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116 results on '"Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS)"'

1. Spontaneous magnetic reconnection of thin current sheets

Author: Del Sarto, Daniele, Ottaviani, Maurizio, Pucci, Fulvia, Tenerani, Anna, Velli, Marco, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), National Institute for Fusion Science (NIFS), Princeton Plasma Physics Laboratory (PPPL), Princeton University, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Éric Falcon, Marc Lefranc, François Pétrélis, Chi-Tuong Pham, Institut Jean Lamour ( IJL ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Institut de Recherche sur la Fusion par confinement Magnétique ( IRFM ), National Institute for Fusion Science ( NIFS ), NIFS, Princeton Plasma Physics Laboratory ( PPPL ), Department of Earth, Planetary and Space Sciences [Los Angeles] ( EPSS ), University of California at Los Angeles [Los Angeles] ( UCLA ), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and University of California-University of California
Subjects: MHD instability, [ NLIN ] Nonlinear Sciences [physics], Magnetic reconnection, Turbulence magnetized plasmas, [NLIN]Nonlinear Sciences [physics], Secondary instabilities, Current sheets
Abstract: International audience; We address the problem of magnetic reconnection rates on large aspect ratio current sheets by presenting a generalisation of the notion of rescaling of the growth rates of tearing-type instabilities. In this, we review some recent results on the application of these notions to nonlinear reconnection processes [1,2,3] and to reconnection on rapidly evolving current sheets [1,4,10].; Nous adressons le problème des taux de reconnexion magnétique spontanée sur couches de courants minces, en présentant une généralisation de la notion de renormalisation des échelles des taux de croissance pour les instabilités du type “tearing mode”. Nous révisons ainsi des résultats recents sur l’application de ces notions aux processus de reconnexion non linéaire [1,2,3] et de reconnexion des couches minces en évolution rapide [1,4,10].
Published: 2018

2. Physical Sedimentology and Stratigraphy of the lower Western Fan (Shenandoah formation) Jezero Crater, Mars:: Results from the Mars 2020 'Delta Front' Campaign

Author: Ives, Libby, Stack‐Morgan, Katie, Gupta, Sanjeev, Caravaca, Gwénaël, Russell, Patrick, Shuster, David L., Williams, Amy, Holm-Alwmark, Sanna, Barnes, Robert, Bell, Jim F., Beyssac, Olivier, Brown, Adrian, Flannery, David, Frydenvang, Jens, Grotzinger, John, Lamb, Michael P., Horgan, Briony, Hurowitz, Joel A., Kalucha, Hemani, Kanine, Oak, Núñez, Jorge, Randazzo, Nicolas, Seeger, Christina, Simon, Justin I., Tice, Michael M., Tebolt, Michelle, Kah, Linda C., Williams, Rebecca M.E., Amundsen, Hans, Annex, Andrew M., Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Earth Science and Engineering [Imperial College London], Imperial College London, 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), 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), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Berkeley Geochronology Center (BGC), Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), University of Copenhagen = Københavns Universitet (UCPH), Arizona State University [Tempe] (ASU), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), NASA Headquarters, Queensland University of Technology [Brisbane] (QUT), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Purdue University [West Lafayette], Department of Geosciences [Stony Brook], Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), University of Alberta, NASA Johnson Space Center (JSC), NASA, Texas A&M University [College Station], University of Texas at Austin [Austin], Department of Earth and Planetary Sciences [Knoxville], The University of Tennessee [Knoxville], Planetary Science Institute [Tucson] (PSI), and Vestfonna Geophysical
Subjects: jezero crater, delta, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Shenandoah formatin, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars 2020, perseverance, Mars, sedimentology, stratigraphy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Abstract: International audience; The Perseverance rover is exploring a sedimentary deposit within the Late Noachian-aged (4.0-4.8 Ga) Jezero Crater interpreted to be the remnants of a delta. From April 2022 through February 2023, Perseverance investigated the basal 25 m of sediments exposed in the fan’s eastern scarp. Rover instruments collected a suite of imaging, geochemical, mineralogical, and ground-penetrating radar data.Perseverance made detailed observations through two sections of the lower fan ~600 m apart. Similar facies and stratigraphic trends are present in both sections. Each section contains two coarsening-up successions. While some finer-grained units are laterally continuous between the two sections, the coarser-grained bodies that cap each section are laterally discontinuous and do not extend between sections.Both sequences are 10 - 15 m thick. Their lower strata are dominated by sulfate-cemented, planar laminated, very fine- to medium-grained sandstone and siltstone with rare low-angle truncations. Soft-sediment deformation occurs in the form of decimeter-scale lateral folds. Laminae are normally graded. These sequences are capped by meter-scale thick sheets of coarse-grained sandstone, pebbly sandstones, and conglomerates that are variably low-angle cross-bedded, trough cross-bedded, and planar-stratified. Plane beds are massive or normally graded.Two hypotheses for the depositional environment have emerged for this succession: a sub-aerial setting with extensive “overbank” facies and shallow braided channels and a proximal pro-deltaic setting with deposition driven by hyperpycnal flows. These hypotheses will be tested against observations made by Perseverance as it traverses the “Fan Top” and by more comprehensive studies of the “Delta Front” data.
Published: 2023

3. Fine-scale sedimentary architecture of the upper part of the Jezero western delta front

Author: Gupta, Sanjeev, Bell III, J.F., Caravaca, Gwénaël, Mangold, Nicolas, Stack‐Morgan, Katie, Kanine, Oak, Tate, Christian, Tice, Michael M., Williams, Amy, Russell, Patrick, Núñez, Jorge, Dromart, Gilles, Williams, R, Le Mouélic, Stéphane, Barnes, Robert, Annex, Andrew, Paar, Gerhard, Holm-Alwmark, Sanna, Rice, Melissa S., Rice, James, Horgan, Briony, Grotzinger, John, Maki, Justin, Hickman Lewis, Keyron, Kah, Lindah, Shuster, David L., Simon, Justin I., Minitti, Michelle, Siebach, Kirsten, Gasnault, Olivier, Wiens, Roger, Maurice, Sylvestre, Farley, Kenneth A., Department of Earth Science and Engineering [Imperial College London], Imperial College London, Arizona State University [Tempe] (ASU), 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), 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), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Cornell University [New York], Texas A&M University [College Station], Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Planetary Science Institute [Tucson] (PSI), Joanneum Research, University of Copenhagen = Københavns Universitet (UCPH), Geology Department, Western Washington University, Western Washington University (WWU), School of Earth and Space Exploration [Tempe] (SESE), Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, The Natural History Museum [London] (NHM), The University of Tennessee [Knoxville], Berkeley Geochronology Center (BGC), NASA Johnson Space Center (JSC), NASA, Planetary Geosciences Institute [Knoxville], Department of Earth and Planetary Sciences [Knoxville], The University of Tennessee [Knoxville]-The University of Tennessee [Knoxville], Rice University [Houston], and Lunar and Planetary Institute
Subjects: Jezero crater, delta, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], Mars 2020, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars, sedimentology
Abstract: International audience; Orbital and rover observations of relict geomorphic features and stratigraphic architectures indicate Mars once had a warmer, wetter climate. Constraining the character, relative timing and persistence of ancient aqueous activity on Mars is possible through detailed interrogation of the stratal geometry of aqueously deposited sedimentary bodies. Such analyses inform interpretations of Martian climate evolution, potential habitability, and search strategies for rocks that might contain potential biosignatures. NASA’s Mars 2020 Perseverance rover mission is seeking signs of ancient life in Jezero crater and is collecting a cache of Martian rock and soil samples for planned return to Earth by a future mission.A prominent sedimentary fan deposit at the western margin of Jezero crater has been interpreted to be a riverdelta that built into an ancient lake basin during the Late Noachian-Early Hesperian epochs on Mars (~3.6-3.8Ga) [1, 2]. The Perseverance rover landed on 18 February 2021 ~2.2 km from the western fan. In March-April 2022, the rover conducted a rapid traverse along the eastern and southeastern side of Jezero fan onlyobtaining a few remote sensing observations along the way. In April 2022, the rover arrived at the base of theancient delta in the Three Forks region of the crater floor adjacent to the delta front (Fig. 1). During the ‘rapidtraverse’ and the exploration of two sections at the delta front - Cape Nukshak and Hawksbill Gap –Perseverance obtained striking images from the Mastcam-Z and SuperCam’s Remote Micro-Imagerinstruments of the stratigraphy exposed stratigraphically higher up in the fan’s erosional front [3]. Images providenew views of the stratigraphy exposed in the erosional front of the western Jezero delta; in particular, showingsections of the delta previously not visible from long distance observations and at much higher resolution.Here, we report its stratigraphy and sedimentology, which provide new constraints on the nature of the fandeposits, and therefore paleoenvironmental implications.
Published: 2023

4. LITHOFACIES, FLOW DIRECTIONS, AND PRELIMINARY DEPOSITIONAL INTERPRETATIONS OF LEDGE-FORMING SANDSTONES AT ALAGNAK, JEZERO CRATER, MARS

Author: Ives, Libby, Stack‐Morgan, Katie, Barnes, Robert, Gupta, Sanjeev, Caravaca, Gwénaël, Russell, Patrick, Annex, Andrew M., Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Earth Science and Engineering [Imperial College London], Imperial College London, 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), 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), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), and Lunar and Planetary Institute
Subjects: Jezero crater, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars 2020, Alagnak, sedimentology, stratigraphy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, mars
Abstract: International audience; The Mars 2020 Perseverance rover is exploring a sedimentary deposit interpreted to be theremnants of a delta within Jezero crater, a 45 km diameter Late Noachian-aged crater. During itsexploration of the “lower delta” exposure of the western delta/fan in Jezero crater, Mars (Fig. 1), Perseveranceacquired image and composition data from Alagnak, a ~2 m thick, well-exposed outcrop of clastic sedimentaryrock located at Cape Nukshak (Fig. 1).This outcrop was thoroughly documented from multiple angles at a cm-scale by the Mastcam-Z camerasystem [1] and the Supercam Remote Micro-Imager (RMI) [2] on the Perseverance rover. Dip and strikemeasurements of sedimentary beds were collected from 3D reconstructions of Mastcam-Z stereo-imagescollected using the Planetary Robotics software tools PRoViP and PRo3D [3].In this study, we examine the physical sedimentology and stratigraphic context of the Alagnakoutcrop. The preliminary depositional interpretation of Alagnak is as a prograding, subaqueous fan builtthrough the deposition of many, meter-scale, gravity driven, sediment-rich flows. Flow directions rangedbetween NNE and SW, with principal directions toward SE and E.
Published: 2023

5. OVERVIEW OF THE BEDROCK GEOCHEMISTRY AND MINERALOGY OBSERVED BY SUPERCAM DURING PERSEVERANCE'S DELTA FRONT CAMPAIGN

Author: Dehouck, Erwin, Forni, Olivier, Quantin-Nataf, Cathy, Beck, Pierre, Mangold, Nicolas, Royer, Clément, Clavé, Elise, Beyssac, Olivier, Johnson, Jeffrey, Mandon, Lucia, Poulet, François, Le Mouélic, Stéphane, Caravaca, Gwénaël, Kalucha, Hemani, Gibbons, Erin, Dromart, Gilles, Gasda, Patrick, Meslin, Pierre-Yves, Schroeder, Susanne, Udry, Arya, Anderson, Ryan B., Clegg, Samuel, Cousin, Agnès, Gabriel, Travis, Lasue, Jérémie, Fouchet, Thierry, Pilleri, Paolo, Pilorget, Cédric, Hurowitz, Joel, Núñez, Jorge, Williams, Amy, Russell, Patrick, Simon, Justin I., Maurice, Sylvestre, Wiens, Roger, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), 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), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), McGill University = Université McGill [Montréal, Canada], Los Alamos National Laboratory (LANL), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), University of Nevada [Las Vegas] (WGU Nevada), US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), United States Geological Survey (USGS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), NASA Johnson Space Center (JSC), NASA, and Lunar and Planetary Institute
Subjects: jezero crater, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars 2020, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, mars, delta front, geochemistry
Abstract: International audience; In February 2021, the Perseverance rover landed in Jezero crater, Mars. The crater floor was found to be composed of lava flows and cumulate rocks [1-5]. These magmatic rocks appear to have undergone some limited aqueous alteration; however, it is not clear whether this alteration is related to the lacustrine phase of the crater [1,3,6,7].After completing its exploration of the crater floor, Perseverance reached the foot of the Jezero western fan in late April 2022 (sol ~422). Long-distance images acquired earlier in the mission had already confirmed the deltaic nature of the fan [8], which had long been suspected from orbital observations [9,10]. Between April and December 2022, Perseverance investigated the basal layers of the delta at two locations named Hawksbill Gap and Cape Nukshak, which are ~400 m apart [11]. Here, we present an overview of the geo-chemistry and mineralogy of the delta rocks as observed by SuperCam, and show that these rocks record a diver-sity of past aqueous alteration environments.
Published: 2023

6. Light-toned veins and material in Jezero crater, Mars, as seen in-situ via NASA's Perseverance rover (Mars 2020 mission): stratigraphic distribution and compositional results from the supercam instrument

Author: Nachon, Marion, López-Reyes, Guillermo, Meslin, Pierre-Yves, M. Ollila, Ann, Mandon, Lucia, Clavé, Elise, Forni, Olivier, Maurice, Sylvestre, Wiens, Roger, Gasnault, Olivier, Quantin-Nataf, Cathy, Mangold, Nicolas, Clegg, Samuel, Cousin, Agnès, Lasue, Jérémie, Dehouck, Erwin, Pilleri, Paolo, Team, The Supercam, Bell III, J.F., Horgan, Briony, Núñez, Jorge, Stack‐Morgan, Katie, Tebolt, Michelle, Caravaca, Gwénaël, Gupta, Sanjeev, Calef, Fred J., Crumpler, Larry, Siljeström, Sandra, Russell, Patrick, Williams, Amy, Shuster, David L., Rice, James, Brown, Adrian, Holm-Alwmark, Sanna, Kanine, Oak, Texas A&M University [College Station], Universidad de Valladolid [Valladolid] (UVa), 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), 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), Los Alamos National Laboratory (LANL), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Arizona State University [Tempe] (ASU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Geological Sciences [Austin], Jackson School of Geosciences (JSG), University of Texas at Austin [Austin]-University of Texas at Austin [Austin], Department of Earth Science and Engineering [Imperial College London], Imperial College London, New Mexico Museum of Natural History and Science (NMMNHS), RISE Research Institutes of Sweden, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), Berkeley Geochronology Center (BGC), School of Earth and Space Exploration [Tempe] (SESE), NASA Headquarters, Plancius Research LLC, University of Copenhagen = Københavns Universitet (UCPH), and Lunar and Planetary Institute
Subjects: Jezero crater, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], Mars 2020, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], sedimentology, veins, diagenesis
Abstract: International audience; Within Jezero crater, the Perseverance rover currently explores the lowermost-exposed scarp of the delta (Fig. 1) [1,2]. Here we: (1) present the distribution of light-toned veins currently observed via the rover along its route in Jezero crater; (2) introduce compositional results of veins as analyzed via Perseverance’s SuperCam instrument, and place them into the context of results from the other instruments.
Published: 2023

7. SEDIMENTOLOGY AND STRATIGRAPHY OF THE LOWER DELTA SEQUENCE, JEZERO CRATER,MARS

Author: Stack‐Morgan, Katie, Gupta, Sanjeev, Tebolt, Michelle, Caravaca, Gwénaël, Ives, Libby, Russell, Patrick, Shuster, David L., Williams, Amy, Holm-Alwmark, Sanna, Barnes, Robert, Bell, Jim F., Beyssac, Olivier, Brown, Adrian, Flannery, David, Grotzinger, John, Horgan, Briony, Hurowitz, Joel, Kalucha, Hemani, Kanine, Oak, Núñez, Jorge, Randazzo, Nicolas, Seeger, Christina, Simon, Justin I., Tice, Michael M., Williams, Rebecca M.E., Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Earth Science and Engineering [Imperial College London], Imperial College London, University of Texas at Austin [Austin], 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), 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), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Berkeley Geochronology Center (BGC), Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), University of Copenhagen = Københavns Universitet (UCPH), Arizona State University [Tempe] (ASU), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), NASA Headquarters, Plancius Research LLC, Queensland University of Technology [Brisbane] (QUT), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Purdue University [West Lafayette], Department of Geosciences [Stony Brook], Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), University of Alberta, NASA Johnson Space Center (JSC), NASA, Texas A&M University [College Station], Planetary Science Institute [Tucson] (PSI), and Lunar and Planetary Institute
Subjects: Jezero crater, delta, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], shenandoah formation, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars 2020, Mars, stratigraphy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Sedimentology
Abstract: International audience; In April 2022, the Mars 2020 Perseverance rover arrived at the base of the ancient delta in Jezero crater after completing the first year of its mission exploring and sampling aqueously altered igneous rocks of the present-day crater floor [1]. Perseverance then spent ~200 sols exploring the lower ~25 m of rock exposed within the eastern scarp of the Jezero delta [2], a sedimentary sequence informally named the ‘Shenandoah’ formation. This studydescribes the sedimentology and stratigraphy of the Shenandoah formation explored by Perseverance at two sections—'Cape Nukshak’ and ‘Hawksbill Gap’— including a description, interpretation, and depositional framework for the facies that comprise it.
Published: 2023

