explanation      blue bibcodes open ADS page with paths to full text
Author name code: mein
ADS astronomy entries on 2022-09-14
author:"Mein, Pierre" OR author:"Mein, Nicole" 

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Title: The SLED project and the dynamics of coronal flux ropes
Authors: Malherbe, Jean-Marie; Mein, Pierre; Sayède, Frédéric;
   Rudawy, Pawel; Phillips, Kenneth; Keenan, Francis; Rybák, Jan
2022AdSpR..70.1562M    Altcode:
  Investigations of the dynamics of the hot coronal plasma are crucial
  for understanding various space weather phenomena and making in-depth
  analyzes of the global heating of the solar corona. We present here
  numerical simulations of observations of siphon flows along loops
  (simple semi-circular flux ropes) to demonstrate the capabilities of
  the Solar Line Emission Dopplerometer (SLED), a new instrument under
  construction for imaging spectroscopy. It is based on the Multi-channel
  Subtractive Double Pass (MSDP) technique, which combines the advantages
  of filters and slit spectrographs. SLED will observe coronal structures
  in the forbidden lines of FeX 6374 Å and FeXIV 5303 Å, and will
  measure Doppler shifts up to 150 km s<SUP>-1</SUP> at high precision
  (50 m s<SUP>-1</SUP>) and cadence (1 Hz). It is optimized for studies
  of the dynamics of fast evolving events such as flares or Coronal
  Mass Ejections (CMEs), as well as for the detection of high-frequency
  waves. Observations will be performed with the coronagraph at Lomnický
  Štít Observatory (LSO), and will also occur during total solar
  eclipses as SLED is a portable instrument.

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Title: Non-LTE Inversion of Prominence Spectroscopic Observations
    in Hα and Mg II h&amp;k lines
Authors: Jejčič, Sonja; Heinzel, Petr; Schmieder, Brigitte; Gunár,
   Stanislav; Mein, Pierre; Mein, Nicole; Ruan, Guiping
2022ApJ...932....3J    Altcode:
  We continued our investigation of the plasma characteristics of a
  quiescent prominence that occurred on 2017 March 30. The prominence
  was observed simultaneously by several instruments, including the
  Interface Region Imaging Spectrograph (IRIS) and the Multichannel
  Subtractive Double Pass (MSDP) spectrograph operating at the Meudon
  solar tower. We focused on IRIS Mg II h&amp;k and MSDP Hα spectra,
  selecting 55 well-coaligned points within the prominence. We computed
  an extensive grid of 63,000 isothermal and isobaric 1D-slab prominence
  models with a non-LTE (i.e., departures from the local thermodynamic
  equilibrium) radiative transfer code. We then performed a 1.5D
  spectral inversion searching for an optimal model that best fits
  five parameters of the observed profiles (observables), namely,
  the integrated intensity of the Hα and Mg II k lines, the FWHM of
  both lines, and the ratio of intensities of the Mg II k and Mg II h
  lines. The latter is sensitive to temperature. Our results show that
  the prominence is a low-temperature structure, mostly below 10,000
  K, with some excursions to higher values (up to 18,000 K) but also
  rather low temperatures (around 5000 K). The microturbulent velocity is
  typically low, peaking around 8 km s<SUP>-1</SUP>, and electron density
  values are of the order of 10<SUP>10</SUP> cm<SUP>-3</SUP>. The peak
  effective thickness is 500 km, although the values range up to 5000
  km. The studied prominence is rather optically thin in the Hα line
  and optically thick in the Mg II h&amp;k lines.

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Title: The Solar Line Emission Dopplerometer project
Authors: Malherbe, Jean-Marie; Mein, Pierre; Sayède, Frédéric;
   Rudawy, Pawel; Phillips, Kenneth; Keenan, Francis; Rybák, Jan
2022ExA....53...83M    Altcode: 2021ExA...tmp..125M; 2021arXiv211001645M
  Observations of the dynamics of solar coronal structures are necessary
  to investigate space weather phenomena and global heating of the
  corona. The profiles of high temperature lines emitted by the hot plasma
  are usually integrated by narrow band filters or recorded by classical
  spectroscopy. We present in this paper details of a new transportable
  instrument (under construction) for imaging spectroscopy: the Solar Line
  Emission Dopplerometer (SLED). It uses the Multi-channel Subtractive
  Double Pass (MSDP) technique, which combines the advantages of both
  filters and narrow slit spectrographs, i.e. high temporal, spatial and
  spectral resolutions. The SLED will measure at high cadence (1 Hz)
  the line-of-sight velocities (Doppler shifts) of hot coronal loops,
  in the forbidden lines of FeX 6374 Å and FeXIV 5303 Å. It will
  follow the dynamics of fast evolving events of solar activity such
  as flares or Coronal Mass Ejections (CMEs), and also study coronal
  heating by short period waves. Observations will be performed with
  the coronagraph at the Lomnický Štít Observatory (LSO, in Slovakia)
  or during total eclipses. The SLED will also observe the dynamics of
  solar prominences in Hα 6563 Å or He D3 5876 Å lines when mounted
  on the Białków coronagraph (near Wrocław, Poland). It is fully
  compatible with polarimetric measurements by various techniques.

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Title: Five decades of solar research at the Mic du Midi Turret-Dome
(1960-2010). Part 1: Overview of instrumentation and observations
Authors: Roudier, Th.; Malherbe, J. -M.; Rozelot, J. -P.; Mein, P.;
   Muller, R.
2021JAHH...24..585R    Altcode:
  The Pic du Midi Turret-Dome, known as 'Lunette Jean Rösch'or LJR
  ('lunette' for refractor in French), was scientifically active
  during five decades between 1960 and 2010. It was dedicated to high
  spatial resolution observations in solar astronomy. We review fifty
  years of advances in solar instrumentation and solar physics made
  by this instrument in various domains, which took advantage of the
  good seeing at Pic du Midi. First, we summarize some of the LJR
  results in broad-band and wide-field imagery of the photosphere;
  as this topic was the initial goal and has been the most important
  contribution of the refractor, details will be provided in Part
  2. Then, we present spectro-polarimetric instrumentation and
  observations with narrow slit and imaging spectroscopy of the
  photosphere and the chromosphere. The Turret-Dome also housed an
  original spectro-coronagraph, and observations of the high temperature
  coronal plasma are highlighted. Finally, we describe progress in the
  determination of the solar shape with the heliometer. The LJR remained
  active until the launch of the Hinode and Solar Dynamics Observatory
  satellites (in 2006 and 2010, respectively).

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Title: Spectro-imagery of an active tornado-like prominence: Formation
    and evolution
Authors: Barczynski, Krzysztof; Schmieder, Brigitte; Peat, Aaron W.;
   Labrosse, Nicolas; Mein, Pierre; Mein, Nicole
2021A&A...653A..94B    Altcode: 2021arXiv210604259B
  Context. The dynamical nature of fine structures in prominences remains
  an open issue, including rotating flows in tornado prominences. While
  the Atmospheric Imaging Assembly imager aboard the Solar Dynamics
  Observatory allowed us to follow the global structure of a tornado-like
  prominence for five hours, the Interface Region Imaging Spectrograph,
  and the Multichannel Subtractive Double Pass spectrograph permitted
  to obtain plasma diagnostics of its fine structures. <BR /> Aims: We
  aim to address two questions. Firstly, is the observed plasma rotation
  conceptually acceptable in a flux rope magnetic support configuration
  with dips? Secondly, how is the plasma density distributed in the
  tornado-like prominence? <BR /> Methods: We calculated line-of-sight
  velocities and non-thermal line widths using Gaussian fitting for Mg II
  lines and the bisector method for Hα line. We determined the electron
  density from Mg II line integrated intensities and profile fitting
  methods using 1D non-LTE radiative transfer theory models. <BR />
  Results: The global structure of the prominence observed in Hα, and
  Mg II h, and k line fits with a magnetic field structure configuration
  with dips. Coherent Doppler shifts in redshifted and blueshifted areas
  observed in both lines were detected along rapidly-changing vertical
  and horizontal structures. However, the tornado at the top of the
  prominence consists of multiple fine threads with opposite flows,
  suggesting counter-streaming flows rather than rotation. Surprisingly
  we found that the electron density at the top of the prominence could
  be larger (10<SUP>11</SUP> cm<SUP>−3</SUP>) than in the inner part
  of the prominence. <BR /> Conclusions: We suggest that the tornado
  is in a formation state with cooling of hot plasma in a first phase,
  and following that, a phase of leakage of the formed blobs with large
  transverse flows of material along long loops extended away from the
  UV prominence top. The existence of such long magnetic field lines on
  both sides of the prominence would stop the tornado-like prominence
  from really turning around its axis. <P />Movies are available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202140976/olm">https://www.aanda.org</A>

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Title: Four Decades of Advances from MSDP to S4I and SLED Imaging
    Spectrometers
Authors: Mein, P.; Malherbe, J. -M.; Sayède, F.; Rudawy, P.; Phillips,
   K. J. H.; Keenan, F. P.
2021SoPh..296...30M    Altcode: 2021arXiv210103918M
  The Multichannel Subtractive Double Pass (MSDP) is an imaging
  spectroscopy technique, which allows observations of spectral line
  profiles over a 2D field of view with high spatial and temporal
  resolution. It has been intensively used since 1977 on various
  spectrographs (Meudon, Pic du Midi, the German Vacuum Tower Telescope,
  THEMIS, Wrocław). We summarize previous developments and describe
  the capabilities of a new design that has been developed at Meudon
  and that has higher spectral resolution and increased channel number:
  Spectral Sampling with Slicer for Solar Instrumentation (S4I), which
  can be combined with a new and fast polarimetry analysis. This new
  generation MSDP technique is well adapted to large telescopes. Also
  presented are the goals of a derived compact version of the instrument,
  the Solar Line Emission Dopplerometer (SLED), dedicated to dynamic
  studies of coronal loops observed in the forbidden iron lines,
  and prominences. It is designed for observing total solar eclipses,
  and for deployment on the Wrocław and Lomnicky peak coronagraphs
  respectively for prominence and coronal observations.

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Title: Spectral inversion of H-alpha and MgII lines in quiescent
    prominences
Authors: Heinzel, Petr; Schmieder, Brigitte; Ruan, Guiping; Mein,
   Pierre; Gunár, Stanislav; Jejcic, Sonja; Mein, Nicole
2021cosp...43E1764H    Altcode:
  Recent spectral analysis of simultaneous H-alpha (MSDP) and MgII
  lines (IRIS) (Guiping et al. 2019) has revealed certain bifurcation
  in resulting models. Two solutions were found from the line inversions
  using the non-LTE modeling: relatively high kinetic temperature and low
  non-thermal motions or temperatures mostly compatible with standard ones
  plus non-thermal motions of the order of 16 km/sec. Here we will present
  an improved spectral line inversion technique which clearly prefers
  the latter solution. Strong non-thermal motions are then interpreted
  as a mixture of microturbulence and the line-of-sight dynamics of
  prominence fine-structure threads. A detailed multithread modeling with
  the 2D non-LTE code and stochastic distributions of threads (position,
  dynamics) is now in progress and we will show our preliminary results.

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Title: Active tornado in a prominence observed in H-alpha with MSDP
    and Mg II with IRIS
Authors: Barczynski, Krzysztof; Schmieder, Brigitte; Mein, Pierre;
   Labrosse, Nicolas; Mein, Nicole; Peat, Aaron
2021cosp...43E.973B    Altcode:
  Large prominences with highly dynamic plasma features expand outwards in
  the solar atmosphere, often in loop or arch-shape or as a tornado. The
  origin of the rotating flow in prominence tornadoes is not fully
  understood yet. We aim to find an answer to two long-standing questions:
  what is the nature of the plasma flow and rotation in the prominence,
  and the role of the magnetic field configuration in the prominence
  dynamics? To this aim, we use observations from the Atmospheric Imaging
  Assembly (AIA) imager aboard the Solar Dynamics Observatory (SDO) to
  follow the plasma dynamics related to magnetic field. Simultaneous
  observations from the Interface Region Imaging Spectrograph (IRIS)
  and the Multi subtractive Double pass spectrograph (MSDP) allow
  us to study the plasma properties (intensity, Doppler velocity,
  non-thermal line broadening) of a tornado-like structure. We calculate
  line-of-sight velocities and non-thermal line width using Gaussian
  fitting for Mg II lines (IRIS) and a bisector method for H$\alpha$
  line (MSDP). We determine the electron density and temperature from
  Mg II line integrated intensities using radiative transfer theory. We
  find that the red and blue Doppler-shifted areas present a coherent
  position in H$\alpha$ and Mg II h\&amp;k lines along the fast-evolving
  prominence features. The EUV observations suggest long magnetic field
  lines on the sides of the prominence. The tornado-like at the top of
  the prominence consists of multiplefine threads with opposite flows, all
  of them being supported in dips of long magnetic field lines. From time
  to time, condensed blobs escape along these field lines. We conjecture
  that micro or macro turbulence exists at the top of the prominence
  and could form the small threads giving the impression of rotation.

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Title: Raymond Michard and his solar physics group at Paris-Meudon
    Observatory
Authors: Mein, Pierre; Mein, Nicole
2020JAHH...23..582M    Altcode:
  During the second half of the twentieth century, an important Solar
  Research Department was developed in the Paris-Meudon Observatory
  thanks to Raymond Michard. After several years devoted to theoretical
  studies about stellar atmospheres at the Institut d'Astrophysique de
  Paris Michard joined the Paris-Meudon Observatory in 1954. He replaced
  Lucien d'Azambuja as Director of the Solar Section, and succeeded
  to attract new young scientists, while building new high-performance
  instruments in good sites such as Pic du Midi. He became Director of
  the Solar and Planetary Department in 1968. All topics of solar physics
  were investigated, providing many results about coronal physics, solar
  activity and flares, but also fine structures of the quiet Sun. Michard
  knew that the best research involved successful collaborations. Eclipse
  missions, international cooperation and access to space instruments
  were developed. Participation to the European JOSO association prepared
  the future THEMIS telescope. In 1971 Michard left the Solar Department
  to be successively the President of Paris Observatory and then Nice
  Observatory. But his Solar Physics group in Meudon went on working
  with topics and means that he had successfully initiated.

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Title: Diagnostics of the Prominence Plasma from Hα and Mg II
    Spectral Observations
Authors: Ruan, Guiping; Jejčič, Sonja; Schmieder, Brigitte; Mein,
   Pierre; Mein, Nicole; Heinzel, Petr; Gunár, Stanislav; Chen, Yao
2019ApJ...886..134R    Altcode:
  The goal of this paper is to derive the physical conditions of the
  prominence observed on 2017 March 30. To do so, we use a unique set
  of data in Mg II lines obtained with the space-borne Interface Region
  Imaging Spectrograph (IRIS) and in Hα line with the ground-based
  Multi-Channel Subtractive Double Pass spectrograph operating at the
  Meudon solar tower. Here, we analyze the prominence spectra of Mg
  II h and k lines, and the Hα line in the part of the prominence
  which is visible in both sets of lines. We compute a grid of 1D
  NLTE (i.e., departures from the local thermodynamical equilibrium)
  models providing synthetic spectra of Mg II k and h, and Hα lines
  in a large space of model input parameters (temperature, density,
  pressure, and microturbulent velocity). We compare Mg II and Hα
  line profiles observed in 75 positions of the prominence with the
  synthetic profiles from the grid of models. These models allow us
  to compute the relationships between the integrated intensities
  and between the optical thickness in Hα and Mg II k lines. The
  optical thickness τ <SUB>Hα </SUB> is between 0.05 and 2, and
  {τ }<SUB>Mg</SUB>{{II}}{{k}}} is between 3 and 200. We show that
  the relationship of the observed integrated intensities agrees well
  with the synthetic integrated intensities for models with a higher
  microturbulence (16 km s<SUP>-1</SUP>) and T around 8000 K, ne =
  1.5 × 10<SUP>10</SUP> cm<SUP>-3</SUP>, p = 0.05 dyne. In this case,
  large microturbulence values could be a way to take into account the
  large mixed velocities existing in the observed prominence.

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Title: Bidirectional Reconnection Outflows in an Active Region
Authors: Ruan, Guiping; Schmieder, Brigitte; Masson, Sophie; Mein,
   Pierre; Mein, Nicole; Aulanier, Guillaume; Chen, Yao
2019ApJ...883...52R    Altcode:
  We report on bidirectional coronal reconnection outflows reaching
  ±200 km s<SUP>-1</SUP> as observed in an active region with the Si
  IV and C II spectra of the Interface Region Imaging Spectrograph
  (IRIS). The evolution of the active region with an emerging flux,
  a failed filament eruption, and a jet is followed in Solar Dynamical
  Observatory (SDO)/Atmospheric Imaging Assembly (AIA) filters from
  304 to 94 Å, IRIS slit jaw images, and SDO/Helioseismic and Magnetic
  Imager movies. The bidirectional outflow reconnection is located at
  a bright point visible in multiwavelength AIA filters above an arch
  filament system. This suggests that the reconnection occurs between
  rising loops above the emergence of magnetic bipoles and the longer,
  twisted magnetic field lines remnant of the failed filament eruption
  one hour before. The reconnection occurs continuously in the corona
  between quasi-parallel magnetic field lines, which is possible in a
  3D configuration. The reconnection also triggers a jet with transverse
  velocities around 60 km s<SUP>-1</SUP>. Blueshifts and redshifts along
  its axis confirm the existence of a twist along the jet, which could
  have been transferred from the filament flux rope. The jet finally
  blows up the material of the filament before coming back during the
  second phase. In the Hα Dopplergrams provided by the MSDP spectrograph,
  we see more redshift than blueshift, indicating the return of the jet
  and filament plasma.

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Title: Exploration of long-period oscillations in an Hα prominence
Authors: Zapiór, M.; Schmieder, B.; Mein, P.; Mein, N.; Labrosse,
   N.; Luna, M.
2019A&A...623A.144Z    Altcode: 2019arXiv190300230Z
  Context. In previous work, we studied a prominence which appeared like
  a tornado in a movie made from 193 Å filtergrams obtained with the
  Atmospheric Imaging Assembly (AIA) imager aboard the Solar Dynamics
  Observatory (SDO). The observations in Hα obtained simultaneously
  during two consecutive sequences of one hour with the Multi-channel
  Subtractive Double Pass Spectrograph (MSDP) operating at the solar
  tower in Meudon showed that the cool plasma inside the tornado was
  not rotating around its vertical axis. Furthermore, the evolution
  of the Dopplershift pattern suggested the existence of oscillations
  of periods close to the time-span of each sequence. <BR /> Aims:
  The aim of the present work is to assemble the two sequences of
  Hα observations as a full data set lasting two hours to confirm the
  existence of oscillations, and determine their nature. <BR /> Methods:
  After having coaligned the Doppler maps of the two sequences, we use a
  Scargle periodogram analysis and cosine fitting to compute the periods
  and the phase of the oscillations in the full data set. <BR /> Results:
  Our analysis confirms the existence of oscillations with periods between
  40 and 80 min. In the Dopplershift maps, we identify large areas with
  strong spectral power. In two of them, the oscillations of individual
  pixels are in phase. However, in the top area of the prominence,
  the phase is varying slowly, suggesting wave propagation. <BR />
  Conclusions: We conclude that the prominence does not oscillate as a
  whole structure but exhibits different areas with their own oscillation
  periods and characteristics: standing or propagating waves. We discuss
  the nature of the standing oscillations and the propagating waves. These
  can be interpreted in terms of gravito-acoustic modes and magnetosonic
  waves, respectively. <P />Movie attached to Fig. 2 is available at <A
  href="https://www.aanda.org/10.1051/0004-6361/201833614/olm">https://www.aanda.org</A>

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Title: On the Dynamic Nature of a Quiescent Prominence Observed by
    IRIS and MSDP Spectrographs
Authors: Ruan, Guiping; Schmieder, Brigitte; Mein, Pierre; Mein,
   Nicole; Labrosse, Nicolas; Gunár, Stanislav; Chen, Yao
2018ApJ...865..123R    Altcode:
  Quiescent solar prominences are generally considered to have a stable
  large-scale structure. However, they consist of multiple small-scale
  structures that are often significantly dynamic. To understand
  the nature of prominence plasma dynamics we use the high spatial,
  temporal, and spectral resolution observations obtained by Interface
  Region Imaging Spectrograph (IRIS) during a coordinated campaign
  with the Multichannel Subtractive Double Pass spectrograph at the
  Meudon Solar Tower. Detailed analysis of the IRIS observations of
  Mg II lines, including the analysis of Dopplershift and line width
  obtained with two different methods (quantile method and Gaussian-fit
  method) are discussed in the frame of the dynamic nature of the
  structures. Large-scale coherent blueshift and redshift features are
  observed in Mg II lines and Hα exhibiting a slow evolution during 1:40
  hr of observations. We explain the presence of several significantly
  asymmetric peaks in the observed Mg II line profiles by the presence
  of several prominence fine structures moving with different velocities
  located along the line of sight (LOS). In such a case, the decrease
  of the intensity of individual components of the observed spectra
  with the distance from the central wavelength can be explained by the
  Doppler dimming effect. We show that C II line profiles may be used
  to confirm the existence of multi-components along the LOS.

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Title: Dynamics in quiescent prominences observed by the IRIS and
    MSDP spectrographs
Authors: Gunár, Stanislav; Schmieder, Brigitte; Ruan, Guiping; Mein,
   Pierre; Heinzel, Petr
2018cosp...42E1314G    Altcode:
  Quiescent solar prominences are generally considered to
  be stable. However, these prominences consist of a multitude of
  small-scale structures or threads that are often significantly
  dynamic. To understand the nature of the plasma dynamics we use the
  high spatial, temporal and spectral resolution observations obtained
  by IRIS during coordinated campaign with the MSDP spectrograph
  at the Meudon Solar Tower. Mg II h and k lines observed by IRIS
  represent a good diagnostic tool for investigation of the prominence
  fine structure dynamics, as they are optically thick under the
  prominence conditions. We will present detailed IRIS observations of
  Mg II lines. We explain significant asymmetries in the observed Mg II
  spectra by the presence of several threads located along the line of
  sight with different velocities. In such a case, the decrease of the
  intensity of individual components of the observed spectra with the
  distance from the central wavelength can be explained by the Doppler
  dimming effect. To interpret the observed Mg II profiles in terms
  of dynamics we use 1D or 2D radiative transfer models including a
  prominence-corona transition region. We also show that the H-alpha
  line which is optically thinner than the Mg II doublet is an important
  constrain for the radiative transfer radiation modelling.

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Title: Prominence/Tornado plasma parameters
Authors: Schmieder, Brigitte; Mein, Pierre; Zapior, Maciej; Labrosse,
   Nicolas; Lopez Ariste, Arturo
2018cosp...42E3025S    Altcode:
  We present a comparison of the plasma physical parameters in prominences
  and tornadoes using IRIS data and ground based polarimetry measurements
  obtained with THEMIS. Mg II lines give a good diagnostics of the
  temperature and optical thickness of the structures. The Stokes
  parameters from the He D3 line allow to distinguish the behaviour
  of the magnetic field in typical prominences and atypical prominences
  (e.g. bubbles, eruptive prominence). We concentrate on the Dopplershifts
  in a tornado observed in transition region lines and in Halpha. Our
  results support the existence of oscillations in tornadoes but not
  rotation.A reconstruction of the 3D geometry of a helical prominence
  obtained by following the trajectory of kernels yields surprising
  results. The loops are shown to be quasi-horizontal structures with
  no curvature.We conclude that it is important to take into account the
  3D structure of the prominence to study the dynamics of the prominence
  plasma.

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Title: Prototype of S4EI (spectral sampling with slicer for
stellar and extragalactical instrumentation): a new generation 3D
    Spectro-imager
Authors: Sayède, F.; Puech, M.; Mein, P.; Galicher, R.; Malherbe,
   J. -M.; Amans, J. -P.
2018SPIE10702E..54S    Altcode:
  S4EI (Spectral Sampling with Slicer for Stellar and Extragalactical
  Instrumentation) is a new concept for extending Multichannel
  Subtractive Double Pass (ie S4I - Spectral Sampling with Slicer for
  Solar Instrumentation) to night-time astronomy. The Multichannel
  Subtractive Double Pass (MSDP) spectrographs have been widely
  used in solar spectroscopy because of their ability to provide
  an excellent compromise between field of view and the spatial and
  spectral resolutions. Compared with other spectrographs, MSDP can
  deliver simultaneous monochromatic images without any time-scanning
  requirements (as the standard Fabry-Perot), with limited loss of
  flux. Spatial resolution is the same as for an Imager given by
  the telescope: it can be very high. It is based on new generation
  reflecting plane image slicers working with large apertures specific
  to night-time telescopes. The resulting design could be potentially
  very attractive and innovative for different domains of astronomy,
  e.g., the simultaneous spatial mapping of accurately flux-calibrated
  emission lines between OH sky lines in extragalactic astronomy or the
  simultaneous imaging of stars, exoplanets and interstellar medium. The
  determination of physical and chemical properties of galaxies needs to
  observe several emission lines at different wavelengths. The combination
  of these lines gives access to the distribution in dust, star formation
  rate, metallicity, the kinematics or even to the electron density of the
  gas in the galaxies. The spatial resolution of MSDP allows, like the 3D
  or integral field spectrographs the construction of spatial distribution
  maps. The advantage of S4EI is that by measuring simultaneously the
  different lines, the relative errors of the flux calibration between
  the different wavelengths of the lines are potentially limited by
  the uncertainty of the calibration source used, which is expected
  to significantly reduce the associated errors and thus increase the
  precision and accuracy of estimates.

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Title: Prominence and tornado dynamics observed with IRIS and THEMIS
Authors: Schmieder, Brigitte; Levens, Peter; Labrosse, Nicolas; Mein,
   Pierre; Lopez Ariste, Arturo; Zapior, Maciek
2017SPD....4820104S    Altcode:
  Several prominences were observed during campaigns in September 2013 and
  July 2014 with the IRIS spectrometer and the vector magnetograph THEMIS
  (Tenerife). SDO/AIA and IRIS provided images and spectra of prominences
  and tornadoes corresponding to different physical conditions of the
  transition region between the cool plasma and the corona. The vector
  magnetic field was derived from THEMIS observations by using the He
  D3 depolarisation due to the magnetic field. The inversion code (PCA)
  takes into account the Hanle and Zeeman effects and allows us to compute
  the strength and the inclination of the magnetic field which is shown
  to be mostly horizontal in prominences as well as in tornadoes. Movies
  from SDO/AIA in 304 A and Hinode/SOT in Ca II show the highly dynamic
  nature of the fine structures. From spectra in Mg II and Si IV lines
  provided by IRIS and H-alpha observed by the Multi-channel Subtractive
  Double Pass (MSDP) spectrograph in the Meudon Solar Tower we derived
  the Doppler shifts of the fine structures and reconstructed the 3D
  structure of tornadoes. We conclude that the apparent rotation of AIA
  tornadoes is due to large-scale quasi-periodic oscillations of the
  plasma along more or less horizontal magnetic structures.

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Title: Hα Doppler shifts in a tornado in the solar corona
Authors: Schmieder, B.; Mein, P.; Mein, N.; Levens, P. J.; Labrosse,
   N.; Ofman, L.
2017A&A...597A.109S    Altcode: 2016arXiv161202232S
  Context. High resolution movies in 193 Å from the Atmospheric
  Imaging Assembly (AIA) on the Solar Dynamic Observatory (SDO)
  show apparent rotation in the leg of a prominence observed during
  a coordinated campaign. Such structures are commonly referred to as
  tornadoes. Time-distance intensity diagrams of the AIA data show the
  existence of oscillations suggesting that the structure is rotating. <BR
  /> Aims: The aim of this paper is to understand if the cool plasma
  at chromospheric temperatures inside the tornado is rotating around
  its central axis. <BR /> Methods: The tornado was also observed in Hα
  with a cadence of 30 s by the MSDP spectrograph, operating at the Solar
  Tower in Meudon. The MSDP provides sequences of simultaneous spectra
  in a 2D field of view from which a cube of Doppler velocity maps is
  retrieved. <BR /> Results: The Hα Doppler maps show a pattern with
  alternatively blueshifted and redshifted areas of 5 to 10” wide. Over
  time the blueshifted areas become redshifted and vice versa, with
  a quasi-periodicity of 40 to 60 min. Weaker amplitude oscillations
  with periods of 4 to 6 min are superimposed onto these large period
  oscillations. <BR /> Conclusions: The Doppler pattern observed in
  Hα cannot be interpreted as rotation of the cool plasma inside the
  tornado. The Hα velocity observations give strong constraints on the
  possible interpretations of the AIA tornado.

---------------------------------------------------------
Title: Height formation of bright points observed by IRIS in Mg II
    line wings during flux emergence
Authors: Grubecka, M.; Schmieder, B.; Berlicki, A.; Heinzel, P.;
   Dalmasse, K.; Mein, P.
2016A&A...593A..32G    Altcode:
  Context. A flux emergence in the active region AR 111850 was observed
  on September 24, 2013 with the Interface Region Imaging Spectrograph
  (IRIS). Many bright points are associated with the new emerging flux
  and show enhancement brightening in the UV spectra. <BR /> Aims:
  The aim of this work is to compute the altitude formation of the
  compact bright points (CBs) observed in Mg II lines in the context
  of searching Ellerman bombs (EBs). <BR /> Methods: IRIS provided two
  large dense rasters of spectra in Mg II h and k lines, Mg II triplet,
  C II and Si IV lines covering all the active region and slit jaws in
  the two bandpasses (1400 Å and 2796 Å) starting at 11:44 UT and
  15:39 UT, and lasting 20 min each. Synthetic profiles of Mg II and
  Hα lines are computed with non-local thermodynamic equlibrium (NLTE)
  radiative transfer treatment in 1D solar atmosphere model including
  a hotspot region defined by three parameters: temperature, altitude,
  and width. <BR /> Results: Within the two IRIS rasters, 74 CBs are
  detected in the far wings of the Mg II lines (at +/-1 Å and 3.5
  Å). Around 10% of CBs have a signature in Si IV and CII. NLTE models
  with a hotspot located in the low atmosphere were found to fit a sample
  of Mg II profiles in CBs. The Hα profiles computed with these Mg II
  CB models are consistent with typical EB profiles observed from ground
  based telescopes e.g. THEMIS. A 2D NLTE modelling of fibrils (canopy)
  demonstrates that the Mg II line centres can be significantly affected
  but not the peaks and the wings of Mg II lines. <BR /> Conclusions:
  We conclude that the bright points observed in Mg II lines can be
  formed in an extended domain of altitudes in the photosphere and/or
  the chromosphere (400 to 750 km). Our results are consistent with the
  theory of heating by Joule dissipation in the atmosphere produced by
  magnetic field reconnection during flux emergence.

---------------------------------------------------------
Title: Fast inversion of Zeeman line profiles using central
    moments. II. Stokes V moments and determination of vector magnetic
    fields
Authors: Mein, P.; Uitenbroek, H.; Mein, N.; Bommier, V.; Faurobert, M.
2016A&A...591A..64M    Altcode:
  Context. In the case of unresolved solar structures or stray light
  contamination, inversion techniques using four Stokes parameters
  of Zeeman profiles cannot disentangle the combined contributions of
  magnetic and nonmagnetic areas to the observed Stokes I. <BR /> Aims:
  In the framework of a two-component model atmosphere with filling factor
  f, we propose an inversion method restricting input data to Q , U, and
  V profiles, thus overcoming ambiguities from stray light and spatial
  mixing. <BR /> Methods: The V-moments inversion (VMI) method uses
  shifts S<SUB>V</SUB> derived from moments of V-profiles and integrals
  of Q<SUP>2</SUP>, U<SUP>2</SUP>, and V<SUP>2</SUP> to determine the
  strength B and inclination ψ of a magnetic field vector through
  least-squares polynomial fits and with very few iterations. Moment
  calculations are optimized to reduce data noise effects. To specify the
  model atmosphere of the magnetic component, an additional parameter
  δ, deduced from the shape of V-profiles, is used to interpolate
  between expansions corresponding to two basic models. <BR /> Results:
  We perform inversions of HINODE SOT/SP data for inclination ranges 0
  &lt;ψ&lt; 60° and 120 &lt;ψ&lt; 180° for the 630.2 nm Fe I line. A
  damping coefficient is fitted to take instrumental line broadening into
  account. We estimate errors from data noise. Magnetic field strengths
  and inclinations deduced from VMI inversion are compared with results
  from the inversion codes UNNOFIT and MERLIN. <BR /> Conclusions:
  The VMI inversion method is insensitive to the dependence of Stokes I
  profiles on the thermodynamic structure in nonmagnetic areas. In the
  range of Bf products larger than 200 G, mean field strengths exceed
  1000 G and there is not a very significant departure from the UNNOFIT
  results because of differences between magnetic and nonmagnetic model
  atmospheres. Further improvements might include additional parameters
  deduced from the shape of Stokes V profiles and from large sets of
  3D-MHD simulations, especially for unresolved magnetic flux tubes.

