explanation      blue bibcodes open ADS page with paths to full text
Author name code: briand
ADS astronomy entries on 2022-09-14
author:"Briand, Carine" 

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Title: Role of hard X-ray emission in ionospheric D-layer disturbances
    during solar flares
Authors: Briand, Carine; Clilverd, Mark; Inturi, Srivani; Cecconi,
   Baptiste
2022EP&S...74...41B    Altcode:
  Any disturbance of the ionosphere may affect operational activities
  based on HF communication. The electron density is a critical parameter
  that controls levels of HF-signal absorption. A significant part
  of the HF absorption takes place in the D-layer. The increase of X
  radiations during solar flares generates noticeable perturbations of
  the electron density of the D-layer. However, the ionosphere reacts
  with some delay to the solar forcing. Several studies have addressed
  this question of ionospheric sluggishness from the time delay between
  VLF narrow-band transmissions and soft X-ray emissions during solar
  flares. Our study initially considers the interpretation of the VLF
  amplitude time profile. In particular, we show that the maximum of
  X-ray emission can be associated with a reversal in the VLF amplitude
  variation with time, i.e. exhibiting a peak or a trough. Then,
  building on this insight, we perform estimates of the time delay
  between VLF and soft X-rays during 67 events between 2017 and 2021,
  thus including the major flares of 2017. We show that the time delay
  can become negative for flares above X2, proving that soft X-rays are
  not the initial source of ionization in the case of major flares. From
  a careful analysis of RHESSI data for some events of September 2017,
  we demonstrate that radiation above 40 keV (i.e. hard X-rays) is an
  important forcing source of the ionosphere. This is of crucial interest
  in the frame of space weather forecasting since the hard X-rays are
  produced several minutes before the peak of soft X-rays.

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Title: The relativistic solar particle event on 28 October 2021:
    Evidence of particle acceleration within and escape from the solar
    corona
Authors: Klein, Karl-Ludwig; Musset, Sophie; Vilmer, Nicole; Briand,
   Carine; Krucker, Säm; Francesco Battaglia, Andrea; Dresing, Nina;
   Palmroos, Christian; Gary, Dale E.
2022A&A...663A.173K    Altcode:
  <BR /> Aims: We analyse particle, radio, and X-ray observations
  during the first relativistic proton event of solar cycle 25 detected
  on Earth. The aim is to gain insight into the relationship between
  relativistic solar particles detected in space and the processes of
  acceleration and propagation in solar eruptive events. <BR /> Methods:
  To this end, we used ground-based neutron monitor measurements of
  relativistic nucleons and space-borne measurements of electrons with
  similar speed to determine the arrival times of the first particles at 1
  AU and to infer their solar release times. We compared the release times
  with the time histories of non-thermal electrons in the solar atmosphere
  and their escape to interplanetary space, as traced by radio spectra and
  X-ray light curves and images. <BR /> Results: Non-thermal electrons
  in the corona are found to be accelerated in different regions. Some
  are confined in closed magnetic structures expanding during the course
  of the event. Three episodes of electron escape to the interplanetary
  space are revealed by groups of decametric-to-kilometric type III
  bursts. The first group appears on the low-frequency side of a type
  II burst produced by a coronal shock wave. The two latter groups
  are accompanied at higher frequencies by bursts with rapid drifts
  to both lower and higher frequencies (forward- or reverse-drifting
  bursts). They are produced by electron beams that propagate both sunward
  and anti-sunward. The first relativistic electrons and nucleons observed
  near Earth are released with the third group of type III bursts, more
  than ten minutes after the first signatures of non-thermal electrons
  and of the formation of the shock wave in the corona. Although the
  eruptive active region is near the central meridian, several tens of
  degrees east of the footpoint of the nominal Parker spiral to the Earth,
  the kilometric spectrum of the type III bursts and the in situ detection
  of Langmuir waves demonstrate a direct magnetic connection between the
  L1 Lagrange point and the field lines onto which the electron beams
  are released at the Sun. <BR /> Conclusions: We interpret the forward-
  and reverse-drifting radio bursts as evidence of reconnection between
  the closed expanding magnetic structures of an erupting flux rope and
  ambient open magnetic field lines. We discuss the origin of relativistic
  particles near the Earth across two scenarios: (1) acceleration at the
  CME-driven shock as it intercepts interplanetary magnetic field lines
  rooted in the western solar hemisphere and (2) an alternative where
  the relativistic particles are initially confined in the erupting
  magnetic fields and get access to the open field lines to the Earth
  through these reconnection events. <P />Movie is available at <A
  href="https://www.aanda.org/10.1051/0004-6361/202243903/olm">https://www.aanda.org</A>

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Title: Solar EUV-Enhancement and Thermospheric Disturbances
Authors: Briand, C.; Doerksen, K.; Deleflie, F.
2021SpWea..1902840B    Altcode:
  The increase of energetic electromagnetic flux during solar flares
  and particle precipitation during geomagnetic activity are among
  the most important sources of neutral density disturbances to the
  Earth's thermosphere. However, disentangling the role of X and EUV
  radiation during solar flares is difficult due to the rarity of
  sufficiently isolated EUV-enhancements. Past work investigating the
  role of EUV-enhancements has been based on simulations only. This
  study focuses on the analysis of the response of the thermosphere to
  relatively long-lasting (between 1 and 2 days) EUV-enhancements. These
  events take place in isolation from coronal mass ejections, but
  often occur during the recovery phase of flare events. Using the
  Gravity Recovery and Climate Experiment and Challenging Minisatellite
  Payload accelerometer-derived density datasets, we show that the
  EUV-enhancements slow the thermosphere's recovery from a flare, and
  maintain a high level density perturbation "plateau" lasting several
  hours. The level of disturbance was found to be between 30% and 70%
  compared to the thermosphere's density without any disturbance. The
  duration of this plateau is long enough that it may be important for
  estimating satellite drag. Over the duration of the EUV-enhancements,
  Dst drops are also observed, indicating ring current activity. The
  proposed physical mechanism driving the Dst changes is linked to the
  increased production of O<SUP>+</SUP> ions of ionospheric origin,
  which may occur over the EUV-enhancement period.

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Title: Observations of Shock Propagation through Turbulent Plasma
    in the Solar Corona
Authors: Carley, Eoin P.; Cecconi, Baptiste; Reid, Hamish A.; Briand,
   Carine; Sasikumar Raja, K.; Masson, Sophie; Dorovskyy, Vladimir;
   Tiburzi, Caterina; Vilmer, Nicole; Zucca, Pietro; Zarka, Philippe;
   Tagger, Michel; Grießmeier, Jean-Mathias; Corbel, Stéphane; Theureau,
   Gilles; Loh, Alan; Girard, Julien N.
2021ApJ...921....3C    Altcode: 2021arXiv210805587C
  Eruptive activity in the solar corona can often lead to the propagation
  of shock waves. In the radio domain the primary signature of such
  shocks are type II radio bursts, observed in dynamic spectra as bands
  of emission slowly drifting toward lower frequencies over time. These
  radio bursts can sometimes have an inhomogeneous and fragmented
  fine structure, but the cause of this fine structure is currently
  unclear. Here we observe a type II radio burst on 2019 March 20th using
  the New Extension in Nançay Upgrading LOFAR, a radio interferometer
  observing between 10-85 MHz. We show that the distribution of size
  scales of density perturbations associated with the type II fine
  structure follows a power law with a spectral index in the range of α =
  -1.7 to -2.0, which closely matches the value of -5/3 expected of fully
  developed turbulence. We determine this turbulence to be upstream of
  the shock, in background coronal plasma at a heliocentric distance of
  ~2 R<SUB>⊙</SUB>. The observed inertial size scales of the turbulent
  density inhomogeneities range from ~62 Mm to ~209 km. This shows that
  type II fine structure and fragmentation can be due to shock propagation
  through an inhomogeneous and turbulent coronal plasma, and we discuss
  the implications of this on electron acceleration in the coronal shock.

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Title: Pulsars with NenuFAR: Backend and pipelines
Authors: Bondonneau, L.; Grießmeier, J. -M.; Theureau, G.; Cognard,
   I.; Brionne, M.; Kondratiev, V.; Bilous, A.; McKee, J. W.; Zarka, P.;
   Viou, C.; Guillemot, L.; Chen, S.; Main, R.; Pilia, M.; Possenti,
   A.; Serylak, M.; Shaifullah, G.; Tiburzi, C.; Verbiest, J. P. W.;
   Wu, Z.; Wucknitz, O.; Yerin, S.; Briand, C.; Cecconi, B.; Corbel, S.;
   Dallier, R.; Girard, J. N.; Loh, A.; Martin, L.; Tagger, M.; Tasse, C.
2021A&A...652A..34B    Altcode: 2020arXiv200902076B
  Context. NenuFAR (New extension in Nançay upgrading LOFAR) is a new
  radio telescope developed and built on the site of the Nançay Radio
  Observatory. It is designed to observe the largely unexplored frequency
  window from 10 to 85 MHz, offering a high sensitivity across its full
  bandwidth. NenuFAR has started its "early science" operation in July
  2019, with 58% of its final collecting area. <BR /> Aims: Pulsars are
  one of the major phenomena utilized in the scientific exploitation of
  this frequency range and represent an important challenge in terms
  of instrumentation. Designing instrumentation at these frequencies
  is complicated by the need to compensate for the effects of both the
  interstellar medium and the ionosphere on the observed signal. We have
  designed a dedicated backend and developed a complete pulsar observation
  and data analysis pipeline, which we describe in detail in the present
  paper, together with first science results illustrating the diversity of
  the pulsar observing modes. <BR /> Methods: Our real-time pipeline LUPPI
  (Low frequency Ultimate Pulsar Processing Instrumentation) is able to
  cope with a high data rate and provide real-time coherent de-dispersion
  down to the lowest frequencies reached by NenuFAR (10 MHz). The full
  backend functionality is described, as the available pulsar observing
  modes (folded, single-pulse, waveform, and dynamic spectrum). <BR />
  Results: We also present some of the early science results of NenuFAR
  on pulsars: the detection of 12 millisecond pulsars (eight of which are
  detected for the first time below 100 MHz); a high-frequency resolution
  mapping of the PSR B1919+21 emission profile and a detailed observation
  of single-pulse substructures from PSR B0809+74 down to 16 MHz; the high
  rate of giant-pulse emission from the Crab pulsar detected at 68.7 MHz
  (43 events per minute); and the illustration of the very good timing
  performance of the instrumentation, which allows us to study dispersion
  measure variations in great detail.

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Title: Observations of shock propagation through turbulent plasma
    in the solar corona
Authors: Carley, Eoin; Cecconi, Baptiste; Reid, Hamish; Briand,
   Carine; Sasikumar Raja, K.; Masson, Sophie; Dorovskyy, Vladimir;
   Tiburzi, Caterina; Zucca, Pietro
2021EGUGA..2313113C    Altcode:
  Eruptive activity in the solar corona can often lead to the propagation
  of shockwaves. In the radio domain the primary signature of such
  shocks are type II radio bursts, observed in dynamic spectra as
  bands of emission slowly drifting towards lower frequencies over
  time. These radio bursts can sometimes have inhomogeneous and
  fragmented fine structure, but the cause of this fine structure is
  currently unclear. Here we observe several type II radio bursts on
  2019-March-20th using the New Extension in Nancay Upgrading LOFAR
  (NenuFAR), a radio interferometer observing between 10-85 MHz. We
  show that the distribution of size-scales of density perturbations
  associated with the fine structure of one type II follows a power law
  with a spectral index of -1.71, which closely matches the value of -5/3
  expected of fully developed turbulence. We determine this turbulence to
  be upstream of the shock, in background coronal plasma at a heliocentric
  distance of ~2 Rsun. The observed inertial size-scales of the turbulent
  density inhomogeneities range from ~62 Mm to ~209 km. This shows that
  type II fine structure and fragmentation can be due to shock propagation
  through an inhomogeneous and turbulent coronal plasma, and we discuss
  the implications of this on electron acceleration in the coronal shock.

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Title: Hard X-ray impact on the ionosphere D-layer: new results from
    VLF measurements
Authors: Briand, Carine; Inturi, Srivani; Cecconi, Baptiste
2021EGUGA..23.5623B    Altcode:
  The ionospheric electron density reacts to a change of ionization
  condition by a time delay Δt. Appleton (1953) demonstrated that this
  time delay is inversely proportional to the product of the electron
  density Ne and recombination rate coefficient α. Thus, the evaluation
  of the time difference between the peak time of VLF emission, which
  is supposed to represent the instant of maximum ionization, and the
  ionization source's peak time provides an easy way to estimate α
  Ne. First used to evaluate the increase of electron density at noon
  from H α peak emission, this technic was also employed to estimate the
  recombination rate during solar flares. The GOES Soft X-ray emissions
  (i.e. in the range 1.5-12keV) are then considered to determine the
  ionising source peak time.Based on VLF measurements obtained from the
  SUPERSID antenna installed at the Meudon site of the Paris Observatory
  (France), we computed each flare's time delay from January 2017. We
  benefit from the events of September 2017, the strongest from the
  last 10 years. We thus demonstrate the prominent role of Hard X-Rays
  in ionizing the D-layer of the ionosphere.

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Title: Impacts of solar events on atmospheric density variations as
    revealed by Satellite Laser Ranging orbits.
Authors: Deleflie, Florent; Hé, Changyong; Briand, Carine; Sammuneh,
   Muhammad Ali; Visser, Pieter
2020EGUGA..2221223D    Altcode:
  This paper is focused on precise orbitography with SLR data, using
  as well when they are available accelerometric data, as in the
  GRACE mission. The main purpose of this paper is to analyse whether
  low SLR satellite orbits (namely Starlette, Stella, Lares, Ajisai)
  are sensitive or not to variations of the atmospheric density due to
  solar events over the period 2003-2019, and including the ones that
  occurred in 2017.The relationships between solar events and the way
  they modify the density of the Earth's thermosphere, as revealed by
  perturbations induced on artificial satellites orbits, are in fact of
  crucial importance for satellite operators. A wide literature focused
  on these issues already exists, but it appears to the authors that some
  improvements of thermosphere models are still expected, especially at
  high latitudes. This paper aims, hence, at contributing to fill a gap
  in that direction. We first select over the period 1984-2019 a list
  of solar events that may be representative of the conditions that may
  heat the terrestrial atmosphere, in terms of geometrical configurations
  and the intensity of solar activity. The goal is to identify whether
  these events have impacted or not the thermospheric density at some
  relevant altitudes; therefore, a post-fit residual analysis is provided,
  accounting for the whole set of tracking data acquired by the stations
  of the ILRS network. A comprehensive comparison between precise results
  obtained with SLR and accelerometric data, using different atmospheric
  drag modelling, is then provided.

