------------------------------------------------------
Title: From the Sun to the Earth: impact of the 27-28 May 2003 solar
    events on the magnetosphere, ionosphere and thermosphere
Authors: Hanuise, C.; Cerisier, J. C.; Auchère, F.; Bocchialini,
   K.; Bruinsma, S.; Cornilleau-Wehrlin, N.; Jakowski, N.; Lathuillère,
   C.; Menvielle, M.; Valette, J. -J.; Vilmer, N.; Watermann, J.; Yaya, P.
2006AnGeo..24..129H    Altcode:
  During the last week of May 2003, the solar active region AR 10365
  produced a large number of flares, several of which were accompanied
  by Coronal Mass Ejections (CME). Specifically on 27 and 28 May three
  halo CMEs were observed which had a significant impact on geospace. On
  29 May, upon their arrival at the L1 point, in front of the Earth's
  magnetosphere, two interplanetary shocks and two additional solar
  wind pressure pulses were recorded by the ACE spacecraft. The
  interplanetary magnetic field data showed the clear signature of a
  magnetic cloud passing ACE. In the wake of the successive increases
  in solar wind pressure, the magnetosphere became strongly compressed
  and the sub-solar magnetopause moved inside five Earth radii. At
  low altitudes the increased energy input to the magnetosphere was
  responsible for a substantial enhancement of Region-1 field-aligned
  currents. The ionospheric Hall currents also intensified and the entire
  high-latitude current system moved equatorward by about 10°. Several
  substorms occurred during this period, some of them - but not all -
  apparently triggered by the solar wind pressure pulses. The storm's
  most notable consequences on geospace, including space weather effects,
  were (1) the expansion of the auroral oval, and aurorae seen at mid
  latitudes, (2) the significant modification of the total electron
  content in the sunlight high-latitude ionosphere, (3) the perturbation
  of radio-wave propagation manifested by HF blackouts and increased
  GPS signal scintillation, and (4) the heating of the thermosphere,
  causing increased satellite drag. We discuss the reasons why the May
  2003 storm is less intense than the October-November 2003 storms,
  although several indicators reach similar intensities.

---------------------------------------------------------
Title: Can the EUV spectrum and its variability be reconstructed
    from a small set of spectral lines ?
Authors: Dudok de Wit, T.; Lilensten, J.; Aboudarham, J.; Amblard,
   P. -O.; Auchère, F.; Kretzschmar, M.
2006cosp...36..991D    Altcode: 2006cosp.meet..991D
  The severe lack of continuously measured and spectrally resolved solar
  EUV spectra is a major obstacle towards modelling the impact of the
  solar irradiance on the ionosphere The usual solution involves the
  measurement of various proxies We consider a different approach in
  which the EUV spectrum and its variability are reconstructed from the
  linear combination of a few spectral lines Using three years of spectra
  from TIMED and a statistical classification technique we demonstrate
  that 5 to 8 lines only are needed and in addition show which lines
  are the best candidates These results are valuable for instrument
  specification and also provide new insight into the comparison of
  solar proxies against the EUV irradiance

---------------------------------------------------------
Title: A brief introduction to SMESE mission
Authors: Wang, C.; Fang, C.; Gan, W.; Prado, J. -Y.; Trottet, G.;
   Vial, J. -C.; Yan, Y.; Auchere, F.; Chang, J.; Molodi, G.
2006ilws.conf..211W    Altcode:
  Small Exploration for Solar Eruptions (SMESE) is a joint mission
  between France and China to investigate the two main types of eruption
  events on the Sun: Coronal Mass Ejections (CME) and solar flares,
  and their relationship. SMESE will provide a set of unprecedented
  and complementary measurements including Ly-alpha imager, Ly-alpha
  coronagraph, EUV imager, Detection of Solar Infra red radiation,
  Hard X-ray/gamma ray spectrometry. SMESE aims to study, among others,
  the CME triggering mechanism and its acceleration in the corona, the
  particle acceleration by CME and solar flare, the physical association
  of the CME and solar flare etc. SMESE will be launched in the next
  solar maximum between 2010-2012.

---------------------------------------------------------
Title: SMESE, a SMall Explorer for the Study of solar Eruptions
Authors: Vial, J. -C.; Auchère, F.; Chang, J.; Fang, C.; Gan, W. Q.;
   Molodij, G.; Prado, J. -Y.; Trottet, G.; Wang, C.; Yan, Y. H.
2006cosp...36.3287V    Altcode: 2006cosp.meet.3287V
  The SMESE Small Explorer for the Study of solar Eruptions mission is
  a microsatellite proposed by France and China The payload of SMESE
  consists of three packages LYOT a suite of two UV and EUV imagers and
  a Lyman alpha coronagraph DESIR an Infra-Red Telescope working at 35
  and 150 mu and HEBS a High Energy Burst Spectrometer working in X-
  and gamma -rays The status of research on Coronal Mass Ejections and
  flares will be briefly recalled in the context of on-going missions
  such as SOHO TRACE and RHESSI The scientific objectives and the profile
  of the mission will be described With a launch around 2011 SMESE will
  provide a unique tool for detecting and understanding eruptions flares
  and coronal mass ejections in the maximum phase of activity when the
  Solar Dynamics Observatory SDO should still be operating

---------------------------------------------------------
Title: SMESE: a Small Explorer for the Study of Solar Eruptions
Authors: Vial, J. -C.; Auchère, F.; Chang, J.; Fang, C.; Gan, W. Q.;
   Molodij, G.; Prado, J. -Y.; Trottet, G.; Wang, C.; Yan, Y. H.
2006cosp...36.3294V    Altcode: 2006cosp.meet.3294V
  The SMESE Small Explorer for the Study of solar Eruptions mission is
  a microsatellite proposed by France and China The payload of SMESE
  consists of three packages LYOT a suite of two UV and EUV imagers and
  a Lyman alpha coronagraph DESIR an Infra-Red Telescope working at 35
  and 150 mu and HEBS a High Energy Burst Spectrometer working in X- and
  gamma -rays The status of research on Coronal Mass Ejections will be
  briefly recalled in the context of on-going missions such as SOHO TRACE
  and RHESSI The scientific objectives and the profile of the mission
  will be described With a launch around 2011 SMESE will provide a unique
  tool for detecting and understanding eruptions flares and coronal mass
  ejections in the maximum phase of activity and for the determination
  of the morphology of the low corona from where the solar wind originates

---------------------------------------------------------
Title: An atlas of solar events: 1996 2005
Authors: Artzner, G.; Auchère, F.; Delaboudinière, J. P.; Bougnet, M.
2006AdSpR..38..390A    Altcode:
  Coronal mass ejections (CMEs) are observed in the plane of the sky in
  coronographic images. As the solar surface is masked by an occulting
  disk it is not clear whether halo CMEs are directed towards or away
  from the Earth. Observations of the solar corona on the solar disk
  by the extreme ultraviolet imaging telescope (EIT) on board the Solar
  Heliospheric Observatory SoHO can help to resolve this. Quasi-continuous
  observations of the solar corona were obtained from April 1997 up to
  the current date at a 12 min cadence in the coronal line of FeXII, as
  part of a “CME watch program”. At a slower 6 h cadence an additional
  synoptic program investigates the chromosphere and the corona at four
  different wavelengths. Large coronal solar events appear when viewing
  animations of the CME watch program. Fainter events do appear when
  viewing running difference animations of the CME watch program. When
  looking for additional spectral information from raw running differences
  of the synoptic program it is difficult to disentangle intrinsic solar
  events from the parasitic effect of the solar rotation. We constructed
  at www.ias.u-psud.fr/medoc/EIT/movies/ an atlas of more than 40,000
  difference images from the synoptic programme, corrected for an
  average solar rotation, as well as more than 200,000 instantaneous and
  difference images from the CME watch program. We present case studies
  of specific events in order to investigate the source of darkenings or
  dimmings in difference images, due to the removal of emitting material,
  the presence of obscuring material or large changes in temperature. As
  the beneficial effect of correcting for the solar rotation vanishes at
  the solar limb, we do not investigate the case of prominence Doppler
  dimming. As a by-product of the atlas of solar events we obtain a
  number of quiet time sequences well suited to precisely measure the
  differential solar rotation by the apparent displacement of tracers.