---------------------------------------------------------
Title: Magnetic Field and Plasma Diagnostics from Coordinated
    Prominence Observations
Authors: Schmieder, B.; Levens, P.; Dalmasse, K.; Mein, N.; Mein,
   P.; Lopez-Ariste, A.; Labrosse, N.; Heinzel, P.
2016ASPC..504..119S    Altcode:
  We study the magnetic field in prominences from a statistical point of
  view, by using THEMIS in the MTR mode, performing spectropolarimetry
  of the He I D<SUB>3</SUB> line. Combining these measurements with
  spectroscopic data from IRIS, Hinode/EIS as well as ground-based
  telescopes, such as the Meudon Solar Tower, we infer the temperature,
  density, and flow velocities of the plasma. There are a number of
  open questions that we aim to answer: - What is the general direction
  of the magnetic field in prominences? Is the model using a single
  orientation of magnetic field always valid for atypical prominences? %-
  Does this depend on the location of the filament on the disk (visible
  in Hα, in He II 304 Å) over an inversion line between weak or strong
  network ? - Are prominences in a weak environment field dominated by
  gas pressure? - Measuring the Doppler shifts in Mg II lines (with IRIS)
  and in Hα can tell us if there are substantial velocities to maintain
  vertical rotating structures, as has been suggested for tornado-like
  prominences. We present here some results obtained with different
  ground-based and space-based instruments in this framework.

---------------------------------------------------------
Title: Understanding the Mg II and Hα Spectra in a Highly Dynamical
    Solar Prominence
Authors: Heinzel, P.; Schmieder, B.; Mein, N.; Gunár, S.
2015ApJ...800L..13H    Altcode:
  Mg ii h and k and Hα spectra in a dynamical prominence have been
  obtained along the slit of the Interface Region Imaging Spectrograph
  (IRIS) and with the Meudon Multi-channel Subtractive Double Pass
  spectrograph on 2013 September 24, respectively. Single Mg ii line
  profiles are not much reversed, while at some positions along
  the IRIS slit the profiles show several discrete peaks that are
  Doppler-shifted. The intensity of these peaks is generally decreasing
  with their increasing Doppler shift. We interpret this unusual behavior
  as being due to the Doppler dimming effect. We discuss the possibility
  to interpret the unreversed single profiles by using a two-dimensional
  (2D) model of the entire prominence body with specific radiative
  boundary conditions. We have performed new 2D isothermal-isobaric
  modeling of both Hα and Mg ii lines and show the ability of such models
  to account for the line profile variations as observed. However, the Mg
  ii line-center intensities require the model with a temperature increase
  toward the prominence boundary. We show that even simple one-dimensional
  (1D) models with a prominence-to-corona transition region (PCTR) fit the
  observed Mg ii and Hα lines quite well, while the isothermal-isobaric
  models (1D or 2D) are inconsistent with simultaneous observations in
  the Mg ii h and k and Hα lines, meaning that the Hα line provides a
  strong additional constraint on the modeling. IRIS far-UV detection of
  the C ii lines in this prominence seems to provide a direct constraint
  on the PCTR part of the model.

---------------------------------------------------------
Title: Open questions on prominences from coordinated observations
    by IRIS, Hinode, SDO/AIA, THEMIS, and the Meudon/MSDP
Authors: Schmieder, B.; Tian, H.; Kucera, T.; López Ariste, A.;
   Mein, N.; Mein, P.; Dalmasse, K.; Golub, L.
2014A&A...569A..85S    Altcode: 2014arXiv1407.3171S
  Context. A large prominence was observed by multiple instruments on the
  ground and in space during an international campaign on September 24,
  2013, for three hours (12:12 UT -15:12 UT). Instruments used in the
  campaign included the newly launched (June 2013) Interface Region
  Imaging Spectrograph (IRIS), THEMIS (Tenerife), the Hinode Solar
  Optical Telescope (SOT), the Solar Dynamic Observatory's Atmospheric
  Imaging Assembly (SDO/AIA), and the Multichannel Subtractive Double
  Pass spectrograph (MSDP) in the Meudon Solar Tower. The movies obtained
  in 304 Å with the EUV imager SDO/AIA, and in Ca II line by SOT show
  the dynamic nature of the prominence. <BR /> Aims: The aim of this
  work is to study the dynamics of the prominence fine structures in
  multiple wavelengths to understand their formation. <BR /> Methods:
  The spectrographs IRIS and MSDP provided line profiles with a high
  cadence in Mg II h (2803.5 Å) and k (2796.4 Å) lines along four
  slit positions (IRIS), and in Hα in a 2D field of view (MSDP). The
  spectropolarimetry of THEMIS (Tenerife) allowed us to derive the
  magnetic field of the prominence using the He D<SUB>3</SUB> line
  depolarization (Hanle effect combined with the Zeeman effect). <BR />
  Results: The magnetic field is found to be globally horizontal with
  a relatively weak field strength (8-15 Gauss). On the other hand,
  the Ca II movie reveals turbulent-like motion that is not organized in
  specific parts of the prominence. We tested the addition of a turbulent
  magnetic component. This model is compatible with the polarimetric
  observations at those places where the plasma turbulence peaks. On the
  other hand, the Mg II line profiles show multiple peaks well separated
  in wavelength. This is interpreted by the existence of small threads
  along the line of sight with a large dispersion of discrete values of
  Doppler shifts, from 5 km s<SUP>-1</SUP> (a quasi-steady component) to
  60-80 km s<SUP>-1</SUP>. Each peak corresponds to a Gaussian profile,
  and not to a reversed profile as was expected by the present non-LTE
  radiative transfer modeling. This is a very surprising behavior for
  the Mg II line observed in prominences. <BR /> Conclusions: Turbulent
  fields on top of the macroscopic horizontal component of the magnetic
  field supporting the prominence give rise to the complex dynamics of
  the plasma. The plasma with the high velocities (70 km s<SUP>-1</SUP> to
  100 km s<SUP>-1</SUP> if we take into account the transverse velocities)
  may correspond to condensation of plasma along more or less horizontal
  threads of the arch-shape structure visible in 304 Å. The steady
  flows (5 km s<SUP>-1</SUP>) would correspond to a more quiescent plasma
  (cool and prominence-corona transition region) of the prominence packed
  into dips in horizontal magnetic field lines. The very weak secondary
  peaks in the Mg II profiles may reflect the turbulent nature of parts
  of the prominence. <P />Movies are available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201423922/olm">http://www.aanda.org</A>

---------------------------------------------------------
Title: The S4I prototype, a beam-slicer dedicated to the new
    generation Multichannel Subtractive Double Pass for EST imaging
    spectropolarimetry
Authors: Sayède, Frédéric; Mein, Pierre; Malherbe, Jean-Marie;
   Amans, Jean-Philippe; Crussaire, Daniel; Lecocguen, Regis
2014SPIE.9147E..6FS    Altcode:
  For the future European Solar Telescope (EST) the Observatoire de Paris
  proposes a new generation of MSDP, an imaging spectro-polarimetry
  instrument. To validate this new generation, we develop a plane
  micro-mirrors beam slicer prototype that is tested and validated on
  an optical bench and on existing telescopes. The prototype called S4I
  (Spectral Sampling with Slicer for Solar Instrumentation) is built and
  tested at the Observatoire de Paris. It validates the opto-mechanical
  feasibility of the new beam slicer. After a complete description of the
  system, we present the first images. We evaluate the performances of
  the prototype and compare them to the requirements for the beam-slicer
  dedicated to the future EST.

---------------------------------------------------------
Title: S4EI (Spectral Sampling with Slicer for Stellar and
    Extragalactical Instrumentation), a new-generation of 3D
    spectro-imager dedicated to night astronomy
Authors: Sayède, Frédéric; Puech, Mathieu; Mein, Pierre;
   Bonifacio, Piercarlo; Malherbe, Jean-Marie; Galicher, Raphaël.;
   Amans, Jean-Philippe; Fasola, Gilles
2014SPIE.9147E..3OS    Altcode:
  Multichannel Subtractive Double Pass (MSDP) spectrographs have
  been widely used in solar spectroscopy because of their ability to
  provide an excellent compromise between field of view and spatial
  and spectral resolutions. Compared with other types of spectrographs,
  MSDP can deliver simultaneous monochromatic images at higher spatial
  and spectral resolutions without any time-scanning requirement (as
  with Fabry-Perot spectrographs), and with limited loss of flux. These
  performances are obtained thanks to a double pass through the dispersive
  element. Recent advances with VPH (Volume phase holographic) Grisms
  as well as with image slicers now make MSDP potentially sensitive to
  much smaller fluxes. We present S4EI (Spectral Sampling with Slicer for
  Stellar and Extragalactical Instrumentation), which is a new concept for
  extending MSDP to night-time astronomy. It is based on new generation
  reflecting plane image slicers working with large apertures specific
  to night-time telescopes. The resulting design could be potentially
  very attractive and innovative for different domains of astronomy,
  e.g., the simultaneous spatial mapping of accurately flux-calibrated
  emission lines between OH sky lines in extragalactic astronomy or the
  simultaneous imaging of stars, exoplanets and interstellar medium. We
  present different possible MSDP/S4EI configurations for these science
  cases and expected performances on telescopes such as the VLT.

---------------------------------------------------------
Title: Proper horizontal photospheric flows in a filament channel
Authors: Schmieder, B.; Roudier, T.; Mein, N.; Mein, P.; Malherbe,
   J. M.; Chandra, R.
2014A&A...564A.104S    Altcode:
  Context. An extended filament in the central part of the active
  region NOAA 11106 crossed the central meridian on Sept. 17, 2010 in
  the southern hemisphere. It has been observed in Hα with the THEMIS
  telescope in the Canary Islands and in 304 Å with the EUV imager (AIA)
  onboard the Solar Dynamic Observatory (SDO). Counterstreaming along the
  Hα threads and bright moving blobs (jets) along the 304 Å filament
  channel were observed during 10 h before the filament erupted at 17:03
  UT. <BR /> Aims: The aim of the paper is to understand the coupling
  between magnetic field and convection in filament channels and relate
  the horizontal photospheric motions to the activity of the filament. <BR
  /> Methods: An analysis of the proper photospheric motions using SDO/HMI
  continuum images with the new version of the coherent structure tracking
  (CST) algorithm developed to track granules, as well as the large
  scale photospheric flows, was performed for three hours. Using corks,
  we derived the passive scalar points and produced a map of the cork
  distribution in the filament channel. Averaging the velocity vectors
  in the southern hemisphere in each latitude in steps of 3.5 arcsec,
  we defined a profile of the differential rotation. <BR /> Results:
  Supergranules are clearly identified in the filament channel. Diverging
  flows inside the supergranules are similar in and out of the filament
  channel. Converging flows corresponding to the accumulation of corks
  are identified well around the Hα filament feet and at the edges of
  the EUV filament channel. At these convergence points, the horizontal
  photospheric velocity may reach 1 km s<SUP>-1</SUP>, but with a mean
  velocity of 0.35 km s<SUP>-1</SUP>. In some locations, horizontal
  flows crossing the channel are detected, indicating eventually large
  scale vorticity. <BR /> Conclusions: The coupling between convection
  and magnetic field in the photosphere is relatively strong. The
  filament experienced the convection motions through its anchorage
  points with the photosphere, which are magnetized areas (ends, feet,
  lateral extensions of the EUV filament channel). From a large scale
  point-of-view, the differential rotation induced a shear of 0.1 km
  s<SUP>-1</SUP> in the filament. From a small scale point-of-view,
  any convective motions favored the interaction of the parasitic
  polarities responsible for the anchorages of the filament to the
  photosphere with the surrounding network and may explain the activity
  of the filament. <P />Two movies are available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201322861/olm">http://www.aanda.org
  </A>

---------------------------------------------------------
Title: Dynamics of a prominence observed in Mg II lines by IRIS
Authors: Schmieder, Brigitte; Mein, Pierre; Dalmasse, Kévin; Tian,
   Hui; Kucera, Therese; Lopez-Ariste, Arturo
2014cosp...40E2927S    Altcode:
  In September 2013 several prominences were observed with the IRIS
  spectrograph during a 60 day-long international program. We will present
  one set of observations obtained using multiple instruments on September
  24. SDO/AIA and IRIS slit jaws provided images of the prominence
  corresponding to different physical conditions of the transition
  region between the cool plasma and the corona. The vector magnetic
  field was derived from THEMIS (Tenerife) observations using the He D3
  depolarisation due to the magnetic field. The inversion code (CPA) takes
  into account the Hanle and the Zeeman effects. Movies from SDO/AIA in
  304 A and Hinode/SOT in Ca II show the dynamics of the fine structures
  in the plane of the sky. From Mg II and Si IV line spectra observed by
  IRIS and H-alpha observed by the Multi-channel subtractive spectrograph
  (MSDP) in the Meudon solar tower we derived the Dopplershifts of the
  fine structures. The profiles of the Mg II lines are narrow (FHWM =0.15
  A) and not reversed, contrary to the predictions of the theoretical
  models (Paletou et al 1993). We could resolve the velocity of several
  structures along the LOS with Dopplershifts as high as 60 km/s.

---------------------------------------------------------
Title: Dynamics in the filament of september 17 2010 and in its
    channel
Authors: Mein, Nicole; Mein, Pierre; Schmieder, Brigitte; Malherbe,
   Jean-Marie; Roudier, Thierry
2014IAUS..300..451M    Altcode:
  Dynamics of a filament is investigated in Hα. Counterstreaming flows
  are observed along the filament. Photospheric horizontal motions have
  been computed by using a Coherent Structure Tracking algorithm in the
  filament environment.

---------------------------------------------------------
Title: Proper horizontal photospheric flows below an eruptive filament
Authors: Schmieder, Brigitte; Mein, Pierre; Mein, Nicole; Roudier,
   Thierry; Chandra, Ramseh
2014cosp...40E2926S    Altcode:
  An analysis of the proper motions using SDO/HMI continuum images with
  the new version of the coherent structure tracking (CST) algorithm
  developed to track the granules as well as the large scale photospheric
  flows, was perfomed during three hours in a region containing a large
  filament channel on September 17, 2010. Supergranules were idenfied
  in the filament channel. Diverging flows inside the supergranules are
  similar in and out the filament channel. Using corks, we derived the
  passive scalar points and produced maps of cork distribution. The
  anchorage structures with the photosphere (feet) of the filament
  are located in the areas of converging flows with accumulations of
  corks. Averaging the velocity vectors for each latitude we defined a
  profile of the differential rotation. We conclude that the coupling
  between the convection and magnetic field in the photosphere is
  relatively strong. The filament experienced the convection motions
  through its feet. On a large scale point-of-view the differential
  rotation induced a shear of 0.1 km/s in the filament. On a small scale
  point-of-view convection motions favored the interaction/cancellation of
  the parasitic polarities at the base of the feet with the surrounding
  network explaining the brightenings,/jets and the eruption that were
  observed in the EUV filament.

---------------------------------------------------------
Title: Multi-purpose grating spectrograph for the 4-meter European
    Solar Telescope
Authors: Calcines, A.; Collados, M.; Feller, A.; Gelly, B.; Grauf, B.;
   Hirzberger, J.; López Ariste, A.; Lopez, R. L.; Mein, P.; Sayéde, F.
2012SPIE.8446E..6TC    Altcode:
  This communication presents a family of spectrographs designed for
  the European Solar Telescope. They can operate in four different
  configurations: a long slit standard spectrograph (LsSS), two devices
  based on subtractive double pass (TUNIS and MSDP) and one based on
  an integral field, multi-slit, multi-wavelength configuration. The
  combination of them composes the multi-purpose grating spectrograph of
  EST, focused on supporting the different science cases of the solar
  photosphere and chromosphere in the spectral range from 3900 Å to
  23000 Å. The different alternatives are made compatible by using
  the same base spectrographs and different selectable optical elements
  corresponding to specific subsystems of each configuration.

---------------------------------------------------------
Title: The S4I prototype: a beam-slicer system dedicated to the
    new generation multichannel subtractive double pass for EST imaging
    spectropolarimetry
Authors: Sayède, Frédéric; Mein, Pierre; Amans, Jean-Philippe;
   Moity, Jacques
2012SPIE.8446E..6ZS    Altcode:
  For the future European Solar Telescope (EST) the Observatoire de
  Paris proposes a new generation of MSDP: an imaging spectro-polarimetry
  instrument. To validate this new generation, we develop a beam slicer
  prototype that will be tested and validated on an optical bench and
  on existing telescopes. The prototype called S4I (Spectral Sampling
  with Slicer for Solar Instrumentation) is under construction and
  tested at the Observatoire de Paris. It validates the opto-mechanical
  feasibility of the new beam slicer. The manufacture is now complete:
  we give a description of the whole system. We give also some results
  of the first tests.

---------------------------------------------------------
Title: Velocity Vector, Ionization Degree, and Temperature of
    Prominence Fine Structures Observed by Hinode/SOT
Authors: Schmieder, B.; Mein, P.; Chandra, R.; Molodij, G.; Heinzel,
   P.; Berlicki, A.; Schwartz, P.; Fárník, F.; Labrosse, N.; Anzer,
   U.; Watanabe, T.
2012ASPC..454..107S    Altcode:
  Prominences have been successfully observed by Hinode in April 2007
  exhibiting a strong dynamics of their fine structures. The dynamics
  of a prominence is a challenge to understand the formation of cool
  prominence plasma embedded in the hot corona. Combining simultaneous
  observations obtained in Hα with Hinode/SOT and the MSDP spectrograph
  operating at the Meudon solar tower, velocity vectors have been
  derived. The Doppler-shifts of bright threads are of the same order
  as the velocities measured perpendicular to the line of sight. This
  suggests that the vertical structures of the prominence could be a pile
  up of dips in magnetic field lines viewed in 3D. Using Hα, Hinode/XRT
  and TRACE data, the hydrogen ionization degree has been determined to
  be 0.5-0.8, and the optical thickness in Hα between 0.2 and 1.3. The
  Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode produced images
  of the prominence in 11 selected lines with formation temperatures
  between log(T) = 4.7 and log(T) = 6.1. We comment on the absorption,
  emissivity blocking and emission involved for interpreting the different
  structures of the prominence in terms of the temperature and density.

---------------------------------------------------------
Title: Prominence fine-structure dynamics as inferred from 2D
    non-LTE models
Authors: Gunar, Stanislav; Schmieder, Brigitte; Mein, Pierre;
   Heinzel, Petr
2012cosp...39..683G    Altcode: 2012cosp.meet..683G
  2D multi-thread prominence fine structure models are able to
  produce synthetic Lyman spectra in very good agreement with spectral
  observations by SOHO/SUMER including the spectral line asymmetries. The
  synthetic differential emission measure curves derived from these
  models are also in a good agreement with observations. Now we show that
  these models are also able to produce synthetic H-alpha line profiles
  in very good agreement with observations which allows us to analyze
  not only the physical parameters of the prominence fine-structure
  plasma but also some aspects of its dynamical behaviour. We compare
  the synthetic H-alpha spectra with the observed spectra of the
  April 26, 2007 prominence using three statistical parameters: the
  line integrated intensity, the line full-width at the half-maximum
  (FWHM), and the Doppler velocity derived from shifts of the line
  profiles. This statistical analysis allows us to conclude that the
  overall statistical distribution of the LOS velocities in the April 26,
  2007 prominence at the time of the observations was below +/-15 km/s
  and in the prominence core was close to +/-10 km/s. In combination
  with the analysis of the Lyman spectra we determine several physical
  parameters of the observed prominence fine structures which show that
  the April 26, 2007 prominence was relatively less massive. We are also
  able to put some constrains on the prominence core temperature that
  might be relatively low, reaching values below 6000 K.

---------------------------------------------------------
Title: Dynamics of quiescent prominence fine structures analyzed by
    2D non-LTE modelling of the Hα line
Authors: Gunár, S.; Mein, P.; Schmieder, B.; Heinzel, P.; Mein, N.
2012A&A...543A..93G    Altcode:
  <BR /> Aims: We analyze the dynamics of the prominence fine
  structures of a quiescent prominence observed on April 26, 2007
  during a coordinated campaign of several spaceborne and ground-based
  instruments. We use Lyman spectra observed by SOHO/SUMER and the
  Hα line spectra obtained by MSDP spectrograph working at the
  Meudon Solar Tower. <BR /> Methods: We employ the 2D multi-thread
  prominence fine-structure modelling that includes randomly distributed
  line-of-sight (LOS) velocities of individual threads to derive models
  producing synthetic Lyman lines in good agreement with the SOHO/SUMER
  observations. We then use these models to produce synthetic Hα
  line spectra that we compare with the observed spectra using three
  statistical parameters: the line integrated intensity, the line
  full-width at half-maximum (FWHM), and the Doppler velocity derived
  from shifts of the line profiles. <BR /> Results: We demonstrate that
  the 2D multi-thread models that produce synthetic Lyman spectra in
  agreement with observations also generate synthetic Hα spectra in
  good agreement with the observed ones. The statistical analysis of the
  FWHM and Doppler velocities of the synthetic Hα line profiles show
  that the overall LOS velocities in the April 26, 2007 prominence at
  the time of the observations were below 15 km s<SUP>-1</SUP> and in
  the prominence core were close to 10 km s<SUP>-1</SUP>. In combination
  with the analysis of the Lyman spectra, we determine several physical
  parameters of the observed prominence fine-structures that show
  that the April 26, 2007 prominence had a relatively low-mass weakly
  magnetized structure. We are also able to impose some constraints
  on the prominence core temperature, which may be relatively low,
  with values below 6000 K. <BR /> Conclusions: The combination of
  2D non-LTE prominence fine-structure modelling with the statistical
  analysis of the observed and synthetic Lyman and Hα spectra allows us
  to analyze the influence of the model input parameters and the velocity
  fields on the synthetic Hα line profiles, thus determine the overall
  dynamics of the observed prominence as well as the physical parameters
  of its plasma. <P />Appendix A is available in electronic form at <A
  href="http://www.aanda.org">http://www.aanda.org</A>

---------------------------------------------------------
Title: Inversion of Zeeman Line Profiles Using Central Moments
Authors: Mein, P.; Uitenbroek, H.; Mein, N.; Bommier, V.; Faurobert, M.
2012EAS....55...83M    Altcode:
  A new inversion method derived from central moments of Zeeman line
  profiles (ICM), is used to determine magnetic field vectors (Mein et
  al. 2011). Two quantities A<SUB>1</SUB> and A<SUB>2</SUB> combining
  moments of profiles I ± S (S = Q,U,V) are nearly linear functions
  of the longitudinal and transverse components and lead to the field
  components through very fast iterations. Optimized exponents reduce
  noise effects. The ICM inversion does not require Milne Eddington
  approximation and can be used in a wide range of solar models.

---------------------------------------------------------
Title: New generation Multichannel Subtractive Double Pass for
    imaging spectropolarimetry - The S4I prototype
Authors: Sayede, F.; Mein, P.; Amans, J. -P.; Moity, J.
2012EAS....55..385S    Altcode:
  Imaging spectropolarimetry is a powerful tool in solar
  physics. Multichannel Subtractive Double Pass (MSDP) spectrographs
  can produce simultaneous 2D images in a number of wavelengths
  covering several line profiles with the following advantages: -
  Contrary to long slit spectroscopy, the spatial resolution can reach
  the diffraction limit. - Contrary to narrow band filters, full line
  profiles are recorded at the same time without any image motion and
  differential seeing effect. MSDP spectrographs use an entrance window
  instead of the usual long slit. A new generation MSDP using slicers
  made of mirrors instead of prisms is proposed for the future 4 m class
  European Solar Telescope. We describe the beam slicer prototype S4I
  (Spectral Sampling with Slicer for Solar Instrumentation) that will
  be tested soon at the 14 m spectrograph of the Meudon Solar Tower.

---------------------------------------------------------
Title: Magnetic Field Structures in a Facular Region Derived from
    THEMIS and Hinode Vector Magnetic Field
Authors: Guo, Y.; Schmieder, B.; Bommier, V.; Mein, P.
2012ASPC..456...55G    Altcode:
  In order to compare vector magnetic fields obtained by two spectral
  polarimeters (THEMIS/MTR and Hinode SOT/SP) and two inversion codes
  (UNNOFIT and MELANIE), we observed a facular region in the active region
  NOAA 10996 on 2008 May 23. We found that they give consistent results
  concerning the distributions of field strengths, azimuth and inclination
  angles. SOT/SP could resolve small magnetic polarities with sizes of
  1” to 2”, and detect convergence and divergence of the horizontal
  components of magnetic fields in the facular cells. These findings
  support the models suggesting the existence of flux tube bundles
  in faculae. With this model and multi spectral line observations,
  we could infer the relative formation heights of those spectral lines.

---------------------------------------------------------
Title: Fast inversion of Zeeman line profiles using central moments
Authors: Mein, P.; Uitenbroek, H.; Mein, N.; Bommier, V.; Faurobert, M.
2011A&A...535A..45M    Altcode:
  Context. Many inversion techniques derive vector magnetic fields and
  other parameters of the solar atmosphere from Stokes profiles with an
  iterative process. <BR /> Aims: We propose a new inversion method, using
  functions derived from central moments (ICM), to determine magnetic
  field vectors with very few iterations. <BR /> Methods: Two quantities
  A<SUB>1</SUB> and A<SUB>2</SUB> that combine moments of profiles I ±
  S (S = Q,U,V) are proposed. They are nearly linear functions of the
  longitudinal and transverse components of the magnetic field, and lead
  to estimates of the field components through a least-squares polynomial
  fit. A third quantity A<SUB>D</SUB> can be used to interpolate between
  expansions that correspond to two basic models. Exponents β<SUB>1</SUB>
  and β<SUB>2</SUB> in the moment expressions are adjusted to minimize
  the sensitivity to data noise. <BR /> Results: Inversion coefficients
  are computed for magnetic fields up to 3000 G in the case of the 630.2
  Fe i line by forward modeling in two selected 1D model atmospheres
  (FALC and MALTM). After inversion of synthetic profiles computed with
  four models at disk center (FALA, FALC, FALF, MALTM), the mean standard
  deviations with respect to the input fields do not exceed 5 G for both
  components over the full range 0-3000 G. A comparison of ICM results
  with inversion by the UNNOFIT code of profiles observed with THEMIS/MTR
  shows good agreement. The typical computing time for a solar map of 100
  000 points is less than 30 s. <BR /> Conclusions: The ICM inversions
  are almost insensitive to thermodynamic properties and solve for vector
  magnetic fields in a wide range of solar conditions, ranging from plage
  to spot, with very little computational effort. They are, therefore,
  extremely suitable for large data sets. Further improvements should
  take into account instrumental profiles and effects of limited spatial
  resolution by using filling factors. Extensions using more parameters
  and models with large departures from the Milne Eddington approximation
  could also be considered.

---------------------------------------------------------
Title: The Shape of the Solar Limb: Models and Observations
Authors: Thuillier, G.; Claudel, J.; Djafer, D.; Haberreiter, M.; Mein,
   N.; Melo, S. M. L.; Schmutz, W.; Shapiro, A.; Short, C. I.; Sofia, S.
2011SoPh..268..125T    Altcode: 2010SoPh..tmp..202T; 2010SoPh..tmp..226T
  In this paper we compare observed, empirical, and modelled solar limb
  profiles and discuss their potential use to derive physical properties
  of the solar atmosphere. The PHOENIX, SolMod3D, and COSI radiative
  transfer codes as well as VAL-C models are used to calculate the
  solar limb shape under different assumptions. The main properties
  of each model are shown. The predicted limb shape as a function of
  wavelength for different features on the solar disk, such as quiet Sun,
  sunspots, and faculae, is investigated. These models provide overall
  consistent limb shapes with some discrepancies that are discussed
  here in terms of differences in solar atmosphere models, opacities,
  and the algorithms used to derive the solar limb profile. Our analysis
  confirms that the most common property of all models is limb shapes that
  are much steeper than what is observed, or predicted by the available
  empirical models. Furthermore, we have investigated the role of the
  Fraunhofer lines within the spectral domain used for the solar limb
  measurements. Our results show that the presence of the Fraunhofer
  lines significantly displaces the limb inflection point from its
  position estimated assuming only the photospheric continuum. The PICARD
  satellite, launched on 15 June 2010, will provide measurements of the
  limb shape at several wavelengths. This work shows that the precision of
  these measurements allows for discrimination among the available models.

---------------------------------------------------------
Title: New generation multichannel subtractive double pass for EST
    imaging spectropolarimetry
Authors: Sayède, Frédéric; Mein, Pierre; Amans, Jean-Philippe;
   Moity, Jacques
2010SPIE.7735E..7NS    Altcode: 2010SPIE.7735E.248S
  Any future solar telescope project should incorporate an imaging
  spectrometer. For the future EST (European Solar Telescope) the
  Observatoire de Paris offers an imaging spectro-porarimetry instrument:
  a new generation of MSDP. To validate this new generation, we develop
  a beam slicer prototype that will be tested and validated on optical
  bench and on existing telescopes. The study assesses the performance
  gain of such an instrument on a solar 4m class telescope. We present
  opto-mechanical solutions of a new beam splitter and its implementation
  in EST.

---------------------------------------------------------
Title: Spectrograph capabilities of the European Solar Telescope
Authors: Calcines, A.; Collados, M.; Feller, A.; Grauf, B.;
   Grivel-Gelly, C.; Hirzberger, J.; López Ariste, A.; López López,
   R.; Mein, P.; Sayède, F.
2010SPIE.7735E..20C    Altcode: 2010SPIE.7735E..68C
  EST is a project for a 4-meter class telescope to be located in the
  Canary Islands. EST will be optimized for studies of the magnetic
  coupling between the photosphere and the chromosphere. This requires
  high spatial and temporal resolution diagnostics tools of properties of
  the plasma, by using multiple wavelength spectropolarimetry. To achieve
  these goals, visible and near-IR multi-purpose spectrographs are being
  designed to be compatible with different modes of use: LsSS (Long-slit
  Standard Spectrograph), multi-slit multi-wavelength spectrograph with
  an integral field unit, TUNIS (Tunable Universal Narrow-band Imaging
  Spectrograph), and new generation MSDP (Multi-channel Subtractive
  Double-pass Spectrograph). In this contribution, these different
  instrumental configurations are described.