8. EXPLORING THE JEZERO DELTA FRONT: OVERVIEW OF RESULTS FROM THE MARS 2020 PERSEVERANCE ROVER'S SECOND SCIENCE CAMPAIGN

Author: Williams, Amy, Russell, Patrick, Sun, Vivian Z., Shuster, David L., Stack‐Morgan, Katie, Farley, Kenneth A., del Sesto, Tyler, Kronyak, Rachel E., Bell, Jim F., Beyssac, Olivier, Brown, Adrian J., Caravaca, Gwénaël, Gupta, Sanjeev, Núñez, Jorge, Randazzo, Nicolas, Simon, Justin I., Wadhwa, Meenakshi, Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Berkeley Geochronology Center (BGC), Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley] (UC Berkeley), California Institute of Technology (CALTECH), Arizona State University [Tempe] (ASU), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Plancius Research LLC, 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), 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), Department of Earth Science and Engineering [Imperial College London], Imperial College London, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), University of Alberta, NASA Johnson Space Center (JSC), NASA, and Lunar and Planetary Institute
Subjects: jezero crater, delta, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars, mars 2020, sedimentology, stratigraphy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, delta front campaign
Abstract: International audience; The Perseverance rover landed in Jezero crater on February 18, 2021, with the mission goals to explore the geology, astrobiological potential, and modern environment of the crater floor and delta, and to collect and cache well-documented samples for Mars Sample Return. After completion of the “Crater Floor” science campaign [1], the rover conducted a rapid traverse (sols 379-414) to the Three Forks region of the crater floor adjacent to the delta front. From here, Perseverance’s second “Delta Front” science campaign (DFC) began on Sol 415, April 20, 2022. The DFC has explored two lobes of the delta front, the neighboring crater floor, and their contact zone, focusing on the lowest geologic exposures composing the Jezero delta (largely mapped within the delta “thin layered unit” [2]). As of January 1, 2023, Perseverance has covered 14325 km of traverse distance and collected 15 rock sample cores, 2 regolith samples, 1 atmospheric sample, and 3 witness tubes, employing a sample pair strategy where each unique sample is paired with a companion sample core from the same location, to enable the construction of two different caches [3]. After sample depot construction at Three Forks, the DFC will conclude upon re-ascent of the delta front, and the next “Delta Top” science campaign will start.
Published: 2023

9. Fine-Scale Sedimentary Architecture of the Jezero Western Delta Front

Author: Gupta, Sanjeev, Bell, Jim F., Caravaca, Gwénaël, Kanine, Oak, Mangold, Nicolas, Stack, Kathryn, Tate, Christian, Tice, Michael M., Williams, Amy, Russell, Patrick, Núñez, Jorge, Dromart, Gilles, Williams, Rebecca M. E., Le Mouélic, Stéphane, Barnes, Robert, Annex, Andrew, Paar, Gerhard, Holm-Alwmark, Sanna, Rice, Melissa S., Rice, James, Horgan, Briony, Grotzinger, John, Maki, Justin, Hickman-Lewis, Keyron, Kah, Linda, Shuster, David L., Simon, Justin I., Minitti, Michelle, Siebach, Kirsten, Gasnault, Olivier, Wiens, Roger, Maurice, Sylvestre, Farley, Kenneth A., Department of Earth Science and Engineering [Imperial College London], Imperial College London, Arizona State University [Tempe] (ASU), 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), 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), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Cornell University [New York], Texas A&M University [College Station], Department of Geological Sciences [Gainesville] (UF|Geological), University of Florida [Gainesville] (UF), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Planetary Science Institute [Tucson] (PSI), Joanneum Research, University of Copenhagen = Københavns Universitet (UCPH), Geology Department, Western Washington University, Western Washington University (WWU), School of Earth and Space Exploration [Tempe] (SESE), Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, The Natural History Museum [London] (NHM), The University of Tennessee [Knoxville], Berkeley Geochronology Center (BGC), NASA Johnson Space Center (JSC), NASA, Planetary Geosciences Institute [Knoxville], Department of Earth and Planetary Sciences [Knoxville], The University of Tennessee [Knoxville]-The University of Tennessee [Knoxville], Rice University [Houston], and American Geophysical Union
Subjects: gibert-delta, Jezero crater, delta, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Mars 2020, sedimentology, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, sedimentary architecture
Abstract: International audience; A key exploration target for the Perseverance rover mission is a sedimentary fan deposit at the western margin of Jezero crater, which has been interpretated to be a river delta that built into a lake basin during the Late Noachian-Early Hesperian epochs on Mars (~3.6-3.8 Ga). Images from the Mastcam-Z and SuperCam Remote Micro-Imager instruments provide striking views of the stratigraphy exposed in the fan’s erosional front. Here, we report its stratigraphy and sedimentology, which place constraints on the nature of the fan deposits and their paleoenvironmental implications.Multiple Mastcam-Z mosaics show spectacular views of the stratigraphy of a prominent embayment in the delta scarp that has been informally named Hawksbill Gap, the lower section of which the rover is investigating and sampling. The prominent cliffs of the eastern and western margin of Hawksbill Gap show distinctive stratal geometries with complex stratigraphic relations. The basal succession comprises poorly exposed thinly bedded, planar laminated sandstones that are interpreted as the deposits of low-density turbidity currents. A locally prominent, resistant unit named Rocky Top comprises planar stratified pebbly sandstones also likely to be high-density turbidite deposits. The stratigraphic mid-sections of the scarps are characterized by packages of decameter-scale inclined tabular strata. These tabular beds are locally conglomeratic but predominantly comprise finer-than-conglomerate lithologies, likely pebbly sandstones. Interstratified within these are poorly sorted matrix-supported conglomerates interpreted to be debris flow deposits. The inclined strata are overlain across a sharp truncation surface by generally planar parallel thin-bedded horizontal strata that we interpret as topset beds. Conglomerate beds containing bouldersare located within the overlying topset strata. The stratal patterns are broadly consistent with deposition in a Gilbert-type delta setting with basal strata representing deposition from sediment gravity flows, inclined strata representing foreset beds, and overlying topset beds deposition from fluvial processes in a delta top environment. The boulder conglomerates indicate sediment-transport on the delta top by episodic high-discharge floods.
Published: 2022

10. Citizen seismology helps decipher the 2021 Haiti earthquake

Author: E. Calais, S. Symithe, T. Monfret, B. Delouis, A. Lomax, F. Courboulex, J. P. Ampuero, P. E. Lara, Q. Bletery, J. Chèze, F. Peix, A. Deschamps, B. de Lépinay, B. Raimbault, R. Jolivet, S. Paul, S. St Fleur, D. Boisson, Y. Fukushima, Z. Duputel, L. Xu, L. Meng, Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), LMI CARIBACT, URGéo, Université d’Etat d’Haïti, Faculté des Sciences (UEH, FDS), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Department of Earth and Atmospheric Sciences [West Lafayette], Purdue University [West Lafayette], Faculté des Sciences, Laboratoire URGéo, Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona] (ICM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), ALomax Scientific, Mouans Sartoux, Instituto Geofisico Del Perú, Lima, Peru, International Research Institute of Disaster Science, Tohoku University [Sendai], Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris (IPG Paris), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), ANR-21-CE03-0010,OSMOSE,Vers un réseau d'observation socio-sismologique multi-acteur pour la réduction du risque sismique en Haiti(2021), Centre National de la Recherche Scientifique (France), Institut de Recherche pour le Développement (France), European Commission, Institut Universitaire de France, Université Côte d'Azur, Ambassade de France en Haïti, Agence Nationale de la Recherche (France), and Agencia Estatal de Investigación (España)
Subjects: [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, Multidisciplinary, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
Abstract: 5 pages, 4 figures, supplementary materials https://doi.org/10.1126/science.abn1045.-- Data and materials availability: All data and code used in this study are openly available. RADAR data can be obtained through ESA (Sentinel) or JAXA (Alos-2). Aftershock data can be obtained from https://ayiti.unice.fr/ayiti-seismes/ (7). The codes used to process or model the data are published and public (8). The catalog of high-precision earthquake relocated with the NLL-SSST-coherence procedure (SM4) is available as supplementary data, On 14 August 2021, the moment magnitude (Mw) 7.2 Nippes earthquake in Haiti occurred within the same fault zone as its devastating 2010 Mw 7.0 predecessor, but struck the country when field access was limited by insecurity and conventional seismometers from the national network were inoperative. A network of citizen seismometers installed in 2019 provided near-field data critical to rapidly understand the mechanism of the mainshock and monitor its aftershock sequence. Their real-time data defined two aftershock clusters that coincide with two areas of coseismic slip derived from inversions of conventional seismological and geodetic data. Machine learning applied to data from the citizen seismometer closest to the mainshock allows us to forecast aftershocks as accurately as with the network-derived catalog. This shows the utility of citizen science contributing to our understanding of a major earthquake, This work was supported by the Centre National de la Recherche Scientifique (CNRS) and the Institut de Recherche pour le Développement (IRD) through their “Natural Hazard” program (E.C., S.S., T.M., B.D., F.C., J.P.A., J.C., A.D., D.B., S.P.); the FEDER European Community program within the Interreg Caraïbes “PREST” project (E.C., S.S., D.B.); Institut Universitaire de France (E.C., R.J.); Université Côte d’Azur and the French Embassy in Haiti (S.P.); the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant no. 758210, Geo4D project to R.J. and grant no. 805256 to Z.D.); the French National Research Agency (project ANR-21-CE03-0010 “OSMOSE” to E.C. and ANR-15-IDEX-01 “UCAJEDI Investments in the Future” to Q.B.); the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant no. 949221 to Q.B.); and HPC resources of IDRIS (under allocations 2020-AD011012142, 2021-AP011012536, and 2021-A0101012314 to Q.B., With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)
Published: 2022

11. Crustal and time-varying magnetic fields at the InSight landing site on Mars

Author: Christopher T. Russell, Matthew Fillingim, Sabine Stanley, Lu Pan, Benoit Langlais, William B. Banerdt, Peter Chi, Catherine L. Johnson, Chloé Michaut, Aymeric Spiga, Philippe Lognonné, Don Banfield, François Forget, Veronique Ansan, Steve Joy, Yanan Yu, Mark A. Wieczorek, Anna Mittelholz, Suzanne E. Smrekar, Shea N. Thorne, C. Quantin-Nataf, Matthew P. Golombek, H. Haviland, Xinping Liu, Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), University of British Columbia (UBC), Planetary Science Institute [Tucson] (PSI), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Cornell University [New York], Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA., Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Marshall Space Flight Center, Huntsville, AL, USA, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA, Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA, Morton K. Blaustein Department of Earth and Planetary Sciences [Baltimore], Johns Hopkins University (JHU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), InSight Project at the Jet Propulsion Laboratory, California Institute of Technology National Aeronautics & Space Administration (NASA) InSight Participating Scientist Program Canadian Space Agency Centre National D'etudes Spatiales Green Foundation for Earth Sciences during leave at the Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography (2019-2020), University of California (UC)-University of California (UC), University of California [Berkeley] (UC Berkeley), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Martian, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Field (physics), MANTLE, Mars Exploration Program, Geophysics, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Magnetic field, Atmosphere, Magnetization, Solar wind, ELECTRICAL-CONDUCTIVITY, [SDU]Sciences of the Universe [physics], 13. Climate action, Physics::Space Physics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, MOON, Geology, 0105 earth and related environmental sciences, Dynamo
Abstract: Magnetic fields provide a window into a planet’s interior structure and evolution, including its atmospheric and space environments. Satellites at Mars have measured crustal magnetic fields indicating an ancient dynamo. These crustal fields interact with the solar wind to generate transient fields and electric currents in Mars’s upper atmosphere. Surface magnetic field data play a key role in understanding these effects and the dynamo. Here we report measurements of magnetic field strength and direction at the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) landing site on Mars. We find that the field is ten times stronger than predicted by satellite-based models. We infer magnetized rocks beneath the surface, within ~150 km of the landing site, consistent with a past dynamo with Earth-like strength. Geological mapping and InSight seismic data suggest that much or all of the magnetization sources are carried in basement rocks, which are at least 3.9 billion years old and are overlain by between 200 m and ~10 km of lava flows and modified ancient terrain. Daily variations in the magnetic field indicate contributions from ionospheric currents at 120 km to 180 km altitude. Higher-frequency variations are also observed; their origin is unknown, but they probably propagate from even higher altitudes to the surface. We propose that the time-varying fields can be used to investigate the electrical conductivity structure of the martian interior. The magnetic field measured by the InSight lander on Mars varies daily and is ten times stronger than expected. The field is inferred to originate from components of basement rocks magnetized by an ancient dynamo of Earth-like strength.
Published: 2020

12. Investigation of the homogeneity of energy conversion processes at dipolarization fronts from MMS measurements

Author: S. W. Alqeeq, O. Le Contel, P. Canu, A. Retinò, T. Chust, L. Mirioni, L. Richard, Y. Aït-Si-Ahmed, A. Alexandrova, A. Chuvatin, N. Ahmadi, S. M. Baraka, R. Nakamura, F. D. Wilder, D. J. Gershman, P. A. Lindqvist, Yu. V. Khotyaintsev, R. E. Ergun, J. L. Burch, R. B. Torbert, C. T. Russell, W. Magnes, R. J. Strangeway, K. R. Bromund, H. Wei, F. Plaschke, B. J. Anderson, B. L. Giles, S. A. Fuselier, Y. Saito, B. Lavraud, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Department of Physics and Astronomy [Uppsala], Uppsala University, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], National Institute of Aerospace [Hampton] (NIA), Institut für Weltraumforschung = Space Research institute [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), University of Texas at Arlington [Arlington], NASA Goddard Space Flight Center (GSFC), Royal Institute of Technology [Stockholm] (KTH ), Southwest Research Institute [San Antonio] (SwRI), Space Science Center & Department of Physics, University of New Hampshire (UNH), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), 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: [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Condensed Matter Physics, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; We report on six dipolarization fronts (DFs) embedded in fast earthward ﬂows detected by the Magnetospheric Multiscale mission during asubstorm event on 23 July 2017. We analyzed Ohm’s law for each event and found that ions are mostly decoupled from the magnetic ﬁeld byHall ﬁelds. However, the electron pressure gradient term is also contributing to the ion decoupling and likely responsible for an electrondecoupling at DF. We also analyzed the energy conversion process and found that the energy in the spacecraft frame is transferred from theelectromagnetic ﬁeld to the plasma (J E > 0) ahead or at the DF, whereas it is the opposite (J E < 0) behind the front. This reversal ismainly due to a local reversal of the cross-tail current indicating a substructure of the DF. In the ﬂuid frame, we found that the energy ismostly transferred from the plasma to the electromagnetic ﬁeld (J E0 < 0) and should contribute to the deceleration of the fast ﬂow.However, we show that the energy conversion process is not homogeneous at the electron scales due to electric ﬁeld ﬂuctuations likely relatedto lower-hybrid drift waves. Our results suggest that the role of DF in the global energy cycle of the magnetosphere still deserves more investigation. In particular, statistical studies on DF are required to be carried out with caution due to these electron scale substructures.
Published: 2022

13. Compositional mapping of Titan's surface using Cassini VIMS and RADAR data

Author: Solomonidou, Anezina, Coustenis, Athena, Le Gall, Alice, Lopes, Rosaly, Malaska, Michael, Schmidtt, Bernard, Lawrence, Kenneth, Elachi, Charles, Schoenfeld, Ashley, Sotin, Christophe, Wall, Stephen, Markonis, Yannis, Matsoukas, Christos, California Institute of Technology (CALTECH), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Faculty of Environmental Sciences [Prague], Czech University of Life Sciences Prague (CZU), PLANETO - 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), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Royal Institute of Technology [Stockholm] (KTH )
Subjects: [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2021

