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7 results on '"Y. I. J. Soobiah"'

1. MAVEN Case Studies of Plasma Dynamics in Low‐Altitude Crustal Magnetic Field at Mars 1: Dayside Ion Spikes Associated With Radial Crustal Magnetic Fields

Author

Robert Lillis, Yuki Harada, J. R. Gruesbeck, Shannon Curry, Jared Espley, James P. McFadden, Shaosui Xu, Jasper Halekas, Laila Andersson, Gina A. DiBraccio, David L. Mitchell, Mehdi Benna, John E. P. Connerney, Glyn Collinson, David Brain, Bruce M. Jakosky, Christopher M. Fowler, Christian Mazelle, Y. I. J. Soobiah, Takuya Hara, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Flux, Atmosphere of Mars, Plasma, Electron, Magnetic field, Ion, Geophysics, [SDU]Sciences of the Universe [physics], Physics::Plasma Physics, Space and Planetary Science, Sputtering, Electric field, Astrophysics::Earth and Planetary Astrophysics, Atomic physics
Abstract

International audience; We report for the first time, simultaneous ion, electron, magnetic field vector and electric field wave measurements made possible by Mars Atmosphere and Volatile EvolutioN, during ion energy flux spikes in low-altitude radial crustal magnetic fields on the Mars dayside. Observations show energetic electrons and ions (E > 25 eV) precipitating on magnetic field lines assumed as closed. Ions (E < 1.4 keV) display broad velocity distributions toward Mars, showing ions flowing from higher altitude possibly after magnetic reconnection or loss cone filling from pitch angle scattering effects. Precipitating ions (E < 1.4 keV) show nonadiabatic features depending on ion mass and energy and returning ions (E < 1.4 keV) show evidence of conserving the first adiabatic invariant in a mirror field. We observe magnetic field perturbations up to 60 nT, electric field wave amplitudes up to 38 mV/m, and brief periods of peaked electron spectra. At ∼175 km and at times Mars Atmosphere and Volatile EvolutioN is below the mirroring altitude of electrons, we observe mirroring and transverse heating of H+ ions alongside increased electric field wave amplitude fluctuations. It suggests field aligned potential drops result from different mirror altitudes of ions and electrons. Ions E > 1.4 keV (O+) occur as injected accelerated ion beams and ions heated after energization or deceleration. Energy dispersed kilo-electron-volt ions suggest a selection effect in radial magnetic fields for lower-energy Marsward ions, compared to reflection of higher-energy anti-Sunward ions. Precipitating kilo-electron-volt ions show energy deposition rates of 3.6 ×10-6 W/m2 and sputtering escape rates from precipitating O+ ions of 1.5 ×105/(cm2.s) and 2.1 ×106/(cm2.s) are calculated.

Published
2019
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2. The Twisted Configuration of the Martian Magnetotail: MAVEN Observations

Author

Shaosui Xu, Gina A. DiBraccio, Jasper Halekas, Yuki Harada, David Brain, Shannon Curry, Chuanfei Dong, Bruce M. Jakosky, Suranga Ruhunusiri, Y. I. J. Soobiah, David L. Mitchell, Jacob Gruesbeck, Jared Espley, Takuya Hara, Janet G. Luhmann, Yingjuan Ma, and John E. P. Connerney

Subjects
Physics, Martian, 010504 meteorology & atmospheric sciences, Field line, Ecliptic, Magnetic reconnection, Mars Exploration Program, Atmosphere of Mars, Astrophysics, 01 natural sciences, Current sheet, Geophysics, Physics::Space Physics, 0103 physical sciences, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Interplanetary magnetic field, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract

Measurements provided by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft are analyzed to investigate the Martian magnetotail configuration as a function of interplanetary magnetic field (IMF) BY. We find that the magnetotail lobes exhibit a ~45deg twist, either clockwise or counterclockwise from the ecliptic plane, up to a few Mars radii downstream. Moreover, the associated cross-tail current sheet is rotated away from the expected location for a Venus-like induced magnetotail based on nominal IMF draping. Data-model comparisons using magnetohydrodynamic simulations are in good agreement with the observed tail twist. Model field line tracings indicate that a majority of the twisted tail lobes are composed of open field lines, surrounded by draped IMF. We infer that dayside magnetic reconnection between the crustal fields and draped IMF creates these open fields and may be responsible for the twisted tail configuration, similar to what is observed at Earth.