---------------------------------------------------------
Title: Velocity vectors of a quiescent prominence observed by
    Hinode/SOT and the MSDP (Meudon)
Authors: Schmieder, B.; Chandra, R.; Berlicki, A.; Mein, P.
2010A&A...514A..68S    Altcode: 2009arXiv0911.5091S
  Context. The dynamics of prominence fine structures present a
  challenge to our understanding of the formation of cool plasma
  prominence embedded in the hot corona. <BR /> Aims: Observations
  performed by the high resolution Hinode/SOT telescope allow us to
  compute velocities perpendicular to the line-of-sight or transverse
  velocities. Combining simultaneous observations obtained in Hα with
  Hinode/SOT and the MSDP spectrograph operating in the Meudon solar
  tower, we derive the velocity vectors of a quiescent prominence. <BR
  /> Methods: The velocities perpendicular to the line-of-sight are
  measured using a time-slice technique and the Doppler shifts velocity
  using the bisector method. <BR /> Results: The Doppler shifts of
  bright threads derived from the MSDP show counterstreaming of the
  order of 5 km s<SUP>-1</SUP> in the prominence and reaching 15 km
  s<SUP>-1</SUP> at the edges of the prominence. Even though they are
  minimum values because of seeing effects, they are of the same order
  as the transverse velocities. <BR /> Conclusions: These measurements
  are very important because they suggest that the vertical structures
  detected by SOT may not be true vertical magnetic structures in the sky
  plane. The vertical structures could be a pile up of dips in more or
  less horizontal magnetic field lines in a 3D perspective, as proposed
  by many MHD modelers. In our analysis, we also calibrate the Hinode
  Hα data using MSDP observations obtained simultaneously. <P />A movie
  is available in electronic form at http://www.aanda.org

---------------------------------------------------------
Title: Counterstreaming in quiescent prominences observed by
    Hinode/SOT and Meudon/MSDP
Authors: Schmieder, Brigitte; Chandra, Ramesh; Berlicki, Arkadiusz;
   Mein, Pierre
2010cosp...38.2943S    Altcode: 2010cosp.meet.2943S
  Prominences have been successfully observed by Hinode in April 2007
  exhibiting a strong dy-namics of their fine structures. The dynamics
  of a prominence is a challenge to understand the formation of cool
  prominence plasma embedded in the hot corona. Combining simultaneous
  observations obtained in Hα with Hinode/SOT and the MSDP spectrograph
  operating at the Meudon solar tower, velocity vectors have been
  derived. The Doppler-shifts of bright threads are of the same order
  as the transverse velocities measured perpendicularly to the line of
  sight. Counterstreamings are detected at the top of the prominence. The
  vertical structures of the prominence could be a pile up of dips in
  magnetic field lines viewed in 3D

---------------------------------------------------------
Title: Model studies of the solar limb shape variation with wavelenght
    within the PICARD project.
Authors: Melo, Stella M. L.; Thuillier, Gerard; Claudel, Jennyfer;
   Haberreiter, Margit; Mein, Nicole; Schmutz, Werner; Shapiro, Alexander;
   Sofia, Sabatino; Short, Christopher I.
2010cosp...38.1756M    Altcode: 2010cosp.meet.1756M
  Solar images in the visible wavelength range show that the disk centre
  is brighter than the limb region. This phenomenon, which is both known
  as "centre to limb variation (CLV)", or "limb darkening function", is
  know to depend on wavelength. Since the CLV is determined by the density
  and temperature stratification, as well as the chemical composition
  of the so-lar photosphere, its measurement is important to validate
  theoretical assumption made when building numerical models of the
  solar atmosphere. The definition of the solar diameter is nor-mally
  adopted as the separation between two inflection points at opposite
  ends of a line passing through the center of the solar disk. Therefore,
  in order to understand long term variability on the solar diameter, it
  is important to understand what drives the dependence of the position
  of the inflection point on wavelength. In this paper we use different
  available solar atmosphere models to study this dependence. The results
  presented here refer to quiet Sun conditions and encompass the visible
  and near infra-red spectral regions, which are the regions of interest
  for the PICARD Satellite Mission. In a first step we utilize the solar
  atmosphere parameters with a radiative transfer code. This allows for
  the study of the impact of different factors such as opacities, electron
  density and temperature from different models on the results. Then, we
  compare results obtained using each solar atmosphere model. Our results
  are compared with existent ground based measurements performed by the
  Pic du Midi telescope, the balloon board measurements with the Solar
  Disk Sextant experiment, and with the measurements by the Michelson
  Doppler Imager on board SoHO satellite. The model simulations show that
  the position of the inflection point is sensitive to the different
  parameters and model assumptions. Furthermore, our study shows, for
  the first time, that the position of the inflection point changes
  dramatically with and outside of Fraunhofer lines.

---------------------------------------------------------
Title: Fast imaging spectroscopy with MSDP spectrometers. Vector
    magnetic maps with THEMIS/MSDP
Authors: Mein, P.; Mein, N.; Bommier, V.
2009A&A...507..531M    Altcode:
  Context: Multichannel subtractive double pass (MSDP) spectrometers
  produce 3D data cubes (x, y, λ) simultaneously across several line
  profiles. They do not suffer from image convolution by any slit width,
  and synchronous observations across all wavelengths avoid differential
  seeing effects. They are very suitable for fast 2D spectroscopy. <BR
  />Aims: (1) We review specifications and capabilities of some existing
  MSDP spectrometers with respect to high-cadence observations. (2)
  THEMIS/MSDP is designed for the spectropolarimetry of strong lines. We
  propose new data reductions also suitable for the spectropolarimetry of
  photospheric lines. <BR />Methods: An off-line algorithm is described
  as a way to increase the spectral resolution. Taking the opportunity
  of 3D data, spatial interpolations are used around each solar point by
  only assuming that intensity gradients partial I(x, y, λ)/partial x
  are constant in the range (x± ɛ_x,λ ± ɛ_λ). The UNNOFIT inversion
  is used to compare vector magnetic maps deduced from THEMIS/MSDP and
  slit-spectropolarimetry THEMIS/MTR data. <BR />Results: Both results
  are in good agreement. In active regions, the rms of the MSDP noise,
  calculated over 1 arcsec^2, is less than 24 G for the LOS magnetic
  field and less than 52 G for B<SUB>x</SUB> and 32 G for B_y. The MSDP
  scanning speed is 10 times the speed of slit-spectropolarimetry. <BR
  />Conclusions: THEMIS/MSDP can provide vector magnetic maps with typical
  temporal resolutions that are less than 1 min for small fields-of-view
  and 10 min for active regions. This allows addressing a number of fast
  events. In the future, MSDP instruments should efficiently complement
  single-slit spectroscopy and tunable filters. Their main capabilities
  should be the multiline aspect and the high temporal and spatial
  resolutions. New optical devices, such as image slicers, should
  substantially increase the signal-to-noise ratio. For polarimetric
  measurements, various compromises are possible between speed, spatial
  resolution, and SNR. A-posteriori image restorations, either using wide
  band proxies or bursts of multi-wavelength short exposures, should help
  improving signal-to-noise ratio and spatial resolution. <P />Based on
  observations made with the French-Italian telescope THEMIS operated by
  the CNRS and CNR on the island of Tenerife in the Spanish Observatorio
  del Teide of the Instituto de Astrofísica de Canarias.

---------------------------------------------------------
Title: Spectro-imagery at the solar tower of meudon.
Authors: Mein, P.
2008LAstr.122f..16M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Spectrophotometric analysis of Ellerman bombs in the Ca II,
    Hα, and UV range
Authors: Pariat, E.; Schmieder, B.; Berlicki, A.; Deng, Y.; Mein,
   N.; López Ariste, A.; Wang, S.
2007A&A...473..279P    Altcode:
  Context: Even if Ellerman bombs have been observed in the Hα line
  within emerging magnetic flux regions since the early 20th century,
  their origin and the mechanisms that lead to their formation have been
  strongly debated. Recently, new arguments in favor of chromospheric
  magnetic reconnection have been advanced. Ellerman bombs seem to be
  the signature of reconnections that take place during the emergence
  of the magnetic field. <BR />Aims: We have observed an active region
  presenting emergence of magnetic flux. We detected and studied
  Ellerman bombs in two chromospheric lines: Ca ii 8542 Å and Hα. We
  investigated the link between Ellerman bombs and other structures and
  phenomena appearing in an emerging active region: UV bright points,
  arch filament systems, and magnetic topology. <BR />Methods: On August
  3, 2004, we performed multi-wavelength observations of the active
  region NOAA 10655. This active region was the target of SoHO Joint
  Observation Program 157. Both SoHO/MDI and TRACE (195 Å and 1600 Å)
  were used. Simultaneously, we observed in the Ca ii and Na D1 lines
  with the spectro-imager MSDP mode of THEMIS. Alternately to the MSDP,
  we used the MTR spectropolarimeter on THEMIS to observe in Hα and
  in the Fe i doublet at 6302 Å. We derived the magnetic field vectors
  around some Ellerman bombs. <BR />Results: We present the first images
  of EBs in the Ca ii line and confirm that Ellerman bombs can indeed
  be observed in the Ca ii line, presenting the same “moustache”
  geometry profiles as in the Hα line, but with a narrower central
  absorption in the Ca ii line, in which the peaks of emission are
  around ±0.35 Å. We noticed that the Ellerman bombs observed in the
  wings of Ca ii line have an elongated shape - the length about 50%
  greater than the width. We derived mean semi-axis lengths of 1.4”
  × 2.0”. In the UV time profiles of the Ellerman bombs, we noticed
  successive enhanced emissions. The distribution of lifetimes of these
  individual impulses presents a strong mode around 210 s. Study of the
  magnetic topology shows that 9 out of the 13 EBs are located on the
  inversion line of the longitudinal field and that some typical examples
  might be associated with a bald patch topology. <BR />Conclusions: We
  provide new arguments in favor of the reconnection origin of Ellerman
  bombs. The different individual impulses observed in UV may be related
  to a bursty mode of reconnection. We also show that this Ca ii 8542
  Å chromospheric line is a good indicator of Ellerman bombs and can
  bring new information about these phenomena.

---------------------------------------------------------
Title: Fast vector magnetographs: THEMIS/MSDP and EST project
Authors: Mein, P.; Bommier, V.; Mein, N.
2007sf2a.conf..601M    Altcode:
  Imaging spectro-polarimetry with Multichannel Subtractive Double
  Pass (MSDP) is able to provide vector magnetic fields with high
  temporal resolution. We present some results obtained with THEMIS and
  reduced with the UNNOFIT code, as well as a new method to achieve
  off-line the required spectral resolution. Performances of slit-
  and imaging-spectroscopy are briefly compared, together with the high
  capabilities expected from the EST project.

---------------------------------------------------------
Title: Dual-line spectral and phase analysis of sunspot oscillations
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, N.; Mein, P.
2007A&A...463.1153T    Altcode:
  Context: Sunspots exhibit a wide range of oscillatory phenomena within
  their umbrae and penumbrae. <BR />Aims: We investigate the behavior
  of intensity and Doppler velocity oscillations in the umbra and the
  penumbra to study sunspot oscillations and their associations. <BR
  />Methods: Simultaneous, high-cadence (8 s), two-dimensional, Ca
  II 8542 Å and Hα 6563 Å observations are used. Doppler velocity
  and intensity variations are studied with a wavelet spectral, phase
  difference and coherence analysis, both at distinct positions and
  within the whole umbra and the penumbra. <BR />Results: The analysis
  reveals the presence of several umbral flashes (UFs) that seem to
  fill the whole umbra. The spectral analysis indicates oscillating
  elements of size 2.5” to 5” within the umbra with periods around
  the 3-min band and oscillation periods around the 5-min band within
  the penumbra. Two remarkable jumps of the oscillation period and the
  intensity-velocity phase difference are present at both umbra-penumbra
  and penumbra-superpenumbra boundaries reflecting a drastic change in
  physical and/or magnetic conditions. The intensity-velocity phase
  analysis shows a delay of the intensity response to the velocity
  variations in accordance with the physics of the observed sawtooth
  velocity behavior. Most of the UFs oscillate incoherently, while the
  calmest umbral area seems to be associated with velocity spreading
  from neighboring UFs. The derived incoherency among UFs in conjunction
  with the existence of coherently oscillating elements within the umbra
  suggests the presence of umbral areas with slightly different physical
  and/or magnetic field conditions. <BR />Conclusions: .The presented
  analysis provides further important constraints for realistic models
  and theoretical interpretations describing sunspot oscillations.

---------------------------------------------------------
Title: Magnetic flux tubes observed with THEMIS/MSDP
Authors: Mein, P.; Mein, N.; Faurobert, M.; Aulanier, G.; Malherbe,
   J. -M.
2007A&A...463..727M    Altcode:
  Aims:We use spectro-polarimetric THEMIS/MSDP data to investigate the 3D
  structure of solar magnetic-flux tubes across the upper photosphere. <BR
  />Methods: Profiles of the sodium D1 line 589.6 nm are analysed by
  the bisector method at different wavelengths from the core to the
  wings, for several bright features. They are compared to synthetic
  profiles derived from 2D magnetic models of flux tubes and from the
  MULTI code for NLTE line profiles. Three different magnetic models of
  flux tubes are investigated. Model (I) consists of a single flux tube
  that compensates for the horizontal Lorentz forces exactly, while model
  (II) uses a compromise between horizontal and vertical components. Model
  (III), a conglomerate of thinner flux tubes, leads to the best agreement
  with observations. <BR />Results: (1) The combination of seeing effects
  (small filling factor) with slopes of line profiles, which are different
  in the flux tubes and the neighbouring quiet sun, account for the
  decrease in observed magnetic field from line core to line wings in
  central parts of magnetic features, as well as the decrease in magnetic
  fluxes integrated over the whole magnetic features. (2) The expansion
  with height of single magnetic flux tubes (models I and II) accounts for
  the increase in the size of magnetic features from line wings to line
  core. (3) Pure thermodynamical criteria characterising Dopplershifts
  and line-intensity fluctuations of magnetic and non-magnetic features
  have been proven by observations. <BR />Conclusions: . We could account
  for differential Zeeman effects along the D1 line profile by combining
  expansion of flux tubes with height, low gas pressure inside flux tubes,
  and small filling factor due to seeing effects. Better agreement with
  observations, in particular with respect to magnetic field amplitudes,
  will probably need 3D models that take velocity fields and horizontal
  gradients of temperature into account.

---------------------------------------------------------
Title: Fast vector magnetic maps with imaging spectroscopy
Authors: Mein, P.; Mein, N.; Bommier, V.
2007MmSAI..78..160M    Altcode:
  We present a new observing mode of THEMIS / MSDP which can provide fast
  vector magnetic maps of the solar photosphere in the 610.27 Ca line.

---------------------------------------------------------
Title: Magnetic flux tubes observed with THEMIS/MSDP .
Authors: Mein, P.; Mein, N.; Faurobert, M.; Aulanier, G.; Malherbe,
   J. -M.
2007MmSAI..78...92M    Altcode:
  We use 2D spectro-polarimetric data of the NaD1 line to investigate
  magnetic flux tubes at several levels of the solar photosphere: <P />-
  magnetic and non-magnetic bright features can be discriminated by simple
  criteria of intensities and dopplershifts. <P />- 2D magnetic models
  and NLTE line profiles are compared to observations : combination of
  seeing effects and departures between slopes of line profiles in flux
  tubes and neighbouring photosphere account for vertical gradients of
  line-of-sight (LOS) magnetic field measurements. <P />- Best qualitative
  agreements are obtained with clusters of magnetic flux tubes.

---------------------------------------------------------
Title: Dual-line analysis of sunspot oscillations
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, N.; Mein, P.
2007MmSAI..78...98T    Altcode:
  Umbral oscillations and running penumbral (RP) waves are studied
  with simultaneous, two-dimensional, high cadence (8 sec), dual-line
  sunspot observations in Ca II 8542 Å and Halpha , obtained with the
  MSDP spectrograph on the German VTT in Tenerife. Doppler velocity and
  intensity images are used to investigate the physical characteristics
  of umbral flashes (UFs) and RP waves while a wavelet spectral and phase
  analysis shows their temporal behaviour and permits us to elaborate
  on their nature and possible association.

---------------------------------------------------------
Title: Spectro polarimetry with liquid crystals .
Authors: Malherbe, J. -M.; Roudier, Th.; Moity, J.; Mein, P.; Arnaud,
   J.; Muller, R.
2007MmSAI..78..203M    Altcode:
  We report spectro polarimetric observations made with the spectrograph
  of the Lunette Jean Rösch at Pic du Midi, France. We have tested
  Ferroelectric (FLC) and Nematic (NLC) Liquid Crystals. The instrument
  setup is briefly decribed, together with first observations of
  magnetic fields obtained with the Multichannel Subtractive Double Pass
  (MSDP). Polarization analysis of various spectral lines performed with
  the single pass (SP) spectrograph in active regions or at the limb is
  also presented.

---------------------------------------------------------
Title: Evolving Photospheric Flux Concentrations and Filament
    Dynamic Changes
Authors: Schmieder, B.; Aulanier, G.; Mein, P.; Ariste, A. López
2006SoPh..238..245S    Altcode: 2006SoPh..tmp...64S
  We analyze the role of weak photospheric flux concentrations that
  evolve in a filament channel, in the triggering of dynamic changes in
  the shape of a filament. The high polarimetric sensitivity of THEMIS
  allowed us to detect weak flux concentrations (few Gauss) associated
  with the filament development. The synoptic instruments (MDI, SOLIS)
  even if their sensitivity is much less than THEMIS were useful to
  follow any subsequent strengthening of these flux concentrations after
  their identification in the THEMIS magnetograms. We found that (1)
  the northern part of the filament develops an Hα barb at the same
  time that weak minority polarity elements develop near a plage; (2)
  a section in the southern part of the Hα filament gradually disappears
  and later reforms at the same time that several mixed-polarity magnetic
  elements appear, then subsequently cancel or spread away from each
  other. These changes correspond to increases in EUV emission, as
  observed by TRACE, EIT, and CDS. This suggests that the plasma is
  temporarily heated along the filament spine. An idealized sequence of
  force-free models of this filament channel, based on plasma-supporting
  magnetic dips occurring in the windings of a very weakly twisted flux
  tube, naturally explains the evolution of its southern part as being
  due to changes in the topology of the coronal magnetic field as the
  photospheric flux concentrations evolve.

---------------------------------------------------------
Title: Long-period astronomical forcing of mammal turnover
Authors: van Dam, Jan A.; Abdul Aziz, Hayfaa; Ángeles Álvarez Sierra,
   M.; Hilgen, Frederik J.; van den Hoek Ostende, Lars W.; Lourens, Lucas
   J.; Mein, Pierre; van der Meulen, Albert J.; Pelaez-Campomanes, Pablo
2006Natur.443..687V    Altcode:
  Mammals are among the fastest-radiating groups, being characterized
  by a mean species lifespan of the order of 2.5millionyears (Myr). The
  basis for this characteristic timescale of origination, extinction
  and turnover is not well understood. Various studies have invoked
  climate change to explain mammalian species turnover, but other studies
  have either challenged or only partly confirmed the climate-turnover
  hypothesis. Here we use an exceptionally long (24.5-2.5Myr ago), dense,
  and well-dated terrestrial record of rodent lineages from central
  Spain, and show the existence of turnover cycles with periods of
  2.4-2.5 and 1.0Myr. We link these cycles to low-frequency modulations
  of Milankovitch oscillations, and show that pulses of turnover occur
  at minima of the 2.37-Myr eccentricity cycle and nodes of the 1.2-Myr
  obliquity cycle. Because obliquity nodes and eccentricity minima are
  associated with ice sheet expansion and cooling and affect regional
  precipitation, we infer that long-period astronomical climate forcing
  is a major determinant of species turnover in small mammals and probably
  other groups as well.

---------------------------------------------------------
Title: Observational characteristics and association of umbral
    oscillations and running penumbral waves
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, N.; Mein, P.
2006A&A...456..689T    Altcode:
  Context: .Umbral flashes (UFs) and running penumbral (RP) waves are
  believed to be closely related oscillatory phenomena of sunspots.<BR />
  Aims: .We investigate the association of UFs and RP waves to see whether
  the latter are a visual pattern created by a common source with UFs
  or a trans-sunspot wave driven by UFs.<BR /> Methods: .Simultaneous,
  two-dimensional, dual-line observations in Ca II 8542 Å and Hα
  6563 Å, obtained with the Multichannel Subtractive Double Pass (MSDP)
  spectrograph mounted on the German VTT at Teide Observatory on Tenerife,
  are used for this study. High-cadence 8 s Doppler velocity images,
  spectrograms, and spectral-analysis results are used to study the
  characteristics and the relationship of UFs and RP waves.<BR /> Results:
  .Several UFs were observed that seem to fill the whole umbra. Doppler
  velocity variations with time indicate a shock behaviour for UFs, as
  well as for umbral and RP waves and a smooth continuous propagation
  of the latter from the umbra through the umbra-penumbra boundary
  out to the edge of the penumbra. Furthermore, the spectral analysis
  shows a decreasing oscillatory frequency as we move from the umbra
  outwards and a jump at the umbra-penumbra boundary that could possibly
  reflect, apart from a change in physical conditions, a drastic change
  of the magnetic field inclination with respect to the vertical.<BR />
  Conclusions: .The results do not permit us to convincingly support one
  scenario over the other (i.e. visual pattern vs. trans-sunspot wave)
  for RP waves; however, they do provide important constraints for future
  models of sunspot oscillations and RP waves.

---------------------------------------------------------
Title: Sub arcsec evolution of solar magnetic fields
Authors: Roudier, Th.; Malherbe, J. M.; Moity, J.; Rondi, S.; Mein,
   P.; Coutard, Ch.
2006A&A...455.1091R    Altcode:
  Context: .The evolution of the concentrated magnetic field in
  flux tubes is one challenge of the nowadays Solar physics which
  requires time sequence with high spatial resolution.<BR /> Aims: .Our
  objective is to follow the properties of the magnetic concentrations
  during their life, in intensity (continuum and line core), magnetic
  field and Doppler velocity.<BR /> Methods: .We have observed solar
  region NOAA 0644 on 2004 July 15 at Pic du Midi observatory with
  the Multichannel Subtractive Double Pass (MSDP) operating mode and
  analysed the circular polarization of the Na D1 589.6 nm spectral
  line in terms of longitudinal magnetic field in 2D field of view (5.6
  arcsec× 80 arcsec), during 41 mn at two altitudes 327 km and 170 km
  in the photosphere.<BR /> Results: .Our data analysis reveals that
  all the concentrated magnetic features are associated with downward
  motions and the magnetic field remains very stable during the 41 mn. At
  different height 327 and 170 km, a clear depth effect is visible on
  Doppler velocity but not in the magnetic field strength.<BR />

---------------------------------------------------------
Title: THEMIS/MSDP magnetic field measurements
Authors: Berlicki, A.; Mein, P.; Schmieder, B.
2006A&A...445.1127B    Altcode:
  We present an analysis of longitudinal magnetic field measurements
  using the spectral data obtained with the French - Italian
  polarisation free telescope THEMIS working in Multichannel Subtractive
  Double Pass (MSDP) mode. We also used SOHO/MDI data to extend our
  analysis. THEMIS observations in the MSDP mode allows us to perform
  imaging spectropolarimetry characterized by high spatial and time
  resolution. In our analysis we used the observations of solar active
  region NOAA 10484 performed on October 20, 2003. From THEMIS 2D
  spectral images recorded in Na D<SUB>1</SUB> 5896 Å line we obtained
  the longitudinal magnetic field in the active region. The value of
  the magnetic field was calculated at different distances from the
  Na D<SUB>1</SUB> line centre. We determine the LOS magnetic field at
  different heights in the solar atmosphere. SOHO/MDI observations provide
  the longitudinal magnetic field in Ni I (6768 Å) line. THEMIS/MSDP
  measurements at Δλ= 0.30 Å are similar to SOHO/MDI results. Gradients
  of longitudinal magnetic fields derived from MSDP measurements at Δλ=
  0.08 and Δλ=0.24 Å exhibit different behaviours according to solar
  targets. A decrease with height is seen in spot umbrae and penumbrae,
  while the gradient in facular and network areas suggests a slight
  increase of the longitudinal magnetic field, which might be explained
  by the 3D-structure of canopies.

---------------------------------------------------------
Title: Active Region Magnetic Field Observed with Themis/msdp and
    Soho/mdi Instruments
Authors: Berlicki, A.; Mein, P.; Schmieder, B.
2005ESASP.600E..57B    Altcode: 2005ESPM...11...57B; 2005dysu.confE..57B
  No abstract at ADS

---------------------------------------------------------
Title: Sunspot Umbral Oscillations and Running Waves
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, N.; Mein, P.
2005ESASP.600E..15T    Altcode: 2005dysu.confE..15T; 2005ESPM...11...15T
  No abstract at ADS

---------------------------------------------------------
Title: Non-LTE diagnostics of velocity fields during the gradual
    phase of a solar flare
Authors: Berlicki, A.; Heinzel, P.; Schmieder, B.; Mein, P.; Mein, N.
2005A&A...430..679B    Altcode:
  We perform an analysis of the velocity field within the Hα ribbons
  during the gradual phase of an M 1.0 solar flare observed on October 22,
  2002. We use spectroscopic observations performed with the German VTT
  (Vacuum Tower Telescope) working in the MSDP (Multichannel Subtractive
  Double Pass spectrograph) observing mode. From these observations
  the Hα line profiles in chosen areas of the flare ribbons were
  reconstructed and these observational profiles were compared with
  a grid of synthetic Hα line profiles calculated by the non-LTE
  radiative-transfer code. This code allows us to calculate different
  models of the chromosphere with a prescribed velocity field. By
  optimising the best fit between the observed and synthetic profiles
  we find the most appropriate models of the chromosphere and vertical
  structure of the velocity field in the analysed areas of the flare
  ribbons. By means of the non-LTE radiative-transfer calculations
  we show that in most analysed areas of the Hα flare ribbons the
  chromospheric plasma exhibited upward motion with a mean velocity of
  a few km;s<SUP>-1</SUP>. These results are consistent with previous
  estimates and support the scenario of a gentle evaporation during the
  gradual phase.

---------------------------------------------------------
Title: High resolution solar magnetometry with the spectrograph of
    the Pic du Midi Turret Dome
Authors: Malherbe, J. -M.; Roudier, Th.; Mein, P.; Moity, J.;
   Muller, R.
2004A&A...427..745M    Altcode: 2000astro.ph..3094R
  We present the first results obtained with a new Ferroelectric Liquid
  Crystal (FLC) polarimeter operating with the spectrograph of the Pic
  du Midi Turret Dome, since September 2003. We observed the solar
  granulation around active region NOAA 0459 with the Multichannel
  Subtractive Double Pass (MSDP) operating mode and analysed the
  circular polarization of the Na D1 589.6 nm spectral line in terms
  of longitudinal magnetic fields in a 2D field of view (16× 142
  arcsec). Image quality was fairly good and limited to 0.4 arcsec due to
  the pixel sampling. This observation reveals the presence of magnetic
  concentrations of several hundred Gauss which are mainly located in the
  intergranular lanes. Data analysis performed at two different optical
  depths (line core and line wings) also suggests that magnetic lines
  are curved and diverge with increasing altitude.

---------------------------------------------------------
Title: On the nature of the chromospheric fine
    structure. II. Intensity and velocity oscillations of dark mottles
    and grains
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, P.
2004A&A...423.1133T    Altcode:
  We study periodicities of dark mottles and grains observed in
  high spatial and temporal resolution Hα 2-D intensity and velocity
  images, obtained with the Multichannel Subtractive Double Pass (MSDP)
  spectrograph at THEMIS in Tenerife, Canary Islands. Intensity and
  velocity variations of individual mottles and grains, as well as of
  large regions containing a substantial number of these structures
  are examined with a wavelet analysis which provides the temporal
  distribution of periods and with a randomization method that gives
  the respective probabilities associated with them. The wavelet
  analysis, which shows that velocity variations are the dominant
  ones, results in a wide range of periods, from 100 to 500 s, with
  variable probabilities. However, it strongly indicates the presence
  of a predominant period of ∼5 min seen in both dark mottle and grain
  oscillations. We suggest that differences in periods found in individual
  mottles as well as in averages of regions containing these structures
  are due to the topology of the local magnetic field which can affect
  oscillatory processes. We report for the first time oscillations of
  dark grains which are more likely vertical structures “anchored"
  in the photosphere. The analysis supports further the suggestion that
  dark mottles and grains are the same structures, the only difference
  between them being their respective inclinations to the line-of-sight.

---------------------------------------------------------
Title: Magnetic changes observed in the formation of two filaments
in a complex active region: TRACE and MSDP observations
Authors: Schmieder, Brigitte; Mein, Nicole; Deng, Yuanyong; Dumitrache,
   Cristiana; Malherbe, Jean-Marie; Staiger, Joachim; Deluca, E. E.
2004SoPh..223..119S    Altcode:
  This paper is focused on the formation of two filaments in a complex
  center of decaying active regions (AR 8329 and AR 8326), located in
  the northern hemisphere. The observations were obtained in Hα by
  the Multi-channel Subtractive Double Pass spectrograph (MSDP mounted
  on the German telescope VTT in Tenerife) and EUV lines with TRACE
  (Transition Region And Corona Explorer). High Doppler shifts are found
  to be related to the ends of filament segments where canceling magnetic
  fields are also located (as seen on magnetograms from Big Bear Solar
  Observatory). At these locations, velocities along the line of sight,
  derived by using a cloud model method reach −20 km s<SUP>−1</SUP>,
  the segments of filaments merge and frequently a time-related sub-flare
  is observed by TRACE. The chirality of the filament segments has been
  determined by different methods: the segments of dextral chirality
  join together and form a long dextral filament, and a single filament
  of sinistral chirality forms end to end with the dextral filament
  but does not merge with it. Assuming a model of twisted flux tube for
  filament material, we suggest that the dextral filament has negative
  helicity and a relationship between its formation and the close by
  sunspot with the same sign of helicity.

---------------------------------------------------------
Title: Multi-wavelength flare study and magnetic configuration
Authors: Schmieder, Brigitte; Berlicki, A.; Vilmer, N.; Aulanier,
   G.; Démoulin, P.; Mein, P.; Mandrini, C.; Deluca, E.
2004IAUS..223..397S    Altcode: 2005IAUS..223..397S
  Recent results of two observation campaigns (October 2002 and October
  2003) are presented with the objective of understanding the onset
  of flares and CMEs. The magnetic field was observed with THEMIS and
  MDI, the chromosphere with the MSDP operating on the German telescope
  VTT and on THEMIS, the EUV images with SOHO/CDS and TRACE, the X-ray
  with RHESSI. We show how important is the magnetic configuration of
  the active region to produce CMEs using two examples: the October 28
  2003 X 17 flare and the October 22 2002 M 1.1 flare. The X 17 flare
  gave a halo CME while the M 1.1 flare has no corresponding CME. The
  magnetic topology analysis of the active regions is processed with a
  linear-force-free field configuration.

---------------------------------------------------------
Title: On the Nature of Chromospheric Umbral Flashes And Running
    Penumbral Waves (Abstract)
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, N.; Mein, P.
2004hell.conf...50T    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Multi-Wavelength Observations of an M1.0 Flare on 22 October
    2002
Authors: Berlicki, A.; Schmieder, B.; Vilmer, N.; Mein, P.; Mein,
   N.; Heinzel, P.; Staiger, J.; Deluca, E. E.
2004IAUS..219..669B    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Magnetic configuration reorganisation before the X 17 flare
    of October28 2003
Authors: Schmieder, B.; Mandrini, C.; Demoulin, P.; Mein, P.
2004cosp...35.1528S    Altcode: 2004cosp.meet.1528S
  The active region NOAA 0486 was observed during a multi-wavelength
  campaign with ground based and space instruments. We analyse the
  magnetic configuration of the region during a pre-event, which
  reorganizes the magnetic connectivities of the field lines before the
  occurence of a X17 flare of October 28 2003. The magnetic field was
  observed with THEMIS and MDI, the chromosphere with the MSDP operating
  on on THEMIS and with the Meudon heliograph, the EUV images with
  SOHO/CDS and TRACE. The X17 flare gave a halo CME while the M1.9 flare
  has no corresponding CME. The magnetic field analysis of the active
  regions is performed by using a linear-force-free field code. The
  pre-flare event before the X17 flare change the connectivities in a
  first phase and allows the stressed field to relax in a second phase
  producing the X17 flare.

---------------------------------------------------------
Title: Spectro-polarimetric observation of the fine structure of a
    quiescent filament
Authors: Zong, W. G.; Tang, Y. H.; Fang, C.; Mein, P.; Mein, N.; Xu,
   A. A.
2003A&A...412..267Z    Altcode:
  This paper presents the spectro-polarimetric measurements of a big
  quiescent filament observed by the MSDP mode of the THEMIS on August
  24, 2000. The Hα , CaII 8542 and NaI D2 line profiles of a segment of
  the filament were obtained. By use of the Hα images with high spatial
  resolution, the two barb endpoints were identified. The parameters at
  the barbs' endpoints, including intensity, velocity and longitudinal
  magnetic field were measured. Using the data with high spatial
  resolution (0.16” per pixel), we have found the following results. 1)
  There was mass motion at the barb endpoints in the chromosphere, the
  values and the directions of the mass motion at the barb endpoints
  change in several minutes. 2) The two barb endpoints are located
  between the majority polarities and the minority polarities.