14. Upper‐Hybrid Waves Driven by Meandering Electrons Around Magnetic Reconnection X Line

Author: Daniel J. Gershman, Cunguo Wang, Wangping Li, Binbin Tang, Benoit Lavraud, Christopher T. Russell, James L. Burch, Cecilia Norgren, Daniel B. Graham, P. A. Lindqvist, Ari Le, Yu. V. Khotyaintsev, Andris Vaivads, Roy B. Torbert, Quanming Lu, Stephen A. Fuselier, Kyunghwan Dokgo, Jan Egedal, Mats André, Jin He, Xiaocheng Guo, Robert E. Ergun, Ferdinand Plaschke, Keizo Fujimoto, Barbara L. Giles, O. Le Contel, State Key Laboratory of Space Weather [Beijing] (SKSW), National Space Science Center [Beijing] (NSSC), Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS), Swedish Institute of Space Physics [Uppsala] (IRF), Department of Physics and Technology [Bergen] (UiB), University of Bergen (UiB), Royal Institute of Technology [Stockholm] (KTH ), Los Alamos National Laboratory (LANL), Department of Physics, University of Wisconsin—Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201, Southwest Research Institute [San Antonio] (SwRI), School of Space and Environment [Beijing], Beihang University (BUAA), School of Earth and Space Sciences [Beijing], Peking University [Beijing], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], University of New Hampshire (UNH), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center (GSFC), 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), 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), Institut für Weltraumforschung = Space Research institute [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), CAS Key Laboratory of Geospace Environment, University of Science and Technology of China [Hefei] (USTC), State Key Laboratory for Space Weather [Beijing] (SKSW), 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), Institut für Weltraumforschung [Graz] (IWF), and University of California-University of California
Subjects: Physics, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Magnetic reconnection, Electron, 01 natural sciences, Computational physics, Geophysics, 0103 physical sciences, General Earth and Planetary Sciences, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Line (formation)
Abstract: International audience
Published: 2021

15. Alfvénic versus non-Alfvénic turbulence in the inner heliosphere as observed by Parker Solar Probe

Author: Victor Réville, Phyllis Whittlesey, Anthony W. Case, Robert J. MacDowall, Olga Panasenco, Davin Larson, Peter Harvey, Justin C. Kasper, Kelly E. Korreck, Keith Goetz, Michael L. Stevens, Michel Moncuquet, Marco Velli, David M. Malaspina, Stuart D. Bale, Milan Maksimovic, Roberto Livi, Marc Pulupa, Thierry Dudok de Wit, Chen Shi, J. W. Bonnell, J. L. Verniero, Anna Tenerani, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), 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), 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), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of California-University of California, 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), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Physics, 010504 meteorology & atmospheric sciences, Magnetic energy, Turbulence, Coronal hole, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Wind speed, Solar wind, Astrophysics - Solar and Stellar Astrophysics, Physics - Space Physics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Magnetohydrodynamics, 010303 astronomy & astrophysics, Heliosphere, 0105 earth and related environmental sciences
Abstract: Context. Parker Solar Probe (PSP) measures the magnetic field and plasma parameters of the solar wind at unprecedentedly close distances to the Sun. These data provide great opportunities to study the early-stage evolution of magnetohydrodynamic (MHD) turbulence in the solar wind. Aims. In this study, we make use of the PSP data to explore the nature of solar wind turbulence focusing on the Alfvénic character and power spectra of the fluctuations and their dependence on the distance and context (i.e., large-scale solar wind properties), aiming to understand the role that different effects such as source properties, solar wind expansion, and stream interaction might play in determining the turbulent state. Methods. We carried out a statistical survey of the data from the first five orbits of PSP with a focus on how the fluctuation properties at the large MHD scales vary with different solar wind streams and the distance from the Sun. A more in-depth analysis from several selected periods is also presented. Results. Our results show that as fluctuations are transported outward by the solar wind, the magnetic field spectrum steepens while the shape of the velocity spectrum remains unchanged. The steepening process is controlled by the “age” of the turbulence, which is determined by the wind speed together with the radial distance. Statistically, faster solar wind has higher “Alfvénicity,” with a more dominant outward propagating wave component and more balanced magnetic and kinetic energies. The outward wave dominance gradually weakens with radial distance, while the excess of magnetic energy is found to be stronger as we move closer toward the Sun. We show that the turbulence properties can significantly vary from stream to stream even if these streams are of a similar speed, indicating very different origins of these streams. Especially, the slow wind that originates near the polar coronal holes has much lower Alfvénicity compared with the slow wind that originates from the active regions and pseudostreamers. We show that structures such as heliospheric current sheets and velocity shears can play an important role in modifying the properties of the turbulence.
Published: 2021

16. Modeling Wind‐Driven Ionospheric Dynamo Currents at Mars: Expectations for InSight Magnetic Field Measurements

Author: Francisco Gonzalez-Galindo, Catherine L. Johnson, François Forget, Anna Mittelholz, Yingjuan Ma, Christopher M. Fowler, Robert Lillis, Matthew Fillingim, Laila Andersson, Christopher T. Russell, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), University of British Columbia (UBC), Planetary Science Institute [Tucson] (PSI), University of Colorado [Boulder], National Aeronautics and Space Administration (US), Consejo Superior de Investigaciones Científicas (España), Ministerio de Ciencia, Innovación y Universidades (España), and Centre National de la Recherche Scientifique (France)
Subjects: Engineering, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], business.industry, Center of excellence, Mars Exploration Program, 010502 geochemistry & geophysics, 7. Clean energy, 01 natural sciences, Prime (order theory), Physics::Geophysics, Wind driven, Geophysics, Aeronautics, State agency, 13. Climate action, Research council, Physics::Space Physics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Ionosphere, business, 0105 earth and related environmental sciences, Dynamo
Abstract: We model expected dynamo currents above, and resulting magnetic field profiles at, InSight's landing site on Mars, including for the first time the effect of electron-ion collisions. We calculate their diurnal and seasonal variability using inputs from global models of the Martian thermosphere, ionosphere, and magnetosphere. Modeled currents primarily depend on plasma densities and the strength of the neutral wind component perpendicular to the combined crustal and draped magnetic fields that thread the ionosphere. Negligible at night, currents are the strongest in the late morning and near solstices due to stronger winds and near perihelion due to both stronger winds and higher plasma densities from solar EUV photoionization. Resulting surface magnetic fields of tens of nanotesla and occasionally >100 nT may be expected at the InSight landing site. We expect currents and surface fields to vary significantly with changes in the draped magnetic field caused by Mars' dynamic solar wind environment. ©2019. American Geophysical Union. All Rights Reserved., R. J. L., C. M. F., and L. A. were funded by the NASA MAVEN mission prime contract. M. O. F. was funded by the NASA Insight mission prime contract. F. G. G. was funded by the Spanish National Research Council (CSIC) under intramural project CSIC 201450E022 and acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia-CSIC (SEV-2017-0709). F. F. was funded by the French Centre National De La Recherche Scientifique.
Published: 2019

17. Variability of Precipitating Ion Fluxes During the September 2017 Event at Mars

Author: Jasper Halekas, Takuya Hara, Ronan Modolo, O. Witasse, Antoine Martinez, J. P. McFadden, Norberto Romanelli, Francis G. Eparvier, Mats Holmström, Robert Lillis, Y. J. Ma, Shannon Curry, Janet G. Luhmann, François Leblanc, Jean-Yves Chaufray, Bruce M. Jakosky, John E. P. Connerney, Davin Larson, 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), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], NASA Goddard Space Flight Center (GSFC), Imaging Sciences and Biomedical Engineering Division [London], Guy's and St Thomas' Hospital [London]-King‘s College London, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), Swedish Institute of Space Physics [Uppsala] (IRF), European Space Research and Technology Centre (ESTEC), and European Space Agency (ESA)
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Spectrometer, Astrophysics::High Energy Astrophysical Phenomena, Magnetosphere, Mars Exploration Program, Space weather, Atmospheric sciences, 01 natural sciences, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Atmosphere, Solar wind, Geophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Coronal mass ejection, Astrophysics::Solar and Stellar Astrophysics, Environmental science, Dynamic pressure, Astrophysics::Earth and Planetary Astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences
Abstract: International audience; In this work, we study the influence of the September 2017 solar event on the precipitating heavy ion fluxes towards Mars' atmosphere as seen by MAVEN/SWIA, an energy and angular ion spectrometer and by MAVEN/STATIC, an energy, mass and angular ion spectrometer. After a careful reconstruction of the background induced by the Solar Energetic Particle (SEP) event in the MAVEN/SWIA spectrometer, we investigate the precipitating ion flux responses to the space weather events that took place in September 2017. This period is a unique opportunity to analyze the respective role of various possible drivers of heavy ion precipitation into Mars’ atmosphere with a wide range of different space weather events occurring during the same month. This study shows an increase in the precipitation flux by more than one order of magnitude during the arrival of the September Interplanetary Coronal Mass Ejection (ICME) compared to the average flux during quiet solar conditions. We also showed that among the possible solar drivers, the solar wind dynamic pressure is the most significant during September 2017.
Published: 2019

18. Patterns of Element Incorporation in Calcium Carbonate Biominerals Recapitulate Phylogeny for a Diverse Range of Marine Calcifiers

Author: Robert N. Ulrich, Maxence Guillermic, Julia Campbell, Abbas Hakim, Rachel Han, Shayleen Singh, Justin D. Stewart, Cristian Román-Palacios, Hannah M. Carroll, Ilian De Corte, Rosaleen E. Gilmore, Whitney Doss, Aradhna Tripati, Justin B. Ries, Robert A. Eagle, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Department of Atmospheric and Oceanic Sciences [Los Angeles] (AOS), Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Interdisciplinary Graduate School for the Blue planet, ANR-17-EURE-0015,ISBlue,Interdisciplinary Graduate School for the Blue planet(2017), and University of California (UC)-University of California (UC)
Subjects: 010504 meteorology & atmospheric sciences, Science, trace elements, ocean acidification, engineering.material, phylogeny, aragonite, 01 natural sciences, Physical Geography and Environmental Geoscience, 03 medical and health sciences, chemistry.chemical_compound, 14. Life underwater, Life Below Water, 030304 developmental biology, 0105 earth and related environmental sciences, Calcite, 0303 health sciences, Aragonite, Geology, Ocean acidification, Marine invertebrates, marine calcification, biomineralization, Geophysics, Calcium carbonate, chemistry, 13. Climate action, Environmental chemistry, [SDE]Environmental Sciences, engineering, General Earth and Planetary Sciences, Carbonate, Seawater, calcite, Biomineralization
Abstract: Elemental ratios in biogenic marine calcium carbonates are widely used in geobiology, environmental science, and paleoenvironmental reconstructions. It is generally accepted that the elemental abundance of biogenic marine carbonates reflects a combination of the abundance of that ion in seawater, the physical properties of seawater, the mineralogy of the biomineral, and the pathways and mechanisms of biomineralization. Here we report measurements of a suite of nine elemental ratios (Li/Ca, B/Ca, Na/Ca, Mg/Ca, Zn/Ca, Sr/Ca, Cd/Ca, Ba/Ca, and U/Ca) in 18 species of benthic marine invertebrates spanning a range of biogenic carbonate polymorph mineralogies (low-Mg calcite, high-Mg calcite, aragonite, mixed mineralogy) and of phyla (including Mollusca, Echinodermata, Arthropoda, Annelida, Cnidaria, Chlorophyta, and Rhodophyta) cultured at a single temperature (25°C) and a range of pCO2 treatments (ca. 409, 606, 903, and 2856 ppm). This dataset was used to explore various controls over elemental partitioning in biogenic marine carbonates, including species-level and biomineralization-pathway-level controls, the influence of internal pH regulation compared to external pH changes, and biocalcification responses to changes in seawater carbonate chemistry. The dataset also enables exploration of broad scale phylogenetic patterns of elemental partitioning across calcifying species, exhibiting high phylogenetic signals estimated from both uni- and multivariate analyses of the elemental ratio data (univariate: λ = 0–0.889; multivariate: λ = 0.895–0.99). Comparing partial R2 values returned from non-phylogenetic and phylogenetic regression analyses echo the importance of and show that phylogeny explains the elemental ratio data 1.4–59 times better than mineralogy in five out of nine of the elements analyzed. Therefore, the strong associations between biomineral elemental chemistry and species relatedness suggests mechanistic controls over element incorporation rooted in the evolution of biomineralization mechanisms.
Published: 2021

19. Geomorphological map of the South Belet Region of Titan

Author: T. Verlander, Alexander Hayes, Paul Corlies, Samuel Birch, David A. Williams, Meghan Florence, Stéphane Le Mouélic, Ashley Schoenfeld, Elizabeth P. Turtle, Alice Le Gall, Michael Malaska, Rosaly M. C. Lopes, Michael A. Janssen, A. Solomonidou, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), California Institute of Technology (CALTECH), Faculty of Environmental Sciences [Prague], Czech University of Life Sciences Prague (CZU), School of Earth and Space Exploration [Tempe] (SESE), Arizona State University [Tempe] (ASU), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Department of Astronomy [Ithaca], Cornell University [New York], PLANETO - 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), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), School of Civil Engineering and Environmental Science [Norman] (CEES), and University of Oklahoma (OU)
Subjects: 010504 meteorology & atmospheric sciences, Terrain, 01 natural sciences, Latitude, symbols.namesake, Impact crater, 0103 physical sciences, 010303 astronomy & astrophysics, Geomorphology, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Alluvial fan, Astronomy and Astrophysics, Crust, 15. Life on land, Alluvial plain, Geologic processes, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Titan surface, symbols, Longitude, Titan (rocket family), Titan, Geology
Abstract: International audience; We mapped in detail Titan's South Belet region which spans from longitude 60°E to 120°E and from latitude 60°S to 0°, encompassing both equatorial and southern mid-latitude regions. We used Cassini RADAR in its Synthetic Aperture Radar (SAR) mode data as our basemap, which covers 31.8% of the region, supplemented with data from the RADAR's radiometry mode, the Imagining Science Subsystem (ISS), the Visual and Infrared Mapping Spectrometer (VIMS), and topographic data. This mapping work is a continuation of the detailed global mapping effort introduced in Malaska et al. (2016a) and continued in Lopes et al. (2020). We followed the mapping procedure described in Malaska et al. (2016a) for the Afekan Crater region and identified four major terrain classes in South Belet: craters, hummocky/mountainous, plains, and dunes. Each terrain class was subdivided into terrain units by characteristic morphology, including border shape, texture, general appearance, and radar backscatter. There are two terrain units that were not included in previous studies but were identified in our mapping of South Belet: “bright alluvial plains” and “pitted hummocky”. Similar to the Afekan Crater region, we find that plains dominate the surface make-up of South Belet, comprising ~47% of the mapped area. Unlike Afekan, the areal extent of the dunes closely rivals the dominance of plains, making up 43% of the mapped area. The next most widespread unit by area in the region following the dunes are the mountains/hummocky terrains (10%), and finally, crater terrains (0.01%). The introduction of two new units, “bright alluvial plains” and “pitted hummocky”, are necessary to capture the full range of morphologies seen in South Belet and expands our understanding of processes typical of Titan's equatorial and mid-latitude regions. For example, the presence of alluvial fans indicates a period in Titan's past where discharges and slopes were such that sediment could be mobilized and deposited. Similarly, the pits associated with the “pitted hummocky” may represent an important erosional feature, with implications for the removal of volatiles from Titan's crust. However, analysis of our geomorphological mapping results suggests the geology of South Belet is consistent with the narrative of organics dominating the equatorial and mid-latitudes. This is similar to the conclusion we arrived at through our mapping and analysis of the Afekan region. Lastly, the applicability of the terrain units from our mapping of the Afekan region, which bears a similar latitude but in the northern hemisphere, to our mapping of South Belet suggests latitudinal symmetry in Titan's surface processes and their evolution.
Published: 2021