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Title: Solar radio emissions: from simulations to laser experiment
Authors: Briand, Carine; Depierreux, Sylvie; Henri, Pierre; Marques,
   Jean-Raphael; Lancia, Livia; Riconda, Caterina; Sgattoni, Andrea;
   Amiranoff, François
2019EGUGA..21.7140B    Altcode:
  Solar flares generate intense electromagnetic radiation in the
  radio domain (1-100 MHz), part of which corresponds to emission at
  the electron plasma frequency ω<SUB>p</SUB> or its second harmonic
  2ω_p. These waves are the signature of electron beams propagating
  in the interplanetary medium. Detected by space and ground-based
  radio telescopes, these electromagnetic waves can be used to remotely
  infer the characteristics of the electron beams. If the main steps
  of the process from electron beam to Electron Plasma Waves and
  mode conversion to electromagnetic radiations are known, several
  questions are still unresolved, in particular: (i) the efficiency
  of the conversion, (ii) the directionality of the process. To tackle
  these questions first PIC simulations, then laboratory laser-plasma
  experiment have been performed. If the parameters of the interplanetary
  plasma and laser-generated plasmas are very different in absolute
  values, they happen to be very similar in relative numbers (such
  as k⪉mbda<SUB>De</SUB> and T_e/T_i), which makes these laser
  experiments suitable for astrophysical purposes. The experiment was
  designed for the LULI 2000 facility (Ecole Polytechnique, France)
  operated at 2ω<SUB>0</SUB> in the nanosecond regime. The results of
  PIC simulations and of the first experiment that hold in September
  2018 will be presented.

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Title: Atmospheric Density Variations and Orbit Perturbations in
    Relation to Isolated Solar X-flare Events
Authors: Deleflie, Florent; Doerksen, Kelsey; Briand, Carine; Sammuneh,
   Muhammad Ali; Sagnières, Luc
2019EGUGA..2115338D    Altcode:
  The relationships between solar flares and the way they modify the
  density of the Earth's thermosphere, as revealed by perturbations
  induced on artificial satellites orbits, are of crucial importance for
  satellite operators. A wide literature dealing with the solar flare
  events and their relationships with geomagnetic storms already exists
  ; but, it appears to the authors that there is a lack of research
  focusing only on the effects of the solar flares, i.e. solar events
  without any accompaniment of Coronal Mass Ejections (CMEs). This paper
  is focused on the investigation of the thermosphere's response to
  X-class solar flare events from 2002-2017. The thermosphere density
  is derived from the on-board accelerometers of the Gravity Recovery
  and Climate Experiment (GRACE) twin satellites, and the CHallenging
  Minisatellite Payload (CHAMP) satellite. The accelerometric data are
  also compared to the accelerations provided by classical and recent
  atmospheric drag models, thanks to a post-fit residual analysis of
  the orbits of those spacecrafts. As a result, the consequences of
  the density disturbances on satellite re-entry are enlightened. It
  appears in particular that the trajectory of the GRACE satellites are
  sensitive to those single events, as their effects to the orbits is
  higher than the current accuracy of the trajectory. As expected, the
  effects of such single events are all the higher as the area-to-mass
  ratio is high, and some examples based on major events (such as the
  ones that occured in early december 2006) are also provided.

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

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Title: Electromagnetic Simulations of Solar Radio Emissions
Authors: Henri, P.; Sgattoni, A.; Briand, C.; Amiranoff, F.;
   Riconda, C.
2019JGRA..124.1475H    Altcode:
  Solar radio emissions are electromagnetic waves emitted in the
  solar wind as a consequence of electron beams accelerated during
  solar flares or interplanetary shocks such as interplanetary coronal
  mass ejections. Different physical mechanisms have been suggested to
  describe their origin. A good understanding of the emission process
  would enable to infer the kinetic energy transferred from accelerated
  electrons to radio waves. Even if the electrostatic case has been
  extensively studied, full electromagnetic simulations were attempted
  only recently. In this work, we report large-scale 2D3V electromagnetic
  particle-in-cell simulations that enable to identify the generation of
  both electrostatic and electromagnetic waves originated by a succession
  of plasma instabilities. They confirm that an efficient mechanism to
  generate solar radio emissions close to T<SUB>2f</SUB>, the harmonic
  of the plasma frequency, is a multistage model based on a succession
  of nonlinear three-wave interaction processes. Through a parametric
  study of the electron beam parameters, we show that (i) the global
  efficiency of the multistep conversion mechanism from the electron
  beam kinetic energy to the T<SUB>2f</SUB> radio wave is independent
  of the beam parameters, approximately 10<SUP>-5</SUP> in all tested
  configurations, while (ii) the directivity of the electromagnetic
  radio wave strongly depends on the origin electron beam. Those results
  represent a step forward toward the use of solar wind radio emissions,
  observed remotely, as a diagnostic for the properties of the electron
  beam located at the source of the radio emission, and therefore to
  eventually better characterize remotely electron acceleration mechanisms
  in space regions not directly accessible to in situ measurements.

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Title: NOIRE Study Report: Towards a Low Frequency Radio
    Interferometer in Space
Authors: Cecconi, Baptiste; Dekkali, Moustapha; Briand, Carine; Segret,
   Boris; Girard, Julien; Laurens, André; Lamy, Alain; Valat, David;
   Delpech, Michel; Bruno, Mickael; Gélard, Patrick; Bucher, Martin;
   Nenon, Quentin; Grießmeier, Jean-Mathias; Boonstra, Albert-Jan;
   Bentum, Mark
2018EGUGA..20.3648C    Altcode: 2017arXiv171010245C
  Ground based low frequency radio interferometers have been developed in
  the last decade and are providing the scientific community with high
  quality observations. Conversely, current radioastronomy instruments
  in space have a poor angular resolution with single point observation
  systems. Improving the observation capabilities of the low frequency
  range (a few kHz to 100 MHz) requires to go to space and to set up a
  space based network of antenna that can be used as an interferometer. We
  present the outcome of the NOIRE (Nanosatellites pour un Observatoire
  Interférométrique Radio dans l'Espace / Nanosatellites for a Radio
  Interferometer Observatory in Space) study which assessed, with help
  of CNES' PASO, the feasibility of a swarm of nanosatellites dedicated
  to a low frequency radio observatory. With such a platform, space
  system engineering and instrument development must be studied as a
  whole: each node is a sensor and all sensors must be used together to
  obtain a measurement. The study was conducted on the following topics:
  system principle and concept (swarm, node homogeneity); Space and time
  management (ranging, clock synchronization); Orbitography (Moon orbit,
  Lagrange point options); Telecommunication (between nodes and with
  ground) and networking; Measurements and processing; Propulsion;
  Power; Electromagnetic compatibility. No strong show-stopper was
  identified during the preliminary study, although the concept is not
  yet ready. Several further studies and milestones are identified. The
  NOIRE team will collaborate with international teams to try and build
  this next generation of space systems.

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Title: French SKA White Book - The French Community towards the
    Square Kilometre Array
Authors: Acero, F.; Acquaviva, J. -T.; Adam, R.; Aghanim, N.; Allen,
   M.; Alves, M.; Ammanouil, R.; Ansari, R.; Araudo, A.; Armengaud, E.;
   Ascaso, B.; Athanassoula, E.; Aubert, D.; Babak, S.; Bacmann, A.;
   Banday, A.; Barriere, K.; Bellossi, F.; Bernard, J. -P.; Bernardini,
   M. G.; Béthermin, M.; Blanc, E.; Blanchet, L.; Bobin, J.; Boissier,
   S.; Boisson, C.; Boselli, A.; Bosma, A.; Bosse, S.; Bottinelli,
   S.; Boulanger, F.; Boyer, R.; Bracco, A.; Briand, C.; Bucher, M.;
   Buat, V.; Cambresy, L.; Caillat, M.; Casandjian, J. -M.; Caux,
   E.; Célestin, S.; Cerruti, M.; Charlot, P.; Chassande-Mottin, E.;
   Chaty, S.; Christensen, N.; Ciesla, L.; Clerc, N.; Cohen-Tanugi, J.;
   Cognard, I.; Combes, F.; Comis, B.; Corbel, S.; Cordier, B.; Coriat,
   M.; Courtin, R.; Courtois, H.; Da Silva, B.; Daddi, E.; Dallier, R.;
   Dartois, E.; Demyk, K.; Denis, J. -M.; Denis, L.; Djannati-Ataï, A.;
   Donati, J. -F.; Douspis, M.; van Driel, W.; El Korso, M. N.; Falgarone,
   E.; Fantina, A.; Farges, T.; Ferrari, A.; Ferrari, C.; Ferrière, K.;
   Flamary, R.; Gac, N.; Gauffre, S.; Genova, F.; Girard, J.; Grenier,
   I.; Griessmeier, J. -M.; Guillard, P.; Guillemot, L.; Gulminelli,
   F.; Gusdorf, A.; Habart, E.; Hammer, F.; Hennebelle, P.; Herpin, F.;
   Hervet, O.; Hughes, A.; Ilbert, O.; Janvier, M.; Josselin, E.; Julier,
   A.; Lachaud, C.; Lagache, G.; Lallement, R.; Lambert, S.; Lamy, L.;
   Langer, M.; Larzabal, P.; Lavaux, G.; Le Bertre, T.; Le Fèvre, O.;
   Le Tiec, A.; Lefloch, B.; Lehnert, M.; Lemoine-Goumard, M.; Levrier,
   F.; Limousin, M.; Lis, D.; López-Sepulcre, A.; Macias-Perez, J.;
   Magneville, C.; Marcowith, A.; Margueron, J.; Marquette, G.; Marshall,
   D.; Martin, L.; Mary, D.; Masson, S.; Maurogordato, S.; Mazauric,
   C.; Mellier, Y.; Miville-Deschênes, M. -A.; Montier, L.; Mottez, F.;
   Mourard, D.; Nesvadba, N.; Nezan, J. -F.; Noterdaeme, P.; Novak, J.;
   Ocvirk, P.; Oertel, M.; Olive, X.; Ollier, V.; Palanque-Delabrouille,
   N.; Pandey-Pommier, M.; Pennec, Y.; Pérault, M.; Peroux, C.; Petit,
   P.; Pétri, J.; Petiteau, A.; Pety, J.; Pratt, G. W.; Puech, M.;
   Quertier, B.; Raffin, E.; Rakotozafy Harison, S.; Rawson, S.; Renaud,
   M.; Revenu, B.; Richard, C.; Richard, J.; Rincon, F.; Ristorcelli,
   I.; Rodriguez, J.; Schultheis, M.; Schimd, C.; Semelin, B.; Sol, H.;
   Starck, J. -L.; Tagger, M.; Tasse, C.; Theureau, G.; Torchinsky, S.;
   Vastel, C.; Vergani, S. D.; Verstraete, L.; Vigouroux, X.; Vilmer,
   N.; Vilotte, J. -P.; Webb, N.; Ysard, N.; Zarka, P.
2017arXiv171206950A    Altcode:
  The "Square Kilometre Array" (SKA) is a large international radio
  telescope project characterised, as suggested by its name, by a total
  collecting area of approximately one square kilometre, and consisting
  of several interferometric arrays to observe at metric and centimetric
  wavelengths. The deployment of the SKA will take place in two sites,
  in South Africa and Australia, and in two successive phases. From its
  Phase 1, the SKA will be one of the most formidable scientific machines
  ever deployed by mankind, and by far the most impressive in terms of
  data throughput and required computing power. With the participation
  of almost 200 authors from forty research institutes and six private
  companies, the publication of this French SKA white paper illustrates
  the strong involvement in the SKA project of the French astronomical
  community and of a rapidly growing number of major scientific and
  technological players in the fields of Big Data, high performance
  computing, energy production and storage, as well as system integration.

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Title: Full PIC simulations of solar radio emission
Authors: Sgattoni, A.; Henri, P.; Briand, C.; Amiranoff, F.;
   Riconda, C.
2017AGUFMSH33B2786S    Altcode:
  Solar radio emissions are electromagnetic (EM) waves emitted in the
  solar wind plasma as a consequence of electron beams accelerated
  during solar flares or interplanetary shocks such as ICMEs. To
  describe their origin, a multi-stage model has been proposed in the
  60s which considers a succession of non-linear three-wave interaction
  processes. A good understanding of the process would allow to infer
  the kinetic energy transfered from the electron beam to EM waves,
  so that the radio waves recorded by spacecraft can be used as a
  diagnostic for the electron beam.Even if the electrostatic problem
  has been extensively studied, full electromagnetic simulations were
  attempted only recently. Our large scale 2D-3V electromagnetic PIC
  simulations allow to identify the generation of both electrostatic
  and EM waves originated by the succession of plasma instabilities. We
  tested several configurations varying the electron beam density and
  velocity considering a background plasma of uniform density. For
  all the tested configurations approximately 105 of the electron-beam
  kinetic energy is transfered into EM waves emitted in all direction
  nearly isotropically. With this work we aim to design experiments
  of laboratory astrophysics to reproduce the electromagnetic emission
  process and test its efficiency.

---------------------------------------------------------
Title: The NOIRE Study
Authors: Cecconi, B.; Laurens, A.; Briand, C.; Girard, J.; Bucher,
   M.; Puy, D.; Segret, B.; Bentum, M.
2016sf2a.conf..339C    Altcode:
  NOIRE (Nanosats pour un Observatoire Interférométrique Radio dans
  l'Espace; Nanosats for a space borne interferometric radio observatory)
  is an ongoing feasibility study with CNES and in collaboration with
  Dutch colleagues. The goal is to assess the feasibility of a low
  frequency space radio interferometer using nanosatellites.

---------------------------------------------------------
Title: Solar radio emissions: 2D full PIC simulations
Authors: Pierre, H.; Sgattoni, A.; Briand, C.; Amiranoff, F.;
   Riconda, C.
2016AGUFMSH21E2569P    Altcode:
  Solar radio emissions are electromagnetic waves observed at the local
  plasma frequency and/or at twice the plasma frequency. To describe
  their origin a multi-stage model has been proposed by Ginzburg
  &amp; Zhelezniakov (1958) and further developed by several authors,
  which consider a succession of non-linear three-wave interaction
  processes. Electron beams accelerated by solar flares travel in the
  interplanetary plasma and provide the free energy for the development
  of plasma instabilities. The model describes how part of the free
  energy of these beams can be transformed in a succession of plasma
  waves and eventually into electromagnetic waves. Following the work of
  Thurgood &amp; Tsiklauri (2015) we performed several 2D Particle In Cell
  simulations. The simulations follow the entire set of processes from the
  electron beam propagation in the background plasma to the generation of
  the electromagnetic waves in particular the 2ωp emission, including
  the excitation of the low frequency waves. As suggested by Thurgood
  &amp; Tsiklauri (2015) it is possible to identify regimes where the
  radiation emission can be directly linked to the electron beams. Our
  attention was devoted to estimate the conversion efficiency from
  electron kinetic energy to the em energy, and the growth rate of the
  several processes which can be identified. We studied the emission
  angles of the 2ωpradiation and compared them with the theoretical
  predictions of Willes et. al. (1995). We also show the role played by
  some numerical parameters i.e. the size and shape of the simulation
  box. This work is the first step to prepare laser-plasma experiments. <P
  />V. L. Ginzburg, V. V. Zhelezniakov On the Possible Mechanisms of
  Sporadic Solar Radio Emission (Radiation in an Isotropic Plasma)
  Soviet Astronomy, Vol. 2, p.653 (1958) <P />J. O. Thurgood and
  D. Tsiklauri Self-consistent particle-in-cell simulations of funda-
  mental and harmonic plasma radio emission mechanisms. Astronomy &amp;
  Astrophysics 584, A83 (2015). <P />A. Willes, P. Robinson and D. Melrose
  (1995). Second harmonic electromagnetic emis- sion via Langmuir wave
  coalescence. Physics of Plasmas, 3(1), 149-159 (1995).