---------------------------------------------------------
Title: High spatial resolution capabilities of Doppler measurements
    with the Pic du Midi MSDP spectrograph
Authors: Roudier, Th.; Malherbe, J. M.; Mein, P.; Muller, R.; Coutard,
   C.; Lafon, M.; Grimaud, F.
2003A&A...409..793R    Altcode:
  We analyse observations in the NaD1 line (lambda 5896 Å) obtained
  with the MSDP spectrograph of the Turret Dome of the Pic du Midi
  Observatory. Individual images reveal high spatial resolution and
  the data reduction shows the high capabilities of the spectrograph
  to get doppler measurements up to the limit of the resolution of the
  refractor (0\farcs3). Dopplershifts are obtained in the middle and
  high photosphere. The smallest granules 0\farcs4 show upward motions
  in the middle photosphere.

---------------------------------------------------------
Title: On the nature of the chromospheric fine structure. I. Dynamics
    of dark mottles and grains
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, P.
2003A&A...402..361T    Altcode:
  We analyze a time series of forty high spatial and temporal resolution
  two-dimensional intensity and Doppler velocity images at different
  wavelengths within the Hα line. The observations were obtained with the
  Multichannel Subtractive Double Pass (MSDP) spectrograph at THEMIS. We
  study the morphology of dark mottles and grains as seen in different
  wavelengths and examine their relation to the MDI magnetic field
  topology. We determine some physical properties of dark mottles with
  an inversion technique based on an iterative cloud model method with
  constant source function, giving the optical thickness tau<SUB>0</SUB>,
  the Doppler width Delta lambda<SUB>D</SUB> , the velocity v and the
  source function S distribution along a structure. The obtained global
  properties of mottles as well as the spatial and temporal evolution of
  several physical parameters along the axes of individual mottles are
  discussed. The derived velocities in mottles as a function of space
  and time (time slice images) exhibit a quasi-periodic, bi-directional
  pattern. It is suggested that magnetic reconnection is the mechanism
  responsible for their formation and dynamics. Furthermore, a similar
  quasi-periodic behaviour of the Doppler velocity variations in dark
  grains and their morphological characteristics both suggest the
  similarity of dark mottles and grains.

---------------------------------------------------------
Title: Na I D<SUB>1</SUB> Stokes V Asymmetries and Velocity Structure
    Around Sunspots
Authors: Eibe, M. T.; Sánchez Almeida, J.; Mein, P.; Aulanier, G.;
   Malherbe, J. M.
2003ASPC..307..374E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Osiris, HD 209458b, une exoplanete a l'allure de comete.
Authors: Ferlet, R.; Vidal-Madjar, A.; Lecavelier Des Etangs, A.;
   Desert, J. -M.; Hebrard, G.; Mein, N.
2003LAstr.117..194F    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Spectral diagnostics of the magnetic field orientation in a
    round-shaped filament
Authors: Schmieder, B.; Mein, N.; Heinzel, P.; Anzer, U.
2002ESASP.506..469S    Altcode: 2002ESPM...10..469S; 2002svco.conf..469S
  During several campaigns focused on prominences we have obtained
  coordinated spectral observations from the ground and from space. The
  SOHO/SUMER spectrometer allows us to observe, among others, the whole
  Lyman series of hydrogen, while the Hα line was observed by the MSDP
  spectrograph at the VTT. For Lyman lines, the non-LTE radiative-transfer
  computations have shown the importance of the prominence-corona
  transition region (PCTR) and its relation to the magnetic field
  orientation for the explanation of the observed line profiles (Schmieder
  et al. 1998, Heinzel et al. 2001). Moreover, Heinzel and Anzer (2001)
  developed new 2D models which demonstrate how the shapes of Lyman
  lines vary depending on the orientation of the magnetic field with
  respect to the line of sight. To confirm this result observationally,
  we focus here on a round-shaped filament observed during three days
  as it was crossing the limb. The Lyman profiles observed on the limb
  are different from day to day and we interpret these differences by
  the change of orientation of the prominence axis (and therefore the
  magnetic field direction) with respect to the line-of-sight.

---------------------------------------------------------
Title: MHD waves in active region filament from SOHO-THEMIS joint
    observations
Authors: Régnier, S.; Solomon, J.; Vial, J. C.; Mein, P.
2002ESASP.505..647R    Altcode: 2002IAUCo.188..647R; 2002solm.conf..647R
  The stability of solar filaments and their implications for eruptive
  events can be revealed by the existence of magnetohydrodynamic
  (MHD) waves. During the MEDOC campaign on May 2000, we performed
  joint observations involving SOHO and THEMIS instruments (CDS and
  MSDP respectively). We analyse the modes of oscillations for several
  spectral lines (Hα at 6563 Å, He I at 584 Å and Mg X at 609 Å):
  intermediate (6-40 min) and short (&lt; 5 min) periods are found and
  are discusssed in terms of MHD waves. The Hα time series (MSDP) in
  both line center intensity and line-of-sight Doppler shifts provide
  constraints on models of filament oscillations.

---------------------------------------------------------
Title: Magnetic cancellation and small-scale activity in an AR
    filament
Authors: Schmieder, B.; Engvold, O.; Yong, Lin; Deng, Y. Y.; Mein, N.
2002ESASP.505..223S    Altcode: 2002solm.conf..223S; 2002IAUCo.188..223S
  A long set of observations obtained with the VTT/MSDP spectrograph
  in September 1998 (8 to 11) allows us to follow the formation of a
  complex filament in and around a nest of active regions during its
  disk passage. Continuous shear of magnetic field in this region can
  explain the formation and the relative stability of the filament
  structure before the occurrence of a flare which leads to important
  changes in the magnetic configuration. The corona overlying the region
  and the flare, as well, is observed by TRACE. The studied filament
  is stable on long term time scale. However, high spatial and temporal
  observations obtained in La Palma (SVST) show high Doppler shifts and
  strong transverse motions of absorbing blobs along the filament. These
  velocities are directly related to magnetic activity as observed with
  the SVST. A small scale magnetic analysis shows emergence of MMFs
  (Moving Magnetic Features) around a decaying sunspot and canceling flux
  with the neighbor network. Magnetic reconnection could occur and explain
  the ejection of blobs along the new magnetic field lines. Formation
  of the transient blobs is discussed.

---------------------------------------------------------
Title: Chromospheric fine structure dynamics
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, P.
2002ESASP.505..163T    Altcode: 2002solm.conf..163T; 2002IAUCo.188..163T
  We investigate the dynamics of chromospheric mottles observed with
  THEMIS. We study a half an hour time series of 2-D intensity and
  Doppler velocity images at different wavelengths within the Hα
  line, obtained with the Multichannel Subtractive Double Pass (MSDP)
  spectrograph with a cadence of 40.5 sec. We determine the physical
  parameters in dark mottles with an inversion technique which is based
  on an iterative cloud model method with constant source function. With
  this method we calculate the optical thickness τ<SUB>max</SUB>,
  the Doppler width Δλ<SUB>D</SUB>, the velocity v and the source
  function S describing the structure. We discuss the results of the
  inversion technique and show the spatial and temporal evolution of
  several physical parameters along the axes of individual mottles. The
  pattern of the derived velocities as a function of space and time
  (time slice images) suggests the presence of magnetic reconnection as
  the driving mechanism of their formation.

---------------------------------------------------------
Title: Theoretical hydrogen population relations for horizontal
    cloud-like solar structures
Authors: Tziotziou, K.; Mein, N.; Mein, P.; Heinzel, P.
2002ESASP.477..183T    Altcode: 2002scsw.conf..183T
  A large set of parameterized NLTE models has been computed for a 1D
  horizontal cloud-like structure standing above the solar surface. The
  used input model parameters are temperature, velocity, microturbulence,
  electronic density and geometrical thickness of the structure. From
  the output of our computations which is the hydrogen level populations
  as a function of the line center optical depth, we calculate several
  relations between the hydrogen population levels and the considered
  electron density. These relations are important for the study of
  prominence-like structures from observations.

---------------------------------------------------------
Title: The 3D Spectroscopy for Adaptive Optics (Invited Talk)
Authors: Le Coarer, E.; Mein, P.
2002ASPC..282..447L    Altcode: 2002gtd..conf..447L
  According to our experience of GRAF, GRIF we try to survey the art
  in matter of 3D Spectrocopy behind Adaptive Optic systems for large
  telescopes. The Fabry Perot Interferometer can continue to play a role
  in future but some important factors as instrument must be taken into
  account in order to offers the best service. We also examine other
  optical mounts with slicers.

---------------------------------------------------------
Title: The MSDP of THEMIS: Capabilities, first results and prospects
Authors: Mein, P.
2002A&A...381..271M    Altcode:
  We present some capabilities and results of the Multi Channel
  Subtractive Double Pass instrument of THEMIS. More details
  and references can be found at http://www.themis.iac.es. MSDP
  imaging spectropolarimetry is characterized by high space and time
  resolution. The spatial resolution is close to seeing limitations,
  and large areas of the Sun can be scanned within short time
  intervals. In the case of THEMIS, polarization measurements are
  possible. 2 Stokes parameters and 16 wavelengths of a line profile
  can be observed simultaneously in a 2D field of view. The scattered
  light is reduced by the use of the long predisperser as a first-pass
  spectrograph. Some results are presented for fine structures of the
  chromosphere and stratification of magnetic fields. The MSDP of THEMIS
  is very efficient to observe fast extended events, such as eruptive
  phenomena and mass ejections, in particular during coordinated campaigns
  with space instruments. General outlines of the data-processing are
  given. All codes are available at http://BASS2000.bagn.obs-mip.fr. In
  conclusion, we mention future prospects with respect to spatial and
  spectral resolution, large field-of-view, multi-line observations,
  and compatibility with other THEMIS observing modes.

---------------------------------------------------------
Title: Vertical structure of sunspots from THEMIS observations
Authors: Eibe, M. T.; Aulanier, G.; Faurobert, M.; Mein, P.; Malherbe,
   J. M.
2002A&A...381..290E    Altcode:
  We have analysed two-dimensional spectro-polarimetric data taken
  with the MSDP observing mode of THEMIS in the Na I D<SUB>1</SUB>
  line to investigate the height variation of the magnetic field
  in sunspot umbrae. From the Zeeman-induced circular polarization
  measured at individual MSDP channels within the line profile, maps of
  the longitudinal magnetic field have been computed. A method based
  on Response Functions has been developed to estimate the depth in
  the atmosphere at which the Zeeman measurements are originated,
  thus providing the line-of-sight field at different altitudes
  in the photosphere. The magnetogram corresponding to the deepest
  level has served as a boundary condition to perform the potential
  field extrapolation into the corona. We have found that the spatial
  distribution of vertical field gradient contours predicted from
  extrapolation is in qualitatively good agreement with that inferred from
  observations. Quantitatively, however, the longitudinal field gradients
  obtained with both methods differ about one order of magnitude, being
  larger for observations. The origin of this discrepancy has been
  discussed with respect to possible observation biases, as well as to
  idealizations used for field extrapolation. This is a crucial problem
  to be addressed in future work, and may have important implications
  for the physics of how the magnetic field evolves through sunspots
  and how the flux is distributed in the corona.

---------------------------------------------------------
Title: Ca II 8542 Å sunspot oscillations observed with THEMIS
Authors: Tziotziou, K.; Tsiropoula, G.; Mein, P.
2002A&A...381..279T    Altcode:
  Oscillations in the umbra and the penumbra of an isolated sunspot
  located near the solar disk centre were investigated. The observations
  were obtained with the Multichannel Subtractive Double Pass (MSDP)
  spectrograph operating in the Ca Ii 8542 Å line and installed at
  the focus of THEMIS (Tenerife). From the MSDP data, two-dimensional
  intensity and Doppler shift images were computed at different
  wavelengths within the line. Intensity and Doppler shift oscillations
  in the umbra and the penumbra of the sunspot showing up as umbral
  flashes and penumbral waves were analyzed using a 23 min time series
  with a cadence of 46 s. The Ca Ii umbral flash intensity profile shows
  an emission core in its blue wing. We investigate the relation between
  umbral flashes and running penumbral waves by a power spectrum analysis
  which shows a 6 mHz frequency for the standing umbral oscillations
  (flashes) which are observed only on the upper half part of the
  umbra. The running penumbral waves propagate with an average phase
  velocity of 16 km s<SUP>-1</SUP> and their frequency is constant in the
  penumbra and equal to 3 mHz. Although the time slice images suggest
  that umbral flashes and running penumbral waves are probably due to
  the same resonator, the power analysis shows no direct relationship
  between the two phenomena. Based on observations made with the THEMIS
  telescope operated on the island of Tenerife by CNRS-CNR in the Spanish
  Observatorio del Teide of the Instituto de Astrof{ísica de Canarias.

---------------------------------------------------------
Title: Recent results from THEMIS/MSDP campaigns
Authors: Tziotziou, K.; Mein, P.
2002joso.book..129T    Altcode:
  We present recent results based on observations of the 2000 campaign
  with the Multichannel Subtractive Double Pass (MSDP) spectrograph of the
  solar telescope THEMIS. The MSDP spectrograph permits the simultaneous
  recording of line profiles at every pixel of a two-dimensional solar
  image. We show results based on inversion methods developed for the
  study of THEMIS observations, either with the use of a non-LTE grid of
  line profiles or with the use of response functions. We also discuss
  results concerning sunspot observations and in particular a study
  of magnetic field gradients in the umbra of sunspots and a study of
  oscillatory phenomena like umbral flashes and running penumbral waves.

---------------------------------------------------------
Title: JOSO national report 2000-2001 - France
Authors: Schmieder, B.; Mein, P.; Lemaire, P.; Pick, M.; Vilmer, N.
2002joso.book...56S    Altcode:
  We report on the scientific advances in solar physics in France. The
  French Solar community is large split in different laboratories and
  observatories. We report on specific groups (THEMIS, SOHO, Nançay).

---------------------------------------------------------
Title: 2D spectroscopy and science with THEMIS
Authors: Tziotziou, K.; Mein, P.; Tsiropoula, G.; Eibe, T.
2001hell.confE..25T    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A Study of Hydrogen Density in Emerging Flux Loops from
    a Coordinated Transition Region and Coronal Explorer and Canary
    Islands Observation Campaign
Authors: Mein, N.; Schmieder, B.; DeLuca, E. E.; Heinzel, P.; Mein,
   P.; Malherbe, J. M.; Staiger, J.
2001ApJ...556..438M    Altcode:
  During an international ground-based campaign in the Canary Islands
  coordinated with space instruments (i.e., Transition Region and Coronal
  Explorer [TRACE]), we observed an active region on 1998 September
  10 with high spatial and temporal resolution. New emerging flux in
  the central part of the active region was observed in magnetograms
  of the Swedish Vacuum Solar Telescope, La Palma. Emerging loops
  (arch-filament systems [AFSs]) are well developed in Hα and Ca II
  according to the observations made at the Vacuum Tower Telescope (VTT)
  and THEMIS telescope in Tenerife with the Multichannel Subtractive
  Double Pass (MSDP) spectrographs. The TRACE images obtained at 171
  and 195 Å show low-emission regions that are easily identified as
  the individual AFS. They are due to absorption by hydrogen and helium
  continua in the cool filament plasma. We compare two techniques of
  measuring the hydrogen density in the cool dense fibrils of AFSs. The
  first method based on TRACE observations derived the neutral hydrogen
  column density of the plasma absorbing coronal lines. The second one
  using Hα line profiles provided by the MSDP spectrographs is based on
  the cloud model. The results are consistent. We derive also electron
  density values using Hα lines that are in good agreement with those
  derived from the 8542 Å Ca II line observed with THEMIS (Mein et
  al.). The three types of observations (TRACE, VTT, THEMIS) are well
  complementary: absorption of coronal lines giving a good approximation
  for the maximum value of the neutral hydrogen column density, the Hα
  line giving a good determination of n<SUB>e</SUB>, and the 8542 Å Ca
  II line a good determination of the electronic temperature.

---------------------------------------------------------
Title: Investigation of temperature and velocity fluctuations through
    the solar photosphere with the Na I D lines
Authors: Eibe, M. T.; Mein, P.; Roudier, Th.; Faurobert, M.
2001A&A...371.1128E    Altcode:
  In this work we explore the diagnostic properties of the Na I D
  resonance lines by calculating the response functions of their line
  profiles to temperature and velocity perturbations in the atmosphere. We
  propose a method to transform spectral line intensity fluctuations
  measured at several wavelengths into temperature and velocity
  disturbances at different height levels. Results from tests done with
  several theoretical models of perturbations are discussed. Perturbations
  that vary as linear functions of depth are efficiently reproduced. The
  method also provides good estimations for exponential models. As an
  example we present an application to solar granulation data obtained
  with Multichannel Subtractive Double Pass (MSDP) spectroscopy.

---------------------------------------------------------
Title: Temporal height properties of the exploding granules
Authors: Roudier, Th.; Eibe, M. T.; Malherbe, J. M.; Rieutord, M.;
   Mein, P.; Mein, N.; Faurobert, M.
2001A&A...368..652R    Altcode:
  Based on time series of 2D MSDP spectrograms, taken at the Turret Dome
  in Pic du Midi, we present the temporal evolution of exploding granules
  in intensity and Doppler velocity through the solar photosphere. We
  describe the penetration of exploding granules in the solar photosphere
  during their lifes and the related phenomena like the “Bright Plumes”
  located in the downflowing plasma just on the edge of the granule. We
  suggest a possible scenario of the exploding granule evolution in the
  solar photosphere.

---------------------------------------------------------
Title: Non-LTE inversion of chromospheric {\Ca Ii} cloud-like features
Authors: Tziotziou, K.; Heinzel, P.; Mein, P.; Mein, N.
2001A&A...366..686T    Altcode:
  A chromospheric cloud-like feature observed in the 8542 Å {{Ca Ii}
  line is studied by a two step inversion procedure which provides
  estimates of its temperature, electronic density, microturbulence,
  geometrical thickness and bulk velocity. The first step involves the
  computation of a large grid of models by a multi-level non-LTE transfer
  code which gives the {{Ca Ii} line depth-dependent mean intensity
  inside an isolated, isothermal cloud lying above the chromosphere. The
  second step involves the inversion of the observed profiles with the
  grid of computed synthetic {{Ca Ii} profiles. A searching and matching
  chi <SUP>2</SUP> algorithm is implemented followed by an interpolation
  algorithm which permits a more accurate determination of the parameters
  on which the profiles depend. The five grid parameters are reduced to
  four by defining the emission measure from the geometrical thickness
  and electronic density. We show that this inversion procedure gives
  accurate results for some of our inversion parameters when dealing
  with solar filaments and is complementary to a previous study of the
  same object in the {{Hα }} line. The main advantages, problems and
  future extension of the inversion approach are also discussed.

---------------------------------------------------------
Title: First hominid from the Miocene (Lukeino Formation, Kenya)
Authors: Senut, Brigitte; Pickford, Martin; Gommery, Dominique; Mein,
   Pierre; Cheboi, Kiptalam; Coppens, Yves
2001CRASE.332..137S    Altcode:
  Remains of an early hominid have been recovered from four localities
  in the Lukeino Formation, Tugen Hills, Kenya, in sediments aged ca 6
  Ma. 13 fossils are known, belonging to at least five individuals. The
  femora indicate that the Lukeino hominid was a biped when on the ground,
  whilst its humerus and manual phalanx show that it possessed some
  arboreal adaptations. The upper central incisor is large and robust,
  the upper canine is large for a hominid and retains a narrow and
  shallow anterior groove, the lower fourth premolar is ape-like, with
  offset roots and oblique crown, and the molars are relatively small,
  with thick enamel. A new genus and species is erected for the remains.

---------------------------------------------------------
Title: Using the Na I D resonance lines to probe the solar photosphere
Authors: Eibe, M. T.; Mein, P.; Faurobert, M.; Roudier, Th.
2001ESASP.464..199E    Altcode: 2001soho...10..199E
  Observational techniques in helioseismology are often based on
  measurements made in the Na I D resonance lines. A good knowledge of
  their spectral profiles is crucial for the purposes of calibration and
  interpretation of data. Here we explore their diagnostic properties by
  calculating response functions of the D<SUB>1</SUB> and D<SUB>2</SUB>
  line profiles to temperature and velocity perturbations in the
  atmosphere. We propose a method to transform spectral line intensity
  fluctuations measured at several wavelenths into temperature and
  velocity disturbances at different height levels. The possibilities
  of such a procedure to trace the vertical structure of the photosphere
  are discussed.

---------------------------------------------------------
Title: Solar arch filaments observed with THEMIS
Authors: Mein, P.; Briand, C.; Heinzel, P.; Mein, N.
2000A&A...355.1146M    Altcode:
  Arch Filaments (AF) have been observed in the Ca Ii 8542 Å line with
  the THEMIS telescope in September 1998. We present a preliminary
  analysis of MSDP spectro-imaging data. A cloud-model fit provides
  line-of-sight velocities and a set of plausible values for the model
  parameters. The high sensitivity of the filament opacity to temperature,
  coupled with the rough linearity versus electronic density, shows that
  this Ca Ii line should be very efficient to complement usual Hα data
  for a more rigorous diagnostics. Based on observations made with the
  THEMIS telescope operated on the island of Tenerife by CNRS-CNR in
  the spanish Observatorio del Teide of the Instituto de Astrofisica
  de Canarias

---------------------------------------------------------
Title: Association of chromospheric sunspot umbral oscillations and
    running penumbral waves. I. Morphological study
Authors: Tsiropoula, G.; Alissandrakis, C. E.; Mein, P.
2000A&A...355..375T    Altcode:
  Observations of a sunspot region located near the center of the solar
  disk were obtained on October 3, 1994, with the Multichannel Subtractive
  Double Pass Spectrograph (MSDP). This instrument, operating in Hα ,
  was installed at the focus of the VTT at Tenerife (Canary Islands)
  and provided Hα intensity profiles at every pixel of the field of
  view. Reconstruction of the Hα profile allowed the computation of
  two dimensional intensity and Doppler velocity images at different
  wavelengths within the line. We analyse a time series of 1 hour and
  8 min, obtained with a cadence of 36 sec and investigate the relation
  between umbral oscillations and running penumbral waves. The Doppler
  velocity as a function of time, along radial cuts through the center of
  the spot, shows several clear cases where waves that originate inside
  the umbra continue to propagate in the penumbra. In one case we were
  able to follow the evolution of an oscillating element for 216 sec,
  from the inner part of the umbra to the penumbra and we describe the
  propagation characteristics. We confirm the close association between
  sunspot oscillations and running penumbral waves and suggest that they
  are probably due to the same resonator.

---------------------------------------------------------
Title: Study of Chromospheric Ca II Cloud-like Structures
Authors: Tziotziou, K.; Heinzel, P.; Mein, P.; Mein, N.
2000ESASP.463..443T    Altcode: 2000sctc.proc..443T
  No abstract at ADS

---------------------------------------------------------
Title: Investigating the Vertical Structure of the Solar Granulation
    with the Sodium D<SUB>2</SUB> Line
Authors: Eibe, M. T.; Roudier, Th.; Mein, P.; Faurobert, M.
2000ESASP.463..309E    Altcode: 2000sctc.proc..309E
  No abstract at ADS

---------------------------------------------------------
Title: Inversion of line profiles and solar fine structures
Authors: Mein, P.
2000ASIC..558..221M    Altcode: 2000asre.conf..221M
  We present some methods to analyse data cubes produced by large solar
  telescopes. Applications to fine structures observed at the disc or
  at the limb are briefly reviewed.

---------------------------------------------------------
Title: 3-D Magnetic Configurations for Filaments and Flares: The
    Role of “Magnetic Dips” and “Bald Patches”
Authors: Aulanier, G.; Schmieder, B.; van Driel-Gesztelyi, L.; Kucera,
   T.; Démoulin, P.; Fang, C.; Mein, N.; Vial, J. -C.; Mein, P.; Tang,
   Y. H.; Deforest, C.
2000AdSpR..26..485A    Altcode:
  The 3-D magnetic configuration of a filament and of a low energy
  flare is reconstructed, using linear mag- netohydrostatic (lmhs)
  extrapolations. In both cases, we find observational signatures
  of energy release at the locations of computed “bald patches”
  separatrices, characterised by field lines which are tangent to
  the photosphere.The filament was observed on Sept. 25, 1996, in Hα
  with the MSDP on the German VTT, Tenerife, as well as in Si IV with
  SOHO/SUMER. It is modeled as a twisted flux-tube deformed by the
  magnetic polarities observed with SOHO/MDI. The shape and location of
  the computed dipped field lines are in good agreement with the shape of
  the filament and its feet observed in Hα. Some “bald patches” (BPs)
  are present where the distribution of dips reaches the photosphere. We
  show that some of the large scale field lines rooted in BPs can be
  related to bright fine structures in Si IV. We propose that the plasma
  there is heated by ohmic dissipation from the currents expected to be
  present along the BP separatrices.The flare was observed on May 18,
  1994, in soft X-rays with Yohkoh/SXT, and in Hα at Mitaka (Japan). The
  magnetic field is directly extrapolated from a photospheric magnetogram
  from Kitt Peak Observatory. The intersections with the photosphere of
  the computed separatrices match well the bright Hα ribbons. The later
  are associated to three BPs, with overlaying dipped field lines. We
  show that enhanced densities are present in these dips, which can be
  correlated with dark Hα fibrils.Both cases show the importance of
  dipped field lines and BPs in the solar atmosphere. Energy release
  via ohmic dissipation as well as reconnection along BP separatrices
  is proposed to provide heating observed as UV brightenings in filament
  channels and even as small flares

---------------------------------------------------------
Title: Bright Rims of Solar Prominences
Authors: Hansen, I.; Engvold, O.; Schmieder, B.; Mein, N.; Mein, P.
1999ESASP.448..491H    Altcode: 1999mfsp.conf..491H; 1999ESPM....9..491H
  No abstract at ADS

---------------------------------------------------------
Title: Association between Umbral Oscillations and Running Penumbral
    Waves
Authors: Alissandrakis, C. E.; Tsiropoula, G.; Mein, P.
1999ESASP.448..217A    Altcode: 1999ESPM....9..217A; 1999mfsp.conf..217A
  No abstract at ADS

---------------------------------------------------------
Title: A Study of Hydrogen Density in Emerging Flux Loops from a
    Coordinated TRACE and Canary Islands Observation Campaign
Authors: Schmieder, B.; Deluca, E.; Mein, N.; Mein, P.; Malherbe,
   J. M.; Wilken, V.; Staiger, J.; Engvold, O.; Hanssen, I.
1999ESASP.448..653S    Altcode: 1999mfsp.conf..653S; 1999ESPM....9..653S
  No abstract at ADS

---------------------------------------------------------
Title: Analysis of evolution of NOAA 7912 active region on 19
    October 1995
Authors: Rudawy, P.; van Driel-Gesztelyi, L.; Cader-Sroka, B.; Mein,
   P.; Mein, N.; Schmieder, B.; Malherbe, J. -M.; Rompolt, B.
1999A&AS..139...89R    Altcode:
  An analysis of a minor (B3.2) flare related to an X-ray jet in the
  reversed polarity NOAA 7912 active region is presented, focusing
  on various kinds of activity observed in the Hα line with the MSDP
  instrument. Using complementary Yohkoh soft X-ray observations and a
  Kitt Peak magnetic field map we study the influence of a rather low
  and graduate energy release on filaments, fibrils and chromospheric
  brightenings and their relevant coronal features. We find that this
  small flare affected the entire AR and was associated with strong up-
  and downflows along remote fibrils and filaments, which appear to be
  connected by large-scale loops. It is shown that at least one of the
  observed brightenings was caused by downflow of the matter, thus, by
  the kinematic heating of the material. The filament in the vicinity
  of the flare footpoints changed the most: it broke into two parts,
  temporarily rose to higher altitudes inside the AR and even erupted
  outside of the AR, re-forming only three hours later. We show that
  even a minor flare can lead to important morphological and dynamical
  changes in an active region.

---------------------------------------------------------
Title: The Role of "Magnetic Dips" and "Bald Patches" for a Filament
    Observed by SOHO and GBO
Authors: Aulanier, G.; Schmieder, B.; Kucera, T.; van Driel-Gesztelyi,
   L.; Démoulin, P.; Mein, N.; Vial, J. -C.; Mein, P.
1999ASPC..184..291A    Altcode:
  The studied filament was observed on Sept. 25, 1996, in Hα with
  the MSDP on the German VTT, Tenerife, as well as in Si IV with
  SOHO/SUMER. The 3-D magnetic configuration of the filament channel is
  reconstructed, using linear magnetohydrostatic (lmhs) extrapolations
  from a SOHO/MDI magnetogram, which is modified by a background magnetic
  component constraining a twisted flux-tube. This flux-tube is deformed
  by the magnetic polarities observed with SOHO/MDI. The shape and
  location of the computed "dipped field lines" are in good agreement
  with the shape of the filament and its feet observed in Hα. Some "bald
  patches" (BPs) are present where the distribution of dips reaches the
  photosphere. We find observational signatures in Si IV brightenings of
  energy release at the locations of computed "bald patch separatrices",
  defined by field lines which are tangent to the photosphere. We propose
  that the plasma is there heated by ohmic dissipation from the expected
  currents in the BP separatrices. The results show the importance of
  "dipped field lines" and "bald patches" in filament channels.

---------------------------------------------------------
Title: Coordinated Prominence Observations by SOHO and Ground-Based
    Observatories
Authors: Schmieder, B.; Heinzel, P.; Vial, J. -C.; Malherbe, J. M.;
   Mein, P.; Rudawy, P.; Ceppatelli, G.
1999ASPC..184..296S    Altcode:
  Coordinated observations obtained during the JOP12 (Joint Observing
  Programme between SOHO and ground-based instruments) allow us to
  analyse the physical conditions in a prominence of 5 June 1997 and
  its environment in the solar corona. The arch-shaped prominence shows
  either vertical or horizontal structures according to the observed
  lines (Hα with the coronagraph of the Wroclaw University Observatory
  at Bialków and lines in a broad temperature range by the Coronal
  Diagnostic Spectrometer CDS). The less dynamic behaviour of this
  prominence was shown by the persistence of bubbles in the prominence
  and confirmed by the Dopplershifts measured in CDS lines and in Hα
  by the Italian Panoramic Monochromator (IPM) filter on the THEMIS
  telescope in Tenerife. We explain the complex morphology of this
  prominence by recent 3D MHD models. Finally, we present prominence
  spectra in higher lines of the hydrogen Lyman series (from Lδ to L-9),
  together with some other UV lines. These data have been obtained by
  the Solar Ultraviolet Measurements of Emitted Radiation (SUMER). We
  demonstrate the basic characteristics of the calibrated line profiles
  of Lyman lines and compare them with the theoretical profiles computed
  from isothermal-isobaric models. This leads to some constraints on
  the environment of the prominence.

---------------------------------------------------------
Title: Cloud model with variable source function for solar Hα
    structures. II. Dynamical models
Authors: Heinzel, P.; Mein, N.; Mein, P.
1999A&A...346..322H    Altcode:
  It was demonstrated in the previous paper (Paper I)that the cloud
  model technique can be largely improved if one considers realistic
  boundary conditions in evaluating the true form of the line source
  function. For structures seen against the solar disk, the Hα line
  source function is decreasing from bottom towards the top. In the
  present paper we investigate the effect of Doppler brightening on Hα
  source function. In frame of 1D non-LTE models it is demonstrated how
  the Hα line source function is increased depending on the velocity
  of the moving cloud and direction of the motion. For the same set of
  cloud models as used in Paper I, we have reevaluated the variations of
  the source function with optical depth including the effect of cloud
  motion. The resulting curves have been approximated by a second-degree
  polynomial and the respective coefficients have been subsequently
  used in a modified iterative method in order to derive the cloud
  model parameters. As expected, dynamical models lead to more precise
  specification of these parameters, namely the optical thickness, as
  compared to the static case investigated in Paper I. We have applied
  this new method to MSDP observations of a dark chromospheric feature
  (loop) with considerable flows.