20. Turbulent Plasma Jet Fronts and Related Ion Acceleration

Author: Drew Turner, Christopher T. Russell, Ian J. Cohen, Per-Arne Lindqvist, Olivier Le Contel, Louis Richard, Daniel B. Graham, Yuri V. Khotyaintsev, Barbara L. Giles, Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), NASA Goddard Space Flight Center (GSFC), Royal Institute of Technology [Stockholm] (KTH ), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), and University of California-University of California
Subjects: Turbulent plasma, Physics, Jet (fluid), [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mechanics, Ion acceleration
Abstract: We investigate an earthward bursty bulk flow (BBF) observed by the Magnetospheric Multiscale (MMS) spacecraft in the Earth’s magnetotail (XGSM ~ -23.88 RE, YGSM ~ 6.72 RE, ZGSM ~ 4.06 RE). At the leading edge of the BBF we observe a complex magnetic field structure. In particular, within this region we identify multiple dipolarization fronts (DFs) and large amplitude oscillations of the magnetic field BX, which correspond to a long wavelength current sheet flapping motion. Within the DFs, we observe increased fluxes of energetic ions and electrons. We investigate the trapping of the ions between two consecutive DFs. We discuss the ion acceleration mechanism and the adiabaticity of the ion energisation process.
Published: 2021

21. A chemical composition map for Titan’s surface

Author: Ashley Schoenfeld, Rosaly M. C. Lopes, Yannis Markonis, Christophe Sotin, Bernard Schmitt, Athena Coustenis, Pierre Drossart, Christos Matsoukas, Kenneth J. Lawrence, Alice Le Gall, S. D. Wall, A. Solomonidou, Charles Elachi, Michael Malaska, California Institute of Technology (CALTECH), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), PLANETO - 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 Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Equator, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Diffuse sky radiation, Context (language use), Geophysics, 15. Life on land, Albedo, Latitude, Atmosphere, symbols.namesake, 13. Climate action, symbols, Radiometry, Titan (rocket family), Geology
Abstract: The investigation of Titan’s surface chemical composition is of great importance for the understanding of the atmosphere-surface-interior system of the moon. The Cassini cameras and especially the Visual and infrared Mapping Spectrometer has provided a sequence of spectra showing the diversity of Titan’s surface spectrum from flybys performed during the 13 years of Cassini’s operation. In the 0.8-5.2 μm range, this spectro-imaging data showed that the surface consists of a multivariable geological terrain hosting complex geological processes. The data from the seven narrow methane spectral “windows” centered at 0.93, 1.08, 1.27, 1.59, 2.03, 2.8 and 5 μm provide some information on the lower atmospheric context and the surface parameters. Nevertheless, atmospheric scattering and absorption need to be clearly evaluated before we can extract the surface properties. In various studies (Solomonidou et al., 2014; 2016; 2018; 2019; 2020a, 2020b; Lopes et al., 2016; Malaska et al., 2016; 2020), we used radiative transfer modeling in order to evaluate the atmospheric scattering and absorption and securely extract the surface albedo of multiple Titan areas including the major geomorphological units. We also investigated the morphological and microwave characteristics of these features using Cassini RADAR data in their SAR and radiometry mode. Here, we present a global map for Titan’s surface showing the chemical composition constraints for the various units. The results show that Titan’s surface composition, at the depths detected by VIMS, has significant latitudinal dependence, with its equator being dominated by organic materials from the atmosphere and a very dark unknown material, while higher latitudes contain more water ice. The albedo differences and similarities among the various geomorphological units give insights on the geological processes affecting Titan’s surface and, by implication, its interior. We discuss our results in terms of origin and evolution theories.[1] Solomonidou, A., et al. (2014), J. Geophys. Res. Planets, 119, 1729; [2] Solomonidou, A., et al. (2016), Icarus, 270, 85; [3] Solomonidou, A., et al. (2018), J. Geophys. Res. Planets, 123, 489; [4] Solomonidou, A., et al. (2020a), Icarus, 344, 113338; [5] Solomonidou, A., et al. (2020b), A&A 641, A16; [6] Lopes, R., et al. (2016) Icarus, 270, 162; [7] Malaska, M., et al. (2016), Icarus 270, 130; [8] Malaska, M., et al. (2020), Icarus, 344, 113764.
Published: 2021

22. Investigating the Origin of the First Ionization Potential Effect With a Shell Turbulence Model

Author: Alexis P. Rouillard, Michael Lavarra, Andrea Verdini, Nicolas Poirier, Victor Réville, Eric Buchlin, Marco Velli, 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), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), 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), 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), University of California (UC)-University of California (UC), Università degli Studi di Firenze = University of Florence (UniFI), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: chromosphere, 010504 meteorology & atmospheric sciences, lcsh:Astronomy, 01 natural sciences, 7. Clean energy, lcsh:QB1-991, Acceleration, slow wind, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Chromosphere, 0105 earth and related environmental sciences, Physics, Turbulence, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], turbulence, lcsh:QC801-809, Astronomy and Astrophysics, Mechanics, Coronal loop, Dissipation, Magnetic field, Alfvén waves, transition region, Alfven waves, Solar wind, lcsh:Geophysics. Cosmic physics, Amplitude, 13. Climate action, Physics::Space Physics
Abstract: International audience; The enrichment of coronal loops and the slow solar wind with elements that have low First Ionization Potential, known as the FIP effect, has often been interpreted as the tracer of a common origin. A current explanation for this FIP fractionation rests on the influence of ponderomotive forces and turbulent mixing acting at the top of the chromosphere. The implied wave transport and turbulence mechanisms are also key to wave-driven coronal heating and solar wind acceleration models. This work makes use of a shell turbulence model run on open and closed magnetic field lines of the solar corona to investigate with a unified approach the influence of magnetic topology, turbulence amplitude and dissipation on the FIP fractionation. We try in particular to assess whether there is a clear distinction between the FIP effect on closed and open field regions.
Published: 2021

23. Fossil Corals With Various Degrees of Preservation Can Retain Information About Biomineralization-Related Organic Material

Author: Jeana L. Drake, Maxence Guillermic, Robert A. Eagle, David K. Jacobs, Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, LabexMER Marine Excellence Research: a changing ocean, ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), and University of California (UC)-University of California (UC)
Subjects: 010504 meteorology & atmospheric sciences, Science, Coral, [SDV]Life Sciences [q-bio], Geochemistry, trace elements, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Physical Geography and Environmental Geoscience, chemistry.chemical_compound, Carboniferous, Organic matrix, 14. Life underwater, 0105 earth and related environmental sciences, Calcite, amino acids, Aragonite, fungi, Geology, Diagenesis, X-ray diffraction, Calcium carbonate, Geophysics, chemistry, scleractinians, engineering, General Earth and Planetary Sciences, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, mineralogy, Biomineralization
Abstract: International audience; Scleractinian corals typically form a robust calcium carbonate skeleton beneath their living tissue. This skeleton, through its trace element composition and isotope ratios, may record environmental conditions of water surrounding the coral animal. While bulk unrecrystallized aragonite coral skeletons can be used to reconstruct past ocean conditions, corals that have undergone significant diagenesis have altered geochemical signatures and are typically assumed to retain insufficient meaningful information for bulk or macrostructural analysis. However, partially recrystallized skeletons may retain organic molecular components of the skeletal organic matrix (SOM), which is secreted by the animal and directs aspects of the biomineralization process. Some SOM proteins can be retained in fossil corals and can potentially provide past oceanographic, ecological, and indirect genetic information. Here, we describe a dataset of scleractinian coral skeletons, aged from modern to Cretaceous plus a Carboniferous rugosan, characterized for their crystallography, trace element composition, and amino acid compositions. We show that some specimens that are partially recrystallized to calcite yield potentially useful biochemical information whereas complete recrystalization or silicification leads to significant alteration or loss of the SOM fraction. Our analysis is informative to biochemical-paleoceanographers as it suggests that previously discounted partially recrystallized coral skeletons may indeed still be useful at the microstructural level.
Published: 2021

24. Geochemical, biological and clumped isotopologue evidence for substantial microbial methane production under carbon limitation in serpentinites of the Samail Ophiolite, Oman

Author: Shuhei Ono, Sebastian H. Kopf, Alexis S. Templeton, Mark E. Conrad, Edward D. Young, Daniel B. Nothaft, Peter B. Kelemen, Hannah M. Miller, Eric S. Boyd, Jeemin H. Rhim, Jabrane Labidi, Juerg M. Matter, David T. Wang, Department of Geological Sciences [Boulder], University of Colorado [Boulder], Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Montana State University (MSU), National Oceanography Centre [Southampton] (NOC), University of Southampton, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], and Lawrence Berkeley National Laboratory [Berkeley] (LBNL)
Subjects: Methanobacterium, Atmospheric Science, 010504 meteorology & atmospheric sciences, Hydrogen, Methanogenesis, Soil Science, chemistry.chemical_element, Aquatic Science, 010502 geochemistry & geophysics, Ophiolite, 01 natural sciences, Methane, 03 medical and health sciences, chemistry.chemical_compound, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Isotopologue, 0105 earth and related environmental sciences, Water Science and Technology, Alkane, chemistry.chemical_classification, 0303 health sciences, Ecology, biology, 030306 microbiology, Paleontology, Forestry, biology.organism_classification, chemistry, 13. Climate action, Environmental chemistry, Carbon
Abstract: International audience; In hyperalkaline (pH > 10) fluids that have participated in low-temperature (< 150°C) serpentinization reactions, the dominant form of C is often methane (CH4), but the origin of this CH4 is uncertain. To assess CH4 origin in serpentinite aquifers within the Samail Ophiolite, Oman, we determined fluid chemical compositions, analyzed taxonomic pro29 files of fluid-hosted microbial communities, and measured isotopic compositions of hy30 drocarbon gases. We found that 16S rRNA gene sequences affiliated with methanogens were widespread in the aquifer. We measured clumped isotopologue (13CH3D and 12CH2D2) relative abundances less than equilibrium, consistent with substantial microbial CH4 pro33 duction. Further, we observed an inverse relationship between dissolved inorganic C concentrations and δ13 CCH4 across fluids bearing microbiological evidence of methanogenic activity, suggesting that the apparent C isotope effect of microbial methanogenesis is mod36 ulated by C availability. An additional source of CH4 is evidenced by the presence of CH4-bearing fluid inclusions in the Samail Ophiolite and our measurement of high δ13 C values of ethane and propane, which are similar to those reported in studies of CH4-rich inclusions in rocks from the oceanic lithosphere. In addition, we observed 16S rRNA gene sequences affiliated with aerobic methanotrophs and, in lower abundance, anaerobic methan41 otrophs, indicating that microbial consumption of CH4 in the ophiolite may further enrich CH4 in 13C. We conclude that substantial microbial CH4 is produced under vary43 ing degrees of C limitation and mixes with abiotic CH4 released from fluid inclusions. This study lends insight into the functioning of microbial ecosystems supported by wa45 ter/rock reactions.
Published: 2021

25. Recycling of nitrogen and light noble gases in the Central American subduction zone: constraints from 15 N 15 N

Author: Labidi, Jabrane, Young, E, Fischer, T, Barry, P, Ballentine, C, De Moor, J, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, The University of New Mexico [Albuquerque], Woods Hole Oceanographic Institution (WHOI), University of Oxford [Oxford], and Universidad Nacional de Costa Rica
Subjects: [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, nitrogen isotopologues, subduction of volatiles, Central American arc
Abstract: International audience; How much nitrogen and light noble gases are recycled in modern subduction zones is unclear. Fumaroles act as a means for passive degassing in arcs. They receive variable contributions of volatiles from arc magmas, themselves sourced from the mantle wedge. The gas compositions reflect the extent of volatile enrichment in sub-arc mantle sources and constrain slab dehydration. However, contributions from atmospheric components in fumaroles are unavoidable. For N2, neon and argon, the atmospheric components are challenging to discern from slab-derived components. Here, we report 15N15N measurements from eight fumaroles and seven bubbling springs, along the Central American arc. Our new 15N15N data are coupled with noble gases measurements and show that air-derived components in volcanic gas discharges can easily be underestimated, in both fumaroles and springs, using conventional stable isotope or noble gases methods. We show that, in the absence of 15N15N data, previously used tracers for air (e.g., δ26 15N N, N2/Ar, N2/He, among others) may lead to erroneous conclusions regarding the origin of volatiles in mixed gases. In contrast, 15N15N data provide quantitative constraints on the nature and contributions of both atmospheric and magmatic components. Most springs are heavily dominated by air-derived N2, while fumaroles show substantial contributions of volcanic endmembers. Based on the fumarole data, we show that magma sources beneath the central American arc are enriched in all volatiles relative to 3He, by two to three orders of magnitude compared to the MORB source. We use new 15N15N data to obtain source N2/3He, 3He/36Ar and 3He/22Ne ratios which we then use to compute volcanic N2, Ar and Ne degassing fluxes. Using this approach, we show that outgassing fluxes appear to match subduction fluxes in the Central America subduction zone. We determine an N2 outgassing flux of between 4.0 x 10^8 and 1.0 x10^9 mol N2/y, comparable to the subduction flux of 5.7 x 108 mol N2/yr determined previously. We obtain a similar conclusion for 22Ne and 38 36Ar. 39 Overall, the volatile fluxes in the central American subduction zone no longer seem to 40 require net transfer of N2, Ar, and Ne, to the deep mantle
Published: 2021

26. The Dynamics of a High Mach Number Quasi-Perpendicular Shock: MMS Observations

Author: H. Madanian, Alexandra L. Brosius, Keiichi Ogasawara, O. Le Contel, Lynn B. Wilson, Robert E. Ergun, Narges Ahmadi, Christopher Russell, Mihir Desai, S. A. Fuselier, Drew Turner, Steven J. Schwartz, D. J. Gershman, Per-Arne Lindqvist, James L. Burch, Southwest Research Institute [San Antonio] (SwRI), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], NASA Goddard Space Flight Center (GSFC), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, and Royal Institute of Technology [Stockholm] (KTH )
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 01 natural sciences, symbols.namesake, Physics - Space Physics, 0103 physical sciences, Perpendicular, Bow shock (aerodynamics), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Spacecraft, business.industry, Astronomy and Astrophysics, Space Physics (physics.space-ph), Physics - Plasma Physics, Magnetic field, Computational physics, Shock (mechanics), Plasma Physics (physics.plasm-ph), Supernova, Nonlinear system, Mach number, Space and Planetary Science, Physics::Space Physics, symbols, business
Abstract: Shock parameters at Earth's bow shock in rare instances can approach the Mach numbers predicted at supernova remnants. We present our analysis of a high Alfv\'en Mach number ($M_A= 27$) shock utilizing multipoint measurements from the Magnetospheric Multiscale (MMS) spacecraft during a crossing of Earth's quasi-perpendicular bow shock. We find that the shock dynamics are mostly driven by reflected ions, perturbations that they generate, and nonlinear amplification of the perturbations. Our analyses show that reflected ions create modest magnetic enhancements upstream of the shock which evolve in a nonlinear manner as they traverse the shock foot. They can transform into proto-shocks that propagate at small angles to the magnetic field and towards the bow shock. The nonstationary bow shock shows signatures of both reformation and surface ripples. Our observations indicate that although shock reformation occurs, the main shock layer never disappears. These observations are at high plasma $\beta$, a parameter regime which has not been well explored by numerical models., Comment: Accepted by the Astrophysical Journal
Published: 2020