---------------------------------------------------------
Title: The Beleinos cornerstone: the Sun, the star close to Earth
Authors: Appourchaux, T.; Auchère, F.; Bocchialini, K.; Bonnet,
   R. M.; Gabriel, A.; Vial, J. -C.
2005ESASP.588..389A    Altcode: 2005tssc.conf..389A
  No abstract at ADS

---------------------------------------------------------
Title: Observations of Solar EUV Radiation with the CORONAS-F/SPIRIT
    and SOHO/EIT Instruments
Authors: Slemzin, V. A.; Kuzin, S. V.; Zhitnik, I. A.; Delaboudiniere,
   J. -P.; Auchere, F.; Zhukov, A. N.; van der Linden, R.; Bugaenko,
   O. I.; Ignat'ev, A. P.; Mitrofanov, A. V.; Pertsov, A. A.; Oparin,
   S. N.; Stepanov, A. I.; Afanas'ev, A. N.
2005SoSyR..39..489S    Altcode:
  The SPIRIT complex onboard the CORONAS-F satellite has routinely
  imaged the Sun in the 171, 175, 195, 284, and 304 Å spectral bands
  since August 2001. The complex incorporates two telescopes. The
  Ritchey-Chretien telescope operates in the 171, 195, 284, and
  304 Å bands and has an objective similar to that of the SOHO/EIT
  instrument. The Herschel telescope obtains solar images synchronously
  in the 175 and 304 Å bands with two multilayer-coated parabolic
  mirrors. The SPIRIT program includes synoptic observations, studies of
  the dynamics of various structures on the solar disk and in the corona
  up to 5 solar radii, and coordinated observations with other spaceborne
  and ground-based telescopes. In particular, in the period 2002-2003,
  synoptic observations with the SPIRIT Ritchey-Chretien telescope were
  coordinated with regular 6-hour SOHO/EIT observations. Since June 2003,
  when EIT data were temporarily absent ( SOHO keyholes), the SPIRIT
  telescope has performed synoptic observations at a wavelength of 175
  A. These data were used by the Solar Influence Data Analysis Center
  (SIDC) at the Royal Observatory of Belgium for an early space weather
  forecast. We analyze the photometric and spectral parameters of the
  SPIRIT and EIT instruments and compare the integrated (over the solar
  disk) EUV fluxes using solar images obtained with these instruments
  during the CORONAS-F flight from August 2001 through December 2003.

---------------------------------------------------------
Title: A Model for Solar EUV Flux Helium Photoionization Throughout
    the 3-Dimensional Heliosphere
Authors: Auchère, F.; McMullin, D. R.; Cook, J. W.; Newmark, J. S.;
   von Steiger, R.; Witte, M.
2005ESASP.592..327A    Altcode: 2005soho...16E..49A; 2005ESASP.592E..49A
  No abstract at ADS

---------------------------------------------------------
Title: EMMA: The EIT MPEG Movies Archive at the Multi Experiment
    Data Operation Center
Authors: Auchère, F.
2005ESASP.592..671A    Altcode: 2005ESASP.592E.133A; 2005soho...16E.133A
  No abstract at ADS

---------------------------------------------------------
Title: CORONAS-F/SPIRIT EUV observations of October-November 2003
    solar eruptive events in combination with SOHO/EIT data
Authors: Grechnev, V. V.; Chertok, I. M.; Slemzin, V. A.; Kuzin, S. V.;
   Ignat'ev, A. P.; Pertsov, A. A.; Zhitnik, I. A.; DelaboudinièRe,
   J. -P.; AuchèRe, F.
2005JGRA..110.9S07G    Altcode: 2005JGRA..11009S07G
  The extraordinary solar activity of October-November 2003 manifested
  itself in many powerful eruptive events, including large coronal mass
  ejections (CMEs) and extremely powerful flares. A number of major
  events were accompanied by practically all known phenomena of the solar
  activity, both local and large-scale, and caused severe space weather
  disturbances. We study large-scale posteruptive activity manifestations
  on the Sun associated with CMEs, i.e., dimmings and coronal waves,
  observed with extreme-ultraviolet telescopes, the SPIRIT on the
  CORONAS-F spacecraft and the EIT on the SOHO. During that period,
  observations with a cadence of 15 to 45 min were carried out by the
  SPIRIT in the 175 Å and 304 Å bands simultaneously. The EIT observed
  with 12-min cadence in the 195 Å band as well as with 6-hour cadence
  in the 171, 284, and 304 Å bands. These data complement each other
  both in the temporal and spectral coverage. Our analysis reveals
  that largest-scale dimmings covered almost the whole southern part of
  the Sun's visible side and exhibited homology, with one homological
  structure being changed to another configuration on 28 October. These
  structures show connections between large superactive and smaller
  regions that constituted a huge activity complex responsible for the
  extraordinary solar activity of that period. Coronal waves were observed
  at 175 Å as well as at 195 Å in some events, in areas where there were
  no active regions, but in the 175 Å images they look fainter. They
  were not accompanied by deep, long-living dimmings. By contrast,
  such dimmings were observed in active regions, in their vicinity,
  and between them. These facts rule out the direct relation of the
  phenomena of long-term dimmings and coronal waves. On 18 November, a
  motion of an ejecta was observed at the solar disk as a propagation of
  a dark feature only in the 304 Å band, which can be interpreted as an
  absorption in a "cloud" formed from material of the eruptive filament,
  which probably failed to become a CME core.

---------------------------------------------------------
Title: Formation flyers applied to solar coronal observations:
    the ASPICS mission
Authors: Vives, S.; Lamy, P.; Auchere, F.; Vial, J. -C.; Koutchmy,
   S.; Arnaud, J.; Prado, J. -Y.; Frassetto, F.; Naletto, G.
2005SPIE.5901..305V    Altcode:
  Classical externally-occulted coronagraphs are presently limited in
  their performances by the distance between the external occulter and
  the front objective. The diffraction fringe from the occulter and the
  vignetted pupil which degrades the spatial resolution prevent observing
  the inner corona inside typically 2-2.5 solar radii. Formation flyers
  open new perspectives and allow to conceive giant, externally-occulted
  coronagraphs using a two-component space system with the external
  occulter on one spacecraft and the optical instrument on the
  other spacecraft at approximately 100 m from the first one. ASPICS
  (Association de Satellites Pour l'Imagerie Coronographique Solaire)
  is a mission proposed to CNES in the framework of their demonstration
  program of formation flyers which is presently under study to exploit
  this technique for coronal observations. In the baseline concept,
  ASPICS includes three coronagraphs operating in three spectral
  domains: the visible continuum (K-corona brightness), the HI Lyman
  alpha emission line at 121.6 nm, and the HeII emission line at 30.4
  nm. Their unvignetted fields of view extend from 1.1 to 3.2 solar radii
  with a typical spatial resolution of 3 arcsec. In order to connect
  coronal activity to photospheric events, ASPICS further includes
  two disk imagers. The first one is devoted to the HI Lyman alpha
  emission line. The second one is a multi-channel instrument similar to
  SOHO/EIT and devoted to the HeII (30.4 nm), FeIX/X (17.1 nm) and FeXII
  (19.5 nm) emission lines. Two concepts of the space system are under
  consideration: a symmetric configuration where the disk imagers and
  the external occulter are on one spacecraft and the coronagraphs on
  the other, an asymmetric configuration where the external occulter is
  on one spacecraft and the scientific instruments are regrouped on the
  other one.