---------------------------------------------------------
Title: Filament channel structures in a SI IV line related to a 3d
    magnetic model
Authors: Kucera, T. A.; Aulanier, G.; Schmieder, B.; Mein, N.; Vial,
   J. -C.
1999SoPh..186..259K    Altcode:
  A recent 3D magnetic model of filament support (Aulanier and Démoulin,
  1998) has shown that specific morphologies derived from the model, based
  on SOHO/MDI magnetograms, match quite well with the observations of a
  filament observed in Hα and Ca ii lines with the German telescope VTT
  in Tenerife on 25 September 1996 (Aulanier et al., 1998, 1999a). Some
  predictions of this model concern the filament channel. To continue the
  comparison of model and data, we have investigated the same filament
  region observed in ultraviolet by the SOHO spectrometers SUMER and
  CDS. The elongated EUV fine structures in the filament channel observed
  in the Si iv 1393.76 Å line by SUMER have similar orientations
  and locations to features predicted by the model of Aulanier et
  al. (1999a). These regions are near the bases of field lines which
  tangentially join to the photosphere in so called 'bald patches' and
  are parts of large arcades above the filament channel. In addition,
  we consider the Si iv Doppler shifts in these structures and compare
  them to what might be expected from the model field structure. Our
  study also suggests that the filament has a very low opacity in Si iv,
  lower than that of the O v line observed by CDS.

---------------------------------------------------------
Title: A non-LTE inversion procedure for chromospheric cloud-like
    features
Authors: Molowny-Horas, R.; Heinzel, P.; Mein, P.; Mein, N.
1999A&A...345..618M    Altcode:
  A fast inversion procedure which provides estimates of the temperature,
  electronic density, microturbulence, geometrical thickness and bulk
  velocity of chromospheric features, so-called “clouds”, has been
  implemented. The procedure has been divided into two steps: 1) the
  construction of a large grid of models by means of a multi-level non-LTE
  transfer code, which solves in a fast and reliable way the radiative
  transfer problem of the formation of the Hα line inside an isolated,
  isothermal cloud laying above the photosphere, and 2) the implementation
  of searching, matching and interpolating algorithms which yield an
  inversion of the observed line profile in terms of the grid's computed
  profiles. The aforementioned 5 parameters, on which the profiles depend,
  can be reduced to 4 if one defines the so-called emission measure from
  the geometrical thickness and electronic density parameters. We show
  that this strategy yields excellent results when dealing with solar
  filaments. The main advantages of this approach are also discussed.

---------------------------------------------------------
Title: 3-D magnetic configurations supporting
    prominences. III. Evolution of fine structures observed in a filament
    channel
Authors: Aulanier, G.; Démoulin, P.; Mein, N.; van Driel-Gesztelyi,
   L.; Mein, P.; Schmieder, B.
1999A&A...342..867A    Altcode:
  On September 25() th 1996, a quiescent filament located near the
  center disc (S2, E5) was observed on the German VTT (Tenerife)
  with the MSDP instrument, in the Hα line center and wings. SOHO/MDI
  line-of-sight magnetograms were co-aligned with the MSDP images, showing
  the position and evolution of the lateral feet of the filament in the
  vicinity of the parasitic magnetic polarities observed in the filament
  channel. Using the assumptions developed in the previous papers of this
  series related to the reconstruction of the 3-D magnetic configuration
  of filaments, we perform “linear magnetohydrostatic” extrapolations
  (taking into account the effects of plasma pressure and gravity) on the
  SOHO/MDI magnetograms. The main hypothesis is the presence of a twisted
  flux-tube located above the photospheric inversion line. Assuming that
  the parameters of the model do not need to be significantly modified
  during the evolution of the configuration for a duration of 1 day,
  we have shown that the 3-D distribution of dipped field lines is well
  correlated with Hα dark absorbing features in the filament channel:
  the filament itself, its lateral feet and some of the surrounding dark
  fibrils. In this way we confirm what was suggested in our earlier
  papers, i.e. that the feet are composed of the dipped portions of
  some field lines, which form a continuous pattern from the corona
  to the photosphere. We propose the same explanation for the magnetic
  configuration of some of the dark Hα fibrils in the channel. We show
  that the plasma effects are not responsible for the existence of most
  of the magnetic dips, however their inclusion helps to get a better
  correspondence between the model and the observations. We find that the
  average Hα Doppler velocities associated with the filament and with
  the chromospheric fibrils is of the order of a few hundred m s(-1)
  (though it can go locally up to 3 km s(-1) in the filament). These
  upward velocities are consistent with a quasi-static evolution of
  the magnetic configuration and with the support of dense plasma in
  magnetic dips.

---------------------------------------------------------
Title: Gradient of the line-of-sight velocities in the dark
    superpenumbral fibrils.
Authors: Tsiropoula, G.; Alissandrakis, C. E.; Mein, P.; Mein, N.
1999joso.proc..116T    Altcode:
  An isolated sunspot located near the centre of the solar disk was
  observed on October 3, 1994. The present high resolution observations
  were obtained with the Multichannel Subtractive Double Pass Spectrograph
  (MSDP) operating in Hα. Two dimensional intensity and Doppler velocity
  maps at several depths in the Hα line were computed. The monochromatic
  intensities at two wavelengths on either side of the line are used in
  terms of the photographic subtraction method expressing the "Doppler
  signal" to give, under some assumptions, the velocities at different
  depths in the Hα line. The values of the velocities obtained by
  this method are compared to those given by the bisector method while
  comparison of the velocities at different depths can give a picture
  of the gradient of the velocity in the dark superpenumbral fibrils.

---------------------------------------------------------
Title: Non-LTE inversions of solar filament in Hα profiles.
Authors: Molowny-Horas, R.; Mein, P.; Mein, N.; Heinzel, P.
1999joso.proc..209M    Altcode:
  Results are shown of a new grid-based, non-LTE inversion procedure
  which can carry out fast and accurate spectral inversions of Hα line
  profiles. The code has been applied to a set of observed MSDP Hα line
  profiles of a solar filament. The results of this inversion are shown
  as 2-D maps of temperature, microturbulence and emission measure.

---------------------------------------------------------
Title: 3-D magnetic configurations supporting prominences. II. The
    lateral feet as a perturbation of a twisted flux-tube
Authors: Aulanier, G.; Demoulin, P.; van Driel-Gesztelyi, L.; Mein,
   P.; Deforest, C.
1998A&A...335..309A    Altcode:
  In a previous paper we have shown that a twisted flux-tube is the
  most probable magnetic configuration supporting prominences. The
  model interprets many observations in a natural way (in particular
  the magnetic measurements in prominences and the chirality
  properties). Moreover, prominence feet appear as a direct consequence
  of the parasitic polarities present in the filament channel. Here we
  investigate further the link between feet and parasitic polarities
  by modelling explicitly these polarities. We show that the prominence
  lateral feet appear naturally, above secondary photospheric inversion
  lines and we describe the morphological change of feet as parasitic
  polarities evolve. This approach is applied to an observed filament
  in Hα with the MSDP on the German VTT (Tenerife) where SOHO/MDI
  magnetograms are available. We show that the shape of the prominence
  is defined by the distribution of the dips in the computed magnetic
  configuration. Then we analyse the topology of the magnetic field using
  the quasi-separatrix layers (QSLs) method. We describe the basic changes
  in the topology as the parasitic polarities evolve, in particular
  how the configuration pass from an OX to an OF topology. We find a
  correspondance between the computed QSLs and some of the chromospheric
  brightenings, observed around the feet of filaments in the y line (Ca
  II, 8542 Angstroms). It confirms the deduced magnetic configuration
  and shows that energy release is present at a low level in the complex
  topology of the filament configuration.

---------------------------------------------------------
Title: Arch Filament Systems Associated with X-Ray Loops
Authors: Malherbe, J. M.; Schmieder, B.; Mein, P.; Mein, N.; Van
   Drielgesztelyi, L.; Von Uexküll, M.
1998SoPh..180..265M    Altcode:
  Using multi-wavelength observations obtained with the Tenerife
  telescopes (VTT and GCT) and with the Yohkoh satellite, we observed
  new emerging flux with an associated arch filament system (AFS) in
  the chromosphere and bright X-ray loops in the corona. We observed the
  change of connectivity of the X-ray loop footpoints which may be at the
  origin of the occurrence of a subflare. Densities, gas and magnetic
  pressures of cold AFS and hot loops were derived and discussed. The
  extrapolation of the photospheric magnetic field observed with the GCT
  in a linear force-free field assumption (constant α) shows that this
  region, in spite of having roughly a global potential configuration,
  consists of two systems of arch filaments. We found these two systems
  best fitted with two sheared magnetic topologies of opposite α values
  of ± 0.1 Mm<SUP>-1</SUP>

---------------------------------------------------------
Title: First Observations with THEMIS
Authors: Rayrole, J.; Mein, P.; Schmieder, B.
1998ASPC..155..260R    Altcode: 1998sasp.conf..260R
  No abstract at ADS

---------------------------------------------------------
Title: The Solar Telescope THEMIS
Authors: Arnaud, J.; Mein, P.; Rayrole, J.
1998ESASP.417..213A    Altcode: 1998cesh.conf..213A
  No abstract at ADS

---------------------------------------------------------
Title: Evolution of the Magnetic Field and Chromospheric Fine
    Structure in a Filament Channel
Authors: van Driel-Gesztelyi, L.; Mein, P.; Mein, N.; Schmieder,
   B.; Malherbe, J. -M.; Aulanier, G.; Démoulin, P.; Deforest, C.;
   Staiger, J.
1998ASPC..155..321V    Altcode: 1998sasp.conf..321V
  No abstract at ADS

---------------------------------------------------------
Title: Umbral and Penumbral Waves in a Chromospheric Sunspot
Authors: Alissandrakis, C. E.; Tsiropoula, G.; Mein, P.
1998ASPC..155...49A    Altcode: 1998sasp.conf...49A
  No abstract at ADS

---------------------------------------------------------
Title: 3-D Modelling of a Filament Observed in Hα and with SOHO
Authors: Aulanier, G.; Schmieder, B.; Démoulin, P.; Mein, N.; van
   Driel-Gesztelyi, L.; Mein, P.; Vial, J. C.; Deforest, C.
1998ESASP.417..217A    Altcode: 1998cesh.conf..217A
  No abstract at ADS

---------------------------------------------------------
Title: X-ray jets in a reversed polarity region and interplanetary
    effects
Authors: Schmieder, B.; van Driel, L.; Mein, N.; Mein, P.; Willson,
   R.; Raoult, A.
1998ESASP.421..157S    Altcode: 1998sjcp.conf..157S
  No abstract at ADS

---------------------------------------------------------
Title: Velocity Fields of a Filament Region Observed with Ground-Based
    Telescopes and from SOHO
Authors: Mein, P.; Schmieder, B.; Malherbe, J. -M.; Wiik, J. E.;
   Engvold, O.; Brekke, P.; Zirker, J. B.; Poland, A. I.; Delaboudiniere,
   J. -P.; Staiger, J.
1998ASPC..150..135M    Altcode: 1998npsp.conf..135M; 1998IAUCo.167..135M
  No abstract at ADS

---------------------------------------------------------
Title: 3-D Modelling of a Filament Observed in Hα and with SOHO/MDI
Authors: Aulanier, G.; Démoulin, P.; van Driel-Gesztelyi, L.; Mein,
   P.; Deforest, C.
1998ASPC..155..326A    Altcode: 1998sasp.conf..326A
  No abstract at ADS

---------------------------------------------------------
Title: Evolution of a reversed polarity active region NOAA 7912 in
    the photosphere, the chromosphere and the corona.
Authors: van Driel-Gesztelyi, L.; Baranyi, T.; Mein, N.; Cader-Sroka,
   B.; Rudawy, P.; Mein, P.; Rompolt, B.; Schmieder, B.; Malherbe,
   J. -M.; Willson, R.; Kile, J. N.; Raoult, A.
1998joso.proc..103V    Altcode:
  The authors follow the evolution and activity of NOAA 7912, a reversed
  polarity region, in the photosphere (Kitt Peak magnetograms and Debrecen
  white-light photoheliograms), chromosphere (MSDP instrument mounted
  on the German VTT at Tenerife), and the corona (Yohkoh/SXT, Nançay
  radioheliograph and the VLA) between October 12-20, 1995. They find
  that in spite of the high shear and creation of several mixed-polarity
  regions through flux emergence, the flares in the group did not
  exceed the M-class level. This might be due to the fact that the
  highly inclined bipolar fields emerging in the following part of the
  primary reversed dipole were relatively small and quickly "consumed"
  by cancellation enhanced by sunspot motions. On the other hand, the
  presence of high shear and minor fast-moving parasitic polarities in
  NOAA 7912 was sufficient to produce eruptive events like X-ray jets
  with important coronal and interplanetary effects.

---------------------------------------------------------
Title: X-Ray Jets and Their Radio Signatures at Metric and Centimeter
    Wavelenths
Authors: van Driel-Gesztelyi, L.; Willson, R. F.; Kile, J. N.; Raoult,
   A.; Klein, L.; Mein, N.; Rudawy, P.; Cader, B.; Rompolt, B.; Schmieder,
   B.; Mein, P.; Malherbe, J. M.
1998ASPC..154..707V    Altcode: 1998csss...10..707V
  On October 19, 1995 at 10:30 UT and 17:00 UT, two semi-homologous X-ray
  jets were observed with the Yohkoh/SXT from AR 7912, a region having a
  reversed polarity group with vortex-like Hα fibril pattern and X-ray
  loops. The jets appeared over a mixed magnetic polarity region in
  the vicinity of the leading spot. The first event was also observed
  with the Nancay radio heliograph at 167, 236, and 327 MHz. Type III
  activity, indicating the presence of electron beams, superimposed on
  a noise-storm was clearly visible. Type III activity first appeared
  at 10:25 UT, coincident with the onset of the X-ray jet, at 164 MHz
  and 236 MHz close to the storm position, and in the direction of the
  X-ray jet. At 10:28:40 UT a new group of sources appeared eastward
  of the former activity, which may correspond to another jet branch
  along a more easterly path seen in the ohkoh} images. The second X-ray
  jet event was also observed with the Very Large Array (VLA) at 6.2,
  20.7, and 91.6 cm. For this event, VLA snapshot maps at 6.2 and 20.7
  cm reveal low-brightness temperature changes in source structure at
  the site of the X-ray jet during the preburst, impulsive, and decay
  phases. The VLA 91.6 cm observations also show noise storm emission
  above the active region but there is no clear temporal correlation
  between this later X-ray jet and the impulsive decimetric bursts that
  were observed during this period. Although the X-ray observations
  show that the two jets had similar temperatures, emission measures,
  speeds and trajectories they appear to have had dissimilar metric
  responses to these events. This surprising result may question our
  understanding of the process of electron beam acceleration in jets.

---------------------------------------------------------
Title: Nouvelles découvertes de Vertébrés miocènes dans le
    synclinal de Dera Bugti (Balouchistan, Pakistan)
Authors: Welcomme, Jean-Loup; Antoine, Pierre-Olivier; Duranthon,
   Francis; Mein, Pierre; Ginsburg, Léonard
1997CRASE.325..531W    Altcode:
  Since Forster-Cooper in 1910, no paleontologist bas visited the
  area of Dera Bugti in Baluchistan (Pakistan). In 1995 and 1996, two
  small French expeditions prospected the syncline of Dera Bugti. They
  established stratigraphical sections ana discovered many fossils,
  mainly reptiles, and mammals. On top of the Eocene marine limestone
  of the Kirthar there lies a Burdigalian marine falun. Above, about
  250 m of continental marls, sands and sandstones are deposited. The
  first 100 m have yielded five fossiliferous levels of MN3 b in age,
  and one of MN4, surrounded by a more sandy series. The top of the
  series has yielded Hipparion of the Upper Miocene.

---------------------------------------------------------
Title: Flare Multi-Line 2D-SPECTROSCOPY
Authors: Mein, P.; Mein, N.; Malherbe, J. -M.; Heinzel, P.; Kneer,
   F.; von Uexkull, M.; Staiger, J.
1997SoPh..172..161M    Altcode: 1997ESPM....8..161M
  A small flare was observed at the Teide Observatory on October 5,
  1994. Simultaneous data were obtained at the German Vacuum Tower
  Telescope (VTT) with the MSDP spectrograph providing high-resolution
  imaging spectroscopy in two chromospheric lines, and the Gregory Coudé
  Telescope (GCT) providing information about the magnetic field. Basic
  flare characteristics are:

---------------------------------------------------------
Title: Evolution in Space and Time of Superpenumbral Chromospheric
    Fibrils
Authors: Tsiropoula, G.; Dialetis, D.; Alissandrakis, C. E.; Mein,
   P.; Mein, N.
1997SoPh..172..139T    Altcode: 1997ESPM....8..139T
  We have studied the spatial structure and temporal evolution of the
  intensity and Doppler velocity of dark fibrils forming the superpenumbra
  of an isolated regular sunspot. The observations were obtained with the
  Multichannel Subtractive Double Pass (MSDP) spectrograph which operates
  in Hα and is installed at the focus of the Vacuum Tower Telescope (VTT)
  at Tenerife (Canary Islands). The fibril pattern shows a remarkable
  stability during the period of our observations (64 min). Moreover,
  almost all individual fibrils are identifiable in all frames, but they
  undergo continual changes in contrast, shape and size. Investigating the
  temporal evolution of intensity and velocity of individual fibrils,
  fluctuations were found which have a quasi periodic behavior. As
  mechanisms for these changes we may suggest (a) change of the Doppler
  shift due to a wave, (b) periodic changes of the density of the Hα
  absorbing material, (c) disappearance and reappearance of fibrils,
  in more or less the same magnetic flux tube, at regular intervals.

---------------------------------------------------------
Title: THEMIS: Latest News
Authors: Mein, P.; Rayrole, J.
1997ASPC..118..334M    Altcode: 1997fasp.conf..334M
  No abstract at ADS

---------------------------------------------------------
Title: Comparison of line-of-sight velocities of chromospheric
    structures derived by three different methods
Authors: Tsiropoula, G.; Christopoulou, E.; Madi, C.; Dialetis, D.;
   Mein, P.; Mein, N.
1997jena.confE..61T    Altcode:
  We have used three different methods to derive line-of-sight velocities
  in dark fibrils forming the superpenumbra of an isolated regular sunspot
  located near the centre of the solar disk (NOOA/AR 7783). The present
  observations were obtained on October 3, 1994. They were performed
  with the Multichannel Subtractive Double Pass (MSDP) spectrograph which
  operates in H-alpha and it is installed at the focus of the Vacuum Tower
  Telescope (VTT) at Tenerife (Canary Islands). This instrument records
  a two dimensional field of view on the solar surface with good spatial
  and temporal resolution. The observations were made simultaneously in 9
  wavelengts, 0.3AA apart in the H-alpha profile. At every pixel of the
  2D field of view the line profile can be restored from the measured
  values of the intensity in the 9 channels and a third degree spline
  interpolation. These profiles were used for the computation of the
  line-of-sight velocity by three different methods: (a) the Doppler
  shift method, (b) the photographic subtraction method expressing the
  “Doppler signal” and (c) the classical Beckers' cloud model. 2D
  maps of the velocity are computed, comparison of the values derived
  by the 3 different methods is performed and the conditions governing
  the validity of the 3 methods are stated.

---------------------------------------------------------
Title: New Ground-Based Solar Instrumentation
Authors: Mein, P.
1997LNP...489..241M    Altcode: 1997shpp.conf..241M
  Solar physics requires more and more multiwavelength observations,
  not only with high spatial and time resolution, but also with wide
  coverage in space and time. We review briefly instruments dedicated to
  the solar interior, visible layers and the corona. In addition to the
  accuracy of spectroscopy and polarization measurements, we emphasize
  the coverage of data sets in the k - ω diagram. New image restoration
  methods are reviewed, in the context of the best compromise between
  spatial resolution and isoplanetic field of view. Ambitious projects do
  exist, as well as new generation telescopes under construction. Progress
  in the establishment of data bases and easier data exchange between
  observatories using complementary facilities look very promising for
  the future.

---------------------------------------------------------
Title: THEMIS: Expected Capabilities for Coordinated Observations
Authors: Mein, P.
1997ASPC..118..320M    Altcode: 1997fasp.conf..320M
  Several spectroscopic modes will be available in THEMIS for coordinated
  observations. They should provide high accuracy vector magnetic fields
  (Multi-line Spectroscopy), fast imaging spectro-polarimetry (MSDP)
  and fast magnetograms (Full Disc).

---------------------------------------------------------
Title: Spatial relation between the 5-minute oscillations and
    granulation patterns.
Authors: Espagnet, O.; Muller, R.; Roudier, T.; Mein, P.; Mein, N.;
   Malherbe, J. M.
1996A&A...313..297E    Altcode:
  A white light, high resolution movie of the quiet photosphere has been
  used to study the spatial relation between the solar granulation and
  the 5-min oscillations of high degree mode (small spatial scale). The
  granular and oscillatory brightness components have been separated with
  the help of a specific filter, in the k-ω diagram. The surface of the
  Sun appears to be covered with adjacent oscillating cells of apparent
  size 2" (1500km) to 3" (2000km). Some cells are noticeable by their
  amplitude which is much larger than average. These strong oscillations
  usually appear in expanding intergranular spaces. Our observations
  suggest that the 5-min oscillations are stochastically generated by
  turbulent convection. However, the most energetic oscillations occur
  in downflows only, well separated of each other in time and space.

---------------------------------------------------------
Title: Periodic and Non-Periodic Phenomena in a Sunspot Region
Authors: Tsiropoula, G.; Alissandrakis, C. E.; Dialetis, D.; Mein, P.
1996SoPh..167...79T    Altcode:
  We have studied running penumbral waves, the homogeneous Evershed
  effect, and the spatial relation between intensity and Doppler velocity
  penumbral features of a chromospheric sunspot. The observations were
  obtained with the multichannel subtractive double-pass spectrograph
  (MSDP) operating in Hα at the Vacuum Tower Telescope (VTT) installed
  at Tenerife (Canary Islands). We derived intensity and Doppler velocity
  maps at Hα ± 0.3 Å over a two-dimensional field of view. We have
  computed the components of the velocity vector (radial, azimuthal,
  vertical) as a function of distance from the center of the spot under
  the assumption of axial symmetry. The results show the well-known,
  from previous observations, general large-scale characteristics of the
  chromospheric Evershed flow. Our measurements show that the axes along
  the discrete structures, where the Evershed flow is confined, are not
  spatially related to the axes along Hα ± 0.3 Å intensity features,
  and we suggest that either the flow is confined in flow channels or that
  it takes place along sheared magnetic field lines. We also detected,
  for the first time in velocity images, running penumbral waves, which
  started in the outer 0.3 of the umbral radius and propagated through
  the penumbra with propagation velocities 13-24 km s<SUP>−1</SUP>. The
  propagation velocity, as well as the velocity amplitude, is greater
  for the waves closer to the center of the spot and diminishes as one
  moves outward.

---------------------------------------------------------
Title: Cloud model with variable source function for solar Hα
    structures.
Authors: Mein, N.; Mein, P.; Heinzel, P.; Vial, J. -C.; Malherbe,
   J. M.; Staiger, J.
1996A&A...309..275M    Altcode:
  The "cloud model" used to derive the physical parameters of solar
  chromospheric features is extended to the cases of non-constant
  source function and of velocity gradients. This model assumes a given
  relationship between the source function and the opacity of the cloud
  which is derived from non-LTE modelling. An algorithm using 4 points
  of the H<SUB>alpha</SUB>_ profile is proposed to derive the optical
  thickness, the line-of-sight velocity and the dopplerwidth. The
  results are compared with a 5-points inversion which does not use the
  given relationship between source function and opacity. Effects of the
  uncertainty about the radiation coming from the underlying chromosphere,
  as well as effects of data noise, are discussed. The inversion method
  is illustrated by some examples of observed profiles obtained with
  the MSDP spectrograph of the VTT telescope (Teide Observatory).

---------------------------------------------------------
Title: Chromospheric ejections and their signatures in X-ray observed
    by YOHKOH
Authors: Schmieder, B.; Mein, N.; Shibata, K.; van Driel-Gesztelyi,
   L.; Kurokawa, H.
1996AdSpR..17d.193S    Altcode: 1996AdSpR..17..193S
  Surges, or condensations of chromospheric material, are commonly
  observed in active regions when new emerging magnetic flux (EMF)
  occurs. In order to study EMF-related phenomena in the corona, observing
  campaigns were organized with the Yohkoh X-ray satellite and ground
  based observatories. EMFs could be detected in magnetograms made in
  Potsdam and Hawaii, surge and arch filament system (AFS) events (on
  Oct 7 1991, May 1 1993, respectively) with the Multichannel Subtractive
  Double Pass instruments operating at Meudon and on the Canary Islands
  and with the Hida telescope at Kyoto University. Bright X-ray loops
  coincident with chromospheric surge activity were detected in the high
  resolution Yohkoh SXT images. We also found coincident brightness
  variations between an X-ray bright point (XBP) and the underlying
  chromospheric plage related to EMF. We interpret the appearance of
  AFS as condensation of material among magnetic field lines, the X-ray
  bright points as the result of a magnetic reconnection process, and
  surges as ejection of cold plasma bubbles squeezed between field lines
  as a result of reconnection.

---------------------------------------------------------
Title: X-Ray Bright Point Flares Due to Magnetic Reconnection
Authors: Van Driel-Gesztelyi, L.; Schmieder, B.; Cauzzi, G.; Mein,
   N.; Hofmann, A.; Nitta, N.; Kurokawa, H.; Mein, P.; Staiger, J.
1996SoPh..163..145V    Altcode:
  Ground-based optical observations coordinated with Yohkoh/SXT X-ray
  observations of an old, disintegrating bipolar active region AR NOAA
  7493 (May 1, 1993) provided a multiwavelength data base to study
  a flaring `active region' X-ray bright point (XBP) of about 16 hr
  lifetime, and the activity related to it in different layers of the
  solar atmosphere. The XBP appeared to be related to a new minor bipole
  of about 10<SUP>20</SUP> Mx. Superposed on a global evolution of soft
  X-ray brightness, the XBP displayed changes of brightness, lasting for
  1-10 min. During the brightenings the XBP apparently had a spatial
  structure, which was (tiny) loop-like rather than point-like. The
  X-ray brightenings were correlated with chromospheric activity: (i)
  brightenings of underlying chromospheric faculae, and (ii) appearance
  of strong turbulent velocities in the arch filament system. We propose
  that the XBP brightenings were due to reconnection of the magnetic
  field lines (sketched in 3D) between the new bipole and a pre-existing
  plage field induced by the motion of one of the new pores (v = 0.2
  km s<SUP>−1</SUP>) towards the plage, and that the XBP itself was
  a reconnected hot loop between them.

---------------------------------------------------------
Title: Dynamics of solar magnetic arches in the photosphere and
    the chromosphere.
Authors: Mein, P.; Demoulin, P.; Mein, N.; Engvold, O.; Molowny-Horas,
   R.; Heinzel, P.; Gontikakis, C.
1996A&A...305..343M    Altcode:
  Mass motions in chromospheric arch filaments have been observed
  with imaging spectroscopy (MSDP) at the VTT telescope of the Teide
  Observatory. Coordinated observations of time sequences of continuum
  images were carried out at the SVST telescope of the Observatorio
  del Roque de los Muchachos, which provided transverse velocities of
  photospheric tracers, by "local correlation tracking." Hα profiles
  along 3 arch filaments are analysed in terms of "differential
  cloud MODel", to discuss the Doppler velocities of chromospheric
  material. Models of ascending arches with downflows in both legs
  are investigated. The gas pressure is neglected, but the free-fall
  equations are integrated versus time (non-stationary case). We first
  assume circular lines of force with constant radius. We can account
  for chromospheric velocities, but we cannot fit the slow motion of
  footpoints derived from photospheric tracers. A better agreement is
  obtained by assuming lines of force with fixed footpoints and variable
  radius. Typical values are: half distance between footpoints of 10 to
  15Mm, upward velocity at the top of loops of 4km/s after an integration
  time of 800s. The obtained values are consistent with the sizes and
  the lifetime of arch filaments.

---------------------------------------------------------
Title: Signatures of New Emerging Flux in the Solar Atmosphere
Authors: Schmieder, B.; Malherbe, J. M.; Mein, P.; Mein, N.; van
   Driel-Gesztelyi, L.; Roudier, T.; Nitta, N.; Harra-Murnion, L. K.
1996ASPC..111...43S    Altcode: 1997ASPC..111...43S
  The emergence of new flux in the low atmosphere leads to magnetic
  reconnection of field lines. In a stable phase the phenomenon is
  observed in the chromosphere by the formation of dark filaments (arch
  filament system, AFS). The authors show how bright loops visible in soft
  X-rays are co-aligned with the AFS. Different types of events appear
  as the released energy increases. With less energetic phenomena than
  flares one observes surges, jets or X-ray bright points, according
  to the configuration of the field lines (open/closed). A low-level
  reconnection process is detectable as an X-ray bright point. If
  the energy is ≡10<SUP>28</SUP>ergs cm<SUP>-3</SUP>, one observes
  subflares. The authors document their statement by showing examples
  observed in coordinated observations obtained with the MSDP (Pic du
  Midi and Tenerife) and Yohkoh/SXT and BCS for the events occurring on
  Oct 5, 1994, Oct 27, 1993, and May 1, 1993.

---------------------------------------------------------
Title: High resolution flare observations with multi-line imaging
    spectroscopy.
Authors: Mein, P.; Heinzel, P.; Malherbe, J. -M.; Staiger, J.
1996joso.proc...68M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Running Penumbral Waves in a chromospheric Sunspot
Authors: Tsiropoula, G.; Dialetis, D.; Alissandrakis, C. E.; Mein, P.
1996hell.conf...37T    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Emerging Flux, Reconnection, and XBP
Authors: van Driel-Gesztelyi, L.; Schmieder, B.; Demoulin, P.;
   Mandrini, C.; Cauzzi, G.; Hofmann, A.; Nitta, N.; Kurokawa, H.; Mein,
   N.; Mein, P.
1996mpsa.conf..459V    Altcode: 1996IAUCo.153..459V
  No abstract at ADS

---------------------------------------------------------
Title: The fine scale Structure of the velocity Field in the
    chromospheric Penumbra of a solar Sunspot
Authors: Tsiropoula, G.; Alissandrakis, C. E.; Dialetis, D.; Mein, P.
1996hell.conf...32T    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Emerging flux seen by Yohkoh.
Authors: van Driel-Gesztelyi, L.; Schmieder, B.; Mandrini, C.;
   Démoulin, P.; Cauzzi, G.; Hofmann, A.; Nitta, N.; Kurokawa, H.;
   Mein, N.; Mein, P.
1996joso.proc..124V    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Penetration of the solar granulation into the photosphere:
    height dependence of intensity and velocity fluctuations.
Authors: Espagnet, O.; Muller, R.; Roudier, T.; Mein, N.; Mein, P.
1995A&AS..109...79E    Altcode:
  A 16-min time series of two-dimensional "Multichanel Subtractive Double
  Pass" spectrograms, recorded in the NaD_2_ 5690 line, has been used to
  study the vertical structure of the photosphere and, in particular,
  the penetration of granules. A statistical and a morphological
  investigations have been made. The 5-min oscillations have been
  carefully filtered in the k-ω space. Intensity fluctuations associated
  to granules disappear in a very short distance, about 60 to 90km above
  the continuum level. The intensity features in the upper photosphere
  are not related to the granules. The velocity fluctuations associated
  to the granulation, cross the whole thickness of the photosphere. The
  photosphere can thus be separated into two distinct layers, but only
  for the intensity features, not for the velocity features which are
  the same from the bottom to the top of the stable atmosphere. In the
  lower photosphere, below 90km, only granules are detected. In the upper
  photosphere, our observations suggest that the weak pattern visible
  there, is turbulent in origin. In addition to this weak pattern,
  bright sinking plumes have been discovered; they are associated with
  strong downflows, often adjacent to strong upflows. The size of most
  plumes is 1" to 2"; however the most outstanding of them may be as
  large as 4". Their origin, which may be photospheric or chromospheric,
  is still unknown.