27. The chemical composition of impact craters on Titan

Author: Christos Matsoukas, Athena Coustenis, Catherine D. Neish, Bernard Schmitt, Ioannis Baziotis, Michael Malaska, Kenneth J. Lawrence, Olivier Witasse, Rosaly M. C. Lopes, Anezina Solomonidou, Ashley Schoenfeld, Nico Altobelli, Pierre Drossart, Coustenis Athena, Alice Le Gall, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Agence Spatiale Européenne (ESA), European Space Agency (ESA), University of Western Ontario (UWO), European Space Astronomy Centre (ESAC), Czech University of Life Sciences Prague (CZU), Department of Earth Sciences [London, ON], Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, PLANETO - 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), European Space Research and Technology Centre (ESTEC), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Royal Institute of Technology [Stockholm] (KTH ), and Agricultural University of Athens
Subjects: geography, geography.geographical_feature_category, Alluvial fan, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 15. Life on land, symbols.namesake, Atmospheric radiative transfer codes, Impact crater, 13. Climate action, [SDU]Sciences of the Universe [physics], Middle latitudes, symbols, Radiative transfer, Ejecta blanket, Titan (rocket family), Chemical composition, Geomorphology, Geology
Abstract: We investigate nine Titan impact craters using Visual and Infrared Mapping Spectrometer (VIMS) data and a radiative transfer code (RT) [e.g. 1] in addition to emissivity data, in order to constrain the spectral behavior and composition of the craters. Past studies have looked at the chemical composition of impact craters either by using qualitative comparisons between craters [e.g. 2;3] or by combining all craters into a single unit [4], rather than separating them by geographic location or degradation state. Here, we use a radiative transfer model to first estimate the atmospheric contribution to the data, then extract the surface albedos of the impact crater subunits, and finally constrain their composition by using a library of candidate Titan materials. Following the general characterization of the impact craters, we study two impact crater subunits, the ‘crater floor’, which refers to the bottom of a crater, and the ‘ejecta blanket’, which is the material thrown out of the crater during an impact event. The results show that Titan’s mid-latitude plain craters: Afekan, Soi, and Forseti, in addition to Sinlap and Menrva are enriched in an OH-bearing constituent (likely water-ice) in an organic based mixture, while the equatorial dune craters: Selk, Ksa, Guabonito, and Santorini, appear to be purely composed of organic material (mainly unknown dune dark material). This follows the pattern seen in [4], where midlatitude alluvial fans, undifferentiated plains, and labyrinths were found to consist of a tholin-like and water-ice mixture, while the equatorial undifferentiated plains, hummocky terrains, dunes, and variable plains were found to consist of a dark material and tholin-like mixture in their very top layers. These observations also agree with the evolution scenario proposed by [3], wherein the impact cratering process produces a mixture of organic material and water ice, which is later “cleaned” through fluvial erosion in the midlatitude plains; a cleaning process that does not appear to operate in the equatorial dunes, which seem to be quickly covered by a thin layer of sand sediment. This scenario agrees with other works that suggest that atmospheric deposition is similar in the low-latitudes and midlatitudes on Titan, but with more rain falling onto the higher latitudes causing additional processing of materials in those regions [e.g. 5]. In either case, it appears that active processes are working to shape the surface of Titan, and it remains a dynamic world in the present day.[1] Hirtzig, M., et al. (2013). Icarus, 226, 470–486; [2] Neish, C.D., et al. (2015), Geophys. Res. Lett. 42, 3746–3754; [3] Werynski, A., et al. (2019), Icarus, 321, 508-521; [4] Solomonidou, A., et al. (2018), J. Geophys. Res, 123, 2, 489-507; [5] Neish, A.C., et al. (2016), Icarus, 270, 114–129.
Published: 2020

28. Methane thermometry in deep-sea hydrothermal systems: Evidence for re-ordering of doubly-substituted isotopologues during fluid cooling

Author: Marvin D. Lilley, Jabrane Labidi, Jeffrey S. Seewald, H. Tang, Thomas Giunta, Gretchen L. Früh-Green, I. E. Kohl, Edward D. Young, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), and University of California-University of California
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, High-resolution mass spectrometry, 010504 meteorology & atmospheric sciences, Hydrogen, Isotope, Chemistry, Black smokers, Analytical chemistry, Mixing (process engineering), Abiotic methane, chemistry.chemical_element, Doubly-substituted isotopologues, 010502 geochemistry & geophysics, 01 natural sciences, Deep sea, Hydrothermal circulation, Methane, chemistry.chemical_compound, 13. Climate action, Geochemistry and Petrology, Carbon dioxide, Isotopologue, Hydrothermalism, 0105 earth and related environmental sciences
Abstract: Deep-sea hydrothermal fluids are often enriched in carbon dioxide, methane, and hydrogen. Methane effuses from metal-rich black smokers such as the Rainbow hydrothermal field, at temperatures higher than 200 °C. At the Lost City field, CH4 emanates from alkaline fluids at < 100 °C. The abundance of the rare, mass-18 CH4 isotopologues, 13CH3D and 12CH2D2, can mitigate degeneracies in the conventional isotopic signatures of methane. We studied the isotopologue compositions of methane from the Rainbow, Lucky Strike, Von Damm, and Lost City hydrothermal fields. At Rainbow, where the vented fluids are at ∼360°C, our coupled Δ12CH2D2 - Δ13CH3D data establish that methane is in internal equilibrium at °C. This may track the formation temperature of abiotic methane, or it may be the result of equilibration of methane isotopologues within the carrier fluid. Lucky Strike and Von Damm have fluid temperatures < 300°C and although Δ13CH3D values are indistinguishable from those at Rainbow, 12CH2D2 abundances are marginally higher. At Lost City, Δ13CH3D data show a range of values, which at face value correspond to apparent temperatures of between °C and °C, far hotter than fluid temperatures. A unique aspect of the Lost City data is the range of large 12CH2D2 excesses. The Δ12CH2D2 data correspond to temperatures of between °C and °C, showing a near-perfect match with fluid temperatures. We find that mixing scenarios involving microbial methane may not account for all of the isotope data. We suggest that Δ12CH2D2 values, unlike Δ13CH3D values, are prone to near-complete re-equilibration at host fluid temperatures. We suggest that 13CH3D isotopologue data are consistent with abiotic methane being synthesized at ∼350 °C. On the other hand, 12CH2D2 isotopologue ordering records post formation residence temperatures. We explore a possible mechanism decoupling the re-equilibration systematics of the doubly-substituted isotopologues.
Published: 2020

29. Observation of Inertial-range Energy Cascade within a Reconnection Jet in Earth's Magnetotail

Author: Matthew R. Argall, Barbara L. Giles, Riddhi Bandyopadhyay, Robert J. Strangeway, Christopher T. Russell, James L. Burch, O. Le Contel, D. J. Gershman, Alexandros Chasapis, Department of Astrophysical Sciences [Princeton], Princeton University, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], NASA Goddard Space Flight Center (GSFC), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of New Hampshire (UNH), and Southwest Research Institute [San Antonio] (SwRI)
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, 01 natural sciences, 7. Clean energy, Physics - Space Physics, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, Scaling, ComputingMilieux_MISCELLANEOUS, Physics, Turbulence, Fluid Dynamics (physics.flu-dyn), Astronomy and Astrophysics, Magnetic reconnection, Physics - Fluid Dynamics, Space Physics (physics.space-ph), Physics - Plasma Physics, Computational physics, Plasma Physics (physics.plasm-ph), Solar wind, 13. Climate action, Space and Planetary Science, Cascade, Energy cascade, Physics::Space Physics, Magnetohydrodynamics, Energy (signal processing)
Abstract: Earth's magnetotail region provides a unique environment to study plasma turbulence. We investigate the turbulence developed in an exhaust produced by magnetic reconnection at the terrestrial magnetotail region. Magnetic and velocity spectra show broad-band fluctuations corresponding to the inertial range, with Kolmorogov $-5/3$ scaling, indicative of a well developed turbulent cascade. We examine the mixed, third-order structure functions, and obtain a linear scaling in the inertial range. This linear scaling of the third-order structure functions implies a scale-invariant cascade of energy through the inertial range. A Politano-Pouquet third-order analysis gives an estimate of the incompressive energy transfer rate of $\sim 10^{7}~\mathrm{J\,kg^{-1}\,s^{-1}}$. This is four orders of magnitude higher than the values typically measured in 1 AU solar wind, suggesting that the turbulence cascade plays an important role as a pathway of energy dissipation during reconnection events in the tail region., Accepted for publication in MNRAS
Published: 2020

30. Low Δ 12 CH 2 D 2 values in microbialgenic methane result from combinatorial isotope effects

Author: Taenzer, Lina, Labidi, Jabrane, Masterson, Andrew, Feng, Xiahong, Rumble, Douglas, Young, Edward, Leavitt, William, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), and University of California-University of California
Subjects: methane, [SDE]Environmental Sciences, clumped isotopes, methanogenesis, C-P lyase
Abstract: International audience; Methane generated by microorganisms is most often depleted in the doubly substituted isotopologue 12 CH 2 D 2 relative to the stochastic reference distribution. To constrain the controls on depleted ∆ 12 CH 2 D 2 values, we experimentally isolated the root cause with microorganisms that produce methane from methylphosphonate via the C-P lyase pathway. This mechanism of methane production preserves the three hydrogens from methylphosphonate and adds one hydrogen from water. When maintaining the same methylphosphonate source, but varying the D/H composition of growth medium water, we observed significant shifts in methane ∆ 12 CH 2 D 2 values, but little to no change in ∆ 13 CH 3 D values. We reproduced these observations with a model that considers only the combinatorial isotope effect. The variation in ∆ 12 CH 2 D 2 values of product methane resulted from the differences in D/H between reactants water and methylphosphonate. This work validates the hypothesis that combinatorial effects can strongly influence methane ∆ 12 CH 2 D 2 values, and must be considered for low temperature, abiotic or biotic systems where methane hydrogen is derived from multiple reservoirs.
Published: 2020

31. The role of temperature in the initiation of the end-Triassic mass extinction

Author: Alexander Farnsworth, Daniel J. Lunt, Victoria A. Petryshyn, Frank A. Corsetti, Aradhna Tripati, Robert Gammariello, Sarah E. Greene, Yadira Ibarra, David J. Bottjer, Anne Marie Kelley, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Laboratoire Géosciences Océan (LGO), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Southern California (USC), School of Geography, Earth and Environmental Sciences [Birmingham], University of Birmingham [Birmingham], Bristol Research Initiative for the Dynamic Global Environment (BRIDGE), School of Geographical Sciences [Bristol], University of Bristol [Bristol]-University of Bristol [Bristol], Cabot Institute, University of Bristol [Bristol], San Francisco State University (SFSU), Department of Earth Sciences [USC Los Angeles], Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA, Department of Atmospheric and Oceanic Sciences [Los Angeles] (AOS), and ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010)
Subjects: 010504 meteorology & atmospheric sciences, Paleoclimate, Large igneous province, Biodiversity, 010502 geochemistry & geophysics, 01 natural sciences, Clumped isotopes, Climate model, Paleoclimatology, 14. Life underwater, 0105 earth and related environmental sciences, Temperature record, Extinction event, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Extinction, Acl, Microbialite, Triassic-Jurassic boundary, Sea surface temperature, Oceanography, 13. Climate action, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, General Earth and Planetary Sciences, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, End-Triassic extinction
Abstract: International audience; The end-Triassic mass extinction coincided with the eruption of the Central Atlantic Magmatic Province, a large igneous province responsible for the massive atmospheric input of potentially climate-altering volatile compounds that is associated with a sharp rise in atmospheric CO2. The extinction mechanism is debated, but both short-term cooling (similar to 10s of years) related to sulfur aerosols and longer-term warming (10,000 yrs) related to CO2 emissions-essentially opposite hypotheses-are suggested triggers. Until now, no temperature records spanning this crucial interval were available to provide a baseline or to differentiate between hypothesized mechanisms. Here, we use clumped-isotope paleothermometry of shallow marine microbialites coupled with climate modeling to reconstruct ocean temperature at the extinction horizon. We find mild to warm ocean temperatures during the extinction event and evidence for repeated temperature swings of similar to 16 degrees C, which we interpret as a signature of strong seasonality. These results constitute the oldest non-biomineralized marine seasonal temperature record. We resolve no apparent evidence for short-term cooling or initial warming across the 1-80kyr of the extinction event our record captures, implying that the initial onset of the biodiversity crisis may necessitate another mechanism.
Published: 2020

32. Latitudinal Dependence of the Kelvin‐Helmholtz Instability and Beta Dependence of Vortex‐Induced High‐Guide Field Magnetic Reconnection

Author: Tai Phan, Takuma Nakamura, Daniel J. Gershman, Vincent Génot, Yoshitaka Saito, S. Toledo-Redondo, Hiroshi Hasegawa, Matteo Faganello, Y. Vernisse, M. Sisti, E. Penou, Francesco Califano, C. Jacquey, Charlie J. Farrugia, Thomas E. Moore, James L. Burch, Masha Kuznetsova, Benoit Lavraud, Jérémy Dargent, W. R. Paterson, S. Fadanelli, Craig J. Pollock, John C. Dorelli, J.‐A. Sauvaud, Barbara L. Giles, I. Kacem, Christopher T. Russell, Robert E. Ergun, R. Kieokaew, Stefan Eriksson, Levon A. Avanov, 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), 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), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Fisica, University of Pisa - Università di Pisa, Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), University of Colorado [Boulder], NASA Goddard Space Flight Center (GSFC), NASA Headquarters, Space Science Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of New Hampshire (UNH), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), National Institute for Environmental Studies (NIES), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), 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), Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), University of California [Berkeley], University of California-University of California, Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS), Dip. di Fisica dell' Universit ádi Milano-Bicocca I-20126 - Italy, Dipartimento di Fisica 'E Fermi' & CNISM, PSL Research University (PSL)-Sorbonne Université (SU)-Observatoire de Paris, PSL Research University (PSL)-École polytechnique (X)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Universités-Université Paris-Saclay, Laboratoire de Parasitologie-Mycologie, Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpital Henri Mondor-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Centre de physique moléculaire optique et hertzienne (CPMOH), Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1, and Hokkaido University [Sapporo, Japan]
Subjects: 010504 meteorology & atmospheric sciences, Field (physics), [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, 010305 fluids & plasmas, Current sheet, space physics, 0103 physical sciences, ComputingMilieux_MISCELLANEOUS, Pressure gradient, 0105 earth and related environmental sciences, Physics, Kelvin-Helmholtz instability, Magnetic reconnection, Space physics, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Computational physics, Vortex, Geophysics, 13. Climate action, Space and Planetary Science, magnetic reconnection, Physics::Space Physics, Diamagnetism, Magnetopause, Earth’s magnetosphere
Abstract: International audience; We investigate both large‐ and small‐scale properties of a Kelvin‐Helmholtz (KH) event at the dusk flank magnetopause using Magnetospheric Multiscale observations on 8 September 2015. We first use two types of 3‐D simulations (global and local) to demonstrate that Magnetospheric Multiscale is close to the most KH unstable region, and so the occurrence of vortex‐induced reconnection may be expected. Because they produce low‐shear current sheets, KH vortices constitute a perfect laboratory to investigate magnetic reconnection with large guide field and low asymmetry. Recent works suggest that magnetic reconnection may be suppressed when a current sheet combines large guide field and pressure gradient (which induces a diamagnetic drift). We thus perform a statistical analysis of high‐resolution data for the 69 KH‐induced low‐shear magnetic reconnection events observed on that day. We find that the suppression mechanism is not at work for most of the observed reconnecting current sheets, as predicted, but we also find that almost all nonreconnecting current sheets should be reconnecting according to this model. This confirms the fact that the model provides a necessary but not sufficient condition for reconnection to occur. Finally, based on the same data set, we study the latitudinal distribution of these magnetic reconnection events combined with global magnetospheric modeling. We find that reconnection associated with KH vortices occurs over a significant range of latitudes at the flank magnetopause. It is not confined to the plane where the growth rate is maximum, in agreement with recent 3‐D simulations.
Published: 2020

33. The chemical composition of impact craters on Titan

Author: Ioannis Baziotis, Rosaly M. C. Lopes, Michael Malaska, Pierre Drossart, Kenneth J. Lawrence, Ashley Schoenfeld, Christos Matsoukas, Anezina Solomonidou, Alyssa Werynski, Athena Coustenis, Olivier Witasse, Nicolas Altobelli, Catherine D. Neish, Alice Le Gall, European Space Astronomy Centre (ESAC), European Space Agency (ESA), Department of Earth Sciences [London, ON], University of Western Ontario (UWO), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, PLANETO - 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), European Space Research and Technology Centre (ESTEC), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Royal Institute of Technology [Stockholm] (KTH ), Agricultural University of Athens, NASA-California Institute of Technology (CALTECH), and Institut de l'élevage (IDELE)
Subjects: geography, geography.geographical_feature_category, Alluvial fan, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mineralogy, Fluvial, symbols.namesake, Atmospheric radiative transfer codes, Impact crater, 13. Climate action, [SDU]Sciences of the Universe [physics], symbols, Radiative transfer, Ejecta blanket, Titan (rocket family), Chemical composition, Geology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; We investigate nine Titan impact craters using Visual and Infrared Mapping Spectrometer (VIMS) data and a radiative transfer code (RT) [e.g. 1] in addition to emissivity data, in order to constrain the spectral behavior and composition of the craters. Past studies have looked at the chemical composition of impact craters either by using qualitative comparisons between craters [e.g. 2;3] or by combining all craters into a single unit [4], rather than separating them by geographic location or degradation state. Here, we use a radiative transfer model to first estimate the atmospheric contribution to the data, then extract the surface albedos of the impact crater subunits, and finally constrain their composition by using a library of candidate Titan materials. Following the general characterization of the impact craters, we study two impact crater subunits, the 'crater floor', which refers to the bottom of a crater, and the 'ejecta blanket', which is the material thrown out of the crater during an impact event. The results show that Titan's mid-latitude plain craters: Afekan, Soi, and Forseti, in addition to Sinlap and Menrva are enriched in an OH-bearing constituent (likely water-ice) in an organic based mixture, while the equatorial dune craters: Selk, Ksa, Guabonito, and Santorini, appear to be purely composed of organic material (mainly unknown dune dark material). This follows the pattern seen in [4], where midlatitude alluvial fans, undifferentiated plains, and labyrinths were found to consist of a tholin-like and water-ice mixture, while the equatorial undifferentiated plains, hummocky terrains, dunes, and variable plains were found to consist of a dark material and tholin-like mixture in their very top layers. These observations also agree with the evolution scenario proposed by [3], wherein the impact cratering process produces a mixture of organic material and water ice, which is later "cleaned" through fluvial erosion in the midlatitude plains; a cleaning process that does not appear to operate in the equatorial dunes, which seem to be quickly covered by a thin layer of sand sediment. This scenario agrees with other works that suggest that atmospheric deposition is similar in the low-latitudes and midlatitudes on Titan, but with more rain falling onto the higher latitudes causing additional processing of materials in those regions [e.g. 5]. In either case, it appears that active processes are working to shape the surface of Titan, and it remains a dynamic world in the present day.[1] Hirtzig, M., et al. (2013). Icarus, 226, 470-486; [2] Neish, C.D., et al. (2015), Geophys. Res. Lett. 42, 3746-3754; [3] Werynski, A., et al. (2019), Icarus, 321, 508-521; [4] Solomonidou, A., et al. (2018), J. Geophys. Res, 123, 2, 489-507; [5] Neish, A.C., et al. (2016), Icarus, 270, 114-129.&
Published: 2020