---------------------------------------------------------
Title: Langmuir waveforms at interplanetary shocks: STEREO statistical
    analysis
Authors: Briand, C.
2016AGUFMSH21A2499B    Altcode:
  Wave-particle interactions and particle acceleration are the two main
  processes allowing energy dissipation at non collisional shocks. Ion
  acceleration has been deeply studied for many years, also for their
  central role in the shock front reformation. Electron dynamics is
  also important in the shock dynamics through the instabilities they
  can generate which may impact the ion dynamics.Particle measurements
  can be efficiently completed by wave measurements to determine the
  characteristics of the electron beams and study the turbulence of the
  medium. Electric waveforms obtained from the S/WAVES instrument of the
  STEREO mission between 2007 to 2014 are analyzed. Thus, clear signature
  of Langmuir waves are observed on 41 interplanetary shocks. These data
  enable a statistical analysis and to deduce some characteristics of
  the electron dynamics on different shocks sources (SIR or ICME) and
  types (quasi-perpendicular or quasi-parallel). The conversion process
  between electrostatic to electromagnetic waves has also been tested
  in several cases.

---------------------------------------------------------
Title: Mapping the radio sky from 0.1 to 100 MHz with NOIRE
Authors: Cecconi, B.; Laurens, A.; Briand, C.; Girard, J.; Bucher,
   M.; Puy, D.; Segret, B.; Bentum, M.
2016sf2a.conf..343C    Altcode:
  The goal of the NOIRE study (Nanosats pour un Observatoire
  Interférométrique Radio dans l'Espace) is to assess the scientific
  interest and technical feasibility of a space borne radio interferometer
  operating from a few kHz to a few 10 MHz. Such observatory would be
  able to build a global sky map with an unprecedented spatial resolution
  depending on the selected technical implementation. We present a review
  of our understanding of the Galactic mapping, assessing the instrument
  requirement for such observations.

---------------------------------------------------------
Title: Space-weather assets developed by the French space-physics
    community
Authors: Rouillard, A. P.; Pinto, R. F.; Brun, A. S.; Briand, C.;
   Bourdarie, S.; Dudok De Wit, T.; Amari, T.; Blelly, P. -L.; Buchlin,
   E.; Chambodut, A.; Claret, A.; Corbard, T.; Génot, V.; Guennou, C.;
   Klein, K. L.; Koechlin, L.; Lavarra, M.; Lavraud, B.; Leblanc, F.;
   Lemorton, J.; Lilensten, J.; Lopez-Ariste, A.; Marchaudon, A.; Masson,
   S.; Pariat, E.; Reville, V.; Turc, L.; Vilmer, N.; Zucarello, F. P.
2016sf2a.conf..297R    Altcode:
  We present a short review of space-weather tools and services developed
  and maintained by the French space-physics community. They include
  unique data from ground-based observatories, advanced numerical
  models, automated identification and tracking tools, a range of space
  instrumentation and interconnected virtual observatories. The aim of
  the article is to highlight some advances achieved in this field of
  research at the national level over the last decade and how certain
  assets could be combined to produce better space-weather tools
  exploitable by space-weather centres and customers worldwide. This
  review illustrates the wide range of expertise developed nationally
  but is not a systematic review of all assets developed in France.

---------------------------------------------------------
Title: The modern radio astronomy network in Ukraine: UTR-2, URAN
    and GURT
Authors: Konovalenko, A.; Sodin, L.; Zakharenko, V.; Zarka, P.;
   Ulyanov, O.; Sidorchuk, M.; Stepkin, S.; Tokarsky, P.; Melnik, V.;
   Kalinichenko, N.; Stanislavsky, A.; Koliadin, V.; Shepelev, V.;
   Dorovskyy, V.; Ryabov, V.; Koval, A.; Bubnov, I.; Yerin, S.; Gridin,
   A.; Kulishenko, V.; Reznichenko, A.; Bortsov, V.; Lisachenko, V.;
   Reznik, A.; Kvasov, G.; Mukha, D.; Litvinenko, G.; Khristenko,
   A.; Shevchenko, V. V.; Shevchenko, V. A.; Belov, A.; Rudavin, E.;
   Vasylieva, I.; Miroshnichenko, A.; Vasilenko, N.; Olyak, M.; Mylostna,
   K.; Skoryk, A.; Shevtsova, A.; Plakhov, M.; Kravtsov, I.; Volvach,
   Y.; Lytvinenko, O.; Shevchuk, N.; Zhouk, I.; Bovkun, V.; Antonov,
   A.; Vavriv, D.; Vinogradov, V.; Kozhin, R.; Kravtsov, A.; Bulakh, E.;
   Kuzin, A.; Vasilyev, A.; Brazhenko, A.; Vashchishin, R.; Pylaev, O.;
   Koshovyy, V.; Lozinsky, A.; Ivantyshin, O.; Rucker, H. O.; Panchenko,
   M.; Fischer, G.; Lecacheux, A.; Denis, L.; Coffre, A.; Grießmeier,
   J. -M.; Tagger, M.; Girard, J.; Charrier, D.; Briand, C.; Mann, G.
2016ExA....42...11K    Altcode: 2016ExA...tmp....7K
  The current status of the large decameter radio telescope UTR-2
  (Ukrainian T-shaped Radio telescope) together with its VLBI system
  called URAN is described in detail. By modernization of these
  instruments through implementation of novel versatile analog and digital
  devices as well as new observation techniques, the observational
  capabilities of UTR-2 have been substantially enhanced. The total
  effective area of UTR-2 and URAN arrays reaches 200 000 m<SUP>2</SUP>,
  with 24 MHz observational bandwidth (within the 8-32 MHz frequency
  range), spectral and temporal resolutions down to 4 kHz and 0.5 msec in
  dynamic spectrum mode or virtually unlimited in waveform mode. Depending
  on the spectral and temporal resolutions and confusion effects, the
  sensitivity of UTR-2 varies from a few Jy to a few mJy, and the angular
  resolution ranges from ~ 30 arcminutes (with a single antenna array)
  to a few arcseconds (in VLBI mode). In the framework of national and
  international research projects conducted in recent years, many new
  results on Solar system objects, the Galaxy and Metagalaxy have been
  obtained. In order to extend the observation frequency range to 8-80
  MHz and enlarge the dimensions of the UTR-2 array, a new instrument -
  GURT (Giant Ukrainian Radio Telescope) - is now under construction. The
  radio telescope systems described herein can be used in synergy with
  other existing low-frequency arrays such as LOFAR, LWA, NenuFAR,
  as well as provide ground-based support for space-based instruments.

---------------------------------------------------------
Title: Langmuir waves: a database from the STEREO mission
Authors: Briand, Carine; Henri, Pierre; Génot, Vincent; Lormant,
   Nicolas; Dufourg, Nicolas; Cecconi, Baptiste; Nguyen, Quynh-Nhu
2016EGUGA..18.6005B    Altcode:
  Langmuir waves are ubiquitous in the planetary environments and the
  interplanetary medium. These electrostatic waves occur in the range
  10-30 kHz in the solar wind. They are of interest as they are linked
  to the electron dynamics. Moreover, they are at the origin of the
  most intense electromagnetic radio waves related to solar flare and
  interplanetary shocks. The waveform analyzers of the WAVES instrument
  onboard of STEREO spacecraft have been observing the interplanetary
  medium since more than seven years. A complete database of the observed
  Langmuir waves is accessible to the community from the CDPP website
  (http://cdpp.eu/). We present here the details of the available
  information, as well as some analysis on different heliophysical
  contexts (interplanetary medium, shocks in particular).

---------------------------------------------------------
Title: Division E Commission 49: Interplanetary Plasma and Heliosphere
Authors: Mann, Ingrid; Manoharan, P. K.; Gopalswamy, Natchimuthuk;
   Briand, Carine; Chashei, Igor V.; Gibson, Sarah E.; Lario, David;
   Hanaoka, Yoichiro; Malandraki, Olga; Kontar, Eduard; Richardson,
   John D.
2016IAUTA..29..300M    Altcode:
  After a little more than forty years of work related to the
  interplanetary plasma and the heliosphere the IAU's Commission 49 was
  formally discontinued in 2015. The commission started its work when
  the first spacecraft were launched to measure the solar wind in-situ
  away from Earth orbit, both inward and outward from 1 AU. It now
  hands over its activities to a new commission during an era of space
  research when Voyager 1 measures in-situ the parameters of the local
  interstellar medium at the edge of the heliosphere. The commission will
  be succeeded by C.E3 with a similar area of responsibility but with more
  focused specific tasks that the community intends to address during the
  coming several years. This report includes a short description of the
  motivation for this commission and of the historical context. It then
  describes work from 2012 to 2015 during the present solar cycle 24 that
  has been the weakest in the space era so far. It gave rise to a large
  number of studies on solar energetic particles and cosmic rays. Other
  studies addressed e.g. the variation of the solar wind structure
  and energetic particle fluxes on long time scales, the detection of
  dust in the solar wind and the Voyager measurements at the edge of the
  heliosphere. The research is based on measurements from spacecraft that
  are at present operational and motivated by the upcoming Solar Probe
  + and Solar Orbiter missions to explore the vicinity of the Sun. We
  also report here the progress on new and planned radio instruments
  and their importance for heliospheric studies. Contributors to this
  report are Carine Briand, Yoichiro Hanaoka, Eduard Kontar, David Lario,
  Ingrid Mann, John D. Richardson.

---------------------------------------------------------
Title: STEREO database of interplanetary Langmuir electric waveforms
Authors: Briand, C.; Henri, P.; Génot, V.; Lormant, N.; Dufourg,
   N.; Cecconi, B.; Nguyen, Q. N.; Goetz, K.
2016JGRA..121.1062B    Altcode:
  This paper describes a database of electric waveforms that is
  available at the Centre de Données de la Physique des Plasmas (CDPP,
  <A href="http://cdpp.eu/">http://cdpp.eu/</A>). This database is
  specifically dedicated to waveforms of Langmuir/Z-mode waves. These
  waves occur in numerous kinetic processes involving electrons in space
  plasmas. Statistical analysis from a large data set of such waves
  is then of interest, e.g., to study the relaxation of high-velocity
  electron beams generated at interplanetary shock fronts, in current
  sheets and magnetic reconnection region, the transfer of energy between
  high and low frequencies, the generation of electromagnetic waves. The
  Langmuir waveforms were recorded by the Time Domain Sampler (TDS) of the
  WAVES radio instrument on board the STEREO mission. In this paper, we
  detail the criteria used to identify the Langmuir/Z-mode waves among the
  whole set of waveforms of the STEREO spacecraft. A database covering the
  November 2006 to August 2014 period is provided. It includes electric
  waveforms expressed in the normalized frame (B,B × Vsw,B × (B ×
  Vsw)) with B and V<SUB>sw</SUB> the local magnetic field and solar
  wind velocity vectors, and the local magnetic field in the variance
  frame, in an interval of ±1.5 min around the time of the Langmuir
  event. Quicklooks are also provided that display the three components of
  the electric waveforms together with the spectrum of E<SUB>∥</SUB>,
  together with the magnitude and components of the magnetic field in
  the 3 min interval, in the variance frame. Finally, the distribution
  of the Langmuir/Z-mode waves peak amplitude is also analyzed.

---------------------------------------------------------
Title: The Storm of Decameter Spikes During the Event of 14 June 2012
Authors: Shevchuk, N. V.; Melnik, V. N.; Poedts, S.; Dorovskyy, V. V.;
   Magdalenic, J.; Konovalenko, A. A.; Brazhenko, A. I.; Briand, C.;
   Frantsuzenko, A. V.; Rucker, H. O.; Zarka, P.
2016SoPh..291..211S    Altcode: 2015SoPh..tmp..171S
  An event on 14 June 2012, observed with the radio telescopes UTR-2
  (Kharkov, Ukraine), URAN-2 (Poltava, Ukraine), and NDA (Nançay, France)
  during a joint Summer campaign, is analyzed and discussed. The high
  solar activity resulted in a storm of spikes, and a storm of Type III
  bursts, Type IIIb bursts, and a Type IV burst observed in the decameter
  band. During the observed time interval, the average flux of radio
  emission changed twice. Using spikes as a tool for diagnostics of
  plasma parameters, we followed variations of the coronal temperature
  and the coronal magnetic field in the observed time interval. Thus,
  in frames of the model described in this article the observed decameter
  spikes' durations of 0.3 - 1 seconds correspond to the coronal plasma
  temperatures of ≈0.1 -0.6 ×10<SUP>6</SUP>K. At the same time the
  spikes' frequency bandwidths of 25 - 80 kHz give us the magnetic-field
  value of about 2 G.

---------------------------------------------------------
Title: Division II: Commission 49: Interplanetary Plasma and the
    Heliosphere
Authors: Gopalswamy, Natchimuthuk; Mann, Ingrid; Bougeret, Jean-Louis;
   Briand, Carine; Lallement, Rosine; Lario, David; Manoharan, P. K.;
   Shibata, Kazunari; Webb, David F.
2015IAUTB..28..112G    Altcode:
  The President of IAU Commission 49 (C49; Interplanetary Plasma and the
  Heliosphere), Nat Gopalswamy, chaired the business meeting of C10,
  which took place on August 23, 2012 in the venue of the IAU General
  Assembly in Beijing (2:00 - 3:30 PM, Room 405).

---------------------------------------------------------
Title: Flare-related radio emission: a kinetic point-of-view
Authors: Briand, Carine
2015IAUGA..2254941B    Altcode:
  During a flare, high energy electrons (1-100 keV) are expelled
  from the solar corona and travel along the interplanetary magnetic
  field lines. These electrons are at the origin of one of the most
  prominent features of the meter-decameter ranges of frequency: the
  so-called solar type III radio emissions.Several theories have been
  proposed to explain the generation of these emissions. They all refer
  to small scale plasma processes. During this talk, we will show how
  STEREO/WAVES measurements have been able to give strong support to the
  model initially proposed by Ginzburg &amp; Zheleznyakov: the three
  wave-coupling.Using new capabilities of waveform analyses provided
  by the instruments onboard the two STEREO spacecraft, we present a
  complete set of direct evidence for three-wave coupling occurring
  during a Type III emission and involving two Langmuir waves and an
  ion acoustic wave. Evidence cover not only the energy and momentum
  conservation but also the phase coupling.Then, we present Vlasov
  numerical simulations that support the observations. We indeed show
  that the amplitude of the wave packets are within the expected values
  when correctly considering the non monochromatic character of the waves
  and their finite interaction time.Finally, during a specific event when
  two electron beams interact, we show that the lack of Langmuir waves
  coherence reduces the efficiency of the Langmuir parametric decay,
  and as a consequence reduces the intensity of the Type III emission.