---------------------------------------------------------
Title: Solar Imaging Spectroscopy: Multichannel Subtractive Double
    Pass Instruments
Authors: Mein, P.
1995ASPC...71..350M    Altcode: 1995IAUCo.149..350M; 1995tosm.conf..350M
  No abstract at ADS

---------------------------------------------------------
Title: THEMIS IR Capabilities
Authors: Roudier, T.; Mein, P.; Rayrole, J.
1995itsa.conf..195R    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: THEMIS: its capabilities and key programs
Authors: Schmieder, B.; Mein, P.
1994ESASP.373..393S    Altcode: 1994soho....3..393S
  No abstract at ADS

---------------------------------------------------------
Title: Dynamical Fine Structure of a Quiescent Filament
Authors: Mein, N.; Mein, P.; Wiik, J. E.
1994SoPh..151...75M    Altcode:
  A quiescent filament was observed near the center of the disk
  (N5, W5) with the MSDP spectrograph of the 50 cm refractor of the
  Pic-du-Midi Observatory on June 17, 1986. We focus our study on
  the statistical moments of the Dopplershift,V<SUB>1</SUB>, and the
  intensity,I<SUB>1</SUB>, at the center of a chord of the Hα profile
  (±0.256 å), versus the minimum intensityI<SUB>0</SUB>. We use a
  statistical model simulating a numbern<SUB>max</SUB> of threads (of
  optical thicknessτ<SUB>0</SUB> and source functionS<SUB>0</SUB>), seen
  over the chromosphere. The threadsj along the same line-of-sighti
  are identical except for the velocityv<SUB>j</SUB> (gaussian
  distributionv<SUB>0</SUB>,σ<SUB>v</SUB>). We search for the best
  fit between the observed and simulated quantities:V<SUB>1</SUB>,σ
  (V<SUB>1</SUB>),I<SUB>1</SUB>,σ(I<SUB>1</SUB>), and the histogram
  of theI<SUB>0</SUB> values over the field of view. A good fit
  is obtained with: (a) threads characterized byτ<SUB>0</SUB> =
  0.2,S<SUB>0</SUB> = 0.06 (unit of the continuum at disk center), mean
  upward velocityv<SUB>0</SUB> = 1.7 km s<SUP>−1</SUP> and gaussian-type
  velocity distributionσ<SUB>v</SUB> = 3.5 km s<SUP>−1</SUP>. Other
  possible values ofτ<SUB>0</SUB> andσ<SUB>v</SUB> are discussed; (b)
  underlying chromosphere deduced from observed quiet Sun (outside the
  filament) by modifying the chromospheric velocities: additional mean
  upward velocity 0.7 km s<SUP>−1</SUP>, standard deviation reduced by
  a factorF<SUB>c</SUB> ∼ 0.7. The results are discussed in connection
  with the values deduced from prominence observations.

---------------------------------------------------------
Title: Fine Structure of Prominences and Filaments (Invited)
Authors: Mein, P.
1994scs..conf..289M    Altcode: 1994IAUCo.144..289M
  The author concentrates on quiescent prominences, and reviews some
  recent results about resolved structures, statistical properties of
  "threads", and detailed analysis of average line profiles. He mentions
  magnetic field measurements and thermal problems. New magnetostatic
  models are very promising. The author discusses briefly the problem
  of the scale of fine structures, and suggests some directions for
  further works.

---------------------------------------------------------
Title: Imaging spectro-polarimetry with THEMIS.
Authors: Mein, P.; Rayrole, J.
1994imfm.conf..116M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: High resolution solar observations: Spectropolarimetry
    with THEMIS
Authors: Landi Degl'Innocenti, E.; Rayrole, J.; Mein, P.
1994LNP...432..315L    Altcode: 1994LNPM...11..315L
  Solar observations now require many capabilities: high resolution to
  detect fine flux tubes, polarization-free optics to measure the vector
  magnetic field, spectral range including many lines to disentangle
  thermodynamic from magnetic signatures. The site of Canary Islands,
  the active optics, the Cassegrain telescope, the long spectrographs
  and the universal filter of THEMIS fulfill many conditions for major
  advances in the near future of solar physics.

---------------------------------------------------------
Title: The THEMIS telescope
Authors: Rayrole, J.; Mein, P.; Cavallini, F.
1994ASIC..433..507R    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Dynamical Fine Structure of a Quiescent Filament
Authors: Mein, N.; Mein, P.; Wiik, J. E.
1994scs..conf..385M    Altcode: 1994IAUCo.144..385M
  A quiescent filament was observed in Hα by the MSDP spectrograph of
  the Pic-du-Midi Observatory. The fitting by a numerical simulation
  provides the velocity distribution of the "threads", and the dynamical
  characteristics of the underlying chromospheric fine structures.

---------------------------------------------------------
Title: Dynamics of solar magnetic arches in photosphere and
    chromosphere
Authors: Mein, P.; Mein, N.; Démoulin, P.; Gontikakis, C.; Engvold,
   O.; Molowby, R.
1994smf..conf..366M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Solar dynamics over solar cycle 21 using sunspots as
    tracers. I. Sunspot rotation.
Authors: Nesme-Ribes, E.; Ferreira, E. N.; Mein, P.
1993A&A...274..563N    Altcode:
  Sunspots observed on spectroheliograms have been used as tracers to
  derive the rotation of the convective layers. Image-processing and
  pattern recognition technique were developed to infer the position
  of the tracer, thereby its motions, with a good accuracy. Some new
  properties of sunspot rotation have been detected, concerning the
  amplitude of the differential rotation and its variability through the
  solar cycle. Comparison is made with similar studies which do not offer
  the same accuracy. The results presented here give a hint of the depth
  where the magnetic field of sunspots is anchored. This is of importance
  for a better understanding of the origin of the differential rotation
  and of the solar dynamo.

---------------------------------------------------------
Title: Turbulent power spectra of solar granulation.
Authors: Espagnet, O.; Muller, R.; Roudier, T.; Mein, N.
1993A&A...271..589E    Altcode:
  High resolution "Multichannel Subtractive Double Pass" spectrograms
  and white light photographs have been used to compute power spectra
  of the solar granulation. The 5 min oscillations have been carefully
  filtered, and the influence of the variation of the mean size of
  granules at the mesogranulation scale has been taken into account. <P
  />It results that both the power spectra of velocity and intensity
  fluctuations, displayed in a log P - log k scale, are characteristic
  of a turbulent atmosphere: they present a discontinuity at 3" =
  2000 km (which corresponds to the size of a large granules) and an
  energy which decreases according to the Kolmogorov -5/3 power law
  in the granulation range; another discontinuity, at 1".4 = 1000 km
  (which corresponds approximately to a Peclet number Pe = 1, for which
  thermal diffusion and advection are of equal importance) is present in
  the intensity power spectrum, which decreases with a -17/3 power law,
  in the range of sizes smaller than 1".4. <P />These results indicate
  that granules are turbulent eddies. They have some convective characters
  (like the correlation between velocities and brightness) because they
  are formed in a strongly superadiabatic atmosphere.

---------------------------------------------------------
Title: Imaging Spectroscopy of Flows in Active Regions
Authors: Mein, P.; Mein, N.
1993ASPC...46..542M    Altcode: 1993mvfs.conf..542M; 1993IAUCo.141..542M
  No abstract at ADS

---------------------------------------------------------
Title: THIEMIS Telescope: Prospects in High Resolution Magnetic
    Field Observations
Authors: Rayrole, J.; Mein, P.
1993ASPC...46..170R    Altcode: 1993IAUCo.141..170R; 1993mvfs.conf..170R
  No abstract at ADS

---------------------------------------------------------
Title: Dynamical Fine Structure of Filaments and Prominences
Authors: Mein, N.; Mein, P.; Wiik, J. E.
1993ASPC...46..391M    Altcode: 1993IAUCo.141..391M; 1993mvfs.conf..391M
  No abstract at ADS

---------------------------------------------------------
Title: Active Region Evolution Through Coordinated Observations
Authors: Mein, N.; Mein, P.; Schmieder, B.; Engvold, O.; Molowny,
   R.; Ai, G. X.
1993ASPC...46...63M    Altcode: 1993mvfs.conf...63M; 1993IAUCo.141...63M
  No abstract at ADS

---------------------------------------------------------
Title: Underneath coronal loops: MSDP observations coordinated with
    SERTS 4 and NIXT flights.
Authors: Schmieder, B.; Mein, N.; Golub, L.; Davila, J. M.; Thomas,
   R.; Brosius, J.
1992ESASP.348..257S    Altcode: 1992cscl.work..257S
  Ground-based coordinated observations with the multichannel subtractive
  double pass spectrograph (MSDP) allowed to portray the chromospheric
  intensity and velocity fields below coronal structures during recent
  launchs of sounding rockets. During SERTS 4 observations (May 7,
  1991), two different active regions presenting flare and filament have
  been coaligned with UV structures. In July 11, 1991 (eclipse day)
  large Hα ejection material in AR 6713 was detected during the NIXT
  flight. Preliminary results are displayed.

---------------------------------------------------------
Title: Dynamique de la photosphère solaire: granulation,
    mésogranulation, oscillations.
Authors: Espagnet, O.; Muller, R.; Roudier, T.; Mein, N.; Mein, P.
1992JAF....43...36E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Time evolution of arch filaments
Authors: Tsiropoula, G.; Georgakilas, A. A.; Alissandrakis, C. E.;
   Mein, P.
1992A&A...262..587T    Altcode:
  We have studied the spatial structure and the temporal evolution of the
  velocity in active region arch filaments. The observations were obtained
  with the Multichannel Double Pass Spectrograph operating in H-alpha
  at the Pic du Midi Observatory. Line profiles were reconstructed and
  monochromatic images and Doppler shift velocities were derived over a 2D
  FOV. Using Beckers' (1964) cloud model we derived physical parameters,
  in particular the line of sight velocity. The arches showed the
  'classical' type of motion, with material moving towards the observer
  near the apex and away from the observer near the footpoints. Assuming
  a symmetric loop, we reconstructed the velocity vector along the arch
  filaments. The results are consistent with the picture where material is
  draining out of the filament, while the whole structure is ascending. In
  one case we observed changes in the geometry and the velocity vector;
  however, other arch filaments did not change appreciably in a time
  period of about 13.5 min.

---------------------------------------------------------
Title: MSDP imaging spectroscopy for high resolution solar physics.
Authors: Mein, P.
1992ESASP.344..153M    Altcode: 1992spai.rept..153M
  Three facilities using Multichannel Subtractive Double Pass
  spectrographs are presently operated at Meudon, Pic du Midi, Tenerife
  (VTT telescope). A fourth one is expected at Tenerife (THEMIS
  telescope). The imaging spectroscopy with MSDP spectrographs allows
  very high spatial resolution and fast time sequences over 2D solar
  targets. The author recalls some capabilities, showing that the MSDP
  are very suitable for coordinated experiments between ground-based
  and space observations.

---------------------------------------------------------
Title: Structure and Dynamics of Cool Flare Loops
Authors: Heinzel, P.; Schmieder, B.; Mein, P.
1992SoPh..139...81H    Altcode:
  MSDP observations of the 16 May, 1981 two-ribbon flare are used to
  study the physical structure and the dynamical behaviour of cool flare
  loops. The loops have been detected in the Hα line just after the
  flare maximum and they appeared in absorption against the disk. Using
  the first-order differential cloud model (DCM1) technique, we derive
  empirically some basic plasma parameters at 15 points along one loop
  leg. The flow velocities and the true heights have been reconstructed
  with respect to a geometrical projection. Subsequently, detailed
  non-LTE models of cool loops have been constructed in order to fit Hα
  source function values previously derived from DCM1 analysis. It is
  demonstrated that this source function is rather sensitive to the radial
  component of the flow velocity (the so-called Doppler brightening)
  and to enhanced irradiation of the loops from the underlying flare
  ribbons. In this way, we have been able to estimate quantitatively
  all plasma parameters which determine the physical structure of cool
  loops (i.e., the temperature, pressure, density), as well as the
  momentum-balance condition within the loops. For these dark loops we
  have arrived at relatively low gas pressures of the order of 0.1-0.5
  dyne cm<SUP>-2</SUP> with corresponding electron densities around
  10<SUP>11</SUP> cm<SUP>-3</SUP>. Pressure-gradient forces have been
  found to be of small importance in the momentum-balance equation, and
  thus they cannot explain departures from a free-fall motion found in our
  MSDP data analysis. We propose three possible solutions to this problem.

---------------------------------------------------------
Title: Dynamics of the solar atmosphere.
Authors: Mein, Pierre
1992soti.book..179M    Altcode:
  Contents: (1) Introduction. (2) Outline of the solar structure: internal
  sun; solar atmosphere; solar activity. (3) One-dimension non-magnetic
  model atmosphere continuum and spectral line formation: model
  atmosphere; spectral intensity and source function; formation of the
  continuous spectrum; formation of spectral lines. (4) Diagnostic methods
  for velocity measurements: in situ measurements; indirect measurements;
  intensity measurements (continuum and lines); Dopplershifts of line
  profiles; averaging effects in line Doppler-shifts; instrumental
  aspects: velocity measurements. (5) Rotation and convection: solar
  rotation from Doppler measurements; solar rotation from tracers;
  large-scale meridional circulation; convection (intermediate and small
  scales). (6) Waves in the non-magnetic atmosphere: the five minutes
  oscillations; the k-ω diagram; power spectrum in the k-ω diagram;
  phase-lags between two lines or between intensity and Dopplershift;
  mechanical energy flux; coronal heating. (7) Motions in magnetic flux
  tubes and spots. (8) Velocity fields in prominences and filaments:
  classification, structure; velocity measurements; steady flows;
  oscillations; instabilities ("disparitions brusques", eruptions). (9)
  Mass ejections - instabilities.

---------------------------------------------------------
Title: Plasma Parameters Derived from MSDP Observations of Cool
    Flare Loops
Authors: Heinzel, P.; Schmieder, B.; Mein, P.
1992LNP...399..134H    Altcode: 1992IAUCo.133..134H; 1992esf..coll..134H
  MSDP observations of 16 May 1981 two-ribbon flare are used to study the
  physical structure and dynamical behaviour of cool flare loops. The
  loops have been detected in the H line just after the flare maximum
  and they appeared in absorption against the disk. Using the first-order
  differential cloud model (DCM1) technique, we derive empirically some
  basic plasma parameters at 15 points along one loop leg. The flow
  velocities and true heights have been reconstructed with respect to
  a geometrical projection. Subsequently, detailed non-LTE models of
  cool loops have been constructed in order to fit H source-function
  values previously derived from DCM1 analysis. It is demonstrated that
  this source function is rather sensitive to the radial component
  of the flow velocity (the so-called Doppler brightening) and to
  the enhanced irradiation of the loops from the underlying flare
  ribbons. In this way, we have been able to estimate quantitatively
  all plasma parameters which determine the physical structure of
  cool loops (i. e. the temperature, pressure, density, etc.), as well
  as the momentum-balance condition within the loops. For these dark
  loops we have arrived at relatively low gas pressures of the order
  of 0.1 - 0.5 dyn cm-2 , with corresponding electron densities around
  1011 cm-3. Pressure-gradient forces have been found to be of small
  importance in the momentum-balance equation. However, the classical
  momentum equation is not capable of explaining significant departures
  from a free-fall motion under the gravity force, found from our MSDP
  data. We propose three possible explanations to this problem.

---------------------------------------------------------
Title: Dynamical Fine Structure of a Quiescent Prominence
Authors: Mein, P.; Mein, N.
1991SoPh..136..317M    Altcode:
  A quiescent prominence has been observed with the MSDP spectrograph at
  the Pic du Midi Observatory. Hα profiles are obtained simultaneously in
  a 2D field, allowing a statistical analysis. The standard deviations
  of Doppler shifts and line widths are investigated as functions of
  the line intensity. The observations are compared with numerical
  simulations assuming that the prominence is made of identical
  `threads', the velocity of which is distributed according to
  gaussian functions. The processing of simulations is very close to
  the processing of observations. The mixing by seeing effects and the
  transfer of radiation across several threads along the line of sight
  are considered. The results are consistent with the values derived by
  Engvold et al. (1989) and Zirker and Koutchmy (1989, 1990, 1991).

---------------------------------------------------------
Title: Solar 2D spectroscopy - A new MSDP instrument
Authors: Mein, P.
1991A&A...248..669M    Altcode:
  The present study describes a new instrument that uses the multichannel
  subtractive double pass (MSDP) technique. Its main capabilities are:
  simultaneous spectro-imaging in two line profiles (medium and strong
  lines), high spatial resolution in all the 2D fields, no differential
  seeing effects at all wavelengths, best compromises between exposure
  time and spectral resolution for lines, fast change of wavelength,
  and the possibility of spectro-imaging with high spectral resolution
  by successive exposures (weak lines). Either 9 or 11 channels are
  recorded simultaneously in each line profile. The field size is
  typically 120 x 1000 or 60 x 1000 diffraction widths of the telescope
  image. The spectral resolving power is 100,000 in one exposure. The
  optical design and the codes for data processing are reviewed. The
  performances of the MSDP and the other 2D spectroscopy techniques are
  briefly compared and possible improvements with regard to the spectral
  resolution are discussed.

---------------------------------------------------------
Title: Dynamics of the solar granulation. II - Statistical analysis:
    Power spectra, coherence, phase
Authors: Roudier, T.; Vigneau, J.; Espagnet, O.; Muller, R.; Mein,
   P.; Malherbe, J. M.
1991A&A...248..245R    Altcode:
  The solar granulation is analyzed statistically by the computation
  of coherence, phase, and power spectra using data provided by the
  Multichannel Subtractive Double Pass spectrograph of the Pic du Midi
  Observatory. The main result of the analysis is that the velocity
  power spectrum of the granulation changes in shape at 3 arcsec: the raw
  spectrum features a slope discontinuity; the corrected spectra have a
  power maximum at 3 arcsec. Between 3 arcsec and the resolution limit
  (0.8 arcsec), the power decreases almost linearly, with a slope close
  to -5/3, consistent with the Kolmogorov power law for a turbulent
  energy cascade.

---------------------------------------------------------
Title: Dynamics of solar granulation. I - Processing of MSDP spectra
Authors: Roudier, T.; Vigneau, J.; Mein, P.; Malherbe, J. M.; Coutard,
   C.; Hellier, R.; Muller, R.
1991A&A...248..237R    Altcode:
  High resolution (about 0.5 arcsec) 2D spectra have been obtained
  with the Multichannel Subtractive Double Pass spectrograph of the Pic
  du Midi Observatory in a quiet region at the solar disk center. The
  adapted image processing which provides 2D intensity and velocity maps
  of the solar granulation, at two intensity levels of the line NaD2,
  is described. A quantitative evaluation of the spatial resolution is
  determined both for the intensity and velocity granulation fields.

---------------------------------------------------------
Title: Projet THEMIS.
Authors: Mein, P.; Rayrole, J.
1991sed..conf..291M    Altcode:
  Contents: (1) Introduciton. (2) Performances atendues: (2.1) Le
  télescope sans polariseur et son analyseur. (2.2) La haute résolution
  spatiale. (2.3) Spectrographe échelle et long prédisperseur. (2.4)
  Caméras CCD et informatique. (3) Programmes et groupes de travail. (4)
  Etat du projet.

---------------------------------------------------------
Title: Results from high resolution solar images and spectra obtained
    at the Pic du Midi Observatory (1986-1990)
Authors: Roudier, Th.; Muller, R.; Vigneau, J.; Auffret, H.; Espagnet,
   O.; Simon, G. W.; Title, A. M.; Frank, Z.; Shine, R. A.; Tarbell,
   T. D.; Mein, P.; Malherbe, J. M.
1991AdSpR..11e.205R    Altcode: 1991AdSpR..11..205R
  We present an overview of our recent results about solar granulation and
  mesogranulation, obtained with Pic du Midi observations. These results
  were obtained during 1986-1990 using image and spectrographic analysis
  of high spatial resolution data. The study of the solar granulation,
  with 2 Dim. “Multichannel Subtractive Double Pass” (M.S.D.P.) spectra,
  shows a clear change of the dynamical regime at 3” (⋍ 2200 km)
  of the photospheric velocity field when oscillatory components are
  filtered out. <P />A three hour movie obtained on film at Pic du Midi
  Observatory and analyzed at the Lockheed Research Laboratory and the
  National Solar Observatory (Sacramento Peak) was used to calculate
  the horizontal flow pattern. The mean lifetime of the diverging areas
  related to mesogranulation is estimated at 3 hours; these diverging
  areas are swept by the supergranulation flow towards the supergranule
  boundary with a mean speed of 0.4 km/s.

---------------------------------------------------------
Title: Oscillations detected in C IV and Hα lines in magnetic
    structures
Authors: Schmieder, B.; Thompson, W. T.; Mein, P.
1991AdSpR..11d.195S    Altcode: 1991AdSpR..11..195S
  Different processes involving the magnetic field and its fine
  structures in the atmosphere have been proposed to explain the heating
  of the corona. To help explore phenomena related to these different
  processes, we will report some new observations of oscillations in fine
  chromospheric structures using the MSDP spectrograph operating at Meudon
  and the UVSP spectrograph aboard SMM. The temporal analysis of radial
  velocities measured in the C IV line shows that no oscillations are
  detectable in the transition zone. It is in good agreement with the wave
  reflection model generally admitted. In the Hα line the 2 D analysis
  points out that the energy observed in an unresolved frequency range
  around 250 s in the chromospheric power spectrum is in fact concentrated
  in structures parallel to chromospheric fibrils along which the phase
  extends coherently. The oscillations appear to be transverse and might
  be interpreted either by Alfvén waves generated in the chromosphere
  and propagating through magnetic filamentary structures or by eigenmodes
  of filamentary structures excited by chromospheric p-modes.

---------------------------------------------------------
Title: Solar Rotation Over SOLAR-CYCLE-21
Authors: Ribes, Elisabeth; Vince, Istvan; Mein, Pierre; Neto Ferreira,
   Eduardo
1991LNP...380..241R    Altcode: 1991sacs.coll..241R; 1991IAUCo.130..241R
  Having measured the rotation rate of sunspots through solar cycle 21,
  from 1977 to 1983, we have found that the mean differential rotation
  averaged over this seven year record is similar to the grand average
  differential rotation determined by Howard et al. (1984) over the
  period 1921-1982. However, the rotation rate does change from year to
  year. These changes are evidenced by a steepening or a flattening of
  the mean differential rotation profile, as well as significant changes
  in the equatorial rate. The presence of a time-dependent pattern of
  azimuthal roils inferred from the meridional circulation pattern of
  the sunspots offers a qualitative explanation of the observed rotation
  rates. The amplitude of the changes is almost one order of magnitude
  larger than that of the torsional oscillations found by Howard and
  LaBonte (1981).

---------------------------------------------------------
Title: Dynamique de l'atmosphère solaire.
Authors: Mein, P.
1991sed..conf..263M    Altcode:
  Contents: (1) Introduction. (2) Conditions physiques dans l'atmosphère
  solaire. (3) Diagnostic des vitesses de matière. (4) Mouvements
  hydrodynamiques: rotation et convection, ondes: (4.1) Rotation
  différentielle. (4.2) Circulation méridienne. (4.3) Supergranulation,
  Mésogranulation, Granulation. (4.4) Ondes en l'absence de champ
  magnétique. (5) Mouvements et champ magnétique: (5.1) Dynamique
  des tubes de flux photosphériques. (5.2) Dynamique des taches. (5.3)
  Protubérances et filaments. (5.4) Ejections de matière.

---------------------------------------------------------
Title: Chromospheric structures and prominences: dynamics and
    magnetic support.
Authors: Mein, P.
1991joso.proc.....M    Altcode:
  The author reports on some examples of investigations concerning
  chromospheric structures and prominences. Two examples refer to flows
  in the vicinity of sunspots. Two other ones concern prominences,
  from theoretical and observational points of view. Some instrumental
  capabilities, presently available at the Canary Island Observatory,
  and well suitable for the study of such objects are mentioned.

---------------------------------------------------------
Title: Current and planned facilities, Canary Islands-France
Authors: Mein, P.; Rayrole, J.
1991AdSpR..11e.151M    Altcode: 1991AdSpR..11..151M
  In the field of high resolution solar physics, the french telescope
  THEMIS is designed to be operated at the Teide Observatory. It is a
  90cm polarization-free telescope, with two 7.5m spectrographs, devoted
  to magnetic field measurements, in a number of simultaneous spectral
  line profiles. The instrument is under construction. The time schedule
  aims at operation during the SOHO observations. <P />In addition to
  this great project, a french spectro-imaging instrument is presently
  working at the german VTT telescope. Using a Multichannel Subtractive
  Double Pass (MSDP), it provides simultaneous images in many wavelengths
  (typically 20), covering two line profiles. The 2D-character is very
  valuable for coordinated observations with space probes.

---------------------------------------------------------
Title: Physical parameters of solar H-alpha absorption features
    derived with the cloud model
Authors: Alissandrakis, C. E.; Tsiropoula, G.; Mein, P.
1990A&A...230..200A    Altcode:
  Observations of a fibril region and of an arch filament region
  obtained by the Multichannel Subtractive Double Pass Spectrograph
  (MSDP) operating in H-alpha at the Pic du Midi Observatory are
  presented. Intensity fluctuations and Doppler shift velocities were
  derived over two dimensional fields of view. The observed contrast
  profiles have been matched with theoretical contrast profiles based on
  the cloud model which has four parameters: the line-of-sight velocity,
  the source function, the optical depth, and the Doppler width. Contour
  maps and histograms of the 4 parameters were made for these regions,
  and a comparison of the velocities given by 3 different methods (cloud
  model, Doppler shift, and the '3-optical depths' method of Mein and
  Mein, 1988) is made.

---------------------------------------------------------
Title: Oscillations detected in Hα filaments.
Authors: Schmieder, B.; Thompson, W. T.; Mein, P.
1990PDHO....7..296S    Altcode:
  The authors report some new observations of oscillations in filaments
  observed at different positions on the disk using the MSDP spectrograph
  operating at Meudon. The velocity power spectra made over whole filament
  regions show a smooth maximum around 200 s period. Oscillations
  are detected principally in discrete areas in the filaments and in
  chromospheric fibrils, with well defined periods around 250 s and 150
  s. The oscillations could be interpreted by Alfvén waves generated
  in the chromosphere and propagating through magnetic filamentary
  structures or by eigenmodes of filamentary structures excited by
  chromospheric p-modes.

---------------------------------------------------------
Title: Spectroheliograms and motions of magnetic tracers
Authors: Mein, P.; Ribes, E.
1990A&A...227..577M    Altcode:
  The series of spectroheliograms of the Paris-Meudon Observatory,
  starting in 1919, is a powerful tool for studies of the solar cycle
  and the solar dynamo. This paper describes a method of data processing
  which corrects most of the predictable distortions by the use of
  Fourier expansions of the shape of the limb. The drifts of magnetic
  tracers (spots and faculae in the case of K1v spectroheliograms) are
  computed automatically. The accuracy is checked by some comparisons
  with results published by the Debrecen Observatory. In most cases,
  the departures are 0.1 or 0.2 heliographic degree, and comparable to
  the spatial resolution of the spectroheliograms.

---------------------------------------------------------
Title: Dynamical Structure of a Quiescent Prominence
Authors: Mein, P.; Mein, N.; Schmieder, B.; Noëns, J. C.
1990LNP...363..252M    Altcode: 1990doqp.coll..252M; 1990IAUCo.117..252M
  A statistic analysis of H profiles in a quiescent prominence is
  consistent with the superposition of individual velocity structures
  (typically 10), with standard deviation ~ 15 km s-1.

---------------------------------------------------------
Title: Hα diagnostics of 16 May 1981 flare loops.
Authors: Heinzel, P.; Mein, P.; Schmieder, B.
1990PDHO....7..272H    Altcode:
  MSDP observations (Meudon) of 16 May 1981 post-flare loops are used
  to derive the hydrogen plasma parameters in flare loops. The authors
  compare two recently developed methods: a differential cloud model
  and a probabilistic transfer technique.

---------------------------------------------------------
Title: Evolution of Fine Structures in a Filament
Authors: Schmieder, B.; Mein, P.
1990LNP...363..235S    Altcode: 1990doqp.coll..235S; 1990IAUCo.117..235S
  A quiescent filament observed in June 1986 underwent a slow Disparition
  Brusque which lasted 4 days. Here, we focus our study on the dynamical
  behaviour of the fine structures ( Full-Width Half-Max ~ 350 km) in
  this filament which were observed at Pic du Midi with the Multi-Channel
  Subtractive Double Pass (MSDP) spectrograph during a period of 30
  minutes. We observed no changes in intensity during this period, but
  we did observe changes in the velocity field with no correlation from
  one minute to the next. High velocities were detected at the footpoints
  where the filament is anchored in the photosphere , of the same order
  than those observed at the boundaries of the supergranules (between
  ±10 km s-1). To explain these observations we suggest a spicule-like
  model which supplies material to the prominence.

---------------------------------------------------------
Title: Granulation velocity field: latest results from Pic-du-Midi -
    processing of MSDP data
Authors: Mein, P.; Roudier, Th.; Vigneau, J.; Muller, R.; Malherbe,
   J. M.; Contard, C.; Hellier, R.
1989hsrs.conf..521M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Prospects of MSDP observations: high spatial resolution and
    adaptive optics
Authors: Mein, P.
1989hsrs.conf..195M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: High resolution observations with THEMIS: prospects in magnetic
    field observations
Authors: Mein, P.
1989hsrs.conf...12M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Oscillations of the sun's chromosphere. V - Importance of
    network dynamics for chromospheric heating
Authors: von Uexkuell, M.; Kneer, F.; Malherbe, J. M.; Mein, P.
1989A&A...208..290V    Altcode:
  A 64-min time sequence of disk center H-alpha spectrograms taken
  with the MSDP spectrograph at the Observatoire du Pic du Midi
  is analyzed. This type of spectrograph allows spectroscopy of a
  two-dimensional field of view. From the H-alpha line profiles at each
  pixel, line-shift and minimum intensity fluctuation are determined as
  functions of spatial and temporal coordinates. A frequency analysis
  with standard Fourier techniques is performed. It is confirmed that
  in the interior of the chromospheric network cells the oscillatory
  behavior dominates, whereas at the boundaries one generally finds random
  motions on scales of 2-10 arcsec. The random behavior of the H-alpha
  structures outlines the permanent rearrangement of the magnetic field
  lines pushed around by the subphotospheric granular flow.

---------------------------------------------------------
Title: Evolution of Fine Structures in a Filament
Authors: Schmieder, B.; Mein, P.
1989HvaOB..13...31S    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Echelle grating spectrograph for LEST. Constraints and
    tentative scheme.
Authors: Mein, P.
1989egsl.book.....M    Altcode:
  The large aperture of LEST combined with adaptive optics should
  lead to a great number of new results in solar physics. The author
  reviews briefly the requirements in the case of the echelle grating
  spectrometer. Then he analyses the capabilities and limitations of
  some special designs and observing modes, proposes a tentative optics
  and lists some available operating modes.

---------------------------------------------------------
Title: A surge in the chromosphere and the transition region:
    velocities and microturbulence.
Authors: Mein, P.; Schmieder, B.; Tandberg-Hanssen, E.
1989sasf.confP.223M    Altcode: 1989IAUCo.104P.223M; 1988sasf.conf..223M
  Simultaneous observations of a surge in Hα and C IV are analysed in
  terms of Doppler velocities and "microturbulence". The behaviour of both
  quantities suggests strong velocity shears with small spatial scales.

---------------------------------------------------------
Title: Chromospheric eruptions, Jan - Dec 1989.
Authors: Cailloce, E.; Mein, N.; Lantos, P.
1989QBSA...31....1C    Altcode:
  This report shows, in a chronological order, a list of all reported
  flare events whatever their importance.