Published
2018
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3. MAVEN observations of tail current sheet flapping at Mars

Author

Charles Bowers, John E. P. Connerney, David Brain, Gina A. DiBraccio, Suranga Ruhunusiri, Bruce M. Jakosky, Y. I. J. Soobiah, J. Dann, Takuya Hara, Yuki Harada, Jacob Gruesbeck, Jasper Halekas, and Jared Espley

Subjects
Martian, Physics, 010504 meteorology & atmospheric sciences, Magnetosphere, Atmosphere of Mars, Mars Exploration Program, Geophysics, 01 natural sciences, Solar wind, Current sheet, Space and Planetary Science, Physics::Space Physics, 0103 physical sciences, Flapping, Astrophysics::Earth and Planetary Astrophysics, Energy source, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

The Martian magnetotail is a complex regime through which atmospheric particles are lost to space. Our current understanding of Mars’ tail continues to develop with the comprehensive particle and field data collected by Mars Atmosphere and Volatile EvolutioN (MAVEN). In this work, we identify periods when MAVEN encounters multiple current sheet crossings through a single tail traversal in order to understand tail dynamics. We apply an analysis technique that has been developed and validated using multi-point measurements in order to separate the spatial and temporal properties associated with current sheet flapping. Events are classified into periods of steady flapping, due to a global motion of the current sheet, and kink-like flapping, resulting from localized wave propagation along the tail current sheet. Out of 106 periods during which multiple current sheet crossings were observed, 20 were due to steady flapping and 10 from kink-like flapping. A majority of the kink-like events resulted from waves propagating in the opposite direction of the solar wind convection electric field, regardless of their location in the tail, unlike at Earth and Venus. This finding suggests that possible magnetosphere energy sources, whereby plasma is accelerated and removed from the Martian environment, are not located in the central magnetotail; rather, these waves may be driven by a source located at the tail flank based on the direction of the solar wind electric field. Therefore, by identifying potential sources of impulsive energy release in the tail, we may better understand mechanisms that drive atmospheric loss at Mars.

Published
2017
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4. The Three-Dimensional Bow Shock of Mars as Observed by MAVEN

Author

Christian Mazelle, Y. I. J. Soobiah, Gina A. DiBraccio, David L. Mitchell, David Brain, Jasper Halekas, Jared Espley, J. Dann, Jacob Gruesbeck, John E. P. Connerney, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Magnetosphere, Mars, MAVEN, 01 natural sciences, bow shock, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Bow shock (aerodynamics), Interplanetary magnetic field, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Martian, Geophysics, Atmosphere of Mars, Mars Exploration Program, Shock (mechanics), Solar wind, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Geology
Abstract

International audience; The Martian magnetosphere is a product of the interaction of Mars with the interplanetary magnetic field and the supersonic solar wind. The location of the bow shock has been previously modeled as conic sections using data from spacecraft such as Phobos 2, Mars Global Surveyor, and Mars Express. The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission spacecraft arrived in orbit about Mars in November 2014 resulting in thousands of crossings to date. We identify over 1,000 bow shock crossings. We model the bow shock as a three-dimensional surface accommodating asymmetry caused by crustal magnetic fields. By separating MAVEN's bow shock encounters based on solar condition, we also investigate the variability of the surface. We find that the shock surface varies in shape and location in response to changes in the solar radiation, the solar wind Mach number, dynamic pressure of the solar wind, and the relative local time location of the strong crustal magnetic fields (i.e., whether they are on the dayside or on the nightside).

Published
2018
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5. Evidence for crustal magnetic field control of ions precipitating into the upper atmosphere of Mars

Author

James P. McFadden, Gina A. DiBraccio, Janet G. Luhmann, David Brain, Yuki Harada, Shannon Curry, Bruce M. Jakosky, Y. I. J. Soobiah, Jasper Halekas, Takuya Hara, Christian Mazelle, Kanako Seki, David L. Mitchell, Shaosui Xu, François Leblanc, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Department of Physics and Astronomy [Ames, Iowa], Iowa State University (ISU), Department of Earth and Planetary Science [Tokyo], The University of Tokyo (UTokyo), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Department of Geophysics [Kyoto], Kyoto University [Kyoto], NASA Goddard Space Flight Center (GSFC), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), Kyoto University, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Martian, Materials science, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Atmosphere of Mars, Mars Exploration Program, Plasma, 01 natural sciences, Molecular physics, Ion, Magnetic field, Physics::Geophysics, Atmosphere, Solar wind, Geophysics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences
Abstract

