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1. Frequency of occurrence of rain from liquid-, mixed-, and ice-phase clouds derived from A-Train satellite retrievals

Author: Universität Leipzig, Institut für Meterologie, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Mülmenstädt, Johannes, Sourdeval, Odran, Delanoë, Julien, Quaas, Johannes, Universität Leipzig, Institut für Meterologie, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Mülmenstädt, Johannes, Sourdeval, Odran, Delanoë, Julien, and Quaas, Johannes
Abstract: A climatology of thermodynamic phase of precipitating cloud is presented derived from global—land and ocean—, retrievals from Cloudsat, CALIPSO, and Moderate Resolution Imaging Spectroradiometer. Like precipitation rate, precipitation frequency is dominated by warm rain, defined as rain produced via the liquid phase only, over the tropical oceans outside the Intertropical Convergence Zone and by cold rain, produced via the ice phase, over the midlatitude oceans and continents. Warm rain is very infrequent over the continents, with significant warm rain found only in onshore flow in the tropics, and over India, China, and Indochina. Comparison of the properties of precipitating and nonprecipitating warm clouds shows that the scarcity of warm rain over land can be explained by smaller effective radii in continental clouds that delay the onset of precipitation. The results highlight the importance of ice-phase processes for the global hydrological cycle and may lead to an improved parameterization of precipitation in general circulation models.
Published: 2016

2. Frequency of occurrence of rain from liquid-, mixed-, and ice-phase clouds derived from A-Train satellite retrievals

Author: Universität Leipzig, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Mülmenstädt, Johannes, Sourdeval, Odran, Delanoë, Julien, Quaas, Johannes, Universität Leipzig, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Mülmenstädt, Johannes, Sourdeval, Odran, Delanoë, Julien, and Quaas, Johannes
Abstract: A climatology of thermodynamic phase of precipitating cloud is presented derived from global—land and ocean—, retrievals from Cloudsat, CALIPSO, and Moderate Resolution Imaging Spectroradiometer. Like precipitation rate, precipitation frequency is dominated by warm rain, defined as rain produced via the liquid phase only, over the tropical oceans outside the Intertropical Convergence Zone and by cold rain, produced via the ice phase, over the midlatitude oceans and continents. Warm rain is very infrequent over the continents, with significant warm rain found only in onshore flow in the tropics, and over India, China, and Indochina. Comparison of the properties of precipitating and nonprecipitating warm clouds shows that the scarcity of warm rain over land can be explained by smaller effective radii in continental clouds that delay the onset of precipitation. The results highlight the importance of ice-phase processes for the global hydrological cycle and may lead to an improved parameterization of precipitation in general circulation models.
Published: 2016

3. Intercomparison of shortwave radiative transfer schemes in global aerosol modeling: Intercomparison of shortwave radiative transfer schemes in globalaerosol modeling: results from the AeroCom Radiative Transfer Experiment