34. Observations of the Source Region of Whistler Mode Waves in Magnetosheath Mirror Structures

Author: Per-Arne Lindqvist, Barbara L. Giles, Scott A. Boardsen, W. R. Paterson, D. J. Gershman, Christopher T. Russell, C. J. Pollock, Shoichiro Yokota, Yoshiharu Omura, N. Kitamura, Takanobu Amano, Robert E. Ergun, James L. Burch, Robert J. Strangeway, O. Le Contel, Narges Ahmadi, Shota Nakamura, Yoshitaka Saito, Radio Science Center for Space and Atmosphere [Kyoto] (RASC), Kyoto University [Kyoto], GSFC Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center (GSFC), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Denali Scientiﬁc, NASA Headquarters, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Institute of Geophysics and Planetary Physics [Los Angeles] (IGPP), Space Science Division [San Antonio], and Southwest Research Institute [San Antonio] (SwRI)
Subjects: Physics, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mode (statistics), whistler mode waves, mirror mode structures, 01 natural sciences, Computational physics, Magnetic field, Geophysics, Magnetosheath, Space and Planetary Science, wave generation, Physics::Space Physics, MMS spacecraft, Whistler mode, 0105 earth and related environmental sciences
Abstract: International audience; In the magnetosheath, intense whistler mode waves, called “Lion roars,” are often detected in troughs of magnetic field intensity in mirror mode structures. Using data obtained by the four Magnetospheric Multiscale (MMS) spacecraft, we show that reversals of gradient of magnetic field intensity along the magnetic field correspond to reversals of the field‐aligned component of Poynting flux of whistler mode waves in the troughs. Such a characteristic is consistent with the idea that the whistler mode waves are effectively generated near the local minima of magnetic field intensity because of the smallest cyclotron resonance velocity and propagate toward regions of larger magnetic field intensity along the magnetic field lines on both sides. We use the reversal of the Poynting flux as an indicator of wave source regions. In these regions, we find that pancake or an outer edge of butterfly electron distributions above ~100 eV are good candidates for wave generation. Unclear correlations of phase difference and amplitude variations of whistler mode waves in cases of ~40 km spacecraft separation indicate that a simple plane wave approximation with a constant amplitude is not valid at this spatial scale that is much smaller than the ion gyroradius. The whistler mode waves consist of small coherent wave packets from multiple sources with spatial scales smaller than tens of electron gyroradii transverse to the background magnetic field in a mirror mode structure.Publication cover image
Published: 2020

35. Alkali magmatism on a carbonaceous chondrite planetesimal

Author: Alice Aléon-Toppani, François Brisset, Kevin D. McKeegan, Jacques-Marie Bardintzeff, Jérôme Aléon, Bernard Platevoet, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Saclay (GEOPS), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), and University of California (UC)-University of California (UC)
Subjects: Planetesimal, Multidisciplinary, 010504 meteorology & atmospheric sciences, Partial melting, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Astrobiology, Meteorite, 13. Climate action, Chondrite, [SDU]Sciences of the Universe [physics], Carbonaceous chondrite, Physical Sciences, Formation and evolution of the Solar System, Planetary differentiation, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Recent isotopic and paleomagnetic data point to a possible connection between carbonaceous chondrites and differentiated planetary materials, suggesting the existence, perhaps ephemeral, of transitional objects with a layered structure whereby a metal-rich core is enclosed by a silicate mantle, which is itself overlain by a crust containing an outermost layer of primitive solar nebula materials. This idea has not received broad support, mostly because of a lack of samples in the meteoritic record that document incipient melting at the onset of planetary differentiation. Here, we report the discovery and the petrologic–isotopic characterization of UH154-11, a ferroan trachybasalt fragment enclosed in a Renazzo-type carbonaceous chondrite (CR). Its chemical and oxygen isotopic compositions are consistent with very-low-degree partial melting of a Vigarano-type carbonaceous chondrite (CV) from the oxidized subgroup at a depth where fluid-assisted metamorphism enhanced the Na content. Its microdoleritic texture indicates crystallization at an increasing cooling rate, such as would occur during magma ascent through a chondritic crust. This represents direct evidence of magmatic activity in a carbonaceous asteroid on the verge of differentiating and demonstrates that some primitive outer Solar System objects related to icy asteroids and comets underwent a phase of magmatic activity early in the Solar System. With its peculiar petrology, UH154-11 can be considered the long-sought first melt produced during partial differentiation of a carbonaceous chondritic planetary body, bridging a previously persistent gap in differentiation processes from icy cometary bodies to fully melted iron meteorites with isotopic affinities to carbonaceous chondrites.
Published: 2020

36. Hydrothermal 15N15N abundances constrain the origins of mantle nitrogen

Author: Guillaume Avice, B. Sherwood Lollar, Edward D. Young, I. E. Kohl, Tobias Fischer, Michael W. Broadley, Thomas Giunta, David V. Bekaert, Chris J. Ballentine, Antonio Caracausi, Sæmundur A. Halldórsson, Mark D. Kurz, Oliver Warr, Bernard Marty, Jabrane Labidi, Andri Stefánsson, Peter H. Barry, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Woods Hole Oceanographic Institution (WHOI), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University of Toronto, The University of New Mexico [Albuquerque], Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Palermo (INGV), Istituto Nazionale di Geofisica e Vulcanologia, University of Oxford [Oxford], University of Iceland [Reykjavik], and Thermo Fisher Scientific (Bremen) GmbH
Subjects: Basalt, geography, Multidisciplinary, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Subduction, chemistry.chemical_element, 010502 geochemistry & geophysics, 01 natural sciences, Nitrogen, Mantle (geology), Plume, chemistry, Volcano, 13. Climate action, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU]Sciences of the Universe [physics], Isotopologue, Petrology, Nitrogen cycle, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience; Nitrogen is the main constituent of the Earth's atmosphere, but its provenance in the Earth's mantle remains uncertain. The relative contribution of primordial nitrogen inherited during the Earth's accretion versus that subducted from the Earth's surface is unclear 1-6. Here we show that the mantle may have retained remnants of such primordial nitrogen. We use the rare 15 N 15 N isotopologue of N 2 as a new tracer of air contamination in volcanic gas effusions. By constraining air contamination in gases from Iceland, Eifel (Germany) and Yellowstone (USA), we derive estimates of mantle δ 15 N (the fractional difference in 15 N/ 14 N from air), N 2 / 36 Ar and N 2 / 3 He. Our results show that negative δ 15 N values observed in gases, previously regarded as indicating a mantle origin for nitrogen 7-10 , in fact represent dominantly air-derived N 2 that experienced 15 N/ 14 N fractionation in hydrothermal systems. Using two-component mixing models to correct for this effect, the 15 N 15 N data allow extrapolations that characterize mantle endmember δ 15 N, N 2 / 36 Ar and N 2 / 3 He values. We show that the Eifel region has slightly increased δ 15 N and N 2 / 36 Ar values relative to estimates for the convective mantle provided by mid-ocean-ridge basalts 11 , consistent with subducted nitrogen being added to the mantle source. In contrast, we find that whereas the Yellowstone plume has δ 15 N values substantially greater than that of the convective mantle, resembling surface components 12-15 , its N 2 / 36 Ar and N 2 / 3 He ratios are indistinguishable from those of the convective mantle. This observation raises the possibility that the plume hosts a primordial component. We provide a test of the subduction hypothesis with a two-box model, describing the evolution of mantle and surface nitrogen through geological time. We show that the effect of subduction on the deep nitrogen cycle may be less important than has been suggested by previous investigations. We propose instead that high mid-ocean-ridge basalt and plume δ 15 N values may both be dominantly primordial features. Differentiated bodies from our Solar System have rocky mantles with 15 N/ 14 N ratios within ±15‰ of modern terrestrial air 16,17. This is true for Earth's convective mantle, which has a δ 15 N value of approximately −5 ± 3‰, based on measurements from diamonds 5,18 and basalts that have been filtered for air contamination 3,11. Conversely, volatile-rich chondritic meteorites exhibit highly variable δ 15 N values between −20 ± 11‰ for enstatite chondrites and 48 ± 9‰ for CI carbonaceous chondrites 16,19. The distinct 15 N/ 14 N of rocky mantles relative to the chon-drites may reflect inheritance of N from a heterogeneous mixture of chondritic precursors 3. Alternatively, the relatively high 15 N/ 14 N values could be the result of evaporative losses 20 , or equilibrium partitioning of N isotopes between metal cores and rocky mantles 21,22. For Earth, plate tectonics allows for another interpretation 1. Geo-chemists have suggested that mantle δ 15 N values reflect subduction of nitrogen from the surface. Some of the evidence comes from studies of gases from mantle plumes. On Earth, mantle plumes with high 3 He/ 4 He ratios relative to mid-ocean-ridge basalts (MORBs) result from melting of relatively undegassed portions of the deep mantle 23. Nitrogen data are sparse, but plumes with both high and low 3 He/ 4 He values have δ 15 N values between 0 and +3‰ (refs. 2,4), higher than the values attributed to the convective mantle and similar to both sediments and altered oceanic crust (Extended Data Fig. 1) 12,13,15,24. One hypothesis is that the convective and deep mantle reservoirs both initially had identical but low enstatite chondrite-like δ 15 N values 6. Over geological time, these
Published: 2020

37. Polynomial Reconstruction of the Reconnection Magnetic Field Observed by Multiple Spacecraft

Author: Denton, R. E., Torbert, R. B., Dors, I., Genestreti, K. J., Argall, M., Gershman, D. J., Le, Contel O., Burch, J. L., Russell, C. T., Strangeway, R. J., Giles, B. L., Fischer, D., Hasegawa, Hiroshi, University of New Hampshire (UNH), Laboratoire des sciences et matériaux pour l'électronique et d'automatique (LASMEA), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS), EOS Space Science Center [Durham], Laboratoire de Physique des Plasmas (LPP), Université Paris-Saclay-Sorbonne Université-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École polytechnique (X)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU), Southwest Research Institute [San Antonio] (SwRI), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Institute of Geophysics and Planetary Physics [Los Angeles] (IGPP), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Polynomial, 010504 meteorology & atmospheric sciences, Spacecraft, business.industry, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Magnetic reconnection, Plasmoid, 01 natural sciences, Magnetic field, Computational physics, Geophysics, Space and Planetary Science, 0103 physical sciences, business, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: 著者人数: 13名, Accepted: 2019-12-11, 資料番号: SA1190210000
Published: 2020

38. Electron Bernstein waves driven by electron crescents near the electron diffusion region

Author: Christopher T. Russell, John C. Dorelli, Ferdinand Plaschke, James L. Burch, Chi Wang, Wenya Li, O. Le Contel, Yuri V. Khotyaintsev, Robert E. Ergun, Kaijun Liu, Andris Vaivads, K. Fujimoto, Mats André, Roy B. Torbert, Daniel J. Gershman, Sergio Toledo-Redondo, Binbin Tang, Kyungguk Min, Benoit Lavraud, Daniel B. Graham, P. A. Lindqvist, Werner Magnes, Cecilia Norgren, A. C. Rager, Barbara L. Giles, National Space Science Center [Beijing] (NSSC), Chinese Academy of Sciences [Beijing] (CAS), Swedish Institute of Space Physics [Uppsala] (IRF), Royal Institute of Technology [Stockholm] (KTH ), Chungnam National University (CNU), Southern University of Science and Technology [Shenzhen] (SUSTech), Beihang University (BUAA), Department of Physics and Technology [Bergen] (UiB), University of Bergen (UiB), 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), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], University of New Hampshire (UNH), Catholic University of America, NASA Goddard Space Flight Center (GSFC), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Southwest Research Institute [San Antonio] (SwRI), Southern University of Science and Technology (SUSTech), 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), 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), and University of California (UC)-University of California (UC)
Subjects: 010504 meteorology & atmospheric sciences, Gyroradius, Science, General Physics and Astronomy, Electron, 01 natural sciences, 7. Clean energy, General Biochemistry, Genetics and Molecular Biology, Article, Fusion, plasma och rymdfysik, Space physics, Physics::Plasma Physics, 0103 physical sciences, Diffusion (business), lcsh:Science, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Multidisciplinary, Magnetic reconnection, General Chemistry, Plasma, Fusion, Plasma and Space Physics, Computational physics, Amplitude, Thermalisation, Magnetospheric physics, Physics::Space Physics, Magnetopause, lcsh:Q, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The Magnetospheric Multiscale (MMS) spacecraft encounter an electron diffusion region (EDR) of asymmetric magnetic reconnection at Earth’s magnetopause. The EDR is characterized by agyrotropic electron velocity distributions on both sides of the neutral line. Various types of plasma waves are produced by the magnetic reconnection in and near the EDR. Here we report large-amplitude electron Bernstein waves (EBWs) at the electron-scale boundary of the Hall current reversal. The finite gyroradius effect of the outflow electrons generates the crescent-shaped agyrotropic electron distributions, which drive the EBWs. The EBWs propagate toward the central EDR. The amplitude of the EBWs is sufficiently large to thermalize and diffuse electrons around the EDR. The EBWs contribute to the cross-field diffusion of the electron-scale boundary of the Hall current reversal near the EDR., Various types of plasma waves are generated around electron diffusion regions (EDRs). Here the authors show electron Bernstein waves (EBWs), at the electron-scale boundary of the Hall current reversal near EDR, are sufficiently strong to diffuse electrons and modify electron pressure tensor.
Published: 2020

39. Recycled selenium in hot spot-influenced lavas records ocean-atmosphere oxygenation

Author: Jabrane Labidi, Stephan König, Ronny Schoenberg, Aierken Yierpan, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Institut de Physique du Globe de Paris (IPGP), and Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Multidisciplinary, 010504 meteorology & atmospheric sciences, Subduction, Geochemistry, chemistry.chemical_element, Sediment, SciAdv r-articles, Geology, Pelagic sediment, 010502 geochemistry & geophysics, 01 natural sciences, Oxygen, Mantle (geology), Abyssal zone, Isotopes of selenium, chemistry, 13. Climate action, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 14. Life underwater, Selenium, Research Articles, 0105 earth and related environmental sciences, Research Article
Abstract: Oceanic lavas erupting today trace ocean-atmosphere oxygenation in Earth’s middle ages., Oxygenation of Earth’s oceans and atmosphere through time has consequences for subducted surface signatures that are now stored in the mantle. Here, we report significant mass-dependent selenium isotope variations in modern hot spot–influenced oceanic lavas. These variations are correlated with tracers of mantle source enrichment, which can only be explained by incorporation of abyssal pelagic sediments subducted from a redox-stratified mid-Proterozoic ocean. Selenium geochemical signatures of these sediments have mostly been preserved during long-term recycling and may therefore complement the global surface sediment record as ancient oxygen archives. Combined deep mantle and surface perspectives, together with emerging models for atmospheric oxygen based on selenium systematics, further imply a significantly oxygenated ocean-atmosphere system throughout the mid-Proterozoic.
Published: 2020