---------------------------------------------------------
Title: Dynamical Structure of a Quiescent Prominence
Authors: Mein, P.; Mein, N.; Schmieder, B.; Noens, J. C.
1989HvaOB..13..113M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Chromospheric ejections associated with type III radio-bursts.
Authors: Mein, N.; Mein, P.
1989sasf.confP.181M    Altcode: 1988sasf.conf..181M; 1989IAUCo.104P.181M
  The authors study the dynamics of an Hα absorbing structure associated
  with a type III radioburst. They use a "Differential Cloud Model"
  to analyse the observed line profiles, in order to determine radial
  velocity and microturbulence (or shear) as functions of time. The
  authors assume that the material is flowing inside magnetic flux tubes,
  with a given velocity distribution. They analyse the motions in a
  phase-diagram (position x, velocity V). The evolution of velocity and
  microturbulence is compared to the observations. The model accounts
  qualitatively for the evolution of velocity, and qualitatively for
  the decrease of microturbulence.

---------------------------------------------------------
Title: Differential cloud models for solar velocity field measurements
Authors: Mein, P.; Mein, N.
1988A&A...203..162M    Altcode:
  The analysis of velocity fields in solar ejecta is an important
  step in understanding mechanisms of acceleration and energy
  transfer. Unfortunately, Beckers' cloud model is not quite valid
  in the case of fast mass flows observed on the disk, because of
  the fluctuations of the chromospheric background in active regions,
  and because of strong velocity gradients along the line of sight. The
  authors propose two kinds of differential cloud models (first order and
  second order) to determine some parameters characterizing the velocity
  field, in spite of these difficulties. They discuss an example of a
  solar ejection observed at Meudon observatory.

---------------------------------------------------------
Title: An example of the association of X-ray and UV emission with
    H-alpha surges
Authors: Schmieder, B.; Mein, P.; Simnett, G. M.; Tandberg-Hanssen, E.
1988A&A...201..327S    Altcode:
  From H-alpha UV, and X-ray data, the nature of a well-observed
  surge on November 12, 1980 has been studied to try to understand the
  relationships between the mechanical motions and the high-temperature
  emissions. The cool (H-alpha) and the hot (O v) parts of the surge
  plasma both show velocities in the range of 100-120 km/s. The kinetic
  and potential energies of the surge are two orders of magnitude
  higher than the radiative energy. The observations suggest that the
  surge occurs in open structures parallel to one leg of a large scale
  coronal magnetic loop. The energy is released principally in the open
  structure (surge) and only a small amount heats the coronal loop (X-ray
  signature). This energy division should probably not be treated as a
  general characteristic of surge events. Different events are expected
  to exhibit a different energy balance, and this can account for the
  lack of a consensus in the previous literature regarding surge/X-ray
  associations.

---------------------------------------------------------
Title: The Evershed flow in the solar photosphere, chromosphere and
    chromosphere-corona transition region
Authors: Alissandrakis, C. E.; Dialetis, D.; Mein, P.; Schmieder,
   B.; Simon, G.
1988A&A...201..339A    Altcode:
  The authors have studied the height dependence of the characteristics
  of the Evershed flow in the photosphere, chromosphere and
  chromosphere-corona transition region. The Multichannel Subtractive
  Double Pass Spectrograph was used to obtain line of sight velocity maps
  in Hα, the Meudon magnetograph for mapping the photospheric velocity
  and magnetic field and the Ultraviolet Spectrometer and Polarimeter on
  the Solar Maximum Mission spacecraft for line-of-sight velocities in C
  IV, in sunspot regions. The observations are practically simultaneous in
  the three atmospheric levels and cover three consecutive days (Sep 28,
  29 and 30, 1980). The emphasis was on the large scale, quasi-stationary
  characteristics of the flow.

---------------------------------------------------------
Title: Photospheric-induced destabilization and ejection of prominence
    material
Authors: Raadu, M. A.; Schmieder, B.; Mein, N.; Gesztelyi, L.
1988A&A...197..289R    Altcode:
  The sequence of events leading up to prominence activation in two
  different cases is studied. In one case, observed on September 3, 1980,
  strong velocity shears were produced indicating filament twisting. In
  the other case, observed on June 22, 1980, activation results in the
  ejection of prominence material. The paper presents new evidence for a
  common initial triggering mechanism, the birth or motion of pores at one
  end of the activated filament sections. This is taken as an indication
  of emerging magnetic flux and current induction in the filaments. The
  difference in the final results is partly due to the different ambient
  magnetic field structures. In particular in the case leading to material
  ejection there is a subsequent associated flare occurred indicating
  the storage of magnetic energy in the region. Models are proposed for
  the two sequences of events, clarifying the underlying similarities
  and interpreting the distinct features of the two sets of observations.

---------------------------------------------------------
Title: Two-dimensional spectroscopy of the Sun in Hα.
Authors: von Uexküll, M.; Kneer, F.; Mein, P.
1988AGAb....1...11V    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Variations of the Solar Limb Brightness with the Oscillations
Authors: Schmieder, B.; Mein, P.
1988IAUS..123..429S    Altcode:
  The aim of this work is to compute the amplitude of the limb darkening
  fluctuations due to oscillations in order to compare it with the
  observations made with the heliometer at the Pic du Midi (Rösch
  and Yerle 1983 - 1984). It is shown that 5 min oscillations lead to
  variation in the brightness gradient of less than 2%.

---------------------------------------------------------
Title: Environment and dynamics of a prominence observed at Pic
    du Midi.
Authors: Noëns, J. C.; Schmieder, B.; Mein, P.
1988dssp.conf..177N    Altcode:
  Simultaneous observations were made at Pic du Midi using the 20 cm
  Coronograph and the Multichannel Subtractive Double Pass spectrograph
  operating in the "Coupole Tourelle". The prominence observed on June
  17, 1987 is composed of three principal vertical structures 50000 km
  high with faint material connecting then. A coronal cavity is visible
  above the prominence. The dynamics of this prominence in Hα is large,
  horizontal circulation is observed. Images in Hα versus time show
  a slow evolution in the general shape with an exchange of material
  between the vertical structures.

---------------------------------------------------------
Title: Mass ejections in the low corona: microturbulence and type
    III associations.
Authors: Mein, Pierre; Mein, Nicole
1988sscd.conf..514M    Altcode:
  Mass ejections visible in Hα have often been correlated with type III
  radio bursts. Among the possible mechanisms which can account for the
  radio emission, energy transfer from turbulence or velocity shears have
  been suggested. The authors analyse velocity fields inside the ejecta
  by using two "Differential Cloud Models" derived from the well-known
  Beckers model. They apply these models to a sample of ejection observed
  with the MSDP of the Meudon Solar Tower. They derive the time evolution
  of radial velocities and microturbulence at the edges of the structure
  as well as the range of radial velocities along the line of sight in
  the middle part.

---------------------------------------------------------
Title: Velocity shear and microturbulence in solar filaments a
    differential cloud model.
Authors: Mein, P.; Schmieder, B.
1988dssp.conf...17M    Altcode:
  The authors analyse the time sequence of an active region
  filament observed at the MSDP of the Meudon Solar Tower. They use a
  "differential cloud model" which is well suited to the interpretation
  of H<SUB>α</SUB> profiles with an inhomogeneous chromospheric
  background. A previous model (Schmieder et al. 1985) suggesting twisting
  motions of magnetic ropes is confirmed.

---------------------------------------------------------
Title: Chromospheric eruptions, Jan - Dec 1988.
Authors: Cailloce, E.; Mein, N.; Lantos, P.
1988QBSA...30....1C    Altcode:
  This report shows, in a chronological order, a list of all reported
  flare events whatever their importance.

---------------------------------------------------------
Title: Post-flare loops: formation and velocity
Authors: Schmieder, B.; Mein, P.; Malherbe, J. -M.; Forbes, T. G.
1988AdSpR...8k.145S    Altcode: 1988AdSpR...8..145S
  Post-flare loops are generally observed between two ribbon flares. The
  formation of post flare loops and active region or plage filaments
  has been explained in a model based on magnetic reconnection and
  chromospheric ablation /1,2/. This model uses a magnetic topology
  which is relevant to solar flares /3/ : a large flare or an instability
  opens the magnetic lines of a coronal arcade (or arch) and a vertical
  current sheet forms. Then the reconnection of the magnetic field
  follows according to the scenario of Kopp and Pneuman /4/. In this
  magnetic configuration, we show that the formation of condensations
  or dense loops is induced by reconnection shocks. <P />We give in
  this communication a new method of diagnostic to derive from Hα
  profiles physical parameters, i.e. source function, optical depth and
  velocity. This method called “differential cloud method” is very
  promising for future observations.

---------------------------------------------------------
Title: Closed Magnetic Structures in the Chromosphere and in the
    Transition Region
Authors: Malherbe, J. M.; Schmieder, B.; Simon, G.; Mein, P.;
   Tandberg-Hanssen, E.
1987SoPh..112..233M    Altcode:
  Using simultaneous observations of the same solar regions in the
  lines Hα and CIV 1548 Å, we have derived schematic models of closed
  magnetic lines from dynamical constraints. We conclude that the magnetic
  loops are closed at higher levels above facular than above non-facular
  regions. This result remains valid whatever are the assumed density
  models and even if we take into account the 3 min oscillations. The
  center-to-limb behaviour is well predicted by taking into account the
  relative opacity in chromosphere and transition region.

---------------------------------------------------------
Title: Inversion of line profile disturbances - A nonlinear method
    applied to solar CaII lines
Authors: Mein, P.; Mein, N.; Malherbe, J. M.; Dame, L.
1987A&A...177..283M    Altcode:
  Thermodynamical disturbances in the solar atmosphere can be deduced from
  observations of line profiles. The authors propose a non-linear method
  based on Fourier analysis: each profile is converted into a "double
  profile" for a fast convergence of Fourier expansions. Disturbances
  of Fourier coefficients are connected theoretically with physical
  disturbances by second order developments. Temperature and velocity
  fluctuations are derived from a least square inversion of these
  developments. The authors apply this method to a time sequence of
  high resolution profiles of the Ca II 3968 Å line. The accuracy of
  the results is discussed. The enhanced blue peaks occurring in the
  asymmetric profiles are interpreted as downward velocity gradients,
  associated with temperature excesses.

---------------------------------------------------------
Title: Material Ejecta in a Disturbed Solar Filament
Authors: Raadu, M. A.; Malherbe, J. M.; Schmieder, B.; Mein, P.
1987SoPh..109...59R    Altcode:
  Hα observations, using the Multichannel Subtractive Double Pass
  (MSDP) spectrograph operating on the Meudon Solar Tower, have been
  made of an active region filament which undergoes a `disparition
  brusque'. The period of observation was from 10 ∶ 45 to 13 ∶ 30
  UT on 22 June, 1981. Velocity and intensity fluctuations in Hα were
  measured. The proper motions of ejecta were followed allowing their
  trajectories and vector velocities to be determined. To model the
  dynamics of ejecta several models using thermal or magnetic driving
  forces are compared. The most promising model explains the motion as
  the consequence of magnetic stresses acting on an isolated magnetized
  plasmoïd in a diverging flux tube.

---------------------------------------------------------
Title: Dynamics of the solar granulation.
Authors: Muller, R.; Roudier, Th.; Malherbe, J. M.; Mein, P.
1987PAICz..66..175M    Altcode: 1987eram....1..175M
  In order to understand the origin of the solar granulation, convective
  or turbulent, in this paper the authors report results about the
  intensity-velocity correlation and the energy power spectrum derived
  from the Doppler shifts measurement on two-dimensional high resolution
  spectrograms.

---------------------------------------------------------
Title: The Evershed flow in the solar photosphere, chromosphere and
    chromosphere-corona transition region.
Authors: Alissandrakis, C. E.; Dialetis, D.; Mein, P.; Schmieder,
   B.; Simon, G.
1987PAICz..66..147A    Altcode:
  The authors have studied the height dependent characteristics of the
  Evershed flow in the photosphere, chromosphere and chromosphere-corona
  transition region.

---------------------------------------------------------
Title: Photospheric Induced Destabilization and Ejection of Prominence
    Material
Authors: Raadu, M. A.; Schmieder, B.; Mein, N.; Gesztelyi, L.
1987HvaOB..11..105R    Altcode:
  The cause of the sudden activation of solar prominences is not
  clear. The authors present observations of two cases which were preceded
  by the emergence and motion of pores (new flux) in the near vicinity
  of the filaments, which seem to be closely related to the process which
  triggered the filament destabilization. These observations may be well
  described by a theoretical model in which the new flux interacts with
  the older "stable" magnetic field.

---------------------------------------------------------
Title: Dynamics of solar filaments. V - Oscillations in the H-alpha
    and 1548 A C IV lines
Authors: Malherbe, J. M.; Schmieder, B.; Mein, P.; Tandberg-Hanssen, E.
1987A&A...172..316M    Altcode:
  Using the Multichannel Subtractive Double Pass Spectrograph operating in
  the Meudon solar tower and the Ultraviolet Spectrometer and Polarimeter
  aboard the Solar Maximum Mission satellite, the authors analyze by
  Fourier transform technique time sequence observations of filaments in
  both the Hα line and in the 1548 Å C IV line. The Hα data confirm
  previous findings that there are no oscillations at the location of
  the filament in the observed range 1 - 10 mHz. In the C IV line the
  authors observe power in some parts of the filament where a steady
  velocity gradient is present, e.g. in the footpoints. The energy is
  probably due to convective motions rather than pressure oscillations.

---------------------------------------------------------
Title: Environment and Dynamics of a Prominence Observed at Pic-Du
Authors: Noens, J. C.; Schmieder, B.; Mein, P.
1987dssp.work..177N    Altcode: 1987ASSL..150..177N
  No abstract at ADS

---------------------------------------------------------
Title: Joint Discussion on Topics of Sessions 9 and 10
Authors: Mein, P.; Roberts, B.
1987rfsm.conf..292M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: La physique solaire et les performances de THÉMIS.
Authors: Mein, P.
1987JAF....29...14M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Chromospheric eruption, Jan - Dec 1987.
Authors: Cailloce, E.; Mein, N.; Lantos, P.
1987QBSA...29....1C    Altcode:
  This report shows, in a chronological order, a list of all reported
  events whatever their importance.

---------------------------------------------------------
Title: On the onset of eruptive prominences and coronal transients.
Authors: Simon, G.; Mein, N.; Schmieder, B.; Tandberg-Hanssen, E.;
   Wu, S. T.
1987PAICz..66..211S    Altcode: 1987eram....1..211S
  During the Maximum Year, preflare and preeruptive phenomena have
  been observed which give a new idea on the association of eruptive
  prominences and coronal transients.

---------------------------------------------------------
Title: Surges as tracers of magnetic lines.
Authors: Schmieder, B.; Mein, P.; Martres, M. J.; Simnett, G.;
   Tandberg-Hanssen, E.
1987PAICz..66..109S    Altcode: 1987eram....1..109S
  The authors focus their study to chromospheric mass ejecta of
  cool material visible in Hα and occurring, with or without any
  flare. Associated with the events are either X ray emission or type
  III bursts.

---------------------------------------------------------
Title: Velocity Shear and Microturbulence in Solar Filaments
Authors: Mein, P.; Schmieder, B.
1987dssp.work...17M    Altcode: 1987ASSL..150...17M
  No abstract at ADS

---------------------------------------------------------
Title: On the existence of oscillations in solar filaments observed
    in H<SUB>&amp;</SUB>alpha; and C IV lines.
Authors: Schmieder, B.; Malherbe, J. M.; Mein, P.; Tandberg-Hanssen, E.
1986NASCP2442..197S    Altcode:
  Time sequence observations of filaments in both the
  H<SUB>&amp;</SUB>alpha; line and the 1548 Å C IV line were analyzed
  with the Fourier transform technique in the frequency range (1 - 10
  mHz). No oscillation is detected in filaments except at the footpoints
  where a steady velocity gradient is large. The energy is probably due
  to convective motions rather than pressure oscillations.

---------------------------------------------------------
Title: Filament eruption connected to photospheric activity.
Authors: Simon, G.; Gesztelyi, L.; Schmieder, B.; Mein, N.
1986NASCP2442..229S    Altcode: 1986copp.nasa..229S
  Two cases of activation of filaments that occured in regions of
  intense magnetic activity was studied. The simultaneous observations
  from Debrecen Observatory (white light and H alpha filtergram), and
  from Meudon Observatory (magnetogram, MSDP dopplergram and intensity
  maps in H alpha) gave a complementary set of data from which can be
  produced evidence of the influence of the photospheric magnetic field
  on the destabilization process of the filaments. On June 22, 1980,
  the eruption of the filament is associated with the motion of pores,
  which are manifestations of emerging flux knots. On September 3, 1980,
  the twisting motions in the filament are associated to the birth of
  a pore in its neighborhood. These observations are discussed.

---------------------------------------------------------
Title: Material ejecta in a disturbed solar filament
Authors: Raadu, Michael A.; Malherbe, Jean-Marie; Schmieder, Brigitte;
   Mein, Pierre
1986STIN...8722594R    Altcode:
  H alpha observations, using a multichannel subtractive double pass
  spectrograph were made of an active region filament which undergoes
  a sudden disappearance. The period of observation was from 10:45 UT
  to 13:30 UT on 22 June, 1981. Velocity and intensity fluctuations
  in H alpha were measured. The proper motions of ejecta were followed
  allowing their trajectories and vector velocities to be determined. To
  model the dynamics of ejecta, models using thermal or magnetic driving
  forces are compared. The most promising model explains the motion as
  the consequence of magnetic stresses acting on an isolated magnetized
  plasmoid in a diverging flux tube.

---------------------------------------------------------
Title: The effect of solar oscillations on the brightness of the limb
Authors: Schmieder, B.; Mein, P.
1986A&A...161....7S    Altcode:
  Using the realistic atmosphere model VALC, and assuming a spherical
  geometry, the intensity of the solar limb is calculated, and measured
  amplitude fluctuations are compared with those expected due to
  oscillations. In the model, the atmosphere is perturbed successively
  by density and temperature fluctuations of amplitude smaller than the 6
  percent limiting value, and the perturbations are defined by exponential
  laws corresponding to propagating or evanscent waves. It is shown that
  5-minute oscillations lead to variations in the brightness gradient of
  less than 2 percent. Limb brightness fluctuation amplitudes observed
  with the Pic du Midi heliometer (Yerle, 1981) show peaks of 10 percent
  which have too high a value to be explained by solar wave theory.

---------------------------------------------------------
Title: Unstable Chromospheric Dark Features and Type-Iii Bursts
    Association
Authors: Chiuderi-Drago, F.; Mein, N.; Pick, M.
1986SoPh..103..235C    Altcode:
  The temporal association between the kinematic parameters of
  chromospheric dark features (DF) and the production of radio type-III
  bursts is investigated during a period of five months. The Doppler
  shifts inside six different DF are measured by means of the Meudon
  Multichannel Subtracting Double Pass Spectrograph (MSDP) during periods
  of some minutes around 24 type-III bursts. The position of the radio
  bursts has been checked to be associated with the same active region
  observed by MSDP, by using the Nançay Radioheliograph.

---------------------------------------------------------
Title: Chromospheric eruption, Jan - Dec 1986.
Authors: Cailloce, E.; Mein, N.; Lantos, P.
1986QBSA...28....1C    Altcode:
  This report shows, in a chronological order, a list of all reported
  events whatever their importance.

---------------------------------------------------------
Title: First evidence of a large-scale circulation in the solar
    convection zone
Authors: Ribes, E.; Mein, P.
1986ASIC..169..103R    Altcode: 1986ssds.proc..103R
  No abstract at ADS

---------------------------------------------------------
Title: THEMIS: un projet solaire national pour une recherche
    internationale.
Authors: Rayrolle, J.; Mein, P.; Malherbe, J. -M.
1986JAF....28....6R    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A large-scale meridional circulation in the convective zone
Authors: Ribes, E.; Mein, P.; Mangeney, A.
1985Natur.318..170R    Altcode:
  Many attempts have been made to detect, at the solar photospheric level,
  large-scale motions related to the Sun's global convection and dynamo
  (see ref. 1). Because these motions are likely to be influenced by solar
  rotation, one might expect that they would take the form of `bananas'
  aligned with the solar rotation axis<SUP>2</SUP>, as a result of the
  Taylor-Proudman constraint. The Paris observatory has one of the longest
  series of spectroheliograms, dating back to 1919. In view of the current
  interest in the history of solar activity, we have started to digitize
  the collection<SUP>3</SUP>. This allows us to measure rotational rate
  and meridional drift for individual sunspots with an accuracy of a
  few ni s<SUP>-1</SUP> for the best seeing conditions at Meudon. A new
  phenomenon, which may lead us drastically to revise our ideas on the
  large-scale convection of the Sun, can immediately be seen. Newly-born
  sunspots trace a roughly axisymmetric meridional circulation, in the
  form of four zonal bands, with relatively large velocity amplitude. If
  these drifts are assumed to trace fluid motions at some level in the
  solar envelope, the resulting circulation pattern cannot be associated
  with the `banana' cells mentioned above. We report here results based
  on two sets of data; one involves a detailed analysis of two periods,
  each covering five solar rotations while the other is essentially
  qualitative and results from eye-estimates of the spot meridional
  drifts over much longer time sequences.

---------------------------------------------------------
Title: Inversion of Chromospheric Line Profiles
Authors: Mein, P.; Mein, N.; Malherbe, J. M.
1985tphr.conf..303M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Mass Motions in Hα Absorbing Structures of the Solar
    Chromosphere
Authors: Mein, P.; Malherbe, J. M.; Mein, N.; Mouradian, Z.;
   Schmeider, B.
1985tphr.conf..316M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The Evershed flow as a steady-state homogeneous phenomenon
Authors: Dialetis, D.; Mein, P.; Alissandrakis, C. E.
1985A&A...147...93D    Altcode:
  The present observations of photospheric and chromospheric line-of-sight
  velocity, as well as the photospheric magnetic field, facilitate the
  comprehensive study of the Evershed (1909) flow, with emphasis on large
  scale, quasi-stationary characteristics of the flow and its association
  with the topology of the magnetic field. A multichannel subtractive
  double pass spectrograph was used to obtain line-of-sight velocity
  maps in H-alpha, together with the Meudon magnetograph. Computations
  are made for the components of the velocity vector as a function of
  distance from the center of the spot, under the assumption of axial
  symmetry. The radial component is the dominant one in both chromosphere
  and magnetosphere. The present analysis of the magnetograms, using
  current-free and force-free models, indicates that the velocity maximum
  occurs in regions where the magnetic field is almost horizontal in both
  layers; the results are judged to appear consistent with subsonic flow
  in magnetic flux tubes.

---------------------------------------------------------
Title: Ejection of Chromospheric Material Associated with Injection
    of Electrons in the Solar Corona
Authors: Mein, N.; Avignon, Y.
1985SoPh...95..331M    Altcode:
  Observations of a type III radio event and of concurrent Hα
  absorbing features are related. They were obtained with the
  Nançay Radioheliograph and the Multichannel Subtractive Double
  Pass spectrograph operating in Hα at Meudon. We are looking for the
  signature at chromosphere levels of the acceleration of the elctron
  beams triggering the type III bursts. Some promising results are pointed
  out: the relationship between velocities in Hα and the occurrence
  of the type III bursts, the shape of Hα line which reveals turbulent
  motions, the presence of parasitic magnetic polarity and the probable
  existence of a shock wave. A schematic scenario of the phenomenon is
  proposed, taking into account the observational constraints.

---------------------------------------------------------
Title: Mass motions in Hα absorbing structures of the solar
    chromosphere.
Authors: Mein, P.; Malherbe, J. M.; Mein, N.; Mouradian, Z.;
   Schmieder, B.
1985MPARp.212..316M    Altcode:
  Two examples of Hα absorbing structures have been observed with the
  Multichannel Subtractive Double Pass spectrograph at the turret dome
  (Pic du Midi) and at the solar tower (Meudon). In both cases, 9 points
  of the line profile are measured simultaneously in a 2D-field of view.

---------------------------------------------------------
Title: Inversion of chromospheric line profiles.
Authors: Mein, P.; Mein, N.; Malherbe, J. M.
1985MPARp.212..303M    Altcode:
  Because of the large amount of high resolution data which becomes
  available now from solar observations, fast codes are urgently needed in
  order to interpret disturbed line profiles. The authors present briefly
  two kinds of algorithms usable in the case of chromospheric lines.

---------------------------------------------------------
Title: Spectrographie des structures fines solaires. Un grand pas
    réalisé au Pic-du-Midi.
Authors: Mein, P.
1985LAstr..99..167M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Search for Giant Convective Cells from the Analysis of Meudon
    Spectroheliograms
Authors: Ribes, E.; Mein, P.
1985LNP...233..282R    Altcode: 1985hrsp.proc..282R
  The results of digitizing the K IV spectroheliograms (violet wing
  of the Ca II line) of the Meudon Collection are discussed. Sunspots
  are found to rotate faster than old facula by two percent, and it is
  concluded that they can be tracers of angular momentum transport at
  the very beginning of their emergence. Afterwards, they become detached
  from the depth of anchorage and float with the photospheric plasma. A
  complex meridional circulation, analogous to zonal belts observed
  on the major planets, has been detected which changes throughout the
  solar cycle. The existence of two active longitudes together with the
  meridional circulation pattern suggests that the solar dynamo works
  as a nonlinear oscillator.

---------------------------------------------------------
Title: Themis solar telescope
Authors: Mein, P.; Rayrole, J.
1985VA.....28..567M    Altcode:
  Thémis is a 90cm solar telescope expected to be constructed at the
  Teide Observatory by 1990 for polarisation analysis simultaneously
  over a broad spectral range.

---------------------------------------------------------
Title: Differential Rotation and Large Scale Convection
Authors: Ribes, E.; Mein, P.
1985spit.conf..212R    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Chromospheric eruption, Jan - Dec 1985.
Authors: Cailloce, E.; Mein, N.; Lantos, P.
1985QBSA...27....1C    Altcode:
  This report shows, in a chronological order, a list of all reported
  events whatever their importance.

---------------------------------------------------------
Title: New instrumentation for diagnostics of chromospheric fine
structure and dynamics: MSDP spectrographs; capabilities and latest
    results.
Authors: Mein, P.
1985cdm..proc..297M    Altcode:
  High spatial resolution can be achieved in bidimensional spectroscopy by
  "Multichannel Subtractive Double Pass" spectrographs. The capabilities
  of such instruments are briefly reviewed, as well as the processing
  of data, the latest results and the plans for the future.

---------------------------------------------------------
Title: Atmospheric structure deduced from disturbed line profiles -
    application to Ca II lines.
Authors: Mein, N.; Mein, P.; Malherbe, J. -M.; Dame, L.; Dumont, S.
1985cdm..proc..167M    Altcode:
  A new method is described in order to derive physical quantities
  (temperature, pressure, radial velocities) from the observation of
  disturbed line profiles. The authors suggest a method of Fourier
  analysis with double profiles and a non linear expansion of the
  coefficient of the Fourier terms. An application to a sequence of H -
  Ca II line is attempted. The method seems a powerful tool allowing
  the determination of at least 4 physical quantities simultaneously.

---------------------------------------------------------
Title: Bright Points in H Wings and Mass Flows in the Solar
    Chromosphere
Authors: Mein, P.; Malherbe, J. -M.; Mouradian, Z.; Mein, N.;
   Schmieder, B.; Muller, R.
1985LNP...233..203M    Altcode: 1985hrsp.proc..203M
  Many mass flows in the chromosphere are physically connected with
  bright photospheric points. Bidimensional spectroscopy with high
  spatial resolution is very well suited for the study of both kinds
  of structures. The authors give some preliminary results derived from
  recent observations of the MSDP at the Pic-du-Midi.

---------------------------------------------------------
Title: Mass fluxes and magnetic structures in the chromosphere and
    the transition region; canopies.
Authors: Mein, P.; Malherbe, J. -M.; Schmieder, B.; Simon, G.;
   Tandberg-Hanssen, E.
1985cdm..proc..206M    Altcode:
  Preliminary results of applying a model of canopy-type magnetic
  lines to account for observed mass fluxes in the chromosphere and
  transiton region are presented. A set of center-to-limb data obtained in
  H-alpha and C IV, and to which the model is applied, is reported. The
  C IV line is assumed to form everywhere at the same height, and the
  H-alpha formation height is derived by assuming that the absorption
  coefficient is proportional to the local density. The density ratio
  between H-alpha and C IV levels is taken to be 100. From the results,
  it is concluded that the model accounts for the low ratio of radial
  velocities C IV/H-alpha at r = 0, the increase of H-alpha velocity
  near the limb, and the general center-to-limb behavior in both lines.

---------------------------------------------------------
Title: Recent Progress in the Physics of Solar Prominences
Authors: Ribes, E.; Mein, P.; Malherbe, J. M.; Schmieder, B.
1985spit.conf..467R    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Dynamic evolution of recurrent mass ejections observed in
    Hα and C iv lines
Authors: Schmieder, B.; Mein, P.; Martres, M. J.; Tandberg-Hanssen, E.
1984SoPh...94..133S    Altcode:
  During a coordinated SMY program, the consecutive formation of two new
  active centers merging together within AR 2646 was observed from 28
  August, to 5 September, 1980. The two preceding spots compressed an
  inverse polarity spot on 1 September 1980, causing recurrent ejecta
  of matter with time intervals around 10 min. The observations of the
  MSDP spectrograph operating in Hα at the Meudon Solar tower and of
  the UVSP spectrometer on SMM in the CIV 1548 Å line show that cold
  and hot material had the same projection, although the upward CIV
  velocity structure was more extended than the Hα one. We present
  evidence that observed contrasts of the Hα absorbing structure
  can be interpreted in terms of a dynamic `cloud model' overlying
  the chromosphere. Hα matter follows a magnetic channel with upward
  velocity around 20-30 km s<SUP>−1</SUP> in the first phase of the
  event and with downward velocity (∼ - 40 km s<SUP>−1</SUP>) in the
  second phase. The stored energy is not sufficient to trigger a flare,
  nor even to propulse matter along the full length of an arch, because
  of the periodic reorganisation of the magnetic field.

---------------------------------------------------------
Title: Dynamics of solar filaments. III - Analysis of steady flows
    in H-alpha and C IV lines
Authors: Schmieder, B.; Malherbe, J. M.; Mein, P.; Tandberg-Hanssen, E.
1984A&A...136...81S    Altcode:
  A statistical analysis of intensities and radial velocities of
  several solar plage filaments (i.e. prominences seen on the solar
  disk) observed at disk center is presented. Intensity and radial (=
  vertical) velocity maps were derived from simultaneous 2D measurements
  of the H-alpha chromospheric line with the Multichannel Subtractive
  Double Pass spectrograph operating on the Meudon solar tower, and also
  obtained from 2D recordings of the C IV transition-zone line (1548 A)
  with the UV Spectrometer and Polarimeter aboard the Solar Maximum
  Mission satellite. A good correlation (around 0.5) is found between
  intensities in both lines, as well as between velocities. Persistent
  upflows are measured in both lines at the filament location. The mean
  vertical velocities are respectively 0.5 km/s in H-alpha and 5.6 km/s
  in C IV. The analysis of mass fluxes suggests that C IV upflows occur
  in the transition region around prominences rather than below, in the
  chromosphere-corona transition zone.

---------------------------------------------------------
Title: Preflare Activity of Solar Prominences
Authors: Simon, G.; Mein, N.; Mein, P.; Gesztelyi, L.
1984SoPh...93..325S    Altcode:
  The preflare activity of a plage filament is analysed from Hα
  observations made with the Multichannel Subtractive Double Pass
  Spectrograph (MSDP) of the Meudon Solar Tower. The June 22, 1980
  event is studied and interpreted in terms of preflare heating of a
  filament, connected to the rise of emerging flux, and the relative
  approach of pores of different magnetic polarity, prior to the onset
  of a two-ribbon flare.

---------------------------------------------------------
Title: Oscillations and stationary motions in filaments
Authors: Schmieder, B.; Malherbe, J. M.; Mein, P.; Tandberg-Hanssen, E.
1984MmSAI..55..325S    Altcode:
  Observation of oscillations in filaments, which are cold magnetic
  structures suspended in the corona, are used to test theories of
  coronal heating by acoustic waves high in the atmosphere. Long lived
  stationary motions observed in filaments suggest exchanges of material
  between them and the surrounding corona. A coupling between upflows in
  filaments and subphotospheric convective motions, dragging the field
  lines of the prominence magnetic support, is possible.