Author: Morgan State University, NASA Goddard Space Flight Center (GSFC), Max-Planck-Institut für Meteorologie, Center for International Climate and Environmental Research (CICERO), Meteorologisk Institutt, University of Oxford, Freie Universität Berlin, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), University of Reading, Finnish Meteorological Institute, University of Maryland, Ludwig-Maximilians-Universität, University of Vienna, NASA GSFC Climate and Radiation Laboratory, Seoul National University, University of L’Aquila, Space Academy Foundation, Universität Leipzig, Science Systems and Applications, Inc. (SSAI), NASA Langley Research Center (LaRC), UK Met Office (UKMO), University of Crete, University of Ioannina, University of the Aegean, National Climate Center, Randles, Cynthia A., Kinne, Stefan, Myhre, Gunnar, Schulz, Michael, Stier, Philip, Fischer, Jürgen, Doppler, Lionel, Highwood, Eleanor, Ryder, Claire, Harris, Bethan, Huttunen, Jani, Ma, Y., Pinker, Rachel T., Mayer, Bernhard, Neubauer, David, Hitzenberger, Regina, Oreopoulos, Lazaros, Lee, Dongmin, Pitari, Giovanni, Di Genova, Glauco, Quaas, Johannes, Rose, Fred G., Kato, Seiji, Rumbold, Steve T., Vardavas, Ilias, Hatzianastassiou, Nikos, Matsoukas, Christos, Yu, Hongbin, Zhang, F., Zhang, Hua, Lu, P., Morgan State University, NASA Goddard Space Flight Center (GSFC), Max-Planck-Institut für Meteorologie, Center for International Climate and Environmental Research (CICERO), Meteorologisk Institutt, University of Oxford, Freie Universität Berlin, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), University of Reading, Finnish Meteorological Institute, University of Maryland, Ludwig-Maximilians-Universität, University of Vienna, NASA GSFC Climate and Radiation Laboratory, Seoul National University, University of L’Aquila, Space Academy Foundation, Universität Leipzig, Science Systems and Applications, Inc. (SSAI), NASA Langley Research Center (LaRC), UK Met Office (UKMO), University of Crete, University of Ioannina, University of the Aegean, National Climate Center, Randles, Cynthia A., Kinne, Stefan, Myhre, Gunnar, Schulz, Michael, Stier, Philip, Fischer, Jürgen, Doppler, Lionel, Highwood, Eleanor, Ryder, Claire, Harris, Bethan, Huttunen, Jani, Ma, Y., Pinker, Rachel T., Mayer, Bernhard, Neubauer, David, Hitzenberger, Regina, Oreopoulos, Lazaros, Lee, Dongmin, Pitari, Giovanni, Di Genova, Glauco, Quaas, Johannes, Rose, Fred G., Kato, Seiji, Rumbold, Steve T., Vardavas, Ilias, Hatzianastassiou, Nikos, Matsoukas, Christos, Yu, Hongbin, Zhang, F., Zhang, Hua, and Lu, P.
Abstract: In this study we examine the performance of 31 global model radiative transfer schemes in cloudfree conditions with prescribed gaseous absorbers and no aerosols (Rayleigh atmosphere), with prescribed scatteringonly aerosols, and with more absorbing aerosols. Results are compared to benchmark results from high-resolution, multiangular line-by-line radiation models. For purely scattering aerosols, model bias relative to the line-by-line models in the top-of-the atmosphere aerosol radiative forcing ranges from roughly −10 to 20 %, with over- and underestimates of radiative cooling at lower and higher solar zenith angle, respectively. Inter-model diversity (relative standard deviation) increases from ~ 10 to 15% as solar zenith angle decreases. Inter-model diversity in atmospheric and surface forcing decreases with increased aerosol absorption, indicating that the treatment of multiple-scattering is more variable than aerosol absorption in the models considered. Aerosol radiative forcing results from multi-stream models are generally in better agreement with the line-by-line results than the simpler two-stream schemes. Considering radiative fluxes, model performance is generally the same or slightly better than results from previous radiation scheme intercomparisons. However, the inter-model diversity in aerosol radiative forcing remains large, primarily as a result of the treatment of multiple-scattering. Results indicate that global models that estimate aerosol radiative forcing with two-stream radiation schemes may be subject to persistent biases introduced by these schemes, particularly for regional aerosol forcing.
Published: 2015