40. Hafnium isotopic disequilibrium during sediment melting and assimilation

Author: C. Zhang, X. Kong, S. Jiang, C. Spencer, D. Liu, M. Jolivet, X. Zhang, J. Zeng, M. Tang, China University of Petroleum, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Lanzhou University, Curtin University [Perth], Planning and Transport Research Centre (PATREC), Rice University [Houston], University of Utah, Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), University of California-University of California, Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Geochemistry, chemistry.chemical_element, Sediment, Geology, Hf isotope disequilibrium, Isotopic disequilibrium, 010502 geochemistry & geophysics, 01 natural sciences, Hafnium, zircon effect, Nd-Hf isotopic decoupling, chemistry, Geochemistry and Petrology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, strongly-peraluminous granites, Environmental Chemistry, 010503 geology, Chinese Altai, 0105 earth and related environmental sciences
Abstract: International audience; Identification of juvenile and mature crustal sources in granite formation relies on radiogenic isotopic systems such as Sm-Nd and Lu-Hf and assumes isotope systems reach equilibrium between the melt and residual phases prior to melt extraction. However, we hypothesise disequilibrium melting and residual zircon result in preferential retention of 177 Hf in residues, generating partial melts with higher 176 Hf/ 177 Hf ratios. To test this hypothesis, we evaluate radiogenic isotopic signatures of strongly-peraluminous granites from the Chinese Altai. These granites show Nd-Hf isotopic decoupling and inherited zircons with negative ε Hf (t) values providing evidence for incomplete Hf release. This is consistent with the significant depletions in Zr and Hf. The Chinese data compilation shows that strongly-peraluminous and calcic to calc-alkalic, magnesian metaluminous or ferroan peraluminous (often respectively referred to as Sand I-type) granites show elevated ε Hf (t) relative to the terrestrial Hf-Nd isotopic array. Hf isotope disequilibrium marked by the preferential release of radiogenic Hf is likely ubiquitous during anatexis of zircon-rich protoliths.
Published: 2020

41. Electron inflow velocities and reconnection rates at earth's magnetopause and magnetosheath

Author: Matthew R. Argall, Hiroshi Hasegawa, James L. Burch, Marc Swisdak, Masaaki Yamada, Kyunghwan Dokgo, James Drake, K. J. Trattner, S. A. Fuselier, Shan Wang, Barbara L. Giles, Paul Cassak, Michael Hesse, Robert J. Strangeway, K. R. Pritchard, Kevin Genestreti, Richard E. Denton, K. J. Hwang, Robert E. Ergun, Roy B. Torbert, A. Marshall, Christopher T. Russell, O. Le Contel, T. D. Phan, G. Paschmann, James Webster, L. J. Chen, D. J. Gershman, Southwest Research Institute [San Antonio] (SwRI), Department of Physics and Astronomy [Houston], Rice University [Houston], Department of Physics and Technology [Bergen] (UiB), University of Bergen (UiB), Department of Physics and Astronomy [Hanover, NH], Darmouth College [Hanover, New Hampshire], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Department of Physics and Astronomy [Morgantown], West Virginia University [Morgantown], Space Science Center & Department of Physics, University of New Hampshire (UNH), NASA Goddard Space Flight Center (GSFC), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), UTSA Department of Physics and Astronomy [San Antonio], The University of Texas at San Antonio (UTSA), Space Science and Engineering Division [San Antonio], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Institute for Research in Electronics & Applied Physics, Department of Physics-Maryland, Princeton Plasma Physics Laboratory (PPPL), Princeton University, and Max-Planck-Institut für Extraterrestrische Physik (MPE)
Subjects: Physics, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Inflow, Electron, Geophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, Magnetosheath, 0103 physical sciences, Physics::Space Physics, General Earth and Planetary Sciences, Magnetopause, 010303 astronomy & astrophysics, Earth (classical element), ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract: Electron inflow and outflow velocities during magnetic reconnection at and near the dayside magnetopause are measured using satellites from NASA's Magnetospheric Multiscale (MMS) mission. A case study is examined in detail, and three other events with similar behavior are shown, with one of them being a recently published electron-only reconnection event in the magnetosheath. The measured inflow speeds of 200–400 km/s imply dimensionless reconnection rates of 0.05–0.25 when normalized to the relevant electron Alfvén speed, which are within the range of expectations. The outflow speeds are about 1.5–3 times the inflow speeds, which is consistent with theoretical predictions of the aspect ratio of the inner electron diffusion region. A reconnection rate of 0.04 ± 25% was obtained for the case study event using the reconnection electric field as compared to the 0.12 ± 20% rate determined from the inflow velocity. publishedVersion
Published: 2020

42. A global geomorphologic map of Saturn’s moon Titan

Author: M. Florence, R. M. C. Lopes, Alexander G. Hayes, Samuel Birch, Michael Malaska, A. Solomonidou, A. Le Gall, Jani Radebaugh, T. Verlander, David A. Williams, Ashley Schoenfeld, Elizabeth Turtle, S. D. Wall, Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, European Space Astronomy Centre (ESAC), European Space Agency (ESA), Department of Astronomy [Ithaca], Cornell University [New York], Arizona State University [Tempe] (ASU), Department of Geological Sciences [BYU], Brigham Young University (BYU), School of Civil Engineering and Environmental Science [Norman] (CEES), University of Oklahoma (OU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and 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)
Subjects: Solar System, 010504 meteorology & atmospheric sciences, Equator, Astronomy and Astrophysics, Terrain, Global Map, Geophysics, 15. Life on land, 01 natural sciences, Article, law.invention, Sedimentary depositional environment, Orbiter, symbols.namesake, 13. Climate action, law, [SDU]Sciences of the Universe [physics], 0103 physical sciences, symbols, Titan (rocket family), 010303 astronomy & astrophysics, Relative dating, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Titan has an active methane-based hydrologic cycle1 that has shaped a complex geologic landscape2, making its surface one of most geologically diverse in the Solar System. Despite the differences in materials, temperatures and gravity fields between Earth and Titan, many of their surface features are similar and can be interpreted as products of the same geologic processes3. However, Titan’s thick and hazy atmosphere has hindered the identification of its geologic features at visible wavelengths and the study of its surface composition4. Here we identify and map the major geological units on Titan’s surface using radar and infrared data from the Cassini orbiter spacecraft. Correlations between datasets enabled us to produce a global map even where datasets were incomplete. The spatial and superposition relations between major geological units reveals the likely temporal evolution of the landscape and provides insight into the interacting processes driving its evolution. We extract the relative dating of the various geological units by observing their spatial superposition in order to get information on the temporal evolution of the landscape. The dunes and lakes are relatively young, whereas the hummocky or mountainous terrains are the oldest on Titan. Our results also show that Titan’s surface is dominated by sedimentary or depositional processes with a clear latitudinal variation, with dunes at the equator, plains at mid-latitudes and labyrinth terrains and lakes at the poles.
Published: 2020

43. Observations of Heating along Intermittent Structures in the Inner Heliosphere from PSP Data

Author: Phyllis Whittlesey, Anthony W. Case, Justin C. Kasper, Marc Pulupa, Kelly E. Korreck, Melvyn L. Goldstein, Tulasi N. Parashar, Stuart D. Bale, Davin Larson, T. Dudok de Wit, Alexandros Chasapis, Roberto Livi, N.-E. Raouafi, R. A. Qudsi, Rohit Chhiber, Riddhi Bandyopadhyay, William H. Matthaeus, Peter Harvey, David M. Malaspina, Michael L. Stevens, Marco Velli, Bennett A. Maruca, Robert J. MacDowall, Keith Goetz, John W. Bonnell, University of Delaware [Newark], Bartol Research Institute, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], NASA Goddard Space Flight Center (GSFC), University of California [Berkeley], University of California, Imperial College London, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), University of Minnesota [Twin Cities] (UMN), University of Minnesota System, Smithsonian Astrophysical Observatory, Smithsonian Institution, Space Sciences Laboratory [Berkeley] (SSL), University of California-University of California, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), and Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL)
Subjects: FOS: Physical sciences, Probability density function, 01 natural sciences, 7. Clean energy, law.invention, Physics - Space Physics, law, Intermittency, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010306 general physics, 010303 astronomy & astrophysics, Physics, integumentary system, Turbulence, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Stellar atmosphere, Astronomy and Astrophysics, Physics - Plasma Physics, Space Physics (physics.space-ph), Computational physics, Plasma Physics (physics.plasm-ph), Solar wind, Nonlinear system, 13. Climate action, Space and Planetary Science, Cascade, Physics::Space Physics, Heliosphere
Abstract: The solar wind proton temperature at 1-au has been found to be correlated with small-scale intermittent magnetic structures, i.e., regions with enhanced temperature are associated with coherent structures such as current sheets. Using Parker Solar Probe data from the first encounter, we study this association using measurements of radial proton temperature, employing the Partial Variance of Increments (PVI) technique to identify intermittent magnetic structures. We observe that the probability density functions of high-PVI events have higher median temperatures than those with lower PVI, The regions in space where PVI peaks were also locations that had enhanced temperatures when compared with similar regions suggesting a heating mechanism in the young solar wind that is associated with intermittency developed by a nonlinear turbulent cascade.n the immediate vicinity., Comment: 6 pages, 3 figures, part of ApJ special issue for PSP
Published: 2020

44. The Role of Alfvén Wave Dynamics on the Large-scale Properties of the Solar Wind: Comparing an MHD Simulation with Parker Solar Probe E1 Data

Author: Keith Goetz, Michael L. Stevens, David M. Malaspina, Samuel T. Badman, Anna Tenerani, Justin C. Kasper, Marc Pulupa, Stuart D. Bale, Phyllis Whittlesey, John W. Bonnell, Thierry Dudok de Wit, Olga Panasenco, Anthony W. Case, Peter Harvey, Davin Larson, Roberto Livi, Robert J. MacDowall, Kelly E. Korreck, Marco Velli, Chen Shi, Victor Réville, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), 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), 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), Advanced Heliophysics, University of Texas at Austin [Austin], University of California [Berkeley] (UC Berkeley), University of California (UC), Imperial College London, Smithsonian Astrophysical Observatory, Smithsonian Institution, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], NASA Goddard Space Flight Center (GSFC), University of California-University of California, 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], and University of California
Subjects: Physics, 010504 meteorology & atmospheric sciences, Scale (ratio), [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Dynamics (mechanics), Astronomy and Astrophysics, Alfvén Waves, 01 natural sciences, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Computational physics, Alfvén wave, Solar wind, Magnetohydrodynamics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Physics::Space Physics, Solar Wind, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: During Parker Solar Probe’s first orbit, the solar wind plasma was observed in situ closer than ever before, the perihelion on 2018 November 6 revealing a flow that is constantly permeated by large-amplitude Alfvénic fluctuations. These include radial magnetic field reversals, or switchbacks, that seem to be a persistent feature of the young solar wind. The measurements also reveal a very strong, unexpected, azimuthal velocity component. In this work, we numerically model the solar corona during this first encounter, solving the MHD equations and accounting for Alfvén wave transport and dissipation. We find that the large-scale plasma parameters are well reproduced, allowing the computation of the solar wind sources at Probe with confidence. We try to understand the dynamical nature of the solar wind to explain both the amplitude of the observed radial magnetic field and of the azimuthal velocities.
Published: 2020

45. Initial results from the InSight mission on Mars

Author: Sharon Kedar, Don Banfield, Scott M. McLennan, Nicholas Schmerr, Justin N. Maki, Gareth S. Collins, John Clinton, Anna Mittelholz, Paul Morgan, Mélanie Drilleau, Sabine Stanley, Chloé Michaut, Nicholas A Teanby, Daniele Antonangeli, Jeroen Tromp, W. Bruce Banerdt, James B. Garvin, Mark A. Wieczorek, Jerzy Grygorczuk, Suzanne E. Smrekar, Catherine L. Johnson, Aymeric Spiga, Peter Chi, Brigitte Knapmeyer-Endrun, Raphaël F. Garcia, Claire E. Newman, Seiichi Nagihara, Matthias Grott, W. Thomas Pike, Philippe Lognonné, Véronique Dehant, Ana-Catalina Plesa, Matthew Fillingim, Domenico Giardini, Taichi Kawamura, Mark T. Lemmon, Antoine Mocquet, Naomi Murdoch, Ebru Bozdag, David Mimoun, Ludovic Margerin, Matthew P. Golombek, Jessica C. E. Irving, Troy L. Hudson, Sami W. Asmar, Günter Kargl, Martin Knapmeyer, Mark P. Panning, Francis Nimmo, Scott D. King, John A. Grant, Sebastien Rodriguez, Martin van Driel, Nicholas H. Warner, Nils Mueller, José Antonio Rodríguez-Manfredi, Christopher T. Russell, Caroline Beghein, Clément Perrin, Ulrich R. Christensen, William M. Folkner, Renee Weber, Neil Bowles, Ingrid Daubar, Simon Stähler, Tilman Spohn, Eléanore Stutzmann, Ralph D. Lorenz, Matthew A. Siegler, Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Cornell Center for Astrophysics and Planetary Science (CCAPS), Cornell University, Institute of Geophysics [ETH Zürich], Department of Earth Sciences [ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (EOAS), University of British Columbia (UBC), Département de géophysique spatiale et planétaire (DGSP (UMR_7096)), Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], Department of Geosciences [Princeton], Princeton University, Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Swiss Seismological Service [ETH Zurich] (SED), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Department of Earth Sciences [ETH Zürich] (D-ERDW), Department of Earth Science and Engineering [Imperial College London], Imperial College London, Department of Earth, Environmental and Planetary Sciences [Providence], Brown University, Royal Observatory of Belgium [Brussels], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Département Electronique, Optronique et Signal (DEOS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Institute of Remote Sensing and Geographic Information System (IRSGIS), School of Earth and Space Sciences [Beijing], Peking University [Beijing]-Peking University [Beijing], Austrian Academy of Sciences (OeAW), Graphics and Vision Research Laboratory (Graphics Lab), University of Otago [Dunedin, Nouvelle-Zélande], Deutsches Zentrum für Luft- und Raumfahrt (DLR), Space Science Institute [Boulder] (SSI), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Department of Geosciences, Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), AstraZeneca, Aeolis Research, Department of Earth and Planetary Sciences [Santa Cruz], University of California [Santa Cruz] (UCSC), Department of Geological Sciences, University of Florida [Gainesville], Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), The Open University [Milton Keynes] (OU), Morton K. Blaustein Department of Earth and Planetary Sciences [Baltimore], Johns Hopkins University (JHU), School of Earth Sciences [Bristol], University of Bristol [Bristol], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), University of Southern California (USC), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Cornell University [New York], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)-Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Royal Observatory of Belgium [Brussels] (ROB), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Southwest Research Institute [Boulder] (SwRI), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), University of California, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), NASA-California Institute of Technology (CALTECH), Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), University of Oxford, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), University of California [Santa Cruz] (UC Santa Cruz), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of California (UC), Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Tromp, J. [0000-0002-2742-8299], Rodríguez, S. [0000-0003-1219-0641], Lognonné, P. [0000-0002-1014-920X], Perrin, C. [0000-0002-7200-5682], Murdoch, N. [0000-0002-9701-4075], Knapmeyer, M. [0000-0003-0319-2514], Rodríguez Manfredi, J. A. [0000-0003-0461-9815], Spiga, A. [0000-0002-6776-6268], Panning, M. P. [0000-0002-2041-3190], García, R. [0000-0003-1460-6663], Johnson, C. [0000-0001-6084-0149], Stutzmann, E. [0000-0002-4348-7475], Knapmeyer-Endrun, B. [0000-0003-3309-6785], Schmerr, N. [0000-0002-3256-1262], Irving, J. C. E. [0000-0002-0866-8246], Morgan, P. [0000-0001-8714-4178], Mueller, N. [0000-0001-9229-8921], Pike, W. [0000-0002-7660-6231], Kawamura, T. [0000-0001-5246-5561], Clinton, J. [0000-0001-8626-2703], Agence Nationale de la Recherche (ANR), Swiss National Science Foundation (SNSF), Agence Nationale de la Recherche (ANR), ANR-10LABX-0023 ANR-11-IDEX-0005-0, Swiss National Science Foundation (SNSF- ANR project), 157133, ETH Research grant, ETH-06 17-02, Lunar and Planetary Institute, 2250, UCL - SST/ELI/ELIC - Earth & Climate, Science and Technology Facilities Council (STFC), and Science & Technology Facilities Council
Subjects: Seismometer, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars, 010502 geochemistry & geophysics, 01 natural sciences, Atmosphere, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Impact crater, Autre, Planet, Inner planets, InSight Mars Geophysik, Meteorology & Atmospheric Sciences, Seismology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Atmospheric dynamics, Geomorphology, Moment magnitude scale, Mars InSight, Geomagnetism, Mars Exploration Program, Geophysics, [SDU]Sciences of the Universe [physics], 13. Climate action, Intraplate earthquake, General Earth and Planetary Sciences, Timekeeping on Mars, [SDU.OTHER]Sciences of the Universe [physics]/Other, InSight mission, Geology
Abstract: Banerdt, William B. et al., NASA’s InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in Elysium Planitia on Mars on 26 November 2018. It aims to determine the interior structure, composition and thermal state of Mars, as well as constrain present-day seismicity and impact cratering rates. Such information is key to understanding the differentiation and subsequent thermal evolution of Mars, and thus the forces that shape the planet’s surface geology and volatile processes. Here we report an overview of the first ten months of geophysical observations by InSight. As of 30 September 2019, 174 seismic events have been recorded by the lander’s seismometer, including over 20 events of moment magnitude M = 3–4. The detections thus far are consistent with tectonic origins, with no impact-induced seismicity yet observed, and indicate a seismically active planet. An assessment of these detections suggests that the frequency of global seismic events below approximately M = 3 is similar to that of terrestrial intraplate seismic activity, but there are fewer larger quakes; no quakes exceeding M = 4 have been observed. The lander’s other instruments—two cameras, atmospheric pressure, temperature and wind sensors, a magnetometer and a radiometer—have yielded much more than the intended supporting data for seismometer noise characterization: magnetic field measurements indicate a local magnetic field that is ten-times stronger than orbital estimates and meteorological measurements reveal a more dynamic atmosphere than expected, hosting baroclinic and gravity waves and convective vortices. With the mission due to last for an entire Martian year or longer, these results will be built on by further measurements by the InSight lander., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)
Published: 2020