---------------------------------------------------------
Title: Innovative designs for the imaging suite on Solar Orbiter
Authors: Auchere, Frederic; Song, Xueyen; Rouesnel, Frederic;
   Appourchaux, Thierry; Fourmon, Jean-Jacques; Le Clec'h,
   Jean-Christophe; Berthe, Michel; Defise, Jean-Marc; Mazy, Emmanuel;
   Rochus, Pierre L.; Mercier, Raymond; Ravet, Marie-Francoise
2005SPIE.5901..298A    Altcode:
  Orbiting around the Sun on an inclined orbit with a 0.2 UA perihelion,
  the Solar Orbiter probe will provide high resolution views of the Sun
  from various angles unattainable from Earth. Together with a set of high
  resolution imagers, the Full Sun Imager is part of the EUV Imaging suite
  of the Solar Orbiter mission. The mission's ambitious characteristics
  draw severe constraints on the design of these instruments. We present
  a photometrically efficient, compact, and lightweight design for the
  Full Sun Imager. With a 5 degrees field of view, this telescope will
  be able to see the global solar coronal structure from high viewing
  angles. Thermal solutions reducing the maximum power trapped in the
  High Resolution Imagers are also proposed.

---------------------------------------------------------
Title: The Heliospheric He II 30.4 nm Solar Flux During Cycle 23
Authors: Auchère, F.; Cook, J. W.; Newmark, J. S.; McMullin, D. R.;
   von Steiger, R.; Witte, M.
2005ApJ...625.1036A    Altcode:
  Because of the orbit characteristics of the vast majority of
  spacecraft, the solar flux has predominantly been measured at Earth
  or at least in the plane of the ecliptic. Therefore, the existing
  data do not directly demonstrate the fact that the latitudinal
  distribution of the extreme-ultraviolet (EUV) solar flux is largely
  anisotropic. Indeed, in the EUV the nonuniform distribution of very
  contrasted bright features (i.e., active regions) and dark features
  (i.e., coronal holes) at the surface of the Sun produces both the
  obvious rotational (or longitudinal) modulation of the flux and also
  a strong latitudinal anisotropy. Although largely ignored up to now,
  the latitudinal anisotropy affects the physical conditions in the
  corona and heliosphere and should therefore be taken into account in
  several solar and heliospheric physics applications. We describe in this
  paper a technique for computing the He II 30.4 nm flux at an arbitrary
  position in the heliosphere from Solar and Heliospheric Observatory
  (SOHO) EUV Imaging Telescope (EIT) images. This procedure was used to
  produce daily all-sky maps of the 30.4 nm flux from 1996 January to 2003
  August, covering the first 8 yr of solar cycle 23. As could be expected
  from the examination of the EIT images, the 30.4 nm flux was found to
  be strongly anisotropic. The anisotropy I<SUB>pol</SUB>/I<SUB>eq</SUB>
  between the fluxes computed for viewpoints located above the solar
  poles and within the solar equatorial plane ranges from 0.9 at solar
  minimum to 0.6 at solar maximum. A 20% difference was also discovered
  between the north and south polar fluxes. The generalization of this
  technique to other lines of the EUV and far-ultraviolet (FUV) spectrum
  is discussed.

---------------------------------------------------------
Title: Effect of the H I Lyα Chromospheric Flux Anisotropy on the
    Total Intensity of the Resonantly Scattered Coronal Radiation
Authors: Auchère, F.
2005ApJ...622..737A    Altcode:
  In modeling of the resonantly scattered solar coronal Lyα line of
  H I, the intensity of the chromospheric source is often assumed to
  be uniform. We investigate the validity of this assumption. After
  establishing a correlation between the H I 121.6 nm and He II 30.4 nm
  line intensities, we build Carrington maps of the Lyα chromosphere from
  SOHO EUV Imaging Telescope data. These maps are used to compute the Lyα
  irradiance throughout the corona and heliosphere. A 15% latitudinal
  anisotropy is found at 1 AU at solar minimum, and this value becomes
  larger closer to the Sun. The effect of the flux anisotropy on the
  total intensity of the Lyα resonantly scattered coronal radiation is
  quantified. We find that at solar minimum, the uniform-disk assumption
  leads to systematic overestimates of the total intensity of the polar
  regions by 15% on average. The evolution of this effect with solar
  activity and the case of other resonantly scattered coronal lines
  are discussed.

---------------------------------------------------------
Title: Model of the all-sky He II 30.4 nm solar flux
Authors: Auchère, F.; Cook, J. W.; Newmark, J. S.; McMullin, D. R.;
   von Steiger, R.; Witte, M.
2005AdSpR..35..388A    Altcode:
  Because of the orbit characteristics of the vast majority of spacecraft,
  the solar flux has been generally measured at Earth or in the plane
  of the ecliptic. So far, most published studies did not consider
  the fact that the extreme ultraviolet (EUV) solar flux is largely
  anisotropic. Indeed, in the EUV, the distribution of very contrasted
  bright and dark features at the surface of the Sun produces both the
  obvious rotational (longitudinal) modulation of the flux, but also a
  strong latitudinal anisotropy. Although largely ignored up to now, the
  latitudinal anisotropy affects the physical conditions in the corona
  and heliosphere. We describe an empirical model of the all-sky He II
  30.4 nm flux based on EIT/ SOHO data. The 30.4 nm flux was found to be
  strongly anisotropic. The anisotropy I<SUB>pol</SUB>/ I<SUB>eq</SUB>
  between the fluxes computed for viewpoints located above the solar
  poles and within the solar equatorial plane ranges from 0.9 at solar
  minimum to 0.6 at solar maximum. A 20% asymmetry was also discovered
  between the north and south polar fluxes.

---------------------------------------------------------
Title: A Model For EUV Flux Throughout The 3-Dimensional Heliosphere
Authors: McMullin, D. R.; Auchere, F.; Cook, J.; Newmark, J. S.;
   Quemerais, E.; von Steiger, R.; Witte, M.
2004AGUFMSH21B0423M    Altcode:
  After July 2001, when Ulysses moved from 30 to 80 degrees in solar
  latitude, the Ulysses GAS instrument measured an apparent increase
  in the neutral He density. This is more naturally interpreted as
  a latitudinal dependence (decrease) of the loss rate due to solar
  photoionization rather than a true increase of the neutral He
  density. We have developed a three-dimensional model for solar EUV
  fluxes observed at any heliospheric position, using daily SOHO EIT
  observations, over successive Carrington rotations, projected to
  any heliospheric position. The combined effects of solar rotational
  and latitude-dependent flux variability are explicitly treated in
  this model. The flux model has been directly compared with other
  direct irradiance observations in the ecliptic plane with the SOHO/SEM
  irradiance time series for validation. We then use this flux to compute
  the photoionization rate of the in-flowing neutral He, and compare the
  modeled change with time along the spacecraft trajectory with the direct
  measurements from the out -of -ecliptic Ulysses GAS observations. The
  3-D model developed will be directly applicable to STEREO EUV images
  from the SECCHI instrument suite. As the two spacecraft separate, the
  amount of the solar surface observed will increase through the mission,
  providing more accurate solar inputs.