4. Solar wind charge exchange X-ray emission from Mars. Model and data comparison

Author: heppi ; Institut Pierre-Simon-Laplace (IPSL) ; CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI - CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI - Université Versailles Saint-Quentin en Yvelines (UVSQ) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI - CNRS, Laboratoire de Physique des Plasmas (LPP) ; CNRS - Université Paris XI - Paris Sud - Polytechnique - X - Université Pierre et Marie Curie (UPMC) - Paris VI, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI, Institut Pierre-Simon-Laplace (IPSL) ; CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI, Université Versailles Saint-Quentin en Yvelines (UVSQ) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of Connecticut ; University of Connecticut, Galaxies, Etoiles, Physique, Instrumentation (GEPI) ; CNRS - INSU - Observatoire de Paris - Université Paris VII - Paris Diderot, Observatoire de Paris - Site de Meudon (OBSPM) ; CNRS - Observatoire de Paris, Koutroumpa, Dimitra, Modolo, Ronan, Chanteur, G., Chaufray, Jean-Yves, Kharchenko, V., Lallement, Rosine, heppi ; Institut Pierre-Simon-Laplace (IPSL) ; CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI - CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI - Université Versailles Saint-Quentin en Yvelines (UVSQ) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI - CNRS, Laboratoire de Physique des Plasmas (LPP) ; CNRS - Université Paris XI - Paris Sud - Polytechnique - X - Université Pierre et Marie Curie (UPMC) - Paris VI, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI, Institut Pierre-Simon-Laplace (IPSL) ; CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI, Université Versailles Saint-Quentin en Yvelines (UVSQ) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of Connecticut ; University of Connecticut, Galaxies, Etoiles, Physique, Instrumentation (GEPI) ; CNRS - INSU - Observatoire de Paris - Université Paris VII - Paris Diderot, Observatoire de Paris - Site de Meudon (OBSPM) ; CNRS - Observatoire de Paris, Koutroumpa, Dimitra, Modolo, Ronan, Chanteur, G., Chaufray, Jean-Yves, Kharchenko, V., and Lallement, Rosine
Abstract: International audience, We study the soft X-ray emission induced by charge exchange (CX) collisions between solar-wind, highly charged ions and neutral atoms of the Martian exosphere. A 3D multi species hybrid simulation model with improved spatial resolution (130 km) is used to describe the interaction between the solar wind and the Martian neutrals. We calculated velocity and density distributions of the solar wind plasma in the Martian environment with realistic planetary ions description, using spherically symmetric exospheric H and O profiles. Following that, a 3D test-particle model was developed to compute the X-ray emission produced by CX collisions between neutrals and solar wind minor ions. The model results are compared to XMM-Newton observations of Mars. We calculate projected X-ray emission maps for the XMM-Newton observing conditions and demonstrate how the X-ray emission reflects the Martian electromagnetic structure in accordance with the observed X-ray images. Our maps confirm that X-ray images are a powerful tool for the study of solar wind - planetary interfaces. However, the simulation results reveal several quantitative discrepancies compared to the observations. Typical solar wind and neutral coronae conditions corresponding to the 2003 observation period of Mars cannot reproduce the high luminosity or the corresponding very extended halo observed with XMM-Newton. Potential explanations of these discrepancies are discussed.

5. IMADYN : A field campaign to evaluate the potential of infrasound monitoring for atmospheric dynamics studies

Author: Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI, Institut Pierre-Simon-Laplace (IPSL) ; CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI, Laboratoire de Géophysique (LDG) ; CEA, Observatoire de Haute-Provence (OHP) ; CNRS - INSU - Université de Provence - Aix-Marseille I, Société Française d'Acoustique - SFA, Hauchecorne, Alain, Dalaudier, Francis, Cot, Charles, Blanc, Elisabeth, Le Pichon, Alexis, Perrin, Jean-Marie, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI, Institut Pierre-Simon-Laplace (IPSL) ; CNRS - Institut de recherche pour le développement [IRD] - CEA - CNES - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - École normale supérieure [ENS] - Paris - Université Pierre et Marie Curie (UPMC) - Paris VI, Laboratoire de Géophysique (LDG) ; CEA, Observatoire de Haute-Provence (OHP) ; CNRS - INSU - Université de Provence - Aix-Marseille I, Société Française d'Acoustique - SFA, Hauchecorne, Alain, Dalaudier, Francis, Cot, Charles, Blanc, Elisabeth, Le Pichon, Alexis, and Perrin, Jean-Marie
Abstract: National audience, The infrasound monitoring is a new technique to study the dynamics of the upper atmosphere. Infrasound waves are reflected by the various atmospheric layers depending on the vertical profile of wind and temperature. The measurement of the characteristics of infrasound signals brings then very useful information on the structure and dynamics of the upper atmosphere. In the IMADYN project proposed to the French Agence National de la Recherche, specialists of atmospheric dynamics and infrasound atmospheric propagation will work together to assess the potential of the IMS network of microbarometers of the Comprehensive Nuclear-Test Ban Treaty-Organisation (CTBT-O), in order to improve our knowledge of the dynamics of the middle and upper atmosphere. The proposal is composed of two parts, the first one based on the exploitation of the existing IMS database in comparison with available meteorological and climatological atmospheric models. The second one is based on the organization of a field campaign at the Haute-Provence Observatory equipped with state of the art lidars and radars systems were microbarometers will be installed for a detailed study of infrasound propagation and atmospheric waves and perturbations.