46. The atmosphere of Mars as observed by InSight

Author: Justin N. Maki, A. Jacob, Stephen R. Lewis, Nicholas A Teanby, Mercedes Marin-Jimenez, Anna Mittelholz, Constantinos Charalambous, Sara Navarro, M. M. Baker, Mark T. Lemmon, Tristram Warren, Javier Gómez-Elvira, Alexander E. Stott, Matthew P. Golombek, Antoine Lucas, Jorge Pla-Garcia, J. Torres, Eric Beucler, Balthasar Kenda, Aymeric Spiga, Rudolf Widmer-Schnidrig, Philippe Lognonné, Veronique Ansan, V. Peinado, Özgür Karatekin, William T. Pike, Nils Mueller, Savas Ceylan, K. Hurst, Daniel Viúdez-Moreiras, Christopher T. Russell, Antonio Molina, Sebastien Rodriguez, Clément Perrin, Naomi Murdoch, David Mimoun, Claire E. Newman, Ralph D. Lorenz, L. Martire, Luis Mora-Sotomayor, Simon Stähler, Tilman Spohn, Lucie Rolland, Stephen Sackett, Ingrid Daubar, Raphaël F. Garcia, W. Bruce Banerdt, Catherine L. Johnson, Domenico Giardini, Brian Carcich, Don Banfield, Suzanne E. Smrekar, John Clinton, François Forget, Ehouarn Millour, Taichi Kawamura, J. A. Rodríguez-Manfredi, Bart Van Hove, A. Lepinette, Anni Määttänen, J. B. McClean, Cornell Center for Astrophysics and Planetary Science (CCAPS), Cornell University, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Aeolis Research, Space Science Institute [Boulder] (SSI), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Royal Observatory of Belgium [Brussels], School of Earth Sciences [Bristol], University of Bristol [Bristol], Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Department of Electrical and Electronic Engineering [London] (DEEE), Imperial College London, Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (EOAS), University of British Columbia (UBC), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Sorbonne Université (SU), School of Physical Sciences [Milton Keynes], The Open University [Milton Keynes] (OU), Swiss Seismological Service [ETH Zurich] (SED), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Department of Earth Sciences [ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Department of Physics [Oxford], University of Oxford [Oxford], Department of Earth, Environmental and Planetary Sciences [Providence], Brown University, Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Université Côte d'Azur (UCA), Universität Stuttgart [Stuttgart], Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Morton K. Blaustein Department of Earth and Planetary Sciences [Baltimore], Johns Hopkins University (JHU), Center for Earth and Planetary Studies [Washington] (CEPS), Smithsonian National Air and Space Museum, Smithsonian Institution-Smithsonian Institution, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Département Electronique, Optronique et Signal (DEOS), Cornell University [New York], École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Royal Observatory of Belgium [Brussels] (ROB), NASA-California Institute of Technology (CALTECH), Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), PLANETO - 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), Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)-Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), University of Oxford, University of California (UC)-University of California (UC), ANR-14-CE36-0012,SEISMARS,Seismology on Mars(2014), ANR-19-CE31-0008,MAGIS,MArs Geophysical InSight(2019), Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Määttänen, A. [0000-0002-7326-8492], Martire, L. [0000-0002-9402-6150], Rodríguez Manfredi, J. A. [0000-0003-0461-9815], Lognonné, P. [0000-0002-1014-920X], Rodríguez, S. [0000-0003-1219-0641], Spiga, A. [0000-0002-6776-6268], Perrin, C. [0000-0002-7200-5682], Molina, A. [0000-0002-5038-2022], García, R. [0000-0003-1460-6663], Murdoch, N. [0000-0002-9701-4075], Lorenz, R. [0000-0001-8528-4644], Mittelholz, A. [0000-0002-5603-7334], Kawamura, T. [0000-0001-5246-5561], Widmer Schnidrig, R. [0000-0001-9698-2739], McClean, J. [0000-0002-7863-0120], Mueller, N. [0000-0001-9229-8921], Lewis, S. [0000-0001-7237-6494], Teanby, N. [0000-0003-3108-5775], Warren, T. [0000-0003-3877-0046], Milliour, E. [0000-0003-4808-9203], Lemmon, M. [0000-0002-4504-5136], Clinton, J. [0000-0001-8626-2703], Ceylan, S. [0000-0002-6552-6850], Banfield, D. [0000-0003-2664-0164], Agence Nationale de la Recherche (ANR), and Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA)
Subjects: Martian, 010504 meteorology & atmospheric sciences, Atmosphere, Mars, Mars Exploration Program, Atmosphere of Mars, 010502 geochemistry & geophysics, Mars Atmosphere, 01 natural sciences, Wind speed, Astrobiology, Autre, 13. Climate action, Dust storm, [SDU]Sciences of the Universe [physics], General Earth and Planetary Sciences, Environmental science, Aeolian processes, [SDU.OTHER]Sciences of the Universe [physics]/Other, Meteorologie, InSight mission, Dust devil, 0105 earth and related environmental sciences, InSight
Abstract: Banfield, D. et al., The atmosphere of Mars is thin, although rich in dust aerosols, and covers a dry surface. As such, Mars provides an opportunity to expand our knowledge of atmospheres beyond that attainable from the atmosphere of the Earth. The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander is measuring Mars’s atmosphere with unprecedented continuity, accuracy and sampling frequency. Here we show that InSight unveils new atmospheric phenomena at Mars, especially in the higher-frequency range, and extends our understanding of Mars’s meteorology at all scales. InSight is uniquely sensitive to large-scale and regional weather and obtained detailed in situ coverage of a regional dust storm on Mars. Images have enabled high-altitude wind speeds to be measured and revealed airglow—faint emissions produced by photochemical reactions—in the middle atmosphere. InSight observations show a paradox of aeolian science on Mars: despite having the largest recorded Martian vortex activity and dust-devil tracks close to the lander, no visible dust devils have been seen. Meteorological measurements have produced a catalogue of atmospheric gravity waves, which included bores (soliton-like waves). From these measurements, we have discovered Martian infrasound and unexpected similarities between atmospheric turbulence on Earth and Mars. We suggest that the observations of Mars’s atmosphere by InSight will be key for prediction capabilities and future exploration., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737); Centro de Desarrollo Tecnológico e Industrial (CDTI), Ministerio de Economía y Competitividad and the Instituto Nacional de Técnica Aeroespacial (INTA).
Published: 2020

47. An experimental study of the mixing of CO 2 and N 2 under conditions found at the surface of Venus

Author: Josette Bellan, Sébastien Lebonnois, Gerald Schubert, Daniel Cordier, Leah M. Nakley, Tibor Kremic, Kyle G. Phillips, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, NASA Glenn Research Center, NASA, Jet Propulsion Laboratory (JPL), and NASA-California Institute of Technology (CALTECH)
Subjects: Materials science, 010504 meteorology & atmospheric sciences, Thermodynamics, Venus, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, 01 natural sciences, Atmosphere of Venus, Critical point (thermodynamics), 0103 physical sciences, Homogeneity (physics), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Molecular diffusion, biology, VeGa-2 temperature profile, Atmosphere, Super-critical fluid, Time constant, Astronomy and Astrophysics, CO2/N2 mixtures, biology.organism_classification, Supercritical fluid, Chemical species, 13. Climate action, Space and Planetary Science, Composition
Abstract: International audience; Based on the only reliable temperature profile available in the deepest ∼10 km layer above Venus' surface (obtained by the VeGa-2 landing probe), the mixing conditions of the main constituents of Venus's atmosphere, CO 2 and N 2 , have been questioned. In this work, we report the results of a series of experiments that were done in the GEER facility at Glenn Research Center to investigate the homogeneity of CO 2 /N 2 gas mixtures at 100 bars and temperatures ranging from ∼296 K to ∼735 K. When the gas mixtures are initially well-mixed, separation of the two gases based on their molecular mass does not occur over the time scales observed; although, small systematic variations in composition remain to be fully interpreted. However, when N 2 is injected on top of CO 2 (layered fill), the very large density ratio makes it more difficult to mix the two chemical species. Timescales of mixing are of the order of 10 2 hours over the height of the test vessel (roughly 60 cm), and even longer when the gas mixture is at rest and only molecular diffusion is occurring. At room temperature, close to the critical point of the mixture, large pressure variations are obtained for the layered fill, as N 2 slowly mixes into CO 2. This can be explained by large density variations induced by the mixing. For conditions relevant to the near-surface atmosphere of Venus, separation of CO 2 and N 2 based on their molecular mass and due to physical properties of the gas mixture is not demonstrated, but cannot be firmly excluded either. This suggests that if the compositional vertical gradient deduced from the VeGa-2 temperature profile is to be trusted, it would most probably be due to some extrinsic processes (not related to gas properties, e.g. CO 2 volcanic inputs) and large mixing time constants.
Published: 2020

48. Compositional variability on the surface of 1 Ceres revealed through GRaND measurements of high-energy gamma rays

Author: David J. Lawrence, Patrick N. Peplowski, Andrew W. Beck, William C. Feldman, Thomas H. Prettyman, Chris T. Russell, Michael J. Toplis, Jack T. Wilson, Eleonora Ammannito, Julie C. Castillo-Rogez, M. C. DeSanctis, Scott C. Mest, Adrian Neesemann, London School of Hygiene and Tropical Medicine (LSHTM), Planetary Science Institute [Tucson] (PSI), 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), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Jet Propulsion Laboratory (JPL), and NASA-California Institute of Technology (CALTECH)
Subjects: Geophysics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Space and Planetary Science, 0103 physical sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 010303 astronomy & astrophysics, 01 natural sciences, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2018

49. Ceres internal structure from geophysical constraints

Author: Michael T. Bland, Scott D. King, Christopher T. Russell, Michael J. Toplis, Carol A. Raymond, Julie Castillo-Rogez, Virginia Tech [Blacksburg], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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), Astrogeology Science Center [Flagstaff], United States Geological Survey [Reston] (USGS), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, S. D. K. is supported by NASA award NNX15AI30G from the Dawn at Ceres Guest Investigator Program. We thank the Dawn team for the development, cruise, orbital insertion, and operations of the Dawn spacecraft at Ceres.C. T. R. is supported by the Discovery Program through contract NNM05AA86C to the University of California, Los Angeles.A portion of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA., We thank Walter Kiefer, Anton Ermakov, and an anonymous reviewer for their constructive comments. We thank Frédéric Chambat for making the Matlab program based on Chambat et al. (2010) available., and Geosciences
Subjects: education.field_of_study, 010504 meteorology & atmospheric sciences, Population, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mineralogy, Crust, 01 natural sciences, Hydrothermal circulation, Silicate, Mantle (geology), Flattening, law.invention, chemistry.chemical_compound, Geophysics, chemistry, Settling, 13. Climate action, Space and Planetary Science, law, 0103 physical sciences, Hydrostatic equilibrium, education, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: Thermal evolution modeling has yielded a variety of interior structures for Ceres, ranging from a modestly differentiated interior to more advanced evolution with a dry silicate core, a hydrated silicate mantle, and a volatile-rich crust. Here we compute the mass and hydrostatic flattening from more than one hundred billion three-layer density models for Ceres and describe the characteristics of the population of density structures that are consistent with the Dawn observations. We show that the mass and hydrostatic flattening constraints from Ceres indicate the presence of a high-density core with greater than a 1 sigma probability, but provide little constraint on the density, allowing for core compositions that range from hydrous and/or anhydrous silicates to a mixture of metal and silicates. The crustal densities are consistent with surface observations of salts, water ice, carbonates, and ammoniated clays, which indicate hydrothermal alteration, partial fractionation, and the possible settling of heavy sulfide and metallic particles, which provide a potential process for increasing mass with depth. NASA from the Dawn at Ceres Guest Investigator Program [NNX15AI30G]; Discovery ProgramAustralian Research Council [NNM05AA86C]; NASANational Aeronautics & Space Administration (NASA) We thank Walter Kiefer, Anton Ermakov, and an anonymous reviewer for their constructive comments. We thank Frederic Chambat for making the Matlab program based on Chambat et al. (2010) available. S. D. K. is supported by NASA award NNX15AI30G from the Dawn at Ceres Guest Investigator Program. We thank the Dawn team for the development, cruise, orbital insertion, and operations of the Dawn spacecraft at Ceres.; C. T. R. is supported by the Discovery Program through contract NNM05AA86C to the University of California, Los Angeles.; A portion of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. The authors have no conflict of interest to declare. Public domain – authored by a U.S. government employee
Published: 2018

50. Terrestrial cooling and changes in hydroclimate in the continental interior of the United States across the Eocene-Oligocene boundary

Author: Aradhna Tripati, Majie Fan, Benjamin H. Passey, Sara A. Ayyash, Elizabeth M. Griffith, Department of Earth and Environmental Sciences [Arlington], University of Texas at Arlington [Arlington], Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Department of Atmospheric and Oceanic Sciences [Los Angeles] (AOS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University (JHU), Ohio State University [Columbus] (OSU), and ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, atmospheric co2, 010504 meteorology & atmospheric sciences, spatial-distribution, ACL, climate transition, antarctic glaciation, Boundary (topology), clumped-isotope geochemistry, Geology, 15. Life on land, north-american midcontinent, 010502 geochemistry & geophysics, 01 natural sciences, northwestern nebraska, Paleontology, 13. Climate action, central rocky-mountains, great-plains, groundwater temperature response, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, 0105 earth and related environmental sciences
Abstract: WOS:000437009200002; International audience; One of the most pronounced climate transitions in Earth's history occurred at the Eocene-Oligocene transition, similar to 34.0-33.6 m.y. ago. Marine sedimentary records indicate a dramatic decline in pCO(2) coeval with global cooling during the transition. However, terrestrial records are relatively sparse, with conflicting interpretations of hydroclimate in continental interiors. Here, we provide quantitative constraints on the response of the continental hydroclimate in the western United States across the Eocene-Oligocene boundary by studying clumped isotope temperatures [T(Delta(47))], delta C-13 and delta O-18 values of vadose carbonates, and delta C-13 values of bulk organic matter (delta C-13(org)) in eastern Wyoming. Our results show that T(Delta(47)) dropped from similar to 28 degrees C to similar to 21 degrees C, indicating similar to 7 degrees C cooling in air temperature, which occurred parallel to the decrease in atmospheric pCO(2) during the latest Eocene-early Oligocene. We find that aridity and the biome were stable, and ice-volume-corrected precipitation PO decreased similar to 1.6 parts per thousand across the Eocene-Oligocene boundary, attributable to reduced vapor condensation temperatures. These new quantitative data add to the growing body of evidence suggesting a marked terrestrial response in temperature and hydroclimate across the Eocene-Oligocene transition. Our findings indicate a pattern of greenhouse-gas- induced global temperature change in the continental interior of the United States that was roughly 1.5-2x the magnitude of cooling in the global ocean.
Published: 2017

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