---------------------------------------------------------
Title: Dynamical behaviour of the corona in association with radio
    emissions
Authors: Trottet, G.; Avignon, Y.; Kerdraon, A.; Mein, N.; Pick, M.
1984AdSpR...4g.271T    Altcode: 1984AdSpR...4..271T
  From a combined analysis of radioheliographic observations and white
  light images of the Corona, it is shown that metric continua onsets or
  enhancements are associated with a great variety of dynamical changes
  of the Corona. It is found that if the most spectacular radio bursts
  (type IV) are associated with mass ejection transients, the more common
  noise storm onsets or enhancements are systematically associated
  with coronal changes which are not necessarly mass ejections. <P
  />Simultaneous observations of Radio type III bursts and Hα mass
  ejecta are related. We are looking to the signature at low levels
  in the corona of the electron beam acceleration triggering type III
  bursts. The results deal with the relationship between the type III
  occurrence and optical features : the presence of velocities in Hα,
  the shape of Hα line which reveals trubulent motions and the probable
  existence of a shock wave.

---------------------------------------------------------
Title: Etude de la rotation des traceurs magnétiques observés sur
    les spectroheliogrammes K IV (Collection de Meudon) - Résultats
    préliminaires.
Authors: Ribes, E.; Mein, P.
1984cms..conf..369R    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Flare build-up study - Homologous flares group - Part I
Authors: Martres, M. -J.; Woodgate, B. E.; Mein, N.; Mouradian, Z.;
   Rayrole, J.; Schmieder, B.; Simon, G.; Soru-Escaut, I.
1984AdSpR...4g...5M    Altcode: 1984AdSpR...4....5M
  According to the definition of the homology (optical) kept in reference,
  the homologous flares (HFl) may be observed wherever flares occur. The
  supposed supplementary preflaring conditions to have HFl may be either
  that the preflaring conditions have not been destroyed by the first
  flare (and then what mechanism has stopped the first and triggered the
  second ?) or that the preflaring conditions have been destroyed and
  rebuilt (and then, how ?). The analysis of data related to some selected
  active regions AR by the members of the working group, and the earlier
  works on HFl, may be used simultaneously to investigate the differences
  between one set of HFl and the others, the location of their sites and
  the evolution of HFl productive AR. This study brings the appearance of
  new footpoints from one flare to the following, the behaviour of cool
  arches (surging arches) leading to information on the changes of the
  magnetic configuration, and to peculiar characteristics of HFl, oif
  2nd, 3rd in the time order concerning the chromospheric transition
  zone or coronal regions. The time delay between two consecutive
  homologous flares appears very quickly as an essential parameter to
  study homology. It was found that every set of flares (same type of
  site) is able to produce “rafales” of homologous flares, i.e. two,
  three, four, oir more flares with Δt in the range of one hour or
  less. The observations show no great chantes in macroscopic photospheric
  patterns (B, V) during this H flaring period. They lead to compare
  their temporal variation curves of flare brightness. A quantitative
  brightness parameter of homology relation has been defined. Some scale
  changes have also been detected in the dynamic spectrum of the site, and
  it is in good agreement with a very interesting theoretical suggestion
  made by P. Sturrock to produce such “rafales”. It may be shown that
  the closely consecutive time-homologous flares (CCHF) or “rafales”
  represent a good tool to analyse the critical conditions related to
  the origin and the amount of energy, mechanism of storage and release,
  necessary and, perhaps, sufficient conditions. New statistical results,
  applied to the different selected homologous flare active regions
  are presented and show the existence in homologous flaring areas of
  a “pivot” of previous filaments interpreted as a signature of an
  anomaly in the Solar rotation.

---------------------------------------------------------
Title: Les traceurs du champ magnétique en physique solaire.
Authors: Mein, P.
1984cms..conf..341M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Activity in the homologous flare site
Authors: Mein, N.; Martres, M. -J.; Simon, G.; Mein, P.; Soru-Escaut,
   I.
1984AdSpR...4g..33M    Altcode: 1984AdSpR...4...33M
  The evolution of a site where homologous flares occured on June 8,
  1980 is analysed by using observations both in the photosphere and
  in the chromosphere. The homology is discussed through space, energy
  and dynamical aspects. The criteria are used in order to propose the
  definition of a coefficient of homology.

---------------------------------------------------------
Title: Analysis of the Homology Criteria of Two Closely Consecutive
    Flares
Authors: Martres, M. J.; Mein, N.; Mein, P.; Rayrole, J.; Simon, G.;
   Soru-Escaut, I.
1984apoa.conf..261M    Altcode:
  The authors study the last two events of a series of closely consecutive
  homologous flares ("rafale"). The main criteria of homology are present:
  localization, evolution, brightness, magnetic structure. Although they
  are among the best cases of homologous flares observed, some differences
  may be detected which affect the dynamics of the region. This feature
  must be taken into account to explain the annihilation of the homologous
  mechanism.

---------------------------------------------------------
Title: Recurrent mass ejections observed in H<SUB>α</SUB> and CIV
Authors: Schmieder, B.; Simon, G.; Martres, M. -J.; Mein, P.; Mein,
   N.; Tandberg-Hanssen, E.
1984AdSpR...4g..27S    Altcode: 1984AdSpR...4...27S
  Time sequences of recurrent mass ejections have been observed during a
  coordinated SMY program (1 Sept. 1980 - 23 Sept. 1980 - 2 Oct. 1980). <P
  />Comparison of the temporal evolution of H<SUB>α</SUB> and CIV
  brightnesses shows a weak phase lag between H α and CIV maxima, in
  the case of homologous flares, with CIV brightness maxima preceding H
  α maxima. The analysis of the variation of the ejection velocities
  is expected to lead to the determination of an energy balance. <P
  />Such recurrent ejections could be due to periodic energy storage
  and periodic reorganisation of magnetic field as envisaged to occur
  for flares, but at lower energy levels.

---------------------------------------------------------
Title: Recommendations on post focus instrumentation for LEST.
Authors: Wöhl, H.; Huber, M. C. E.; Mein, P.; Smaldone, L.
1984LFTR....5.....W    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Chromospheric eruption, Jan - Dec 1984.
Authors: Cailloce, E.; Mein, N.; Lantos, P.
1984QBSA...26....1C    Altcode:
  This report shows, in a chronological order, a list of all reported
  events whatever their importance.

---------------------------------------------------------
Title: Dynamics of a surge observed in the C IV and H alpha lines
Authors: Schmieder, B.; Mein, P.; Vial, J. -C.; Tandberg-Hanssen, E.
1983A&A...127..337S    Altcode:
  Time sequences of a surge have been obtained in Active Region 2701
  during a coordinated SMY program, on October 2nd, 1980, while the MSDP
  spectrograph operated in H-alpha at the Meudon Solar Tower and the UVSP
  spectrometer on SMM observed in the 1548 A C IV resonance line. The cold
  (H-alpha) and hot (C IV) material follow the same channel, and the event
  lasts about 10 min in both lines. A good correlation is found between
  H-alpha and C IV velocities; radial velocities along the surge are in
  the range 40-60 km/s in both cases. The observations are consistent
  with the hypothesis that a pressure gradient drives the surge. The
  H-alpha data seem to indicate the presence of a shock wave in the
  chromosphere, while the C IV quantities (velocities, accelerations)
  vary on a very short time scale. Their maxima occur at some locations
  which could be interpreted as 'pinched' zones.

---------------------------------------------------------
Title: Evidence of high chromospheric activity in Hyades dwarfs from
    spectroscopic observations.
Authors: Cayrel, R.; de Strobel, G. Cayrel; Campbell, B.; Mein, N.;
   Mein, P.; Dumont, S.
1983A&A...123...89C    Altcode:
  The Hα Balmer line and the infrared Ca II triplet have been observed
  in two solar type dwarfs of the Hyades at the Coudé Spectrograph
  of the Canada-France-Hawaii Telescope. Noticeable differences appear
  in the cores of the lines between the stellar spectra and the solar
  spectrum (moonlight). These differences are ascribed to a more active
  chromosphere in the relatively young Hyades stars. Non-LTE computations
  show that the average disk of one of the Hyades dwarf is similar to
  a very bright element of the solar chromospheric network.

---------------------------------------------------------
Title: Dynamics of solar filaments. II - Mass motions in an active
    region filament from H-alpha center to limb observations
Authors: Malherbe, J. M.; Schmieder, B.; Ribes, E.; Mein, P.
1983A&A...119..197M    Altcode:
  The authors present the observations of a solar filament obtained at
  Meudon with the Hα spectroheliograph over a period of 10 d. They show
  a morphologically stable feature. The authors perform a statistical
  analysis of the radial velocity field. Assuming long-lived (several
  days) stationary motions, they compute a 3-dimensional velocity field
  from center to limb observations of the radial component of velocity
  in the stable feature. Different pictures of stationary material
  circulations are suggested and compared with theoretical models of
  filaments. On the contrary, in the case of short-lived (a few 10
  min) flows of material, the authors interpret their data in terms
  of velocity loops in the magnetic structure supporting the filament,
  and they compare the results with the MHD model proposed by Ribes and
  Unno (1980). Possible improvements to this model are pointed out in
  the conclusion.

---------------------------------------------------------
Title: Measurements of solar transition zone velocities and line
    broadening using the ultraviolet spectrometer and polarimeter on
    the Solar Maximum Mission
Authors: Simon, G.; Mein, P.; Vial, J. C.; Shine, R. A.; Woodgate,
   B. E.
1982A&A...115..367S    Altcode:
  The UVSP instrument on SMM is able to observe solar regions at two
  wavelengths in the same line with a band-pass of 0.3 A. Intensity and
  Doppler velocity maps are derived. It is shown that the numerical
  values are sensitive to the adopted Doppler width and the range of
  velocities is limited to within 30 km/sec. A method called Double
  Dopplergram Determination (DDD) is described for deriving both the
  Doppler width and the velocity (up to 80 km/sec), and the main sources
  of uncertainties are discussed. To illustrate the method, a set of C
  IV 1548 A observations is analyzed according to this procedure. The
  mean C IV Doppler width measured (0.15 A) is comparable to previous
  determinations. A relation is found between bright regions and
  down-flows. Large Doppler widths correspond to strong velocity
  gradients.

---------------------------------------------------------
Title: Dynamics of the eruptive prominence of 6 May 1980 and its
    relationship to the coronal transient
Authors: Mein, N.; Schmieder, B.; Simon, G.; Tandberg-Hanssen, E.;
   Wu, S. T.
1982A&A...114..192M    Altcode:
  The active prominence of the 6 May 1980 has been observed between 5.23
  and 10.22 UT with the Ultraviolet Spectrometer and Polarimeter (UVSP)
  on board the Solar Maximum Mission (SMM) satellite. Intensities of
  1548 A line of CIV and dopplershifts have been derived. A motion of
  the magnetic tube maintaining the prominence material is noted. This
  motion is followed by a coronal transient observed with the Coronagraph
  and Polarimeter (C/P) between 11 and 13 UT. It is suggested that the
  event is related to a MHD wave induced by a flare occurring behind
  the solar disk, and a MHD modeling of the perturbation is proposed.

---------------------------------------------------------
Title: Dynamics of POST Flare Ejections and Magnetic Loop Geometry
Authors: Mein, P.; Mein, N.
1982SoPh...80..161M    Altcode:
  Flare-associated mass ejections have been observed at the solar limb
  on June 29, 1980 in the Hα line, with the Multichannel Subtractive
  Double Pass spectrograph of the Meudon solar tower. Radial velocities
  were measured as a function of time in a two dimensional field, and
  kinematics investigated in one selected fine structure. A simple
  model of locally dipole-type magnetic field increasing with time
  can be fitted to the data. It can be checked from extrapolation that
  the model is consistent with an ejection starting roughly from the
  same point at the same time. Height of the loops (∼ 135 000 km)
  is consistent with other determinations. Magnetic field is found to
  be increasing locally by a factor 1.14 within 10 min.

---------------------------------------------------------
Title: Mass motions in the solar chromosphere and transition zone
Authors: Mein, P.; Simon, G.; Vial, J. C.; Shine, R. A.
1982A&A...111..136M    Altcode:
  A comparison is made between H-alpha and C IV observations of Active
  Region 2717 on October 9, 1980. On the basis of this comparison,
  it is found that upward velocities are present above sunspots in the
  chromosphere-corona transition zone (20 km/s). The downward velocities
  are found to be well correlated in both lines. Doppler-shift ratios
  between C IV and H-alpha levels (approximately 10) are seen to be much
  smaller than expected from density ratio estimates. The comparison is
  seen as suggesting that flow lines are probably far from vertical in
  the transition zone. It is pointed out, however, that this depends
  on model densities that may not be correct. A simple method for
  comparing matter flows is presented. The best fit between H-alpha and
  C IV levels is obtained when C IV Doppler shifts are multiplied by
  the line intensity to the power 0.5 (approximately) in order to make
  allowance for density fluctuations.

---------------------------------------------------------
Title: Preflare heating of filaments
Authors: Malherbe, J. M.; Simon, G.; Mein, P.; Mein, N.; Schmieder,
   B.; Vial, J. C.
1982AdSpR...2k..53M    Altcode: 1982AdSpR...2...53M
  Disappearances of preflare filaments have been observed on June 22,
  1980 (S07,W13) (flare at 13.04 U.T.) and September 3, 1980 (flare
  at 7.52 U.T.). The analysis of MSDP data (MEUDON) leads to the
  followings conclusions : - Disappearances begin a few minutes before
  the Hα impulsive phase. - The filaments can be seen again after the
  flares. - Upwards motions occur in several points, without disturbing
  significantly preëxisting downflows. <P />Velocity maps suggest shears
  or velocity loops. <P />The filament disappearance seems to be due to
  a heating mechanism beginning before the flare maximum.

---------------------------------------------------------
Title: A surge obsrved in Hα and CIV
Authors: Schmieder, B.; Mein, P.; Vial, J. C.; Tandberg-Hanssen, E.
1982AdSpR...2k.225S    Altcode: 1982AdSpR...2..225S
  Simultaneous Hα (MSDP at Meudon) and C IV (UVSP aboard SMM)
  measurements of Active Region 2701 were made on October 2,
  1980. Isodensity and velocity maps were derived for both lines
  and superposed. A good correlation was found between Hα and C IV
  velocities. A surge was observed for 10 minutes. The base was located
  in a bright point in CIV and Hα, and escaping matter followed the same
  channel (“absorbing” in Hα, “emitting” in C IV). The velocity
  along the surge was about 80 kms.-1 in Hα and 100 km s-1 in C IV. A
  loop appeared in C IV. We discuss the existing models and conclude
  that the vertical pressure gradient was capable of driving the surge.

---------------------------------------------------------
Title: Mass motions in a quiescent filament
Authors: Malherbe, J. M.; Mein, P.; Schmieder, B.
1982AdSpR...2k..57M    Altcode: 1982AdSpR...2R..57M
  The “disparition brusque” (DB) of a filament (N20, E35) has been
  observed above an active region with the Multichannel Subtractive
  Double Pass (MSDP) spectrograph operating on the Meudon Solar Tower,
  from 10h45 UT to 13h30 UT on June 22, 1981. <P />Velocity fields and
  intensity fluctuations are measured in the Hα line. The DB doesn't
  take place simultaneously in all parts of the filament : thin threads
  (thickness &lt;3 arc seconds) with upward radial velocities reaching
  about 50 km/s are successively observed inside the prominence from S
  to N regions. These motions correspond likely to the rise of material
  along magnetic loops closely related to the prominence structure. The
  dynamics inside such a magnetic loop is investigated : a high speed flow
  (supersonic, likely superalfvénic) strongly accelerated is evidenced
  and a deformation of the flux tube, probably due to the centrifugal
  forces exerted by the flow on the magnetic lines, is suggested. <P
  />These results are compared with some theoretical works on dynamics
  inside magnetic loops, especially to siphon flow models. However,
  as in the case of the prominence support problem, better theoretical
  models are still needed.

---------------------------------------------------------
Title: About the onsets of closely-consecutive homologous flares
Authors: Martres, M. J.; Mein, N.; Mein, P.; Mouradian, Z.; Rayrole,
   J.; Schmieder, B.; Simon, G.; Soru-Escaut, I.; Woodgate, B.; Strong, K.
1982AdSpR...2k.109M    Altcode: 1982AdSpR...2R.109M
  The onsets of closely consecutive homologous flares (CCHF), which
  are separated by less than 6 hours and most often by about 1 hour,
  are compared with that of isolated flares (no flare in the region half
  a day before). Isolated flares appear to be formed of two components,
  a surging arch and a flaring arch, while a set of CCHF may be composed
  of consecutive elementary flares or of a series of complex ones. It
  is shown that the onset of eruptive flare phenomena is not the same
  for an isolated event and for a member of CCHF (excluding the first)
  as found in H-alpha and EUV observations, and probably in X-ray
  observations also. It is suggested that a CCHF set would become a
  single flare with episodic enhancement of brightness by taking account
  of the common H-alpha behavior of surging and flaring arches as well
  as the EUV emission.

---------------------------------------------------------
Title: Dynamics in the filaments. I - Oscillations in a quiescent
    filament
Authors: Malherbe, J. M.; Schmieder, B.; Mein, P.
1981A&A...102..124M    Altcode:
  A quiescent filament is observed by the 9 channel MSDP spectrograph
  operating on the Meudon Observatory tower during 720 s with a 30 s
  time step. The field view of 6 x 1 arcmin permits the study of the
  dynamics of 50 oscillation cells which increases the freedom degree
  comparatively to the one slit spectrograph techniques. A Fourier
  analysis of the radial velocity measured in the H-alpha line shows
  that the steady velocities are upward in the filament, while the
  chromospheric oscillations are almost undetectable inside the filament.

---------------------------------------------------------
Title: Mechanical flux in the solar chromosphere. III - Variation
    of the mechanical flux
Authors: Mein, N.; Schmieder, B.
1981A&A....97..310M    Altcode:
  The mechanical flux in the photosphere and the chromosphere is inferred
  from observations of atmospheric oscillations made over a large range
  of periods (60s-400s). Observations of Doppler shifts in Ca II and Mg
  I lines are related to velocities by means of heights of formation and
  modulation transfer functions deduced from weighting functions. The
  flux is derived from estimates of the amplitude and phase of the
  velocity at different heights in the atmosphere. The results imply
  that the energy dissipated by waves in a plane-parallel atmospheric
  model is insufficient to balance the radiative losses. The short-fall
  can reach a factor 100 in the high chromosphere. Heating of the corona
  by shock wave dissipation is inconsistent with our results.

---------------------------------------------------------
Title: Structure and Evolution of Velocities in Quiescent Filaments
Authors: Martres, M. -J.; Mein, P.; Schmieder, B.; Soru-Escaut, I.
1981SoPh...69..301M    Altcode:
  Simultaneous observations of radial velocities in a `quiescent'
  prominence seen in Hα on the disk and in the underlaying photosphere
  have been obtained in the Meudon Observatory: Doppler shifts in
  photospheric lines are weaker than in the surrounding regions (&lt;0.3
  km s<SUP>-1</SUP>); the scale of velocity structures is smaller
  (&lt;10<SUP>4</SUP> km). The vertical component of velocities cannot
  be neglected. Hα Doppler shifts show that: (a) Highest velocities
  are often correlated with high brightness horizontal gradients,
  which suggests that filament and surrounding bright regions belong
  to the same geometrical and dynamical structure. (b) Fast motions
  (7 km s<SUP>-1</SUP>) have short life-times (a few minutes). (c) Slow
  motions in dark regions (&lt;3 km s<SUP>-1</SUP>) are associated with
  blue shifts and may last several hours. This behaviour was confirmed
  in many other cases by filament observations with the 3-wavelength Hα
  patrol. This is consistent with EUV observations of the transition zone
  around prominences, but disagrees with `downward motions' as seen at
  the limb, unless these motions do not refer to material velocities.

---------------------------------------------------------
Title: Mechanical flux in the solar chromosphere.
Authors: Mein, P.
1981ASIC...68..265M    Altcode: 1981spss.conf..265M
  Energy transport by pressure waves in the solar atmosphere is studied
  on the basis of observations of chromospheric line profiles. Mechanical
  fluxes are deduced as a function of frequency from Doppler shifts in
  the 3933 and 8542 Ca II lines; and integrated over the period range
  800 to 30 sec to obtain a total flux of 6000 erg/sq cm per sec. Flux
  values determined as a function of height from the Doppler shifts and
  intensity fluctuations of one or more lines are also presented. It
  is pointed out that the values of mechanical flux derived are almost
  two orders of magnitude less than the 300,000 erg/sq cm per sec of
  radiant energy lost from the transition region and corona, requiring an
  additional mechanism to account for the heating of the upper atmosphere.

---------------------------------------------------------
Title: The sites of solar flares
Authors: Mein, P.
1981soac.rept.....M    Altcode:
  Observations of solar flares were studied. Results on the magnetic field
  structure associated with an elementary flare are discussed. Conditions
  which prelude the triggering of instabilities (homologous flares,
  disappearance of filaments) are covered. The postflare relaxation phase
  is also considered. Linear polarization of lines during flare events and
  the variable geometry of magnetic field lines (mass ejection dynamics)
  are treated. The importance of continuous observation over several
  hours in interpreting these events is shown.

---------------------------------------------------------
Title: Mechanical flux in the solar chromosphere. I - Velocity and
    temperature weighting functions for CA II lines
Authors: Mein, N.; Mein, P.
1980A&A....84...96M    Altcode:
  Weighting functions for velocity and temperature disturbances are
  computed in the case of Ca II 3933, 8498, and 8542 with the HSRA
  model atmosphere. Temperature W-functions are generally broader than
  velocity W-functions, due to coupling between lines. Subsequently,
  formation altitudes and transfer functions for doppler shifts and
  intensity fluctuations are very different. Results are plotted against
  frequency with a view to the derivation of wave mechanical flux from
  line observations.

---------------------------------------------------------
Title: Mechanical flux in the solar chromosphere. II - Determination
    of the mechanical flux
Authors: Schmieder, B.; Mein, N.
1980A&A....84...99S    Altcode:
  The observations of two lines of Ca II (8542-8498) made with the
  Sacramento Peak Tower and formation altitudes values Z(omega) for these
  two lines determined by weighting functions are used to evaluate, for
  each frequency omega, the mechanical flux F(omega) corresponding to
  the altitude Z(omega). Corrections taking into account the weakening
  of waves of wavelengths smaller than the line formation layer were
  applied to the flux. The corrected flux does not show a significant
  increase with the frequency (up to 10 mHz), which seems to indicate
  that nonthermal microturbulence does not correspond necessarily to
  progressive wave. The mechanical flux integrated over the frequency
  range 0-10 mHz reaches at the most 2000 erg/sq cm s in the middle
  chromosphere (1100 km). This is not sufficient to balance the energy
  losses of the transition zone and the corona.

---------------------------------------------------------
Title: Motions and Oscillations in Filaments
Authors: Malherbe, J. M.; Martres, M. J.; Mein, P.; Schmieder, B.;
   Soru-Escaut, I.
1980jfss.conf..166M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Multi-Channel Subtractive Double Pass Spectrograph
Authors: Mein, P.
1980jfss.conf..285M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Observational Proof of the Inefficiency of the Chromospheric
    Heating by Acoustic Waves
Authors: Mein, P.; Mein, N.; Schmieder, B.
1980jfss.conf...70M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Dynamics of a Quiescent Filament
Authors: Schieder, B.; Martres, M.; Mein, P.; Soru-Escaut, I.
1980IAUS...91..213S    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Wave Reflections in the Solar Atmosphere
Authors: Provost, J.; Mein, N.
1979SoPh...64...43P    Altcode:
  The small phase-lag between velocities observed at different
  chromospheric levels is interpreted as being due to acoustic waves
  reflected by the very hot atmospheric layers of the chromosphere-corona
  transition zone. We consider first an isothermal slab, then a
  realistic solar atmospheric model and calculate weighting functions
  for velocities in Ca II lines. It is shown that taking into account
  these functions and integrating over horizontal wave numbers leads
  to a good agreement with previous observations (Mein, 1977) in the
  case of 8498 and 8542 Ca II lines. For the K line, the less good
  agreement shows that magnetoacoustic waves become important in the
  upper chromospheric layers.

---------------------------------------------------------
Title: Mechanical energy transport in the solar photosphere and
    chromosphere.
Authors: Mein, P.
1979ssms.conf...15M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Relation between the mode of oscillation and the velocity
    amplitude of chromospheric waves.
Authors: Mein, N.
1978SoPh...59....3M    Altcode:
  The distribution of oscillation-amplitude for Doppler shifts in
  chromospheric lines is computed as a function of position on the disk
  and time frequency. High amplitude regions are restricted to a small
  part of the solar surface. Propagation modes are investigated with
  respect to the oscillation amplitude in the K line. Waves seem to be
  standing or evanescent for most of the points (small amplitude in K)
  and progressive for some other ones, with perhaps upward and downward
  motions (partial reflections). Mechanical energy could only escape
  into corona from narrow chromospheric structures.

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Title: The Evolution of a transient Hα Feature probably associated
    with a Type III Burst
Authors: Mein, P.; Martres, M. J.; Soru-Escaut, I.
1978pfsl.conf..233M    Altcode: 1978ESPM....2..233M
  No abstract at ADS

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Title: Multi-channel subtractive spectrograph and filament
    observations.
Authors: Mein, P.
1977SoPh...54...45M    Altcode:
  A Multi-Channel Subtractive Double Pass spectrograph (MSDP) has
  been achieved at the Meudon solar tower. Line profiles are obtained
  simultaneously in a two dimensional field. Space and time resolutions
  are very suitable for observation of fast chromospheric phenomena.

---------------------------------------------------------
Title: Wave propagation in the quiet solar chromosphere.
Authors: Mein, N.
1977SoPh...52..283M    Altcode:
  In order to precise previous results about wave propagation in the
  quiet chromosphere (N. Mein and P. Mein, 1976), we study the behaviour
  of Doppler shifts and intensity fluctuations in 3 lines of Ca II.

---------------------------------------------------------
Title: Velocity waves in the quiet solar chromosphere.
Authors: Mein, N.; Mein, P.
1976SoPh...49..231M    Altcode:
  Propagation of velocity waves are investigated in the solar
  chromosphere, with a special view to high frequencies (periods
  ≥ 60 s). Four line profiles have been observed during 27 mn with
  the Sacramento Peak vacuum telescope (Hα, 3933, 8498 and 8542 Ca
  II). Three Fourier analysis are performed according to the location
  in the cells of the chromospheric network. Phase-shifts and amplitude
  ratios between the line Doppler shifts are computed as functions of
  frequency. The "pollution" of high frequency results by energetic low
  frequency oscillations is investigated.

---------------------------------------------------------
Title: Radiation and structure of the solar atmosphere (Radiation
    et structure de l'atmosphère solaire).
Authors: Giovanelli, R. G.; Mein, P.; Bappu, M. K. V.; Jordan, C.;
   MacQueen, R. M.
1976IAUTA..16b..55G    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Propagation des ondes dans la chromosphère
Authors: Mein, N.; Mein, P.
1976pmas.conf..269M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The Photosphere
Authors: Mein, P.
1976IAUTA..16...55M    Altcode: 1976IAUT...16A..55M
  No abstract at ADS

---------------------------------------------------------
Title: The Hydrogen Balmer Lines and the Structure of the Quiet
Solar Chromosphere. I: Observations at the Limb
Authors: Mein, P.; Mein, N.
1975SoPh...40..317M    Altcode:
  Spectra of Hα, Hβ and Hδ have been taken under good seeing
  conditions with the vacuum tower telescope of Sacramento Peak
  Observatory. Intensity curves are given at various wavelengths in these
  lines to permit further comparison with a theoretical model. Moreover,
  considering in each case the range of height in which the lines are
  almost optically thin and using a few approximations, the following
  results are derived: between 2000 and 6000 km above the limb the
  average thermal + turbulent velocity of the atoms is found to increase
  from 20 km s<SUP>−1</SUP> to 30 km s<SUP>−1</SUP> and the mean
  number of hydrogen atoms per cm<SUP>3</SUP> in level 2 is given by log
  n<SUB>2</SUB> = 4.5 - 0.00056(z-2000) z being the altitude above the
  limb in km. For line profile computations a new interpolation formula
  is presented; it gives good profiles with a small number of scans,
  saving microphotometer time.

---------------------------------------------------------
Title: A Substractive Double Pass Spectrograph for Solar Observations
Authors: Mein, P.; Blondel, M.
1972SoPh...27..489M    Altcode:
  Two-dimensional images in locally monochromatic light are obtained,
  using a subtractive double pass spectrograph. The spatial resolution
  is high and independent of the spectral bandwidth. The system is very
  suitable for fine structure observations in strong lines.

---------------------------------------------------------
Title: Inhomogeneities in the Solar Atmosphere from the Ca II
    Infra-Red Lines
Authors: Mein, Pierre
1971SoPh...20....3M    Altcode:
  From a time sequence of high dispersion spectra taken by Evans, the
  solar fine structures are studied in the CaII infra-red triplet. The
  Doppler shifts and the intensity fluctuations in different points
  of the profiles are converted into fluctuations of the model
  atmosphere. A weighting function method is worked out in that
  purpose. The theoretical line profiles are computed in non LTE from a
  program written by Dumont. The results are arranged in two parts: Low
  temporal frequencies. A three-column model describes the steady field
  of temperature, microturbulence and radial velocities fluctuations in
  the photosphere-chromosphere transition zone.

---------------------------------------------------------
Title: Propagation of Magneto-Acoustic Waves along the Gravitational
    Field in an Isothermal Atmosphere
Authors: Bel, N.; Mein, P.
1971A&A....11..234B    Altcode:
  We study the local dispersion equation obtained by MoLellan and
  Winterberg (1968) for magneto-acoustic waves propagating in an
  isothermal atmosphere. We restrict ourselves to wave propagation
  vectors along the gravitational field, for an arbitrary direction of
  the magnetic field. The propagation of the waves is shown to depend
  on two parameters, namely the ratios of the Alfve'n velocity and of
  the Alfv6n velocity for the vertical component of the magnetic field
  to the speed of sound. For typical values of these two parameters,
  we obtain representative curves for the phase and the amplitude of
  the waves as functions of the frequency. We find two modes, which are
  the counterparts of the usual fast and slow magneto-acoustic waves. A
  comparison with the case of an isothermal and compressible atmosphere
  without a magnetic field shows that the new mode is the slow one. We
  find that the magnetic field decreases the hydrodynarnic cut-off
  frequency and that, for large values of the magnetic field, the fast
  and the slow modes can intersect. The theoretical curves thus obtained
  make possible a direct comparison with observational data concerning
  the solar atmosphere. Key wor : waves - magnetic field - gravity -
  solar atmosphere

---------------------------------------------------------
Title: Observations du rapport H<SUB>α</SUB>/[N II] par une méthode
    interférométrique. Application à la nébuleuse de la Rosette
Authors: Mein, N.
1968AnAp...31..579M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Étude spatio-temporelle de la granulation
    solaire. Amélioration des images déformées par l'agitation
    atmosphérique
Authors: Mein, P.
1968AnAp...31..115M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Champ macroscopique des vitesses dans l'atmosphère solaire
    d'après les mesures de déplacements des raies de Fraunhofer
Authors: Mein, P.
1966AnAp...29..153M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Déformation du Profil des Raies Liées aux Ondes Sonores
    dans le Cas Solaires
Authors: Mein, P.
1966IAUTB..12..563M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Propagation Horizontale des Oscillations de Vitesse Observées
    sur le Disque Solaire
Authors: Mein, P.
1965CRASB.260.1867M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Etude d'une Raie Solaire Perturbée par des Ondes Acoustiques
    Planes; Résultats Numériques
Authors: Mein, P.
1964CRASB.258..819M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Etude d'une Raie Solaire Perturbée par des Ondes Acoustiques
    Planes; Exposé d'une Méthode
Authors: Mein, P.
1964CRASB.258..453M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Spectre continu du Soleil
Authors: Mein, P.
1959LAstr..73....5M    Altcode:
  No abstract at ADS