6. Ondes de gravité produites par le passage de l'éclipse du 1er Août 2008

Author: DAM Île-de-France (DAM/DIF) ; CEA, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI, Laboratoire de Géophysique (LDG) ; CEA, RCAG ; RCAG, Société Française d'Acoustique - SFA, Marty, Julien, Dalaudier, Francis, Ponceau, Damien, Blanc, Elisabeth, Munkhuu, Ulziibat, DAM Île-de-France (DAM/DIF) ; CEA, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; CNRS - INSU - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie (UPMC) - Paris VI, Laboratoire de Géophysique (LDG) ; CEA, RCAG ; RCAG, Société Française d'Acoustique - SFA, Marty, Julien, Dalaudier, Francis, Ponceau, Damien, Blanc, Elisabeth, and Munkhuu, Ulziibat
Abstract: National audience, Les ondes de gravité sont une composante essentielle de la dynamique de l'atmosphère petite échelle à cause de leur capacité à transporter de l'énergie et de la quantité de mouvement sur de très grandes distances. Elles produisent des variations de pression au niveau du sol qui peuvent être détectées par des microbarographes. Dans le but d'estimer les caractéristiques des signaux attendus au niveau du sol, un nouveau modèle linéaire spectral numérique de propagation d'ondes de gravité internes a été développé (Marty, J. and Dalaudier, F.: Linear spectral numerical model for internal gravity wave propagation,. J. Atmos. Sci. (in press)). Les éclipses solaires sont connues pour agir comme une source temporaire d'ondes de gravité et produire des ondes en lame d'étrave de très grande échelle à la surface de la Terre. La réponse asymptotique à un forçage thermique se déplaçant à vitesse constante ainsi que la réponse transitoire à l'éclipse du 4 Décembre 2002 sont étudiées en utilisant notre modèle. Les résultats sont en bon accord avec les simulations numériques précédentes. Le modèle est ensuite appliqué au cas de l'éclipse du 1er Août 2008. Ces estimations sont comparées aux données des stations infrasons du Système de Surveillance International (SSI) et de stations temporaires spécialement installées pour cette occasion. La validité de la mesure obtenue avec les microbarographes pour l'observation d'ondes aussi basse fréquences est scrupuleusement étudiée. Les variations de pression produites par une éclipse solaire se situent dans une bande de fréquence fortement perturbée par les marées atmosphériques. Ces dernières sont donc caractérisées et ôtées du signal. Une onde basse fréquence commençant juste après le passage de l'éclipse est mise en évidence sur l'ensemble des stations. Sa fréquence et son amplitude sont proches de celle estimée avec notre modèle ce qui suggère fortement que cette onde a été produite par le passage de l'éclipse.