---------------------------------------------------------
Title: Cancellation analysis of current density in solar active
    region NOAA10019
Authors: De Vita, Gaetano; Vecchio, Antonio; Sorriso-Valvo, Luca;
   Briand, Carine; Primavera, Leonardo; Servidio, Sergio; Lepreti, Fabio;
   Carbone, Vincenzo
2015JSWSC...5A..28D    Altcode:
  Solar flares are often associated with changes in the fine magnetic
  structure of the emitting active region. Such topological modification
  results in variations of both the scaling properties of the fields'
  fluctuations, and the fractal dimension of the associated gradients. The
  use of cancellation analysis of the current density has been attempted
  for the identification and quantitative estimation of such changes. The
  characteristics of the magnetic vector as measured by THEMIS telescope
  for the active region NOAA10019 have been studied in this paper,
  suggesting the presence of disrupted current filaments. The variation
  of the fractal dimension of the current structures, and in particular
  their smoothing, is discussed in relationship with occurrence of one
  flare in the active region.

---------------------------------------------------------
Title: Langmuir waves across the heliosphere
Authors: Briand, C.
2015JPlPh..81b3204B    Altcode:
  All the bodies of the solar system are embedded in the supersonic flux
  of energetic particles emitted by the Sun. Since the advent of the space
  age, the models to describe the interaction of this plasma flow with
  the planets, asteroids, comets etc. have drastically progressed. The
  possibilities of in situ measurements of the particle distributions
  and electromagnetic fields have enabled the plasma theories to be
  tested under astrophysical conditions. Energy transfer from the Sun
  to the outermost regions of the heliosphere as well as the processes
  leading to the dissipation of this energy are central questions
  for heliophysicists. Understanding the dynamics of the particles is
  thus critical. It is a particularly complicated subject since the
  medium is (almost) non-collisional. Thus, next to the description of
  the particles, the development of waves must be considered. Indeed,
  they participate to the exchange of energy between different species
  that would not interact otherwise. In other words, waves may play the
  role of collisions. This paper concentrates on Langmuir waves for
  their strong links with the electron dynamics. The basic processes
  of growth and saturation of the Langmuir waves are reviewed to stress
  their diagnostic capabilities. Then, the characteristics of the waves
  are described in the several heliophysical contexts: the planetary
  environments (in particular the ionosphere, the magnetotail and the
  foreshock) and in the interplanetary medium (in quiescent conditions
  of the solar wind or during transient events). A particular emphasis
  is given to results obtained in the last 15 years.

---------------------------------------------------------
Title: Decameter Type III Bursts with Changing Frequency Drift-Rate
    Signs
Authors: Melnik, V. N.; Brazhenko, A. I.; Konovalenko, A. A.;
   Briand, C.; Dorovskyy, V. V.; Zarka, P.; Frantsuzenko, A. V.; Rucker,
   H. O.; Rutkevych, B. P.; Panchenko, M.; Denis, L.; Zaqarashvili, T.;
   Shergelashvili, B.
2015SoPh..290..193M    Altcode: 2018arXiv180208336M; 2014SoPh..tmp..117M
  We discuss properties of type III bursts that change the sign of their
  drift rate from negative to positive and vice versa. Moreover, these
  bursts may change the sign of their drift rates more than once. These
  particular type III bursts were observed simultaneously by the
  radio telescopes UTR-2 (Ukrainian T-shaped Radio telescope, Kharkov,
  Ukraine), URAN-2 (Ukrainian Radio telescope of the Academy of Sciences,
  Poltava, Ukraine), and by the NDA (Nançay Decametric Array, Nancay,
  France) in the frequency range 8 - 41 MHz. The negative drift rates
  of these bursts are similar to those of previously reported decameter
  type III bursts and vary from −0.7 MHz s<SUP>−1</SUP> to −1.7
  MHz s<SUP>−1</SUP>, but their positive drift rates vary in a wider
  range from 0.44 MHz s<SUP>−1</SUP> to 6 MHz s<SUP>−1</SUP>. Unlike
  inverted U-bursts, the tracks of these type III bursts have C- or
  inverted C-shapes.

---------------------------------------------------------
Title: The Planeterrella: A planetary auroral simulator
Authors: Lilensten, J.; Lamy, L.; Briand, C.; Barthélémy, M.;
   Cecconi, B.
2014CAPJ...16...18L    Altcode:
  This article presents a plasma physics experiment which makes it
  possible to produce polar lights. The experiment, named Planeterrella,
  involves shooting electrons onto a magnetised sphere placed in a vacuum
  chamber. Inspired by Kristian Birkeland's Terrella, but with several
  different configurations and technical improvements, the experiment
  allows the user to simulate and visualise simple geophysical and
  astrophysical situations. Several Planeterrellas are now used across
  Europe and the USA. The design of the original experiment and the
  expertise of its first authors are shared freely with any public
  institute and are outlined in this article.

---------------------------------------------------------
Title: Sapce based low frequency interferometric radioastronomy:
    the path towards the imaging of the inner heliosphere.
Authors: Cecconi, B.; Zarka, P. M.; Girard, J. N.; Klein Wolt, M.;
   Boonstra, A. J.; Baan, W.; Briand, C.; Maksimovic, M.; Segret, B.
2014AGUFMSM31A4155C    Altcode:
  Low frequency radioastronomy observatories for the heliosphere have been
  using similar instrumentation for decades. The Cassini, STEREO, and
  the future Solar Orbiter mission are embarking goniopolarmetric radio
  receiver connected to 3 electric wire antennas. Such instrument provides
  the spectral matrix (or part of it) from which the wave parameters
  can be derived. They require a point source assumption (plane wave) to
  derive the direction of arrival of the wave, the polarization and the
  flux density. In case of a spatially extended source (disk shaped, with
  a given radial profile), the source centroid direction and the apparent
  source size can also be derived. This type of instrumentation cannot
  provide much more parameters, as there is a maximum of to 9 independent
  measurements for each time-frequency step (i.e. an instantaneous set
  of measurements). Radio maps can be produced a posteriori combining
  consecutive data at the cost of averaging out small scale temporal
  variations. Furthermore, these inversion do not allow solving for
  several sources, or for complex source geometry. We present a concept
  of radioastronomy instrumentation using a swarm of small satellites
  (possibly cubesats) with sensitive radio receivers measuring the wave
  front and phase of the radio waves on each spacecraft. This instrument
  will also provide 3-dimensional interferometric measurement from which
  real imaging capabilities will arise, as it is now occurring on ground
  at frequencies above 15 MHz, with the LOFAR interferometer in Europe,
  or the LWA in teh USA. The proposed concept will be very complementary
  to these instruments, as they will be orepating from a few kHz to a
  few 10 Mhz from space, and thus not affected by the ionospheric cutoff
  at 10 MHz. Such resolved imaging capabilities of the inner heliosphere
  would be a real step forward to better understand the radio emissions
  mechanisms and the energetic at the orgin of the radio sources,
  as well as the propagation processes. We will present the various
  existing projects and the roadmap to reach this goal.

---------------------------------------------------------
Title: The science case for an orbital mission to Uranus: Exploring
    the origins and evolution of ice giant planets
Authors: Arridge, C. S.; Achilleos, N.; Agarwal, J.; Agnor, C. B.;
   Ambrosi, R.; André, N.; Badman, S. V.; Baines, K.; Banfield, D.;
   Barthélémy, M.; Bisi, M. M.; Blum, J.; Bocanegra-Bahamon, T.;
   Bonfond, B.; Bracken, C.; Brandt, P.; Briand, C.; Briois, C.; Brooks,
   S.; Castillo-Rogez, J.; Cavalié, T.; Christophe, B.; Coates, A. J.;
   Collinson, G.; Cooper, J. F.; Costa-Sitja, M.; Courtin, R.; Daglis,
   I. A.; de Pater, I.; Desai, M.; Dirkx, D.; Dougherty, M. K.; Ebert,
   R. W.; Filacchione, G.; Fletcher, L. N.; Fortney, J.; Gerth, I.;
   Grassi, D.; Grodent, D.; Grün, E.; Gustin, J.; Hedman, M.; Helled,
   R.; Henri, P.; Hess, S.; Hillier, J. K.; Hofstadter, M. H.; Holme,
   R.; Horanyi, M.; Hospodarsky, G.; Hsu, S.; Irwin, P.; Jackman, C. M.;
   Karatekin, O.; Kempf, S.; Khalisi, E.; Konstantinidis, K.; Krüger,
   H.; Kurth, W. S.; Labrianidis, C.; Lainey, V.; Lamy, L. L.; Laneuville,
   M.; Lucchesi, D.; Luntzer, A.; MacArthur, J.; Maier, A.; Masters, A.;
   McKenna-Lawlor, S.; Melin, H.; Milillo, A.; Moragas-Klostermeyer,
   G.; Morschhauser, A.; Moses, J. I.; Mousis, O.; Nettelmann, N.;
   Neubauer, F. M.; Nordheim, T.; Noyelles, B.; Orton, G. S.; Owens, M.;
   Peron, R.; Plainaki, C.; Postberg, F.; Rambaux, N.; Retherford, K.;
   Reynaud, S.; Roussos, E.; Russell, C. T.; Rymer, A. M.; Sallantin, R.;
   Sánchez-Lavega, A.; Santolik, O.; Saur, J.; Sayanagi, K. M.; Schenk,
   P.; Schubert, J.; Sergis, N.; Sittler, E. C.; Smith, A.; Spahn, F.;
   Srama, R.; Stallard, T.; Sterken, V.; Sternovsky, Z.; Tiscareno,
   M.; Tobie, G.; Tosi, F.; Trieloff, M.; Turrini, D.; Turtle, E. P.;
   Vinatier, S.; Wilson, R.; Zarka, P.
2014P&SS..104..122A    Altcode:
  Giant planets helped to shape the conditions we see in the Solar System
  today and they account for more than 99% of the mass of the Sun's
  planetary system. They can be subdivided into the Ice Giants (Uranus
  and Neptune) and the Gas Giants (Jupiter and Saturn), which differ
  from each other in a number of fundamental ways. Uranus, in particular
  is the most challenging to our understanding of planetary formation
  and evolution, with its large obliquity, low self-luminosity, highly
  asymmetrical internal field, and puzzling internal structure. Uranus
  also has a rich planetary system consisting of a system of inner natural
  satellites and complex ring system, five major natural icy satellites,
  a system of irregular moons with varied dynamical histories, and a
  highly asymmetrical magnetosphere. Voyager 2 is the only spacecraft to
  have explored Uranus, with a flyby in 1986, and no mission is currently
  planned to this enigmatic system. However, a mission to the uranian
  system would open a new window on the origin and evolution of the
  Solar System and would provide crucial information on a wide variety
  of physicochemical processes in our Solar System. These have clear
  implications for understanding exoplanetary systems. In this paper
  we describe the science case for an orbital mission to Uranus with
  an atmospheric entry probe to sample the composition and atmospheric
  physics in Uranus' atmosphere. The characteristics of such an orbiter
  and a strawman scientific payload are described and we discuss the
  technical challenges for such a mission. This paper is based on a white
  paper submitted to the European Space Agency's call for science themes
  for its large-class mission programme in 2013.

---------------------------------------------------------
Title: Electrostatic fluctuations in the solar wind: An evidence of
    the link between Alfvénic and electrostatic scales
Authors: Vecchio, A.; Valentini, F.; Donato, S.; Carbone, V.; Briand,
   C.; Bougeret, J.; Veltri, P.
2014JGRA..119.7012V    Altcode:
  Electrostatic activity in the frequency range of few kHz represents
  a very common phenomenon observed in the solar wind since first
  observation from Helios spacecraft. In this paper we present a
  detailed comparison between electrostatic fluctuations detected by
  STEREO spacecraft and the results of kinetic numerical simulations. By
  using a novel approach, made by a combination of two different
  numerical models, we provide a convincing interpretation of the space
  observations in terms of the electrostatic branch of the so-called
  ion-bulk waves able to survive against Landau damping even at small
  values of T<SUB>e</SUB>/T<SUB>p</SUB>. The comparison between data and
  numerical simulations allows to characterize the chain of physical
  mechanisms, able to efficiently transfer energy from the Alfvénic
  scales down to scales of the order of the Debye length, through the
  excitation of the observed electrostatic fluctuations.

---------------------------------------------------------
Title: The Nonlinear and Nonlocal Link between Macroscopic Alfvénic
    and Microscopic Electrostatic Scales in the Solar Wind
Authors: Valentini, F.; Vecchio, A.; Donato, S.; Carbone, V.; Briand,
   C.; Bougeret, J.; Veltri, P.
2014ApJ...788L..16V    Altcode:
  The local heating of the solar-wind gas during its expansion represents
  one of the most intriguing problems in space plasma physics and
  is at present the subject of a relevant scientific effort. The
  possible mechanisms that could account for local heat production in
  the interplanetary medium are most likely related to the turbulent
  character of the solar-wind plasma. Nowadays, many observational and
  numerical analyses are devoted to the identification of fluctuation
  channels along which energy is carried from large to short wavelengths
  during the development of the turbulent cascade; these fluctuation
  channels establish the link between macroscopic and microscopic
  scales. In this Letter, by means of a quantitative comparison between
  in situ measurements in the solar wind from the STEREO spacecraft and
  numerical results from kinetic simulations, we identify an electrostatic
  channel of fluctuations that develops along the turbulent cascade in a
  direction parallel to the ambient magnetic field. This channel appears
  to be efficient in transferring the energy from large Alfvénic to
  short electrostatic acoustic-like scales up to a range of wavelengths
  where it can finally be turned into heat, even when the electron to
  proton temperature ratio is of the order of unity.

---------------------------------------------------------
Title: Inhibition of type III radio emissions due to the interaction
between two electron beams: Observations and simulations
Authors: Briand, C.; Henri, P.; Hoang, S.
2014JGRA..119.2365B    Altcode:
  We report the peculiar interaction of two type III bursts observed in
  the solar wind. As electron beams propagating on the same magnetic field
  lines cross, a spectacular depletion of the type III radio emission
  is observed. We combine observations from the WAVES experiment on
  board the STEREO mission together with kinetic plasma simulations to
  study the extinction of type III radio emission resulting from the
  interaction between two electron beams. The remote observations enable
  to follow the electron beams in the interplanetary medium and show
  that the level of radiated radio waves is recovered after the beam
  crossing. The in situ observations of beam-driven Langmuir waves give
  evidence for Langmuir decay. The density fluctuations are extracted
  from in situ observations. The velocity of the beams is independently
  evaluated from in situ observations of decaying Langmuir waves and
  remote radio observations. The kinetic simulations show that the level
  of beam-driven Langmuir waves is reduced as the two beams cross. We
  show that the slow beam induced a strong reduction of the quasilinear
  relaxation of the fast beam, limiting the amplitude of the generated
  Langmuir waves. Moreover, in the case of two electron beams, the lack
  of Langmuir wave coherence reduces the efficiency of the Langmuir
  parametric decay. We thus conclude that the observed depletion of the
  type III radio emission is independent of the radio emission mechanism,
  as long as it depends on the Langmuir amplitude and coherence.