---------------------------------------------------------
Title: HERSCHEL Suborbital Program: 3-D Applications for the STEREO
    Mission
Authors: Moses, J. D.; Newmark, J.; McMullin, D.; Antonucci, E.;
   Fineschi, S.; Gardiol, D.; Zangrilli, L.; Romoli, M.; Pace, E.; Gori,
   L.; Landini, F.; Gherardi, A.; da Deppo, V.; Naletto, G.; Nicolosi, P.;
   Pelizzo, M.; Malvezzi, M.; Auchere, F.; Delaboudiniere, J.; Howard, R.
2004AGUFMSH23A..08M    Altcode:
  The HERSCHEL (HElium Resonance Scatter in the Corona and HELiosphere)
  Suborbital Program is an international collaborative program between
  a consortium of Italian Universities &amp; Observatories led by
  Dr. E. Antonucci (and funded by the Italian Space Agency, ASI), the
  French IAS (funded in part by CNES) and the Solar Physics Branch of
  NRL (by NASA SEC and the Office of Naval Research). HERSCHEL will:
  investigate the slow and fast solar wind, determine the helium
  distribution and abundance in the corona, and test solar wind
  acceleration models; by obtaining simultaneous observations of
  the electron, proton and helium solar coronae. HERSCHEL will also
  establish proof-of-principle for the Ultra-Violet Coronagraph, which
  is in the ESA Solar Orbiter Mission baseline. The HERSCHEL launch date
  has been linked to the STEREO launch date to allow coordinated science
  between the two missions. One aspect of this scientific coordination is
  establishing the 3-D structure of the inner corona. HERSCHEL provides
  a third viewpoint for the inner corona covered by the A&amp;B STEREO
  SECCHI COR-1. HERSCHEL is the only scheduled, space-based asset that
  could provide this third viewpoint for the critical inner corona viewed
  by STEREO COR-1 (although lower resolution, ground-based cononagraphs
  will make a contribution). A third viewpoint dramatically increases
  one's ability to establish the 3-D structure of an optically thin object
  (e.g. the metric in Fig. 7 of Davila 1994, ApJ 423, 871). HERSCHEL will
  provide at least a snapshot of that viewpoint, plus a wide range of
  additional information on the H and He composition of the inner corona.

---------------------------------------------------------
Title: On the nature of EIT waves, EUV dimmings and their link to CMEs
Authors: Zhukov, A. N.; Auchère, F.
2004A&A...427..705Z    Altcode:
  EIT waves and extreme-ultraviolet (EUV) dimmings attract particular
  attention as they frequently accompany Coronal Mass Ejections
  (CMEs). We present several examples of EIT waves and EUV dimmings with
  particular morphologies previously unreported in the literature. We
  report for the first time an EIT wave in the Fe XV (284 Å) bandpass
  of the SOHO/EIT instrument. The observations of this event confirm
  previous results that an EIT wave is a purely coronal phenomenon
  that does not propagate in the transition region plasma. Two EIT
  wave events initiated close to the solar limb are investigated,
  thus permitting us to see simultaneously the wave and the magnetic
  configuration of the CME. These observations suggest that EIT wave
  can be regarded as a bimodal phenomenon. The wave mode represents a
  wave-like propagating disturbance. Its characteristic features are
  propagation of a bright front to large distances from dimming sites
  and quasi-circular appearance. The eruptive mode is the propagation
  of a dimming and of an EIT wave as a result of successive opening of
  magnetic field lines during the CME lift-off. It can be identified by
  noting the expansion of a dimming and the appearance of another dimming
  ahead of a bright front. We reveal the temperature structure of the EUV
  dimmings that appeared after the classical EIT wave event on May 12,
  1997, using differential emission measure (DEM) maps obtained through
  the analysis of images in four EIT bandpasses. The part of the CME
  mass contained in the low corona observed by the EIT is estimated to
  be about 10<SUP>15</SUP> g. It appears that around 50% of this total
  CME mass in the low corona is contained outside of transient coronal
  holes. It is shown that at present it is difficult to reconcile all
  the observational facts into a coherent physical model. In particular,
  the physical nature of the wave mode of EIT waves remains elusive. <P
  />Movies are available in electronic form at http://www.edpsciences.org

---------------------------------------------------------
Title: EIT Observations of the 15 November 1999 Mercury Transit
Authors: Auchère, F.; Artzner, G. E.
2004SoPh..219..217A    Altcode:
  The Mercury transit of 15 November 1999 has been observed from space
  by the SOHO and TRACE spacecraft. We exploited the data recorded by
  EIT/SOHO to determine the stray-light level and the plate-scale of
  the instrument. The asymmetric distribution of stray light across the
  images is confirmed, but the absolute amount was found to be higher
  than previously estimated. The plate scale averaged over wavelengths
  was found to be 2.627±0.001 arc sec pixel<SUP>−1</SUP>, in excellent
  agreement with two previous and independent determinations.

---------------------------------------------------------
Title: MAGRITTE: an instrument suite for the solar atmospheric
    imaging assembly (AIA) aboard the Solar Dynamics Observatory
Authors: Rochus, Pierre L.; Defise, Jean-Marc; Halain, Jean-Philippe;
   Jamar, Claude A. J.; Mazy, Emmanuel; Rossi, Laurence; Thibert,
   Tanguy; Clette, Frederic; Cugnon, Pierre; Berghmans, David; Hochedez,
   Jean-Francois E.; Delaboudiniere, Jean-Pierre; Auchere, Frederic;
   Mercier, Raymond; Ravet, Marie-Francoise; Delmotte, Franck; Idir,
   Mourad; Schuehle, Udo H.; Bothmer, Volker; Fineschi, Silvano; Howard,
   Russell A.; Moses, John D.; Newmark, Jeffrey S.
2004SPIE.5171...53R    Altcode:
  The Solar Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics
  Observatory will characterize the dynamical evolution of the solar
  plasma from the chromosphere to the corona, and will follow the
  connection of plasma dynamics with magnetic activity throughout the
  solar atmosphere. The AIA consists of 7 high-resolution imaging
  telescopes in the following spectral bandpasses: 1215Å. Ly-a,
  304 Å He II, 629 Å OV, 465 Å Ne VII, 195 Å Fe XII (includes Fe
  XXIV), 284 Å Fe XV, and 335 Å Fe XVI. The telescopes are grouped
  by instrumental approach: the MAGRITTE Filtergraphs (R. MAGRITTE,
  famous 20th Century Belgian Surrealistic Artist), five multilayer EUV
  channels with bandpasses ranging from 195 to 1216 Å, and the SPECTRE
  Spectroheliograph with one soft-EUV channel at OV 629 Å. They will be
  simultaneously operated with a 10-second imaging cadence. These two
  instruments, the electronic boxes and two redundant Guide Telescopes
  (GT) constitute the AIA suite. They will be mounted and coaligned on a
  dedicated common optical bench. The GTs will provide pointing jitter
  information to the whole SHARPP assembly. This paper presents the
  selected technologies, the different challenges, the trade-offs to be
  made in phase A, and the model philosophy. From a scientific viewpoint,
  the unique combination high temporal and spatial resolutions with the
  simultaneous multi-channel capability will allow MAGRITTE / SPECTRE
  to explore new domains in the dynamics of the solar atmosphere, in
  particular the fast small-scale phenomena. We show how the spectral
  channels of the different instruments were derived to fulfill the
  AIA scientific objectives, and we outline how this imager array will
  address key science issues, like the transition region and coronal waves
  or flare precursors, in coordination with other SDO experiments. We
  finally describe the real-time solar monitoring products that will be
  made available for space-weather forecasting applications.