7. Sample return of primitive matter from the outer Solar System

Author: Andreas Morlok, Mathieu Roskosz, Martin Rubin, Hugues Leroux, Sara S. Russell, J. Carter, Vinciane Debaille, Brigitte Zanda, Ernesto Palomba, Laurette Piani, Emmanuel Jehin, Johan Villeneuve, Vassilissa Vinogradoff, Maria Schönbächler, Joern Helbert, Yves Marrocchi, Peter Wurz, C. Cartier, Ottaviano Ruesch, Addi Bischoff, Pierre Beck, Evelyn Füri, Jérémie Lasue, A. Guilbert-Lepoutre, N. Thomas, Philippe Lamy, Laurent Jorda, Eric Quirico, Mauro Ciarniello, O. Mousis, Olivier Groussin, Henner Busemann, Ingo Leya, Rosario Brunetto, Cristian Carli, A. Delsanti, Louis Le Sergeant d'Hendecourt, T. Magna, Pierre Vernazza, Ashley J. King, Peter Hoppe, Lydie Bonal, Gregory A. Brennecka, Thorsten Kleine, C. Le Guillou, Laurent Remusat, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-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, Institut für Planetologie [Münster], Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Lawrence Livermore National Laboratory (LLNL), 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), Institute of Geochemistry and Petrology [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), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), 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), Laboratoire Géochimie, Traçage Isotopique, Minéral et élémentaire - G-Time (Bruxelles, Belgium), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-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), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Chemie (MPIC), Max-Planck-Gesellschaft, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, The Natural History Museum [London] (NHM), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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 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), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Physics Institute [Bern], University of Bern, Czech Geological Survey [Praha], 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), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lille, CNRS, INRA, ENSCL, Laboratoire d'Astrophysique de Marseille [LAM], Institut de Planétologie et d'Astrophysique de Grenoble [IPAG ], Lawrence Livermore National Laboratory [LLNL], Institut d'astrophysique spatiale [IAS], Istituto di Astrofisica e Planetologia Spaziali - INAF [IAPS], Centre de Recherches Pétrographiques et Géochimiques [CRPG], Physique des interactions ioniques et moléculaires [PIIM], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [LGL-TPE], German Aerospace Center [DLR], Max Planck Institute for Chemistry [MPIC], Space Sciences, Technologies and Astrophysics Research Institute [STAR], The Natural History Museum [London] [NHM], Laboratoire Atmosphères, Milieux, Observations Spatiales [LATMOS], Institut de recherche en astrophysique et planétologie [IRAP], Unité Matériaux et Transformations - UMR 8207 [UMET], Institut de minéralogie, de physique des matériaux et de cosmochimie [IMPMC], Institut de minéralogie et de physique des milieux condensés [IMPMC], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), 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), Westfälische Wilhelms-Universität Münster (WWU), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-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), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut 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), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centrale Lille Institut (CLIL)
Subjects: Solar System, P/D type asteroids, Cryogenic, Comet, Sample return, 010502 geochemistry & geophysics, Primitive small body, 01 natural sciences, Astrobiology, Jupiter, Sample return mission, Neptune, 0103 physical sciences, Comets, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 520 Astronomy, Giant planet, Astronomy and Astrophysics, 620 Engineering, Planetary science, 13. Climate action, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], Geology
Abstract: The last thirty years of cosmochemistry and planetary science have shown that one major Solar System reservoir is vastly undersampled in the available suite of extra-terrestrial materials, namely small bodies that formed in the outer Solar System (>10 AU). Because various dynamical evolutionary processes have modified their initial orbits (e.g., giant planet migration, resonances), these objects can be found today across the entire Solar System as P/D near-Earth and main-belt asteroids, Jupiter and Neptune Trojans, comets, Centaurs, and small (diameter < 200 km) trans-Neptunian objects. This reservoir is of tremendous interest, as it is recognized as the least processed since the dawn of the Solar System and thus the closest to the starting materials from which the Solar System formed. Some of the next major breakthroughs in planetary science will come from studying outer Solar System samples (volatiles and refractory constituents) in the laboratory. Yet, this can only be achieved by an L-class mission that directly collects and returns to Earth materials from this reservoir. It is thus not surprising that two White Papers advocating a sample return mission of a primitive Solar System small body (ideally a comet) were submitted to ESA in response to its Voyage 2050 call for ideas for future L-class missions in the 2035-2050 time frame. One of these two White Papers is presented in this article., Experimental Astronomy, 54 (2-3), ISSN:0922-6435, ISSN:1572-9508
Published: 2021