International audience; We present the effects of the local magnetic field configurations on ions precipitating into the upper atmosphere of Mars using MAVEN observations. Precipitating pickup planetary heavy ions (O+, O2+, and CO2+) are of particular interest in the Martian plasma environment because they potentially enhance the sputtering loss of ambient neutral particles. In addition, solar wind protons (and H+ pickup ions) penetrate into the dayside atmosphere due to the direct interaction with the Martian obstacle. We present a statistical study showing that precipitating ion fluxes are typically enhanced by a factor of 2‐3 under radial field configurations. We also show that the crustal fields have a shielding effect; the precipitating fluxes are significantly reduced by ∼50 % under the strong crustal fields (≳ 100 nT), where the local magnetic field is oriented with a more horizontal component to the surface. These trends are seen consistently regardless of ion species, as well as the observed locations including dayside/nightside, subsolar longitudes, and ±E hemispheres in the Mars‐centered Solar Electric (MSE) coordinates. In particular, the local magnetic field configurations control precipitating ions with energies lower than a few keV, while precipitating high‐energy ion fluxes are likely independent of the local magnetic field configurations. Precipitating ion fluxes are known to vary by at least an order of magnitude depending on the upstream solar wind. Therefore, the local magnetic field configurations turn out to be the secondary factor in modulating precipitating ion fluxes at Mars.

Published
2018
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6. Loss of the Martian atmosphere to space: Present-day loss rates determined from MAVEN observations and integrated loss through time

Author

Phillip C. Chamberlin, Jane L. Fox, Jared Espley, Andrew F. Nagy, Daniel Lo, Yuki Harada, Ali Rahmati, Casey L. Flynn, Valeriy Tenishev, Shotaro Sakai, Shannon Curry, Shaosui Xu, Franck Montmessin, Jean-Yves Chaufray, Tristan Weber, Anna Kotova, Michael Mendillo, Christy Lentz, David Brain, Kyle Connour, J. P. McFadden, Nicholas M. Schneider, Roger V. Yelle, Christina O. Lee, Bruce M. Jakosky, F. J. Crary, Matthew Fillingim, Arnaud Stiepen, Michael R. Combi, W. K. Peterson, Thomas E. Cravens, Joseph M. Grebowsky, Jared Bell, Kaori Terada, Anders Eriksson, K. Roeten, Jeffrey Trovato, Frank Eparvier, Zachary Girazian, S. Inui, P. Dunn, Paul Withers, Majd Mayyasi, Scott L. England, Yaxue Dong, Meredith Elrod, Edward Thiemann, David E. Siskind, Paul R. Mahaffy, Robert H. Tolson, François Leblanc, Gina A. DiBraccio, David L. Mitchell, David Andrews, Kirk Olsen, Ronan Modolo, K. Fallows, Dolon Bhattacharyya, Marissa F. Vogt, Masaki Fujimoto, Michael Chaffin, S. Houston, Nicolas André, Mehdi Benna, Chuanfei Dong, Kyle Crabb, Naoki Terada, J. R. Gruesbeck, Takeshi Kuroda, Yingjuan Ma, Yuni Lee, Alexander S. Medvedev, Robert Lillis, Glyn Collinson, Hiromu Nakagawa, Christopher M. Fowler, K. G. Hanley, Richard W. Zurek, R. M. Dewey, Hilary Egan, Robert E. Ergun, S. R. Shaver, Takuya Hara, Sonal Jain, Suranga Ruhunusiri, Jasper Halekas, Morgane Steckiewicz, S. Stone, Stephen W. Bougher, Jacob Hermann, Janet G. Luhmann, Hannes Groeller, Y. I. J. Soobiah, David Pawlowski, Xiaohua Fang, A. Fogle, Davin Larson, Yosuke Matsumoto, T. M. Esman, R. Jolitz, Darren Baird, Karim Meziane, O. Q. Hamil, Clara Narvaez, William E. McClintock, J. Correira, Gabor Toth, John E. P. Connerney, M. Slipski, Melissa L. Marquette, Christopher T. Russell, Kanako Seki, Matteo Crismani, Michael L. Stevens, Greg Holsclaw, John Clarke, Philippe Garnier, Mika Holmberg, Erdal Yiğit, Ian Stewart, Rafael Lugo, G. T. Delory, Laila Andersson, Justin Deighan, C. F. Bowers, Scott Evans, Zachariah Milby, Norberto Romanelli, R. Sharrar, Franck Lefèvre, Christian Mazelle, Daniel N. Baker, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, NASA Goddard Space Flight Center (GSFC), Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), NASA Johnson Space Center (JSC), NASA, National Institute of Aerospace [Hampton] (NIA), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), Communications and Power Industries (CPI), Department of Physics and Astronomy [Lawrence Kansas], University of Kansas [Lawrence] (KU), Princeton University, University of Arizona, Wright State University, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Department of Physics and Astronomy [Ames, Iowa], Iowa State University (ISU), University of Kansas [Kansas City], The University of Tokyo (UTokyo), National Institute of Information and Communications Technology [Tokyo, Japan] (NICT), PLANETO - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Analytical Mechanics Associates, Inc., University of California [Los Angeles] (UCLA), University of California, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, University of New Brunswick (UNB), Tohoku University [Sendai], Eastern Michigan University, University of Michigan System, Institute of Geophysics and Planetary Physics [Los Angeles] (IGPP), Department of Earth and Planetary Science [Tokyo], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), Naval Research Laboratory (NRL), Laboratoire de Physique Atmosphérique et Planétaire (LPAP), Université de Liège, Graduate School of Information Sciences [Sendai], Lunar and Planetary Laboratory [Tucson] (LPL), Department of Physics and Astronomy [Fairfax], George Mason University [Fairfax], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), and California Institute of Technology (CALTECH)-NASA