---------------------------------------------------------
Title: EUVI: the STEREO-SECCHI extreme ultraviolet imager
Authors: Wuelser, Jean-Pierre; Lemen, James R.; Tarbell, Theodore
   D.; Wolfson, C. J.; Cannon, Joseph C.; Carpenter, Brock A.; Duncan,
   Dexter W.; Gradwohl, Glenn S.; Meyer, Syndie B.; Moore, Augustus S.;
   Navarro, Rosemarie L.; Pearson, J. D.; Rossi, George R.; Springer,
   Larry A.; Howard, Russell A.; Moses, John D.; Newmark, Jeffrey S.;
   Delaboudiniere, Jean-Pierre; Artzner, Guy E.; Auchere, Frederic;
   Bougnet, Marie; Bouyries, Philippe; Bridou, Francoise; Clotaire,
   Jean-Yves; Colas, Gerard; Delmotte, Franck; Jerome, Arnaud; Lamare,
   Michel; Mercier, Raymond; Mullot, Michel; Ravet, Marie-Francoise;
   Song, Xueyan; Bothmer, Volker; Deutsch, Werner
2004SPIE.5171..111W    Altcode:
  The Extreme Ultraviolet Imager (EUVI) is part of the SECCHI instrument
  suite currently being developed for the NASA STEREO mission. Identical
  EUVI telescopes on the two STEREO spacecraft will study the structure
  and evolution of the solar corona in three dimensions, and specifically
  focus on the initiation and early evolution of coronal mass ejections
  (CMEs). The EUVI telescope is being developed at the Lockheed Martin
  Solar and Astrophysics Lab. The SECCHI investigation is led by the
  Naval Research Lab. The EUVI"s 2048 x 2048 pixel detectors have a
  field of view out to 1.7 solar radii, and observe in four spectral
  channels that span the 0.1 to 20 MK temperature range. In addition to
  its view from two vantage points, the EUVI will provide a substantial
  improvement in image resolution and image cadence over its predecessor
  SOHO-EIT, while complying with the more restricted mass, power, and
  volume allocations on the STEREO mission.

---------------------------------------------------------
Title: H/He+ intensity variations of the cool corona
Authors: Noens, J. -C.; Balestat, M. -F.; Jimenez, R.; Rochain, S.;
   Romeuf, D.; Auchere, F.; Delaboudiniere, P.; Koutchmy, S.
2004IAUS..223..291N    Altcode: 2005IAUS..223..291N
  No abstract at ADS

---------------------------------------------------------
Title: An atlas of solar events: 1997-2004
Authors: Artzner, G.; Auchère, F.; Delaboudinière, J. P.; Bougnet, M.
2004cosp...35.2494A    Altcode: 2004cosp.meet.2494A
  Coronal mass ejections (CMEs) are observed in the plane of the sky
  from coronographic images. As the solar surface is then masked by an
  occulting disk, it is not clear wether halo CMEs are directed towards
  the Earth or in the opposite direction. Observations of the solar corona
  on the solar disk from the Extreme Ultraviolet Imaging Telescope EIT on
  board the Solar Heliospheric Observatory SoHO do help in order to make
  a choice. Quasi-continuous observations of the corona of the Sun have
  been therefore obtained from april 1997 up to now at a twelve minute
  cadence in the coronal line of FeXII, as a CME watch program. At a
  slower six hours cadence an additional synoptic program investigates
  the chromosphere and the corona at four different wavelengths. Large
  coronal solar events appear when viewing animations of the CME watch
  program. Fainter events do appear when viewing running difference
  animations of the CME watch program. When looking for additional
  spectral information from raw running differences of the synoptic
  program it is difficult to disentangle intrinsic solar events from
  the parasitic effect of the solar rotation. We constructed from the
  synoptic program observations an atlas of more than 20 000 difference
  images corrected for an average solar rotation. We present case studies
  of specific events in order to investigate the source of darkenings in
  difference images, either removal of emitting material, interposition
  of obscuring material or large changes of temperature. Statistics
  of brigtenings and darkenings along solar cycle 23 are presented. We
  speculate about future observations from the STEREO mission in order
  to obtain better diagnostics about darkenings. As a by product of the
  atlas of solar events we obtain a number of quiet time sequences well
  suited in order to precisely measure the differnetial solar rotation
  by the apparent displacement of tracers.

---------------------------------------------------------
Title: Model for 3-D Heliospheric EUV Irradiance and Photoionization
Authors: Auchère, F.; McMullin, D.; Cook, J.; Newmark, J.; Vonsteiger,
   R.; Witte, M.; Quémerais, E.
2004cosp...35.2558A    Altcode: 2004cosp.meet.2558A
  For 8 years now, the EIT instrument on board SOHO continuously monitored
  the solar activity in four passbands of the EUV spectrum. With the
  SOHO mission extended, it is likely that the final EIT data set will
  cover one complete solar cycle. This exceptional data set offers an
  unprecedented opportunity to investigate the long-term variations of
  the solar EUV irradiance. Furthermore, with the spatial resolution of
  the EIT/SOHO instrument, the data can also be used to study variations
  of the solar irradiance with heliocentric latitude. It is indeed
  clear that the wide intensity range of the various emitting regions
  (polar coronal holes, equatorial active regions, etc.) produces
  a latitude-dependant irradiance. To date, due to the small number
  of off-ecliptic measurements, very few attempts have been made to
  investigate these variations. We present here an empirical model of the
  EUV solar flux at any point in the heliosphere derived from EIT/SOHO
  data. At 30.4 nm, the anisotropy I_⊥ / I_∥ between the irradiance
  above (⊥) and within (∥) the ecliptic plane is found to range
  from about 0.8 at solar minimum to about 0.6 at solar maximum. Our
  anisotropic EUV fluxes are used to improve the present estimates of
  the photoionization rate of in-flowing neutral helium. These new rates
  are compared to the relative changes of neutral helium density measured
  by the GAS/Ulysses instrument.

---------------------------------------------------------
Title: The Ultraviolet and Visible-light Coronagraph of the HERSCHEL
    experiment
Authors: Romoli, M.; Antonucci, E.; Fineschi, S.; Gardiol, D.;
   Zangrilli, L.; Malvezzi, M. A.; Pace, E.; Gori, L.; Landini, F.;
   Gherardi, A.; da Deppo, V.; Naletto, G.; Nicolosi, P.; Pelizzo, M. G.;
   Moses, J. D.; Newmark, J.; Howard, R.; Auchere, F.; Delaboudinière,
   J. P.
2003AIPC..679..846R    Altcode:
  The Herschel (HElium Resonant Scattering in the Corona and HELiosphere)
  experiment, to be flown on a sounding rocket, will investigate the
  helium coronal abundance and the solar wind acceleration from a
  range of solar source structures by obtaining the first simultaneous
  observations of the electron, proton and helium solar corona. The
  HERSCHEL payload consists of the EUV Imaging Telescope (EIT), that
  resembles the SOHO/EIT instrument, and the Ultraviolet and Visible
  Coronagraph (UVC).UVC is an imaging coronagraph that will image
  the solar corona from 1.4 to 4 solar radii in the EUV lines of HI
  121.6 nm and the HeII 30.4 nm and in the visible broadband polarized
  brightness. The UVC coronagraph is externally occulted with a novel
  design as far as the stray light rejection is concerned. Therefore,
  HERSCHEL will also establish proof-of-principle for the Ultraviolet
  Coronagraph, which is in the ESA Solar Orbiter Mission baseline.The
  scientific objectives of the experiment will be discussed, togetherwith
  a description of the UVC coronagraph.

---------------------------------------------------------
Title: The solar high-resolution imager - coronagraph LYOT mission
Authors: Vial, Jean-Claude; Song, Xueyan; Lemaire, Philippe; Gabriel,
   Alan H.; Delaboudiniere, Jean-Pierre; Bocchialini, Karine; Koutchmy,
   Serge L.; Lamy, Philippe L.; Mercier, Raymond; Ravet, Marie Francoise;
   Auchere, Frederic
2003SPIE.4853..479V    Altcode:
  The LYOT (LYman Orbiting Telescope) solar mission is proposed to
  be implemented on a micro-satellite of CNES (France) under phase A
  study. It includes two main instruments, which image the solar disk
  and the low corona up to 2.5 R<SUB>o</SUB> in the H I Lyman-α line
  at 121.6 nm. The spatial resolution is about 1” for the disk and
  2.5” for corona. It also carries an EIT-type telescope in the He II
  (30.4 nm) line. The coronagraph needs a super polished mirror at the
  entrance pupil to minimize the light scattering. Gratings and optical
  filters are used to select the Lyman-α wavelength. VUV cameras with
  2048×2048 pixels record solar images up to every 10 seconds. The
  satellite operates at a high telemetry rate (more then 100 kb/s,
  after onboard data compression). The envisaged orbits are either
  geostationary or heliosynchronous. Possible launch dates could be end
  of 2006 - beginning of 2007.