8. Clouds in the Martian Atmosphere

Author: Franck Montmessin, Anni Määttänen, 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), Peter Read, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), and Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: Martian, Ice crystals, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Mars Exploration Program, Atmosphere of Mars, Astrobiology, Physics::Geophysics, Atmosphere, 13. Climate action, Planet, Ice nucleus, Environmental science, Astrophysics::Earth and Planetary Astrophysics, Water vapor, [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Physics::Atmospheric and Oceanic Physics
Abstract: Although resembling an extremely dry desert, planet Mars hosts clouds in its atmosphere. Every day somewhere on the planet a part of the tiny amount of water vapor held by the atmosphere can condense as ice crystals to form mainly cirrus-type clouds. The existence of water ice clouds has been known for a long time and they have been studied for decades, leading to the establishment of a well-known climatology and understanding on their formation and properties. Despite their thinness, they have a clear impact on the atmospheric temperatures, thus affecting the Martian climate. Another, more exotic type of clouds forms as well on Mars. The atmospheric temperatures can plunge to such frigid values that the major gaseous component of the atmosphere, CO2, condenses as ice crystals. These clouds form in the cold polar night where they also contribute to the formation of the CO2 ice polar cap, and also in the mesosphere at very high altitudes, near the edge of space, analogously to the noctilucent clouds on Earth. The mesospheric clouds, discovered in the early 2000s, have put our understanding of the Martian atmosphere to a test. On Mars, cloud crystals form on ice nuclei, mostly provided by the omnipresent mineral dust. Thus, the clouds link the three major climatic cycles: those of the two major volatiles, H2O and CO2, and that of dust, which is a major climatic agent itself.
Published: 2021

9. Halogen chemistry in volcanic plumes: a 1D framework based on MOCAGE 1D (version R1.18.1) preparing 3D global chemistry modelling

Author: Virginie Marécal, Ronan Voisin-Plessis, Tjarda Jane Roberts, Alessandro Aiuppa, Herizo Narivelo, Paul David Hamer, Béatrice Josse, Jonathan Guth, Luke Surl, Lisa Grellier, Centre national de recherches météorologiques (CNRM), 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)-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 -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), Dipartimento di Scienze della Terra e del Mare [Palermo] (DiSTeM), Università degli studi di Palermo - University of Palermo, Norwegian Institute for Air Research (NILU), Department of Chemistry [Aberdeen], School of Natural and Computing Sciences, University of Aberdeen-University of Aberdeen, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Centre Interprofessionnel Technique d'Etude des Pollutions Atmosphériques (CITEPA), 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-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), Norsk Institutt for Luftforskning (NILU), VOLC-HAL-CLIM: ANR-18-CE1-0018, and ANR-18-CE01-0018,VOLC-HAL-CLIM,Halogènes volcaniques : de la Terre profonde aux impacts atmosphériques(2018)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Halogen chemistry, [SDE]Environmental Sciences, Volcanic emissions, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, General Medicine
Abstract: HBr emissions from volcanoes lead rapidly to the formation of BrO within volcanic plumes and have an impact on tropospheric chemistry, at least at the local and regional scales. The motivation of this paper is to prepare a framework for further 3D modelling of volcanic halogen emissions in order to determine their fate within the volcanic plume and then in the atmosphere at the regional and global scales. The main aim is to evaluate the ability of the model to produce a realistic partitioning of bromine species within a grid box size typical of MOCAGE (Model Of atmospheric Chemistry At larGE scale) 3D (0.5∘ × 0.5∘). This work is based on a 1D single-column configuration of the global chemistry-transport model MOCAGE that has low enough computational cost to allow us to perform a large set of sensitivity simulations. This paper uses the emissions from the Mount Etna eruption on 10 May 2008. Several reactions are added to MOCAGE to represent the volcanic plume halogen chemistry. A simple plume parameterisation is also implemented and tested. The use of this parameterisation tends to only slightly limit the efficiency of BrO net production. Both simulations with and without the parameterisation give results for the partitioning of the bromine species, of ozone depletion and of the BrO/SO2 ratio that are consistent with previous studies. A series of test experiments were performed to evaluate the sensitivity of the results to the composition of the emissions (primary sulfate aerosols, Br radical and NO) and to the effective radius assumed for the volcanic sulfate aerosols. Simulations show that the plume chemistry is sensitive to all these parameters. We also find that the maximum altitude of the eruption changes the BrO production, which is linked to the vertical variability of the concentrations of oxidants in the background air. These sensitivity tests display changes in the bromine chemistry cycles that are generally at least as important as the plume parameterisation. Overall, the version of the MOCAGE chemistry developed for this study is suitable to produce the expected halogen chemistry in volcanic plumes during daytime and night-time.
Published: 2023