---------------------------------------------------------
Title: Low frequency radioastronomy of the inner heliosphere: the
    way forward.
Authors: Cecconi, Baptiste; Zarka, Philippe; Bergman, Jan; Falcke,
   Heino; Boonstra, Albert-Jan; Briand, Carine; Girard, Julien; Klein
   Wolt, Marc; Baan, Willem; Segret, Boris; Maksimovic, Milan
2014cosp...40E.468C    Altcode:
  Low frequency radioastronomy observatories for the heliosphere have
  been using similar instrumentation for decades. The Cassini, STEREO,
  and the future Solar Orbiter mission are embarking goniopolarmetric
  radio receiver connected to 3 electric antennas. Such instrument
  provides the spectral matrix (or part of it) from which the wave
  parameters can be derived. With a point source assumption (plane wave),
  we derive the direction of arrival of the wave, the polarization and
  the flux density. In case of a spatially extended source (disk shaped,
  with a given radial profile), the source centroid direction and the
  apparent source size is provided. This type of instrumentation cannot
  provide much more parameters, as there is a maximum of to 9 independent
  measurements for each time-frequency step. We propose a concept of
  radioastronomy instrumentation using a swarm of small satellites
  (possibly cubesats) with sensitive radio receivers measuring the wave
  front and phase of the radio waves on each spacecraft. This instrument
  will also provide 3-dimensional interferometric measurement. Such
  resolved imaging capabilities of the inner heliosphere would be a
  real step forward to better understand the radio emissions mechanisms
  and the propagation processes. We will present the various existing
  projects and the roadmap to reach the goal.

---------------------------------------------------------
Title: Decameter type III bursts with positive and negative frequency
    drift rates
Authors: Melnik, V. N.; Brazhenko, A. I.; Konovalenko, A. A.; Briand,
   C.; Dorovskyy, V. V.; Zarka, P.; Frantzusenko, A. V.; Rucker, H. O.;
   Rutkevych, B. P.; Panchenko, M.; Zaqarashvili, T.; Shergelashvili, B.
2013EPSC....8..738M    Altcode:
  We report about observations of decameter type III bursts
  whose frequency drift rates vary their signs from negative to
  positive. Moreover drift rates of some bursts vary the sign some
  times. Positive drift rates for some bursts are changed from 0.44
  MHz/s to 12 MHz/s. At the same time the negative drift rates of these
  bursts are standard values for decameter type III bursts. A possible
  interpretation of such phenomenon on the base of plasma mechanism of
  type III burst generation is discussed. The sense of this interpretation
  is that group velocity of type III electromagnetic waves generated
  by fast electrons at some conditions can be smaller than velocity of
  these electrons.

---------------------------------------------------------
Title: Synchronized observations by using the STEREO and the largest
    ground-based decametre radio telescope
Authors: Konovalenko, A. A.; Stanislavsky, A. A.; Rucker, H. O.;
   Lecacheux, A.; Mann, G.; Bougeret, J. -L.; Kaiser, M. L.; Briand, C.;
   Zarka, P.; Abranin, E. P.; Dorovsky, V. V.; Koval, A. A.; Mel'nik,
   V. N.; Mukha, D. V.; Panchenko, M.
2013ExA....36..137K    Altcode: 2013ExA...tmp....5K; 2013ExA...tmp....8K
  We consider the approach to simultaneous (synchronous) solar
  observations of radio emission by using the STEREO-WAVES instruments
  (frequency range 0.125-16 MHz) and the largest ground-based
  low-frequency radio telescope. We illustrate it by the UTR-2 radio
  telescope implementation (10-30 MHz). The antenna system of the
  radio telescope is a T-shape-like array of broadband dipoles and is
  located near the village Grakovo in the Kharkiv region (Ukraine). The
  third observation point on the ground in addition to two space-based
  ones improves the space-mission performance capabilities for the
  determination of radio-emission source directivity. The observational
  results from the high sensitivity antenna UTR-2 are particularly useful
  for analysis of STEREO data in the condition of weak event appearances
  during solar activity minima. In order to improve the accuracy of flux
  density measurements, we also provide simultaneous observations with
  a large part of the UTR-2 radio telescope array and its single dipole
  close to the STEREO-WAVES antennas in sensitivity. This concept has
  been studied by comparing the STEREO data with ground-based records
  from 2007-2011 and shown to be effective. The capabilities will be
  useful in the implementation of new instruments (LOFAR, LWA, MWA,
  etc.) and during the future Solar Orbiter mission.

---------------------------------------------------------
Title: Decametric type III bursts with variable sign of frequency
    drift rate
Authors: Melnik, V. M.; Brazhenko, A. I.; Konovalenko, O. O.; Briand,
   C.; Rutkevych, B. P.; Zarka, P.; Zaqarashvili, T.; Dorovskyy, V. V.;
   Frantsuzenko, A. V.; Stanislavsky, A. A.
2013RRPRA..18..117M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Observational properties of decameter type IV bursts
Authors: Melnik, Valentin; Brazhenko, Anatoly; Rucker, Helmut;
   Konovalenko, Alexander; Briand, Carine; Dorovskyy, Vladimir; Zarka,
   Philippe; Frantzusenko, Anatoly; Panchenko, Michael; Poedts, Stefan;
   Zaqarashvili, Teimuraz; Shergelashvili, Bidzina
2013EGUGA..1510206M    Altcode:
  Oscillations of decameter type IV bursts were registered during
  observations of solar radio emission by UTR-2, URAN-2 and NDA in
  2011-2012. Large majority of these bursts were accompanied by coronal
  mass ejections (CMEs), which were observed by SOHO and STEREO in the
  visible light. Only in some cases decameter type IV bursts were not
  associated with CMEs. The largest periods of oscillations P were some
  tens of minutes. There were some modes of long periods of oscillations
  simultaneously. Periods of oscillations in flux and in polarization
  profiles were close. Detailed properties of oscillations at different
  frequencies were analyzed on the example of two type IV bursts. One of
  them was observed on April 7, 2011 when a CME happened. Another one
  (August 1, 2011) was registered without any CME. The 7 April type IV
  burst had two periods in the frames 75-85 and 35-85 minutes. Interesting
  feature of these oscillations is decreasing periods with time. The
  observed decreasing rates dP/dt equaled 0.03-0.07. Concerning type
  IV burst observed on August 1, 2011 the period of its oscillations
  increases from 17 min. at 30 MHz to 44 min. at 10 MHz. Connection of
  type IV burst oscillations with oscillations of magnetic arches and
  CMEs at corresponding altitudes are discussed. The work is fulfilled
  in the frame of FP7 project "SOLSPANET".

---------------------------------------------------------
Title: Planetary and exoplanetary low frequency radio observations
    from the Moon
Authors: Zarka, P.; Bougeret, J. -L.; Briand, C.; Cecconi, B.;
   Falcke, H.; Girard, J.; Grießmeier, J. -M.; Hess, S.; Klein-Wolt,
   M.; Konovalenko, A.; Lamy, L.; Mimoun, D.; Aminaei, A.
2012P&SS...74..156Z    Altcode:
  We analyze the planetary and exoplanetary science that can be carried
  out with precursor as well as future low frequency radio instruments on
  the Moon, assessing the limiting noise sources, comparing them to the
  average and peak spectra of all planetary radio components as they will
  be seen from the Lunar surface or orbit. We identify which objectives
  will be accessible with each class of instrument, and discuss the
  interest of these observations compared to observations by planetary
  probes and to ground-based observations by large low-frequency radio
  arrays. The interest of goniopolarimetry is emphasized for pathfinder
  missions.

---------------------------------------------------------
Title: Simultaneous observations of solar sporadic radio emission
    by the radio telescopes UTR-2, URAN-2 and NDA within the frequency
    range 8-42 MHz
Authors: Melnik, V.; Konovalenko, A.; Brazhenko, A.; Briand, C.;
   Dorovskyy, V.; Zarka, P.; Denis, L.; Bulatzen, V.; Frantzusenko, A.;
   Rucker, H.; Stanislavskyy, A.
2012epsc.conf..540M    Altcode: 2012espc.conf..540M
  From 25 June till 12 August 2011 sporadic solar radio emission was
  observed simultaneously by three separate radio telescopes: UTR-2
  (Kharkov, Ukraine), URAN-2 (Poltava, Ukraine) and NDA (Nancay,
  France). During these observations some interesting phenomena were
  observed. Some of them are discussed in this paper.

---------------------------------------------------------
Title: Radio Astronomy from the Moon
Authors: Cecconi, Baptiste; Bougeret, J. -L.; Zarka, Philippe; Thide,
   Bo; Bergman, Jan; Falcke, Heino; Berthelier, Jean-Jacques; Gurvits,
   Leonid; Griessmeier, Jean-Mathias; Briand, Carine; Zaslavsky, Arnaud;
   Roettgering, Huub; Aminaei, A.; Klein-Wolt, Marc; Konovalenko,
   Alexander; Woan, Graham; Garrett, Mike; Gizani, Nectaria
2012cosp...39..282C    Altcode: 2012cosp.meet..282C
  No abstract at ADS

---------------------------------------------------------
Title: Commission 49: Interplanetary Plasma and Heliosphere
Authors: Gopalswamy, Natchimuthuk; Mann, Ingrid; Bougeret, Jean-Louise;
   Briand, Carine; Lallement, Rosine; Lario, David; Manoharan, P. K.;
   Shibata, Kazunari; Webb, David F.
2012IAUTA..28...95G    Altcode:
  Commission 49 (Interplanetary Plasma and Heliosphere) is part of
  IAU Division II (Sun and Heliosphere). The research topics include
  large-scale solar disturbances such as coronal mass ejections (CMEs),
  shocks, and corotating interaction regions (CIRs) propagating into
  the heliosphere. The disturbances propagate through the solar wind,
  which essentially defines the heliosphere. The solar disturbances
  provide large-scale laboratory to study plasma processes over various
  time and spatial scales, the highest spatial scale being the size
  of the heliosphere itself (~100 AU). These solar disturbances are
  related to solar activity in the form of active regions and coronal
  holes. Solar eruptions are accompanied by particle acceleration and
  the particles can be hazardous to life on earth in various ways from
  modifying the ionosphere to damaging space technology and increasing
  lifetime radiation dosage to astronauts and airplane crew. Particle
  acceleration in solar eruptions poses fundamental physics questions
  because the underlying mechanisms are not fully understood. One of
  important processes is the particle acceleration by shocks, which occurs
  throughout the heliosphere. The heliosphere has both neutral and ionized
  material, with interesting interaction between the two components.

---------------------------------------------------------
Title: Alfvén: magnetosphere—ionosphere connection explorers
Authors: Berthomier, M.; Fazakerley, A. N.; Forsyth, C.; Pottelette,
   R.; Alexandrova, O.; Anastasiadis, A.; Aruliah, A.; Blelly, P. -L.;
   Briand, C.; Bruno, R.; Canu, P.; Cecconi, B.; Chust, T.; Daglis,
   I.; Davies, J.; Dunlop, M.; Fontaine, D.; Génot, V.; Gustavsson,
   B.; Haerendel, G.; Hamrin, M.; Hapgood, M.; Hess, S.; Kataria, D.;
   Kauristie, K.; Kemble, S.; Khotyaintsev, Y.; Koskinen, H.; Lamy, L.;
   Lanchester, B.; Louarn, P.; Lucek, E.; Lundin, R.; Maksimovic, M.;
   Manninen, J.; Marchaudon, A.; Marghitu, O.; Marklund, G.; Milan, S.;
   Moen, J.; Mottez, F.; Nilsson, H.; Ostgaard, N.; Owen, C. J.; Parrot,
   M.; Pedersen, A.; Perry, C.; Pinçon, J. -L.; Pitout, F.; Pulkkinen,
   T.; Rae, I. J.; Rezeau, L.; Roux, A.; Sandahl, I.; Sandberg, I.;
   Turunen, E.; Vogt, J.; Walsh, A.; Watt, C. E. J.; Wild, J. A.;
   Yamauchi, M.; Zarka, P.; Zouganelis, I.
2012ExA....33..445B    Altcode: 2011ExA...tmp...35V; 2011ExA...tmp..160B; 2011ExA...tmp..136B
  The aurorae are dynamic, luminous displays that grace the night skies
  of Earth's high latitude regions. The solar wind emanating from
  the Sun is their ultimate energy source, but the chain of plasma
  physical processes leading to auroral displays is complex. The
  special conditions at the interface between the solar wind-driven
  magnetosphere and the ionospheric environment at the top of Earth's
  atmosphere play a central role. In this Auroral Acceleration Region
  (AAR) persistent electric fields directed along the magnetic field
  accelerate magnetospheric electrons to the high energies needed
  to excite luminosity when they hit the atmosphere. The "ideal
  magnetohydrodynamics" description of space plasmas which is useful in
  much of the magnetosphere cannot be used to understand the AAR. The
  AAR has been studied by a small number of single spacecraft missions
  which revealed an environment rich in wave-particle interactions,
  plasma turbulence, and nonlinear acceleration processes, acting on a
  variety of spatio-temporal scales. The pioneering 4-spacecraft Cluster
  magnetospheric research mission is now fortuitously visiting the AAR,
  but its particle instruments are too slow to allow resolve many of
  the key plasma physics phenomena. The Alfvén concept is designed
  specifically to take the next step in studying the aurora, by making
  the crucial high-time resolution, multi-scale measurements in the
  AAR, needed to address the key science questions of auroral plasma
  physics. The new knowledge that the mission will produce will find
  application in studies of the Sun, the processes that accelerate the
  solar wind and that produce aurora on other planets.

---------------------------------------------------------
Title: Simultaneous observations of solar sporadic radio emission
    by the radio telescopes UTR-2, URAN-2 and NDA within the frequency
    range 8-41MHz
Authors: Melnik, V. N.; Konovalenko, A. A.; Rucker, H. O.; Brazhenko,
   A. I.; Briand, C.; Dorovskyy, V. V.; Zarka, P.; Denis, L.; Bulatzen,
   V. G.; Frantzusenko, A. V.; Stanislavskyy, A. A.
2012EGUGA..14.9905M    Altcode:
  From 25 June till 12 August 2011 sporadic solar radio emission
  was observed simultaneously by three separate radio telescopes:
  UTR-2 (Kharkov, Ukraine), URAN-2 (Poltava, Ukraine) and NDA (Nancay,
  France). During these observations several type II bursts with double
  and triple harmonics were registered, as well as type II bursts with
  complex herringbone structure. The events of particular interest were
  type II bursts registered on 9 and 11 August 2011. These bursts had
  opposite sign of circular polarization at different parts of their
  dynamic spectra. In our opinion we registered the emissions, which came
  from the different parts of the shock propagating through the solar
  corona. We have observed also groups of type III bursts merged into
  one burst, type III bursts with triple harmonics and type III bursts
  with "split" polarization. In addition some unusual solar bursts were
  registered: storms of strange narrow-band (up to 500kHz) bursts with
  high polarization degree (about 80%), decameter spikes of extremely
  short durations (200-300ms), "tadpole-like" bursts with durations of
  1-2s and polarization degree up to 60%.