---------------------------------------------------------
Title: MAGRITTE / SPECTRE : the Solar Atmospheric Imaging Assembly
    (AIA) aboard the Solar Dynamics Observatory
Authors: Rochus, P.; Defise, J. M.; Halain, J. P.; Mazy, E.; Jamar, C.;
   Clette, F.; Cugnon, P.; Berghmans, D.; Hochedez, J. F.; Delaboudiniere,
   J. P.; Artzner, G.; Auchere, F.; Mercier, R.; Ravet, M. F.; Delmotte,
   M.; Idir, M.; Fineschi, S.; Antonucci, E.; Harrison, R. A.; Howard,
   R. A.; Moses, J. D.; Newmark, J. S.
2002AGUFMSH21C..05R    Altcode:
  The Solar Atmospheric Imaging Assembly (AIA) aboard the Solar
  Dynamics Observatory will characterize the dynamical evolution of
  the solar plasma from the chromosphere to the corona, and will follow
  the connection of plasma dynamics with magnetic activity throughout
  the solar atmosphere. The AIA consists of 7 high resolution imaging
  telescopes in the following spectral bandpasses: 1215 \x8F Ly-a, 304
  \x8F He II, 629 \x8F OV, 465 \x8F Ne VII, 195 \x8F Fe XII (includes Fe
  XXIV), 284 \x8F Fe XV, and 335 \x8F Fe XVI. The telescopes are grouped
  by instrumental approach: the Magritte Filtergraphs (R. Magritte,
  famous 20th Century Belgian Surrealistic Artist), five multilayer EUV
  channels with bandpasses ranging from 195 to 1216 \x8F, and the SPECTRE
  Spectroheliograph with one soft-EUV channel at OV 629 \x8F. They will
  be simultaneously operated with a 10-second imaging cadence. These two
  instruments, the electronic boxes and two redundant Guide Telescopes
  (GT) constitute the AIA suite. They will be mounted and coaligned on a
  dedicated common optical bench. The GTs will provide pointing jitter
  information to the whole SHARPP assembly. This poster presents the
  selected technologies, the different challenges, the trade-offs to be
  made in phase A, and the model philosophy. From a scientific viewpoint,
  the unique combination high temporal and spatial resolutions with the
  simultaneous multi-channel capability will allow Magritte/SPECTRE
  to explore new domains in the dynamics of the solar atmosphere, in
  particular the fast small-scale phenomena. We show how the spectral
  channels of the different instruments were derived to fulfill the
  AIA scientific objectives, and we outline how this imager array will
  address key science issues, like the transition region and coronal waves
  or flare precursors, in coordination with other SDO experiments. We
  finally describe the real-time solar monitoring products that will be
  made available for space-weather forecasting applications.

---------------------------------------------------------
Title: HElium Resonance Scattering in the Corona and HELiosphere
    (HERSCHEL)
Authors: Moses, J. D.; Newmark, J.; Howard, R.; Auchere, F.; Antonucci,
   E.; Fineschi, S.; Romoli, M.
2002AGUSMSH21B..03M    Altcode:
  The proposed HERSCHEL (HElium Resonance Scattering in the Corona and
  HELiosphere) program will investigate coronal heating and solar wind
  acceleration from a range of solar source structures by obtaining
  simultaneous observations of the electron, proton and helium solar
  coronae. The HERSCHEL will establish proof-of-principle for the
  Ultra-Violet Coronagraph (UVC), which is in the ESA Solar Orbiter
  Mission baseline. The NRL Solar Physics Branch is joining with the
  Italian UVC Consortium to address the objectives of the International
  Living With a Star program with this combination of NASA suborbital
  program and ESA Solar Orbiter flight opportunities. Indeed, while
  the Solar Orbiter flight is still many years away, the 3 year program
  being proposed here is essential in order to prove the validity of this
  exciting new concept before the Solar Orbiter instrument selection is
  finalized. This proposal aims to develop instrumentation that for the
  first time will directly image and characterize on a global coronal
  scale the two must abundant elements, hydrogen and helium. This will
  directly address three outstanding questions in the Sun-Earth Connection
  theme: 1) Origin of the slow solar wind, 2) Acceleration mechanisms of
  the fast solar wind, and 3) Variation of Helium abundance in coronal
  structures. Additionally, by establishing proof of concept for the
  UVC on Solar Orbiter, this will facilitate future investigations
  of CME's kinematics, and solar cycle evolution of the electron,
  proton, and helium coronae. Lastly, this mission fits the goals of
  the International Living With a Star (ILWS) program. This work has
  been supported by the Office of Naval Research.

---------------------------------------------------------
Title: The Radiometric Calibration of the Extreme Ultraviolet
    Imaging Telescope
Authors: Clette, F.; Hochedez, J. -F.; Newmark, J. S.; Moses, J. D.;
   Auchère, F.; Defise, J. -M.; Delaboudinière, J. -P.
2002ISSIR...2..121C    Altcode: 2002ESASR...2..121C; 2002rcs..conf..121C
  After a five-year effort, the analysis of the pre-flight and in-flight
  calibrations of EIT is finally yielding firm results. In this
  introductory overview, we will summarize what we learned "internally"
  from EIT itself. This includes the interpretation of the pre-flight
  calibrations, the original flat-field components (CCD, grid), the
  in-flight determination of the point-spread function and straylight and
  the compensation of the in-orbit response degradation. Based on this
  experience, we conclude with some suggestions of possible improvements
  to future calibrations, on SOHO and other planned missions.

---------------------------------------------------------
Title: SWRI/LASP Sounding Rocket Inter-Calibration With The Eit
    Instrument On Board SOHO
Authors: Auchère, Frédéric; Hassler, Donald M.; Slater, David C.;
   Woods, Thomas N.
2001SoPh..202..269A    Altcode:
  Two successful sounding rocket flights were launched on 15 May 1997 and
  2 November 1998 with an objective of providing inter-calibration with
  several of the instruments on board SOHO and TRACE. We will discuss
  here the results of the inter-calibration between the SwRI/LASP rocket
  imaging instruments and the Extreme-ultraviolet Imaging Telescope (EIT)
  on SOHO. The Multiple XUV Imager (MXUVI) sounding rocket instrument
  is a multi-layer mirror telescope equipped with an internal occulter
  and light trap to provide full-disk images of Fe ix/x 17.1 nm and
  off-limb observations of He ii 30.4 nm. The SOHO/EIT instrument is
  also a full-disk multi-layer imager with four channels, Fe ix/x 17.1
  nm, Fe xii 19.5 nm, Fe xv 28.4 nm and He ii 30.4 nm. By comparison
  with the EIT observations taken at the same time, we provide new
  flat-field determinations for EIT which help quantify the sensitivity
  degradation of the EIT detector, as well as provide a measure of the
  off-limb stray-light characteristics of the two instruments. We find
  that the EIT stray-light function is strongly asymmetric, with greater
  stray light in the 17.1 and 19.5 nm quadrants than the 30.4 and 28.4
  nm quadrants. Two possible causes of this asymmetry are the polishing
  processes of the EIT mirrors and the asymmetric support grid pattern
  in the foil mesh at the EIT pupil.