Subjects
010504 meteorology & atmospheric sciences, Solar wind, Extrapolation, Mars, Present day, Atmospheric sciences, Mars climate, 01 natural sciences, Atmosphere, Mars atmosphere, Planet, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Spacecraft, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Astronomy and Astrophysics, Atmosphere of Mars, Mars Exploration Program, 13. Climate action, Space and Planetary Science, Magnetospheres, Environmental science, business
Abstract

International audience; Observations of the Mars upper atmosphere made from the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft have been used to determine the loss rates of gas from the upper atmosphere to space for a complete Mars year (16 Nov 2014 – 3 Oct 2016). Loss rates for H and O are sufficient to remove ∼2-3 kg/s to space. By itself, this loss would be significant over the history of the planet. In addition, loss rates would have been greater early in history due to the enhanced solar EUV and more-active Sun. Integrated loss, based on current processes whose escape rates in the past are adjusted according to expected solar evolution, would have been as much as 0.8 bar CO2 or 23 m global equivalent layer of H2O; these losses are likely to be lower limits due to the nature of the extrapolation of loss rates to the earliest times. Combined with the lack of surface or subsurface reservoirs for CO2 that could hold remnants of an early, thick atmosphere, these results suggest that loss of gas to space has been the dominant process responsible for changing the climate of Mars from an early, warmer environment to the cold, dry one that we see today.

Published
2018
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7. Comparative study of the Martian suprathermal electron depletions based on Mars Global Surveyor, Mars Express, and Mars Atmosphere and Volatile EvolutioN mission observations

Author

Laila Andersson, Morgane Steckiewicz, David Brain, Jared Espley, David L. Mitchell, Bruce M. Jakosky, Andrei Fedorov, Davin Larson, Janet G. Luhmann, J. A. Sauvaud, Arnaud Beth, Emmanuel Penou, N. André, Christian Mazelle, Y. I. J. Soobiah, Jasper Halekas, J. P. McFadden, Philippe Garnier, Robert Lillis, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, nightside suprathermal electron depletions, Mars, Electron, 01 natural sciences, MGS mission, Astrobiology, Altitude, 0103 physical sciences, Mars global surveyor, 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, Martian, Spacecraft, business.industry, Mars Exploration Program, Atmosphere of Mars, Geophysics, MAVEN mission, Space and Planetary Science, [SDU]Sciences of the Universe [physics], MEX mission, business, Geology
Abstract

International audience; Nightside suprathermal electron depletions have been observed at Mars by three spacecraft to date: Mars Global Surveyor, Mars Express, and the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. This spatial and temporal diversity of measurements allows us to propose here a comprehensive view of the Martian electron depletions through the first multispacecraft study of the phenomenon. We have analyzed data recorded by the three spacecraft from 1999 to 2015 in order to better understand the distribution of the electron depletions and their creation mechanisms. Three simple criteria adapted to each mission have been implemented to identify more than 134,500 electron depletions observed between 125 and 900 km altitude. The geographical distribution maps of the electron depletions detected by the three spacecraft confirm the strong link existing between electron depletions and crustal magnetic field at altitudes greater than 170 km. At these altitudes, the distribution of electron depletions is strongly different in the two hemispheres, with a far greater chance to observe an electron depletion in the Southern Hemisphere, where the strongest crustal magnetic sources are located. However, the unique MAVEN observations reveal that below a transition region near 160-170 km altitude the distribution of electron depletions is the same in both hemispheres, with no particular dependence on crustal magnetic fields. This result supports the suggestion made by previous studies that these low-altitudes events are produced through electron absorption by atmospheric CO2.

Published
2017
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