---------------------------------------------------------
Title: New results on interplanetary type III radio storms from
    multi-spacecraft combined STEREO-A/B and WIND observations
Authors: Briand, C.; Belyaev, V.; Bougeret, J. H.; Krupar, V.; Bonnin,
   X.; Cecconi, B.; Hoang, S.
2011AGUFMSH13A1928B    Altcode:
  Interplanetary (IP) type III radio storms were intensively studied in
  the 80's (Bougeret et al. 1984a,b) using observations from a single
  radio instrument on the ISEE-3 spacecraft located at the Lagrange
  point L1. These studies showed that the IP storms trace long lasting
  (several days) streams of energetic electrons occurring in corotating
  regions of enhanced density, appearing to be the extension of active
  regions through the IP space at levels 0.05 - 0.8 AU. These studies
  were consistent with the hypothesis of steady conditions in the storm
  region over periods of several days. We propose the hypothesis that the
  overall duration of an IP storm observed from one vantage point directly
  results from the beaming of the radio radiation when the steady radio
  source corotates with the Sun. The goal of the present study is to
  track the evolution of the IP radio storms observed from three vantage
  points separated by about 90 degrees and spanning 180 degrees (STEREO-B,
  WIND, STEREO-A), over a time period of the order of a solar rotation,
  in order to test the limits of the above hypothesis and to track the
  evolution of the IP radio storms over periods close to a solar rotation.

---------------------------------------------------------
Title: Observations of Langmuir ponderomotive effects using the
    Solar TErrestrial RElations Observatory spacecraft as a density probe
Authors: Henri, P.; Meyer-Vernet, N.; Briand, C.; Donato, S.
2011PhPl...18h2308H    Altcode:
  Langmuir ponderomotive effects are nonlinear effects that enable
  to couple the electron and ion dynamics in space plasmas. The main
  difficulty to provide observational evidence of such nonlinear coupling
  is to simultaneously observe both fluctuations of plasma density
  and electric field. We have thus developed a new method to measure
  and to calibrate in situ small scale density fluctuations. Density
  fluctuations in the solar wind are measured using the observed
  quasistatic fluctuations of the STEREO spacecraft floating
  potential in the frequency range, where the spacecraft floating
  potential is in quasistatic equilibrium between photoionization
  and electron attachment, whereas the potential of the antenna,
  of much longer equilibrium time scale, is blind to the density
  fluctuations. Density fluctuations and Langmuir waves are thus
  directly and simultaneously measured using a dataset of more than
  three years of STEREO/WAVES measurements. We present here the first
  observational evidence for ponderomotive effects in the solar wind that
  nonlinearly couple density fluctuations to high energy Langmuir waves
  ((ɛ<SUB>0</SUB>E<SUP>2</SUP>)/(nk<SUB>B</SUB>T)&gt;10<SUP>-4</SUP>).

---------------------------------------------------------
Title: Waves at the electron plasma frequency associated with solar
wind magnetic holes: STEREO/Cluster observations
Authors: Briand, C.; Soucek, J.; Henri, P.; Mangeney, A.
2010JGRA..11512113B    Altcode:
  Magnetic depressions are common structures of the interplanetary
  medium. These magnetic holes can be just isolated dips of the amplitude
  of the field or they can be associated with discontinuities in the
  field orientation (tangential or rotational). Electrostatic waves
  at the plasma frequency (Langmuir waves) are often observed in these
  magnetic structures. The aim of the present paper is to provide the
  main characteristics of these waves and to propose a mechanism to
  explain their formation. The study is based on a statistical analysis
  of observations performed by STEREO (between March 2007 and August
  2009) and Cluster (between 2002 and 2005) when each mission was in
  the free solar wind. Complementary information is provided by the
  two missions through the different instrumental configurations. We
  first provide new characteristics of the waves (polarization, energy,
  spectrum, occurrence). We then show that the occurrence of Langmuir
  waves activity inside a hole is closely linked to the presence of a
  significant electron strahl outside the hole. Finally, we propose a
  scenario for the generation of the Langmuir waves inside the holes.

---------------------------------------------------------
Title: Temporal Evolution of the Solar-Wind Electron Core Density
    at Solar Minimum by Correlating SWEA Measurements from STEREO A and B
Authors: Opitz, A.; Sauvaud, J. -A.; Fedorov, A.; Wurz, P.; Luhmann,
   J. G.; Lavraud, B.; Russell, C. T.; Kellogg, P.; Briand, C.; Henri,
   P.; Malaspina, D. M.; Louarn, P.; Curtis, D. W.; Penou, E.; Karrer,
   R.; Galvin, A. B.; Larson, D. E.; Dandouras, I.; Schroeder, P.
2010SoPh..266..369O    Altcode: 2010SoPh..tmp..152O
  The twin STEREO spacecraft provide a unique tool to study the
  temporal evolution of the solar-wind properties in the ecliptic since
  their longitudinal separation increases with time. We derive the
  characteristic temporal variations at ∼ 1 AU between two different
  plasma parcels ejected from the same solar source by excluding
  the spatial variations from our datasets. As part of the onboard
  IMPACT instrument suite, the SWEA electron experiment provides the
  solar-wind electron core density at two different heliospheric vantage
  points. We analyze these density datasets between March and August
  2007 and find typical solar minimum conditions. After adjusting for
  the theoretical time lag between the two spacecraft, we compare the
  two density datasets. We find that their correlation decreases as
  the time difference increases between two ejections. The correlation
  coefficient is about 0.80 for a time lag of a half day and 0.65 for two
  days. These correlation coefficients from the electron core density are
  somewhat lower than the ones from the proton bulk velocity obtained in
  an earlier study, though they are still high enough to consider the
  solar wind as persistent after two days. These quantitative results
  reflect the variability of the solar-wind properties in space and time,
  and they might serve as input for solar-wind models.

---------------------------------------------------------
Title: Vlasov-Poisson simulations of electrostatic parametric
    instability for localized Langmuir wave packets in the solar wind
Authors: Henri, P.; Califano, F.; Briand, C.; Mangeney, A.
2010JGRA..115.6106H    Altcode: 2013arXiv1301.5155H; 2010JGRA..11506106H
  Recent observation of large-amplitude Langmuir waveforms during a type
  III event in the solar wind has been interpreted as the signature of
  the electrostatic decay of beam-driven Langmuir waves. This mechanism
  is thought to be a first step to explain the generation of type III
  radio emission. The threshold for this parametric instability in
  the typical solar wind condition has been investigated through 1D-1V
  Vlasov-Poisson simulations. We show that the amplitude of the observed
  Langmuir beatlike waveforms is of the order of the effective threshold
  computed from the simulations. The expected levels of associated ion
  acoustic density fluctuations have also been computed for comparison
  with observations.

---------------------------------------------------------
Title: Waves at the plasma frequency inside magnetic holes: STEREO
    and Cluster observations
Authors: Briand, C.; Soucek, J.; Mangeney, A.; Bale, S. D.; Goetz, K.
2010AIPC.1216..271B    Altcode:
  Magnetic isolated large amplitude depressions in the interplanetary
  magnetic field are commonly observed in the solar wind. Some of these
  magnetic structures are accompanied by bursts of electrostatic waves
  close to electron plasma frequency. Combining STEREO/WAVES and IMPACT
  data we are able to accurately localize the waves emission. We show
  that they also appear inside kinetic holes, themselves situated inside
  larger holes. We provide, for the first time, the detailed waveform
  of the waves that reveal their very bursty nature. These results are
  complemented by CLUSTER data, which allow to resolve the electron
  distribution and obtain a better description of spatio-temporal
  variations in Langmuir wave activity. Such observations are confronted
  to different emission mechanisms.

---------------------------------------------------------
Title: Vlasov simulations of Langmuir Electrostatic Decay and
    consequences for Type III observations
Authors: Henri, P.; Califano, F.; Briand, C.; Mangeney, A.
2010AIPC.1216..288H    Altcode: 2013arXiv1301.3066H
  The electrostatic decay enables energy transfer from a finite amplitude
  Langmuir to a backscattered daughter Langmuir wave and ion acoustic
  density fluctuations. This mechanism is thought to be a first step
  for the generation of type III solar radio emissions at twice the
  plasma frequency. The electrostatic decay is here investigated through
  Vlasov-Poisson simulations by considering Langmuir localized wave
  packets in the case T<SUB>e</SUB> = T<SUB>p</SUB>. Simulation results
  are found to be in good agreement with recently reported observations
  from the STEREO mission of the electrostatic decay of beam-driven
  Langmuir waves during a type III burst.

---------------------------------------------------------
Title: Vlasov simulations of strong Langmuir turbulence
Authors: Henri, P.; Mangeney, A.; Califano, F.; Briand, C.
2009AGUFMSH53A1304H    Altcode:
  Strong Langmuir turbulence describes the evolution of intense and
  coherent electric fields that couple to the ion background, in an
  unmagnetized plasma. It is of common interest in ionospheric physics
  and laboratory plasmas and may be of great relevance in space physics
  where electric fields are high (shocks, early stage of type III). Strong
  Langmuir turbulence has been intensively studied for more than three
  decades by using the Zakharov equations that couple the evolution
  of the enveloppe of the high frequency electric field and the plasma
  density. These have successfully described self-focusing and collapse
  of intense Langmuir fluctuations, as well as the formation of density
  cavitons. However, the fluid like approximation underlying the Zakharov
  equations breaks out when the electric field gets close to the electron
  thermal energy, what commonly happens at the end of the Langmuir
  collapse. In this case, a kinetic approach has to be considered for
  the study of the long time evolution of strong turbulence, including in
  particular the kinetic effects on heated particules and the ion fluid
  nonlinearities. We perform 1D and 2D Vlasov-Poisson simulations with
  periodic boundary conditions to investigate strong Langmuir turbulence
  in an unmagnetized plasma. We observe self-focusing of Langmuir waves
  and formation of cavitons. We also analyse the difference between
  1D and 2D strong Langmuir turbulence. A special emphasis is given
  to electronic kinetic effects and proton dynamics to illustrate the
  discrepancies with the Zakharov model.

---------------------------------------------------------
Title: Microscale properties of Langmuir waves observed by STEREO
    and CLUSTER inside solar wind magnetic holes
Authors: Soucek, J.; Briand, C.; Mangeney, A.; Bale, S.; Goetz, K.;
   Pickett, J. S.
2009AGUFMSH13B1527S    Altcode:
  Magnetic holes, solitary large amplitude depressions in the
  interplanetary magnetic field, are commonly observed in the solar
  wind. Some of these magnetic structures are accompanied by bursts of
  electrostatic waves close to the electron plasma frequency localized
  inside the magnetic holes. In this study we used data from the S/WAVES
  instrument on board of the STEREO spacecraft to demonstrate the first
  waveform observations of these waves and to analyze their polarization
  and modulation. The results are complemented by multi-spacecraft
  Cluster observations of these phenomena, which allow to resolve the
  electron distribution and obtain a better description of spatio-temporal
  variations in Langmuir wave activity. Comparing to previous studies of
  this phenomenon, the high resolution of the data allows to study the
  structure of these waves at electron scales. We present a detailed
  analysis of several observed magnetic holes and discuss possible
  mechanisms responsible for excitation of these waves.

---------------------------------------------------------
Title: Direct evidence for three-wave coupling in the solar wind
    during a type~III emission from STEREO/SWAVES data.
Authors: Henri, P.; Briand, C.; Califano, F.; Mangeney, A.
2009epsc.conf...50H    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Preface to the Proceedings of the European General Assembly
    on IHY 2007
Authors: Briand, C.; Antonucci, E.; Haubold, H. J.
2009EM&P..104....1B    Altcode: 2009EM&P..tmp....3B
  No abstract at ADS

---------------------------------------------------------
Title: Evidence for wave coupling in type III emissions
Authors: Henri, P.; Briand, C.; Mangeney, A.; Bale, S. D.; Califano,
   F.; Goetz, K.; Kaiser, M.
2009JGRA..114.3103H    Altcode: 2009JGRA..11403103H
  Using new capabilities of waveform analyses provided by the S/WAVES
  instruments onboard the two STEREO spacecraft, we present for the first
  time a complete set of direct evidence for three-wave coupling occurring
  during a type III emission and involving two Langmuir waves and an
  ion acoustic wave. Information on the Doppler-shifted frequencies and
  especially the phases of the waves are used in order to check first
  the conservation of momentum and energy, through Fourier analyses,
  and second the phase locking between the waves, through bicoherence
  analyses. Wavelet analyses allow us to resolve for the first time the
  coupling regions, in which spatial length is estimated to be 18 +/- 5
  km. The wave packets travel at comparable speed, and the characteristic
  available interaction time is about 1 s. Interpretations of the phase
  coupling and evaluation of the growth rate of the waves tend to favor
  the parametric decay, at least in the observational events considered
  in this work.

---------------------------------------------------------
Title: Bipolar electrostatic structures observed in the solar wind :
    comparative study between WIND/WAVES and STEREO/WAVES
Authors: Briand, C.; Califano, F.; Mangeney, A.; Henri, P.; Bale,
   S. D.; Goetz, K.; Kaiser, M.
2008AGUFMSH43A1636B    Altcode:
  Bipolar electrostatic structures are commonly observed in planetary
  magnetospheric environments but also in the solar wind. They may play a
  crucial role in transporting energy over long distances. In an earlier
  work, Mangeney et al. (1998) and Lacombe et al. (2002) have shown,
  in the solar wind, the presence of a small potential drop across the
  structures. This work was based on in-situ measurements obtained by the
  WAVES radio instrument of the WIND mission. The STEREO/WAVES instruments
  provide us with new in-situ measurements of bipolar electrostatic
  structures. We will present a comparative study of the observations
  from the three instruments. A model based on Vlasov-Ampere simulations
  will be proposed to explain the differences between the measurements
  of the two instruments.

---------------------------------------------------------
Title: Electrostatic coupling: STEREO/WAVES observations in the
    solar wind and Vlasov simulations.
Authors: Henri, P.; Califano, F.; Briand, C.; Mangeney, A.; Bale,
   S. D.; Goetz, K.; Kaiser, M.
2008AGUFMSH21A1566H    Altcode:
  The TDS (Time Domain Sampler) part of the WAVES experiment on board
  STEREO enables the study of high resolution in-situ electric field
  waveforms in the solar wind. From different TDS datasets, we show
  evidence for three-wave coupling, involving Langmuir waves and ion
  acoustic waves. The three waves show the expected resonant relations
  for doppler-shifted frequencies and bicoherence studies show a good
  phase locking between the three waves. Vlasov-Ampere simulations have
  also been performed to study the electrostatic coupling mechanism in
  1D and compared to the STEREO/WAVES observations.