---------------------------------------------------------
Title: The Height Variations of the Solar Chromosphere
Authors: Auchère, F.
2001AGUSM..SH21B03A    Altcode:
  We present a five year survey of the height of the solar chromosphere,
  as observed by the Extreme Ultraviolet Imaging Telescope (EIT) in
  its four bandpasses : 17.1 nm (FeIX/FeX), 19.5 nm (FeXII), 28.4 nm
  (FeXV), and 30.4 nm (HeII). Spatial pole-equator variations, as well
  as long-term temporal variations were investigated. The chromosphere
  was found to be prolate in all four wavelengths, with typical values
  of Δ D/D = 5x 10<SUP>-3</SUP> in HeII and 1x 10<SUP>-3</SUP> in the
  three iron lines. We found a very good correlation of the prolateness
  effect with the presence of polar coronal holes, and could follow
  its vanishing as the solar cycle peaked. The similitude between our
  results and previous observations made in various other lines suggest
  that the prolateness is a fundamental aspect of the solar atmosphere.

---------------------------------------------------------
Title: In-flight Calibration of SOHO EIT
Authors: Newmark, J. S.; Cook, J. W.; Auchere, F.; Moses, J. D.;
   Clette, F.
2001AGUSM..SP21B06N    Altcode:
  The SOHO EIT response has varied both temporally and spatially
  throughout the mission. A large effort has been put forth into
  understanding instrument responsivity changes, the spectral response
  and absolute calibration. The latter two have been completed (Dere et
  al. 2000, Newmark 2000). The response degradation process consists of
  several components which are difficult to separate in detail. The two
  basic processes contributing to the degradation are 1) the absorption
  of EUV before it interacts with the CCD by a surface contaminant plus
  possible blackening of the entrance filter and 2) the reduction of
  charge collection efficiency (CCE) in the CCD due to EUV induced device
  damage. A method utilizing the in-flight calibration lamps has been
  developed which accurately characterizes the sensitivity changes. We
  present absolutely calibrated SOHO EIT data from 1996 - 2000.

---------------------------------------------------------
Title: An Observational Study of Helium in the Solar Corona with
    the EIT Instrument on Board the SOHO Spacecraft
Authors: Auchere, F.
2000PhDT........69A    Altcode:
  Helium is the second most abundant element in the Universe. The
  understanding of the physicals processes associated with helium as well
  as the determination of the helium abundance both have implications
  in various research fields such as cosmology, stellar evolution
  or the physics of the solar wind. Helioseismology techniques give
  accurate measurements of the helium abundance in the solar interior,
  spectroscopic techniques provide diagnostics in the photosphere and
  in the chromosphere, and in situ measurements in the solar wind at 1
  A.U. are carried out with particle detectors. But very few observations
  of helium exist in the corona and therefore, our knowledge of helium
  at intermediate distances between the photosphere and the solar wind
  is essentially based on theoretical studies. The present work is a
  tentative contribution to help constraint the observational knowledge
  of helium in the solar corona. The EIT telescope on board the SOHO
  spacecraft can observe the solar corona up to 2 Rs in an interval
  of wavelengths in the extreme ultraviolet spectrum including the
  resonance line of the He+ ion at 30.378 nm. This line being formed in
  the solar corona by resonant scattering of the chromospheric flux by
  coronal He+ ions, its intensity is proportional to the number density
  of He+ ions. Therefore, the observation of this line in the corona can
  potentially provide interesting diagnostics of the coronal helium. In
  spite of the contamination by other spectral lines, it seems that a
  non negligible fraction of the signal recorded by EIT in its 30.4 nm
  bandpass can be attribuated to the resonance line of He+. Furthermore,
  a preliminary study seems to show that the observed intensity gradients
  are anomalously low in the polar regions. The aim of the present work
  was to investigate further these preliminary results. We first carried
  out a detailed critical analysis of the characteristics of the EIT
  instrument in order to confirm that the 30.378 nm line of He+ in the
  corona can be detected in the 30.4 nm bandpass of EIT. This analysis
  implies a precise evaluation of several calibration parameters such
  as the flat-field of the detector, the contamination of the 30.4 nm
  bandpass and the instrumental stray light level. In order to interpret
  the intensities measured with EIT, we developed a model of the intensity
  of the resonance line of He+ in the corona, with the existing models
  for the Lyman alpha line of neutral hydrogen as a starting point. This
  model requires as an input some physical parameters such as the
  electron temperature and electron density, which were independently
  determined either from previous results or from new observations. The
  comparisons between the observed intensity and the prediction of the
  model seem to confirm the results of the preliminary analysis. In
  the equatorial regions, the intensity gradient of the resonance line
  of He+ is compatible with the electron density scale height. But at
  high latitudes in the polar coronal holes, the intensity gradient seems
  significatively smaller than what is expected from the computations. One
  can interpret this observation by an accumulation of helium in the polar
  coronal holes, where the fast solar wind originate. If the coronal
  ionisation balance computed in the model is valid, this accumulation
  of He+ could be the signature of an enhanced helium abundance in the
  corona. Some theoretical models of the corona/solar wind system show
  that the helium abundance could indeed be 20% or more in the corona,
  even though it is 10% in the solar interior and 4% in the solar
  wind. Because helium is four times more massive than hydrogen, it is
  clear the an enhanced helium abundance in the corona would greatly
  impact the energy and momentum uxes in the solar wind. However, further
  observations, especially with a better spectral resolution and a lower
  stray light level, are needed to confirm those of EIT.

---------------------------------------------------------
Title: Results from the 2 November 1998 SwRI/LASP Sounding Rocket
    Campaign
Authors: Hassler, D. M.; Auchere, F.; Handy, B.; Strachan, L.; Slater,
   D.; Woods, T. N.
2000SPD....31.0216H    Altcode: 2000BAAS...32..813H
  We present results from the November 2, 1998 SwRI/LASP sounding rocket
  campaign with the dual purpose of providing inter-calibration for the
  SOHO/EIT and TRACE instruments and providing a measure of the coronal
  helium abundance by direct comparison of the coronal Ly-alpha lines
  of He II (304 angstroms) and H I (1216 angstroms). The sounding rocket
  payload provided full-disk solar images of Fe IX/X 171 and H I Ly-alpha
  1216 for inter-calibration with the SOHO/EIT and TRACE instruments,
  respectively, as well as off-limb observations of the He II 304 line to
  be compared with off-limb SOHO/UVCS observations of the H I 1216 line
  to provide a constraint on the coronal helium abundance. This work
  has been funded in part by NASA under grant NAG5-5140 to Southwest
  Research Institute.

---------------------------------------------------------
Title: In-Flight Determination of the Plate Scale of the
    Extreme-Ultraviolet Imaging Telescope
Authors: Auchère, F.; DeForest, C. E.; Artzner, G.
2000ApJ...529L.115A    Altcode:
  Using simultaneous observations of the Michelson Doppler Imager
  and Extreme-Ultraviolet Imaging Telescope (EIT) on board the Solar
  and Heliospheric Observatory spacecraft, we determined in flight
  the plate scale of the EIT. We found a value of 2.629"+/-0.001"
  pixel<SUP>-1</SUP>, in fair agreement with the 2.627"+/-0.001"
  pixel<SUP>-1</SUP> value deduced from recent laboratory measurements
  of the focal length and much higher by 7 σ than the 2.622"
  pixel<SUP>-1</SUP> value of the preflight calibrations. The plate
  scale is found to be constant across the field of view, confirming
  the negligible distortion level predicted by the theoretical models
  of the EIT. Furthermore, the 2 σ difference between our results and
  the latest laboratory measurements, although statistically small, may
  confirm a recent work suggesting that the solar photospheric radius
  may be 0.5 Mm lower than the classically adopted value of 695.99 Mm.

---------------------------------------------------------
Title: In Flight Determination of the Plate Scale of the EIT
Authors: Auchere, F.; DeForest, C. E.; Artzner, G.
1999astro.ph.12213A    Altcode:
  Using simultaneous observations of the MDI and EIT instruments on
  board the SoHO spacecraft, we determined in flight the plate scale
  of the EIT. We found a value of 2.629+-0.001 arc seconds per pixel,
  in fair agreement with the 2.627+-0.001 arc seconds per pixel value
  deduced from recent laboratory measurements of the focal length, and
  much higher by 7 sigma than the 2.622 arc seconds per pixel value of
  the pre-flight calibrations. The plate scale is found to be constant
  across the field of view, confirming the negligible distortion level
  predicted by the theoretical models of the EIT. Furthermore, the 2 sigma
  difference between our results and the latest laboratory measurements,
  although statistically small, may confirm a recent work suggesting that
  the solar photospheric radius may be 0.5 Mm lower than the classically
  adopted value of 695.99 Mm.

---------------------------------------------------------
Title: SwRI/LASP sounding rocket intercalibration with the EIT
    instrument on board SoHO
Authors: Auchere, Frederic; Hassler, Donald M.; Slater, David C.;
   Woods, Thomas N.
1999SPIE.3765..351A    Altcode:
  Two successful sounding rocket flights were launched on May 15, 1997
  and November 2, 1998 with an objective of providing inter-calibration
  with several of the instruments on board SoHO and TRACE. We will
  discuss here the results of the inter-calibration between the SwRI/LASP
  rocket imaging instruments and the Extreme-UV Imaging Telescope (EIT)
  on SoHO. The MXUVI sounding rocket instrument is a multi-layer mirror
  telescope equipped with a special internal occulter and light trap to
  provide full disk imags of Fe IX/X 17.1 nm and off-limb observations of
  He II 30.4 nm. The SoHO/EIT instrument is also a full disk multi-layer
  imager with four channels, Fe IX/X 17.1 nm, FE XII 19.5 nm, Fe XV 28.4
  nm and He II 30.4 nm. By comparison with the EIT observations taken at
  the same time we can quantify the sensitivity degradation of the EIT
  detector, as well as measure the off-limb stray- light characteristics
  of the two instruments.

---------------------------------------------------------
Title: The Prolate Solar Chromosphere
Authors: Koutchmy, S.; di Folco, E.; Auchere, F.; Baudin, F.;
   Delaboudinière, J. -P.; Koutchmy, O.; Noëns, J. -C.; Rondi, S.;
   Jimemez, R.; Smartt, R. N.
1999ESASP.446..385K    Altcode: 1999soho....8..385K
  The solar prolateness above h=2Mm is now well established from
  measurements performed during the years of solar minimum in HeII, Hα
  and K3CaII lines. Low level coronal emissions usually penetrate deep
  enough to completely mask this effect and show CH, quite similarly to
  the behaviour of the HeI lines (D3; 1083nm) which does not show the
  prolateness. We discuss the most recent observations for 1999 given
  by a new facility developped at Pic du Midi Observatory (HACO II)
  and we compare the results with EIT results in HeII. We also brielfly
  discuss the possible interpretations of the prolateness effect. We
  favor topological effects implying a large number of nano-flares
  and ejecta during the interactions of small-scale low level network
  magnetic fields with the more static large-scale magnetic field.

---------------------------------------------------------
Title: In-flight characterization and compensation of the optical
    properties of the EIT instrument
Authors: Defise, Jean-Marc; Clette, Frederic; Auchere, Frederic
1999SPIE.3765..341D    Altcode:
  Onboard the SOHO spacecraft, the Extreme UV Imaging Telescope
  (EIT) is imagin successfully the EUV solar corona since January
  96. EIT is a normal incidence telescope, segmented in 4 separate
  quadrants. Each of those quadrants reflects extreme UV (EUV) light
  in a narrow bandpass defined by multilayer coatings deposited on
  the mirrors and by aluminum filters used to reject the visible and
  IR part of the solar irradiance. The specific configuration of the
  optical system is generating artifacts that must be compensated in the
  raw solar images. However, the only information available to improve
  image quality comes from the continuous survey of the solar corona
  accomplished in flight by EIT. In-flight image characteristics and
  instrumental aspects are discussed in this paper, showing how methods
  can be derived to clean up the EIT data. The current investigations
  are addressing the internal vignetting, the shadow pattern of grids
  supporting the focal filters, the determination of the instrumental
  point spread function and the assessment of the telescope focusing,
  as well as the relation between those factors.

---------------------------------------------------------
Title: SwRI/LASP sounding rocket inter-calibration with SOHO/EIT.
Authors: Hassler, D. M.; Auchere, F.; Slater, D.; Woods, T. N.
1999BAAS...31.1241H    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: SwRI/LASP Sounding Rocket Inter-calibration with SOHO/EIT
Authors: Hassler, D. M.; Auchere, F.; Slater, D.; Woods, T. N.
1999AAS...19410803H    Altcode:
  Two successful sounding rocket flights were launched on May 15, 1997
  and Nov. 2, 1998 with an objective of providing inter-calibration with
  several of the instruments on SOHO and TRACE. We will discuss here
  the results of this inter-calibration between the SwRI/LASP rocket
  imaging instruments and the Extreme Ultraviolet Imaging Telescope (EIT)
  on SOHO. The Multiple XUV Imager (MXUVI) sounding rocket instrument is
  a multi-layer mirror telescope equiped with a special internal occulter
  and light trap to provide full disk images of Fe IX/X 171 A and off-limb
  observations of He II 304 A. The SOHO/EIT instrument is also a full disk
  multi-layer imager with four channels, Fe IX/X 171 A, Fe XII 195 A,
  Fe XV 284 A and He II 304 A. By comparison with the EIT observations
  taken at the same time we can quantify the sensitivity degradation or
  "limb-burning" of the EIT detector and construct a "flat field", as
  well as measure the off-limb stray light characteristics of the EIT
  He II 304 A channel. We will also discuss the radiometric calibration
  transfer between the rocket instrument and EIT.

---------------------------------------------------------
Title: Equivalent focal length measurements
Authors: Artzner, Guy E.; Auchere, Frederic; Delaboudiniere,
   Jean-Pierre; Hochedez, Jean-Francois E.
1999SPIE.3737...32A    Altcode:
  Converting linear coordinates in the plane of the detector of
  an astronomical instrument to celestial coordinates involves in
  principle the equivalent focal length of the instrument. However,
  most methods in astrometry manage to reduce observations in a global
  manner without actually measuring a focal length. We point out a case
  for solar space observations where the long term stability of angular
  distance measurements is better than the ground calibration of the
  angular value of a pixel. We report and discuss this ground calibration.

---------------------------------------------------------
Title: The prolate solar chromosphere
Authors: Auchere, F.; Boulade, S.; Koutchmy, S.; Smartt, R. N.;
   Delaboudiniere, J. P.; Georgakilas, A.; Gurman, J. B.; Artzner, G. E.
1998A&A...336L..57A    Altcode:
  We present a comparative analysis of the chromospheric solar
  limb prolateness, using strictly simultaneous H_alpha ground-based
  observations and Heriptsize{II} space-based observations. The typical
  prolateness is found to be Delta D/D=5.5*E(-3) in Heriptsize{II}
  and 1.2*E(-3) in H_alpha . The first measurements in the 30.4 nm
  Heriptsize{II} line over a period of two years, as well as coronal
  data, are discussed to explore further the origin of the prolateness
  and its possible consequences.

---------------------------------------------------------
Title: The polar extension of the solar chromosphere
Authors: Auchère, F.; Delaboudinière, J. P.; Koutchmy, S.;
   Boulade, S.
1998ESASP.421..245A    Altcode: 1998sjcp.conf..245A
  No abstract at ADS