---------------------------------------------------------
Title: Faint solar radio structures from decametric observations
Authors: Briand, C.; Zaslavsky, A.; Maksimovic, M.; Zarka, P.;
   Lecacheux, A.; Rucker, H. O.; Konovalenko, A. A.; Abranin, E. P.;
   Dorovsky, V. V.; Stanislavsky, A. A.; Melnik, V. N.
2008A&A...490..339B    Altcode:
  Aims: Decameter radio observations of the solar corona reveal the
  presence of numerous faint frequency drifting emissions, similar to
  “solar S bursts” which are reported in the literature. We present
  a statistical analysis of the characteristics of these emissions and
  propose a mechanism to excite the Langmuir waves thought to be at
  the origin of these emissions. <BR />Methods: The observations were
  performed between 1998 and 2002 with the Digital Spectro Polarimeter
  (DSP) receivers operated at the UTR-2 and Nançay decameter radio
  telescopes in the frequency range 15-30 MHz. Our theoretical
  explanation is based on Vlasov-Ampère simulations. <BR />Results:
  Based on the frequency drift rate, three populations of structures can
  be identified. The largest population presents an average negative
  frequency drift of -0.9 MHz s<SUP>-1</SUP> and a lifetime up to 11
  s (median value of 2.72 s). A second population shows a very small
  frequency drift of -0.1 MHz s<SUP>-1</SUP> and a short lifetime of
  about 1 s. The third population presents an average positive frequency
  drift of +0.95 MHz s<SUP>-1</SUP> and a lifetime of up to 3 s. Also,
  the frequency drift as a function of frequency is consistent with the
  former results, which present results in higher frequency range. No
  specific relationship was found between the occurrence of these
  emissions and the solar cycle or presence of flares. Assuming that these
  emissions are produced by “electron clouds” propagating the solar
  corona, we deduce electron velocities of about 3-5 times the electron
  thermal velocity. As previously shown, a localized, time-dependent
  modulation of the electron distribution function (heating) leads to
  low velocity electron clouds (consistent with observations), which,
  in turn, can generate Langmuir waves and electromagnetic signals by
  nonlinear processes.

---------------------------------------------------------
Title: Eigenmode Structure in Solar-Wind Langmuir Waves
Authors: Ergun, R. E.; Malaspina, D. M.; Cairns, Iver H.; Goldman,
   M. V.; Newman, D. L.; Robinson, P. A.; Eriksson, S.; Bougeret, J. L.;
   Briand, C.; Bale, S. D.; Cattell, C. A.; Kellogg, P. J.; Kaiser, M. L.
2008PhRvL.101e1101E    Altcode:
  We show that observed spatial- and frequency-domain signatures of
  intense solar-wind Langmuir waves can be described as eigenmodes
  trapped in a parabolic density well. Measured solar-wind electric
  field spectra and waveforms are compared with 1D linear solutions and,
  in many cases, can be represented by 1 3 low-order eigenstates. To
  our knowledge, this report is the first observational confirmation
  of Langmuir eigenmodes in space. These results suggest that linear
  eigenmodes may be the starting point of the nonlinear evolution,
  critical for producing solar type II and type III radio bursts.

---------------------------------------------------------
Title: Coherent electric structures: Vlasov-Ampère simulations and
    observational consequences
Authors: Briand, C.; Mangeney, A.; Califano, F.
2008JGRA..113.7219B    Altcode:
  Coherent electrostatic structures, like bipolar electric pulses
  (also called electrostatic solitary waves) or Langmuir waves,
  are frequently observed in many astrophysical plasma of the Earth
  environment (plasma sheet boundary layer, Earth bow shock, auroral
  regions etc.) or in the solar wind. They are thought to play a
  crucial role in the energy transfer from small to large scale and
  to reconnection processes. Numerous simulations have studied their
  emergence and evolution. Most of them are based on the development
  of two stream instabilities. Another mechanism is investigated here:
  the plasma is excited by a localized, time dependent modulation of
  the electron distribution function (heating of the electrons). The
  investigation is performed through a 1D Vlasov-Ampere code, in open
  boundary conditions. We explore the response of the plasma to several
  heating conditions, mass ratio and density gradient. We find that the
  heating leads to the development of an extended turbulent domain. We
  also show that the history of the electrostatic solitary waves (ESW)
  strongly depends on the presence of a density gradient and the mass
  ratio between species. If the positive charged neutralizing background
  is composed of heavy ions, the ESW turns back to the entrance domain
  when a density gradient is included. From the observational point of
  view, this means that the electric field shows a polarity reversal
  with time.

---------------------------------------------------------
Title: S/WAVES: The Radio and Plasma Wave Investigation on the
    STEREO Mission
Authors: Bougeret, J. L.; Goetz, K.; Kaiser, M. L.; Bale,
   S. D.; Kellogg, P. J.; Maksimovic, M.; Monge, N.; Monson, S. J.;
   Astier, P. L.; Davy, S.; Dekkali, M.; Hinze, J. J.; Manning, R. E.;
   Aguilar-Rodriguez, E.; Bonnin, X.; Briand, C.; Cairns, I. H.; Cattell,
   C. A.; Cecconi, B.; Eastwood, J.; Ergun, R. E.; Fainberg, J.; Hoang,
   S.; Huttunen, K. E. J.; Krucker, S.; Lecacheux, A.; MacDowall, R. J.;
   Macher, W.; Mangeney, A.; Meetre, C. A.; Moussas, X.; Nguyen, Q. N.;
   Oswald, T. H.; Pulupa, M.; Reiner, M. J.; Robinson, P. A.; Rucker,
   H.; Salem, C.; Santolik, O.; Silvis, J. M.; Ullrich, R.; Zarka, P.;
   Zouganelis, I.
2008SSRv..136..487B    Altcode: 2008SSRv..tmp....9B
  This paper introduces and describes the radio and plasma wave
  investigation on the STEREO Mission: STEREO/WAVES or S/WAVES. The
  S/WAVES instrument includes a suite of state-of-the-art experiments
  that provide comprehensive measurements of the three components of the
  fluctuating electric field from a fraction of a hertz up to 16 MHz, plus
  a single frequency channel near 30 MHz. The instrument has a direction
  finding or goniopolarimetry capability to perform 3D localization
  and tracking of radio emissions associated with streams of energetic
  electrons and shock waves associated with Coronal Mass Ejections
  (CMEs). The scientific objectives include: (i) remote observation and
  measurement of radio waves excited by energetic particles throughout
  the 3D heliosphere that are associated with the CMEs and with solar
  flare phenomena, and (ii) in-situ measurement of the properties of
  CMEs and interplanetary shocks, such as their electron density and
  temperature and the associated plasma waves near 1 Astronomical Unit
  (AU). Two companion papers provide details on specific aspects of the
  S/WAVES instrument, namely the electric antenna system (Bale et al.,
  Space Sci. Rev., 2007) and the direction finding technique (Cecconi
  et al., Space Sci. Rev., 2007).

---------------------------------------------------------
Title: International Heliophysical Year: European Activities
Authors: Briand, C.
2007SunGe...2....5B    Altcode:
  The First European General Assembly of the "International Heliophysical
  Year" (IHY) took place at the headquarters of the Centre Nationial
  de la Recherche Scientifique (CNRS) in Paris, France, 10-13 January
  2006. There were 113 participants representing 27 nations. The
  science concerned with the International Heliophysical Year programme
  was first illustrated. Then, the status of current instruments as
  well as practical information on the campaign management policy was
  given. Twenty European National Coordinators described the progress
  of their IHY activities. Representatives from Egypt, Angola and the
  coordinator of the Balkan, Black and Caspian Sea Region also reported
  on the progress of IHY activities in their respective regions. People
  from the IHY Secretariat provided a summary of the global IHY efforts
  including the United Nations Basic Space Sciences Program. In the
  education and public outreach front, a variety of activities have been
  planned: TV and radio shows, board games on space weather, specific
  programmes for schools and universities, workshops for teachers are some
  of the actions that were presented by the delegates. Beyond of these
  national and individual initiatives, specific activities requiring
  European coordination were discussed. This paper provides an extended
  summary of the main talks and discussions that held during the meeting.

---------------------------------------------------------
Title: First Results of the S/WAVES Experiment on the STEREO Mission.
Authors: Bonnin, X.; Maksimovic, M.; Bougeret, J. -L.; Goetz, K.;
   Bale, S. D.; Kaiser, M. L.; Reiner, M. J.; Cecconi, B.; Briand, C.;
   Krucker, S.; S/Waves Team
2007sf2a.conf..582B    Altcode:
  We present the first results of the STEREO/Waves (S/Waves) investigation
  on the STEREO Mission. The S/Waves instrument includes a suite of
  state-of-the-art sub-instruments that provide comprehensive measurements
  of the three components of the electric field from a fraction of a
  Hertz up to 16 MHz, plus a single frequency channel near 30 MHz. The
  instrument has a direction finding or goniopolarimetry capability,
  used to perform 3-D localization and tracking of streams of energetic
  electrons and of shock waves associated with Coronal Mass Ejections
  (CMEs). The scientific objectives include (i) remote observation and
  measurement of energetic phenomena throughout the 3-D heliosphere
  that are associated with the CMEs and with solar flare phenomena,
  and (ii) in-situ measurement of the properties of CMEs, such as their
  electron density and temperature and the associated plasma waves near
  1 Astronomical Unit.

---------------------------------------------------------
Title: T he Faint Drifting Decameter Radio Bursts From The Solar
    Corona
Authors: Briand, C.; Zaslavsky, A.; Lecacheux, A.; Zarka, P.;
   Maksimovic, M.; Mangeney, A.
2007ESASP.641E..56B    Altcode:
  The radio observations of solar corona at decameter wavelengths reveal
  the presence of numerous faint, frequency drifting structures. We
  analyse observations performed on July 13th , 2002 with the DSP
  wideband spectrometer instrument implemented at the UTR-2 radiote-
  lescope. The main characteristics of these structures are statistically
  studied. Three populations of bursts are iden- tifies. The largest
  one presents negative frequency drifts of about -0.89 MHz.s-1 and a
  lifetime extending up to 11 sec (median value 2.72 sec). A second one
  shows positive frequency drifts of about +0.95 MHz.s-1 and a life- time
  extending up to 3 sec. The last population consists in structures with
  very small frequency drifts of about -0.1 MHz.s-1 and a shorter lifetime
  (about 1 sec). Assuming that those emissions are the signature of elec-
  tron beams propagating through the solar corona, we deduce that they
  have a velocity of about 3-5 times the electron thermal velocity. A
  new mechanism is proposed to explain the formation of plasma waves with
  such low beam velocity: spatially localized, temporal fluctuations of
  the electron distribution function width (heating).

---------------------------------------------------------
Title: Science Plans for the International Heliophysical Year
Authors: Davila, J. M.; Gopalswamy, N.; Harrison, R. A.; Stamper,
   R.; Briand, C.; Potgieter, M. S.
2006AGUSM.U34A..04D    Altcode:
  On October 4, 1957, only 53 years after the beginning of flight in Kitty
  Hawk, the launch of Sputnik 1 marked the beginning of the space age;
  as mankind took the first steps to leaving the protected environment of
  Earth's atmosphere. Discovery of the radiation belts, the solar wind,
  and the structure of Earth's magnetosphere prepared the way for the
  inevitable human exploration to follow. Soon, Cosmonauts and Astronauts
  orbited Earth, and then in 1969, Astronauts landed on the Moon. Today
  a similar story is unfolding, the spacecraft Voyager has crossed the
  termination shock, and will soon leave the heliosphere. For the first
  time, man will begin to explore the local interstellar medium. It is
  inevitable that, during the next 50 years, exploration of the solar
  system including the Moon, Mars and the outer planets will be the
  focus of the space program, and like 50 years ago, unmanned probes
  will lead the way, followed by human exploration. The International
  Geophysical Year (IGY) of 1957, a broad-based and all-encompassing
  effort to push the frontiers of geophysics, resulted in a tremendous
  increase of knowledge in space physics, Sun-Earth Connection, planetary
  science and the heliosphere in general. Now, 50 years later, we have
  the unique opportunity to further advance our knowledge of the global
  heliosphere and its interaction with the interstellar medium through
  the International Heliophysical Year (IHY) in 2007, and to raise
  public awareness of space physics. This presentation will focus on
  global science planning efforts and campaigns for all participating
  IHY nations.

---------------------------------------------------------
Title: Mercury Transit for Stray Light Evaluation: IPM-THEMIS Case
Authors: Briand, C.; Mattig, W.; Ceppatelli, G.; Mainella, G.
2006SoPh..234..187B    Altcode:
  Mercury's transit on the solar disk offers ideal conditions to determine
  the stray light level of instruments. We present here the results on the
  stray light level deduced from the observation of the Mercury transit
  on 2003 May 7th at the secondary focus of the THEMIS telescope with the
  broad-band and spectral channels of the IPM instrument. The scattered
  light in the broad-band channel is about 17% and about 25% in the
  spectral channel. The spread function was deduced for the two channels
  taking into account the observations on the limb and on Mercury's disk.

---------------------------------------------------------
Title: IHY Science and Organization in Europe
Authors: Bougeret, J. -L.; Briand, C.; Bonet Navaro, J. A.; Breen,
   A.; Candidi, M.; Georgevia, K.; Harrison, R.; Marsden, R.; Schmieder,
   B.; von Steiger, R.
2006cosp...36.3226B    Altcode: 2006cosp.meet.3226B
  We present the scientific and organizational approach to the
  International Heliophysical Year in Europe A summary is given of the
  First European General Assembly of the IHY that was held in Paris in
  January 2006 Initiatives and expected returns are described

---------------------------------------------------------
Title: Variable Coronal Heating and Beam Formation
Authors: Briand, C.; Mangeney, A.; Califano, F.
2005ESASP.600E..81B    Altcode: 2005ESPM...11...81B; 2005dysu.confE..81B
  No abstract at ADS

---------------------------------------------------------
Title: The Detection of Photospheric Impacts from Chromospheric
    Impulsive Events
Authors: Moretti, P. F.; Berrilli, F.; Sebastianelli, A.; Briand,
   C.; Pietropaolo, E.
2003ApJ...589L.109M    Altcode:
  Multiwavelength solar observations were carried out at the THEMIS
  telescope in order to investigate the propagation of the plasma jets
  during and after a flare occurrence. The data obtained in the Hα,
  Na I D2, and Fe I 557.6 nm lines show that the perturbations detected
  in the higher layers due to a B-class flare do penetrate down to
  the photosphere. The observational evidence of such perturbations is
  crucial for the identification of the source of the solar oscillations.

---------------------------------------------------------
Title: Chromospheric polarity reversal on sunspots: New insight
    from spectro-polarimetric measurements
Authors: Briand, C.; Vecchio, A.
2003A&A...403L..33B    Altcode:
  We present here spectro-polarimetric observations of chromospheric
  and photospheric lines on an active region. We show that the presence
  of polarity reversal between photosphere and chromosphere cannot be
  detected relying on magnetograms and broad band and even narrow band
  filters only. We demonstrate that opposite signs in CaII magnetograms in
  sunspots compare to photospheric magnetograms are not due to a reversal
  of the magnetic field, but rather due to the presence of line core
  emission as suggested from theoretical arguments by Sánchez Almeida
  (\cite{Sanchez97}).

---------------------------------------------------------
Title: Phase diversity at THEMIS : first implementation
Authors: Del Moro, D.; Criscuoli, S.; Bonet, J. A.; Márquez, I.;
   Lemen, C.; Briand, C.
2003MmSAI..74..811D    Altcode:
  Phase diversity techniques actually provide robust post-processing
  methods to restore solar images degraded by seeing-optical
  aberrations. We present preliminary results of the application of a
  Partitioned Phase-Diverse Speckle (PPDS) technique at THEMIS. The images
  have been acquired using the IPM broad-band CCD camera and reduced
  using a suitable IDL code. The spectral analysis of unrestored/restored
  images shows a significant improvement of image quality, achieving
  diffraction limited resolution.

---------------------------------------------------------
Title: Phase diversity at THEMIS : first implementation
Authors: Del Moro, D.; Lemen, C.; Bonet, J. A.; Márquez, I.;
   Criscuoli, S.; Briand, C.
2003AN....324..299D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: THEMIS : Status and perspectives
Authors: Ceppatelli, G.; Briand, C.
2003MmSAI..74..790C    Altcode:
  A brief presentation of the scientific results obtained with THEMIS is
  given together with the improvements which are imperative to maintain
  THEMIS in the group of the most relevant solar telescopes in the
  world. <P />Based on observations made with THEMIS telescope operated
  on the island of Tenerife by THEMIS SL in the Spanish Observatorio
  del Teide of the Instituto de Astrofisica de Canarias

---------------------------------------------------------
Title: Pointing and tracking analysis of alt-azimuthal multi-focus
telescopes: the THEMIS case
Authors: Mainella, G.; Briand, C.; Maréchal, L.; Le Men, C.
2003AN....324..309M    Altcode:
  We discuss the pointing and tracking configuration of THEMIS which may
  be considered as representative of those alt-azimuthal telescopes with
  an optical configuration with multiple focal planes, not all locked to
  both the alt-azimuthal coordinates. In the THEMIS case two focal planes
  are present. The primary focus F1 is locked to the alt-azimuthal mount,
  while the secondary focus F2 (which is used by the instruments), is
  only locked to the azimuth angle. The different contributions to the
  final accuracy of both absolute pointing and tracking as observed at F2
  are defined, and an extimation of the contribution of each component
  of the whole chain which affects the field position at F2 (software,
  mechanical and optical) is given. The experimental data are the
  result of a test campaign carried on at THEMIS in February and March
  2002. We can say that (a) for all the used observing configurations,
  the tracking accuracy is coherent at any point along the trajectory with
  the correspondent absolute pointing accuracy, which is an indication
  for the quality of the telescope dynamical performances (b) the main
  contribution to the residual field shift which is observed at F2 arises
  from the opto-mechanical alignment configuration of the optics between
  F1 and F2, which therefore is the crucial point for such multi-focus
  configuration. More informations can be found at the official THEMIS
  website (http://www.themis.iac.es).

---------------------------------------------------------
Title: Solar activity I: aspects of magnetic activity
Authors: Briand, C.
2003AN....324..357B    Altcode:
  It is now accepted that the solar activity has direct impact on the
  Earth climate, but is also responsible for the geomagnetic storms. It
  is thus fundamental to understand the mechanisms responsible for this
  activity. We present here first some aspects of the solar activity
  at the different atmospheric layers of the sun: active region at
  photospheric levels, filaments (prominences) and flares at chromospheric
  level and CME's at coronal level. A quick sum-up of the principal
  characteristics of each is given as well as the key questions still
  under investigation. In the second part, two principal parameters are
  presented to describe these features: helicity and topology. Finally,
  we sum-up the observational challenges for new solar telescopes.

---------------------------------------------------------
Title: THEMIS and DOT joint observations on NOAA 9716
Authors: Briand, C.; Collados, M.; Sütterlin, P.
2002ESASP.505..361B    Altcode: 2002IAUCo.188..361B; 2002solm.conf..361B
  Ephemeral magnetic emergence has been detected in a decaying β region
  observed in December 2001 simultaneously with the DOT and THEMIS. We
  present here the main characteristics of this phenomenon. Also the
  time evolution of a small group of pores is shown together with the
  time evolution of an horizontal magnetic field overlying them.

---------------------------------------------------------
Title: THEMIS: instrumentation, results and perspectives
Authors: Briand, C.; Ceppatelli, G.
2002ESASP.505...11B    Altcode: 2002IAUCo.188...11B; 2002solm.conf...11B
  THEMIS was built with very specific scientific objectives which
  implied severe instrumental constraints. Both are presented in this
  paper. Taking into account these constraints, we detail the present
  instrumental set-up and explain the mid-term projects. Some scientific
  results are presented in order to illustrate the observational
  capabilities of the telescope.

---------------------------------------------------------
Title: Telescope guide and pointing precision at THEMIS
Authors: Mainella, G.; Briand, C.
2002NCimC..25..709M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: THEMIS: Status and Perspectives
Authors: Ceppatelli, G.; Briand, C.
2002sf2a.conf...95C    Altcode:
  We will briefly present here the scientific results obtained with
  THEMIS, through the publications issued in 2001. We will then describe
  the mid-term improvements, stressing that they are imperative to
  maintain the position of THEMIS in the group of the most relevant
  solar telescopes in the world.

---------------------------------------------------------
Title: ASP Observations - First Analysis of Mgb<SUB>2</SUB> Stokes
    Parameters
Authors: Briand, C.; Martínez Pillet, V.
2001ASPC..236..565B    Altcode: 2001aspt.conf..565B
  No abstract at ADS

---------------------------------------------------------
Title: Last news from THEMIS
Authors: Ceppatelli, Guido; Briand, Carine
2001MmSAI..72..558C    Altcode:
  THEMIS started a new observing campaign on May 1st 2000. In this
  paper a sum up of the main aims of THEMIS will be presented. Then, the
  present status of the observing modes will be described. Finally, we
  will present some results obtained during the last observing campaigns.

---------------------------------------------------------
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

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Title: Scaling behavior of the vertical velocity field in the solar
    photosphere
Authors: Consolini, G.; Carbone, V.; Berrilli, F.; Bruno, R.;
   Bavassano, B.; Briand, C.; Caccin, B.; Ceppatelli, G.; Egidi, A.;
   Ermolli, I.; Florio, A.; Mainella, G.; Pietropaolo, E.
1999A&A...344L..33C    Altcode:
  We analyze, for the first time, the scaling behavior of the photospheric
  vertical velocity field. Our analysis is based on data collected by the
  Italian Panoramic Monocromator (IPM) mounted at the THEMIS telescope
  at the Spanish “Observatorio del Teide” (Tenerife) of the Instituto
  de Astrofisica de Canarias. We investigate the occurrence of scaling in
  the cancellations between downflow and upflow of the vertical velocity
  field, showing that the field possesses well pronunced sign-singularity
  in the range of scales from more than 10 Mm down to the granulation
  scale. Based on THEMIS/CNRS--INSU/CNR telescope observations

---------------------------------------------------------
Title: Dependence of the photospheric vertical flow characteristics
    on the granule dimension
Authors: Berrilli, F.; Florio, A.; Consolini, G.; Bavassano, B.;
   Briand, C.; Bruno, R.; Caccin, B.; Carbone, V.; Ceppatelli, G.; Egidi,
   A.; Ermolli, I.; Mainella, G.; Pietropaolo, E.
1999A&A...344L..29B    Altcode:
  The first high spectral resolution and white-light images obtained at
  the THEMIS telescope with the Italian Panoramic Monochromator (IPM), are
  analyzed to study intensity and velocity fluctuations in the photosphere
  of the sun. Monochromatic images, in two spectral ranges around 538.03
  nm (C I line) and 557.61 nm (Fe I line), are used to characterize the
  vertical structure of the photosphere. Granulation cells and granules
  are obtained by segmentation of white-light images using suitable
  finding algorithms. We observe the height dependence of velocity
  vs. intensity fluctuations, and we found a dependence of velocity and
  intensity on granule dimension. Our results show that granules increase
  their intensity with dimension in the lower solar photosphere. In the
  higher photosphere, on the contrary, the intensity decreases with the
  dimension. Based on THEMIS/CNRS-INSU/CNR telescope observations

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Title: Spectral Law and Polarization Properties of the Low-Frequency
    Waves at the Magnetopause
Authors: Rezeau, L.; Belmont, G.; Cornilleau-Wehrlin, N.; Reberac,
   F.; Briand, C.
1999GeoRL..26..651R    Altcode:
  The magnetic fluctuations, at the magnetopause and in the adjacent
  magnetosheath, exhibit power law spectra which are very reminiscent
  of turbulent spectra. In prospect of future modelizations of such a
  turbulence, new information is brought about the experimental properties
  of these fluctuations. The power laws spectra previously obtained in
  the ULF range are shown to hold also in VLF, up to the lower hybrid
  frequency. Concerning the polarization, 1) the direction with respect
  to the static magnetic field is shown to be dominantly perpendicular
  at low frequencies, consistently with Shear Alfven modes in this range,
  and 2) no right-hand sense of rotation can be evidenced at frequencies
  higher than the proton gyrofrequency, although one could expect the
  fast magnetosonic mode to be dominant in this range. The physical
  implications of this last observation for the non linear effects at
  work in the turbulence are briefly discussed.

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Title: First observational campaign at the THEMIS: image quality
    and seeing
Authors: Arnaud, J.; Briand, C.; Ceppatelli, G.
1998NewAR..42..499A    Altcode:
  The THEMIS and its instrumentation are described. The well known diurnal
  seeing pattern is confirmed by the seeing measurements taken to date.

---------------------------------------------------------
Title: Velocity fields below the magnetic canopy of solar flux tubes:
    evidence for high-speed downflows?
Authors: Briand, C.; Solanki, S. K.
1998A&A...330.1160B    Altcode:
  It is well-established that velocities in the immediate surroundings of
  solar magnetic elements produce an asymmetry in the Stokes V profiles
  emerging from the magnetic feature. Conversely, the observed Stokes V
  asymmetry can be used to infer the velocity field. Taking as constraints
  the area asymmetries of the Stokes V profiles of two lines of neutral
  magnesium (lambda 457nm and lambda 517nm) observed near the center of
  the solar disk, the (vertical) component of the velocity field below
  the magnetic canopy of flux tubes is investigated. We find that the
  strong Mg I b_2 line at 517nm qualitatively extends the diagnostic
  capabilities of Stokes V asymmetry, mainly due to the fact that it is
  sensitive to velocities over a large range of heights and hence also at
  relatively large distances from the flux tube axis. In order to retrieve
  the observed area asymmetry of both lines, up- as well as downflows
  have to be introduced in the models. If the temperature differences
  between the two flows are neglected then a downflow of 1.5 - 2km s(-1)
  close to the edge of the flux tube and an almost equally strong upflow
  at greater distances (corresponding to the central part of a granule)
  reproduces the observed area asymmetries. If we take into account
  that the temperature in the downflow is lower than in the upflow,
  we can only reproduce the observations if the downflow is fast (&gt;=
  5 km s(-1) ) and concentrated into narrow lanes.

---------------------------------------------------------
Title: THEMIS-IPM: performance analysis of the system and future
    developments
Authors: Mainella, G.; Bavassano, B.; Berrilli, F.; Briand, C.; Bruno,
   R.; Caccin, B.; Cantarano, S.; Ceppatelli, G.; Egidi, A.
1998MmSAI..69..659M    Altcode:
  No abstract at ADS

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Title: High spatial resolution observations of the solar spectral
    lines.
Authors: Kostyk, R. I.; Shchukina, N. G.; Briand, C.
1998IBUAA..12...39K    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Velocity fields around magnetic flux tubes.
Authors: Briand, C.; Solanki, S. K.
1997joso.proc...55B    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: THEMIS: Télescope Héliographique pour l'Étude du Magnétisme
    et des Instabilités Solaires.
Authors: Arnaud, J.; Briand, C.; Rayrole, J.
1996JAF....53....5A    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The MG i lambda 285.21 Nanometer Line: an Example of Non-LTE
    Line Formation
Authors: Uitenbroek, Han; Briand, Carine
1995ApJ...447..453U    Altcode:
  We discuss how the Mg I λ285.21 nm line is formed in the context of
  standard plane-parallel modeling. The line appears to be very sensitive
  to the nonlocal radiation field determining the balance between neutral
  and singly ionized magnesium. We resolve between conflicting results
  in earlier λ285.21 nm line modeling by showing that, in the quite
  Sun, the line forms at sufficiently low density for partial frequency
  redistribution to take effect and give rise to small emission reversals
  in the core. We find this to be true only if we take proper account
  of UV line blanketing at the relevant Mg I ionization edges. In
  this case there is good agreement between theoretical line profiles
  and spatially averaged spectra from the Solar Maximum Mission (SMM)
  Ultraviolet Spectrometer and Polarimeter (UVSP) and from the French
  RASOLBA balloon experiment. Spatially resolved spectra obtained with
  the latter instrument show considerable variation in the line core,
  with emission present only in some locations and absent in others.

---------------------------------------------------------
Title: Empirical models of solar magnetic elements: constraints
    imposed by MgI Stokes profiles.
Authors: Briand, C.; Solanki, S. K.
1995A&A...299..596B    Altcode:
  Although the temperature structure of small-scale magnetic features
  in the lower and middle photosphere has been constrained quite well,
  there are still considerable uncertainties in the upper photospheric
  and lower chromospheric thermal structure. As a step towards an
  improvement of this situation we investigate, using a non-LTE analysis,
  the diagnostic capabilities of the Stokes I and V profiles of the Mg
  I b_2_ 517.3nm and the Mg I 457.1nm lines. We find that the V profile
  of the former line can constrain the magnetic element thermal and
  velocity structure near the temperature minimum, which goes beyond
  the capabilities of the commonly used Fe I and II lines. The λ457.1nm
  line, on the other hand, does not provide any additional information
  on its own. A comparison of synthetic profiles with plage and network
  Stokes I and V spectra confirms the findings of Bruls &amp; Solanki
  (???) that the chromospheric temperature rise starts at a substantially
  lower height in magnetic elements than in the quiet Sun. Some of the
  ambiguities in previous empirical models of magnetic elements are also
  removed. We confirm that small-scale magnetic features are associated
  with larger line broadening velocities than the quiet Sun, particularly
  in the higher layers. Finally, the Mg I b_2_ line is revealed to be
  a direct diagnostic of the merging height of magnetic elements.

---------------------------------------------------------
Title: Center-to-limb observations of the lambda 285.2 NM MgI UV
    resonance line
Authors: Briand, C.; Lemaire, P.
1994A&A...282..621B    Altcode:
  We present here new results about the 285.212 nm Mg I resonance
  line. The spectra have been obtained from the RASOLBA balloon experiment
  of the LPSP launched in 1986 from France. The data have both high
  spectral (1.5 pm) and spatial (1 sec) resolution. Spectra of either
  the Sun center and the solar limb have been recorded in the 280 nm
  range. We paid a careful attention on the spatial evolution of the Mg
  I absorption line with the hope to find predicted but not confirmed
  emission feature in the central core. The very faint emission detected
  at Sun center becomes bright when observed off-limb. We give some
  measurements of the Mg I core Doppler shifts.

---------------------------------------------------------
Title: Mg I UV and IR Lines of the Quiet Sun
Authors: Briand, C.; Lemaire, P.
1994emsp.conf...53B    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: High Resolution Measurements of the 273-293 nm Solar Spectrum
    from a Balloon Instrumentation
Authors: Lemaire, P.; Briand, C.; Staath, E.; Samain, D.
1993BAAS...25.1221L    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Exploitation des observations de Jupiter.
Authors: Briand, C.
1990EuAst...4..288B    Altcode:
  No abstract at ADS