10. Key positive ion precursors to tholin formation

Author: David Dubois, Nathalie Carrasco, Lora Jovanovic, Westlake, J., Ludovic Vettier, Thomas Gautier, 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), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Dubois, David, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), and Johns Hopkins University Applied Physics Laboratory [Laurel, MD] ( APL )
Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [ SDU.STU.PL ] Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology
Abstract: International audience; In Titan's upper atmosphere, Cassini detected mass signatures compatible with the presence of heavily charged molecules which are volatile precursors to the solid core of the aerosols. INMS measurements revealed molecular groupings of masses below 100 amu, while CAPS-IBS saw positive ions up to ~350 amu, well beyond the INMS detection limit. Photochemical processes are also influenced by dayside vs. nightside conditions, with photoionization dominating the dayside. From a dynamical and transport viewpoint, the ion densities were also found to be sensitive to modeled turbulent neutral transport. A previous laboratory study has also explored the influence of trace species on the first and intermediate steps of the neutral and positive ion chemistry, in hydrocarbon-enriched mixtures. Furthermore, models have indicated that primary production processes and ion-molecule reactions mainly control the production of the lighter and subsequent heavier positive ions. These reactions rely on the large abundancies of hydrocarbon building blocks (e.g. C2H2 and C2H4). These observations indicate that ion chemistry has an important role for organic growth in the upper atmosphere. However, the processes coupling ion chemistry and the formation of larger tholins have yet to be further explored. In this study, we investigate the positive ion chemistry in the laboratory, responsible for the efficient organic growth producing tholins, simulated in the PAMPRE plasma reactor. We use a RF-generated plasma at 1 mbar pressure, coupled with an ion mass spectrometer , probing the gas phase volatiles in situ. We study N2:CH4 mixtures with 1-10% CH4 mixing ratios, and investigate the impact of light ions on the larger ones. We further compare our results to Cassini Ion and Neutral Mass Spectrometer (INMS) measurements taken during the T40 flyby.
Published: 2018

11. Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars

Author: Patrice Coll, Arnaud Buch, Paul R. Mahaffy, Pamela G. Conrad, John P. Grotzinger, Heather B. Franz, Sanjeev Gupta, Caroline Freissinet, Daniel P. Glavin, Brad Sutter, Maeva Millan, Dawn Y. Sumner, Andrew Steele, P. D. Archer, Joel A. Hurowitz, Amy McAdam, Jennifer L. Eigenbrode, Rafael Navarro-González, Cyril Szopa, Charles Malespin, D. W. Ming, Roger E. Summons, NASA Goddard Space Flight Center (GSFC), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science [Washington], PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Georgetown University [Washington] (GU), Instituto de Ciencias Nucleares [Mexico], Universidad Nacional Autónoma de México (UNAM), Jacobs Technology ESCG, Astromaterials Research and Exploration Science (ARES), NASA Johnson Space Center (JSC), NASA-NASA, Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Department of Earth Science and Engineering [Imperial College London], Imperial College London, Department of Earth and Planetary Sciences [Davis], University of California [Davis] (UC Davis), University of California-University of California, Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center ( GSFC ), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] ( EAPS ), Massachusetts Institute of Technology ( MIT ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Georgetown University [Washington] ( GU ), Universidad Nacional Autónoma de México ( UNAM ), Astromaterials Research and Exploration Science ( ARES ), NASA Johnson Space Center ( JSC ), Stony Brook University [The State University of New York] ( SBU ), California Institute of Technology ( CALTECH ), Department of Earth Science and Engineering [London], University of California [Davis] ( UC Davis ), Laboratoire de Génie des Procédés et Matériaux - EA 4038 ( LGPM ), Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Carnegie Institution for Science, 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), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Department of Earth and Planetary Sciences [Univ California Davis] (EPS - UC Davis), University of California (UC)-University of California (UC), Laboratoire de Génie des Procédés et Matériaux (LGPM), CentraleSupélec-Université Paris-Saclay, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Science and Technology Facilities Council (STFC)
Subjects: 010504 meteorology & atmospheric sciences, Evolved gas analysis, General Science & Technology, chemistry.chemical_element, 01 natural sciences, Astrobiology, PHASES, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 0103 physical sciences, Organic matter, 010303 astronomy & astrophysics, [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], 0105 earth and related environmental sciences, Total organic carbon, Martian, chemistry.chemical_classification, Science & Technology, Multidisciplinary, [ SDU.STU.PL ] Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], PYROLYSIS, Mars Exploration Program, 15. Life on land, Multidisciplinary Sciences, chemistry, 13. Climate action, Sample Analysis at Mars, Science & Technology - Other Topics, Environmental science, Carbon, Pyrolysis
Abstract: Measuring martian organics and methane The Curiosity rover has been sampling on Mars for the past 5 years (see the Perspective by ten Kate). Eigenbrode et al. used two instruments in the SAM (Sample Analysis at Mars) suite to catch traces of complex organics preserved in 3-billion-year-old sediments. Heating the sediments released an array of organics and volatiles reminiscent of organic-rich sedimentary rock found on Earth. Most methane on Earth is produced by biological sources, but numerous abiotic processes have been proposed to explain martian methane. Webster et al. report atmospheric measurements of methane covering 3 martian years and found that the background level varies with the local seasons. The seasonal variation provides an important clue for determining the origin of martian methane. Science , this issue p. 1096 , p. 1093 ; see also p. 1068
Published: 2018

12. Imaging Plasma Density Structures in the Soft X-Rays Generated by Solar Wind Charge Exchange with Neutrals

Author: David G. Sibeck, R. Allen, H. Aryan, D. Bodewits, P. Brandt, G. Branduardi-Raymont, G. Brown, J. A. Carter, Y. M. Collado-Vega, M. R. Collier, H. K. Connor, T. E. Cravens, Y. Ezoe, M.-C. Fok, M. Galeazzi, O. Gutynska, M. Holmström, S.-Y. Hsieh, K. Ishikawa, D. Koutroumpa, K. D. Kuntz, M. Leutenegger, Y. Miyoshi, F. S. Porter, M. E. Purucker, A. M. Read, J. Raeder, I. P. Robertson, A. A. Samsonov, S. Sembay, S. L. Snowden, N. E. Thomas, R. von Steiger, B. M. Walsh, S. Wing, NASA Goddard Space Flight Center ( GSFC ), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] ( APL ), Department of Astronomy [College Park], University of Maryland [College Park], Mullard Space Science Laboratory ( MSSL ), University College of London [London] ( UCL ), Lawrence Livermore National Laboratory ( LLNL ), University of Leicester, University of Alaska Fairbanks ( UAF ), University of Kansas [Lawrence] ( KU ), Tokyo Metropolitan University [Tokyo], Department of Physics [Coral Gables], University of Miami [Coral Gables], Swedish Institute of Space Physics [Kiruna] ( IRF ), Institute of Space and Astronautical Science ( ISAS ), HEPPI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Johns Hopkins University ( JHU ), University of Maryland Baltimore County [Baltimore] ( UMBC ), Nagoya University, University of New Hampshire ( UNH ), St Petersburg State University ( SPbU ), Department of Physics and Astronomy [Leicester], International Space Science Institute ( ISSI ), Boston University [Boston] ( BU ), NASA Goddard Space Flight Center (GSFC), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), University of Maryland System-University of Maryland System, Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Lawrence Livermore National Laboratory (LLNL), University of Alaska [Fairbanks] (UAF), University of Kansas [Lawrence] (KU), Tokyo Metropolitan University [Tokyo] (TMU), Swedish Institute of Space Physics [Kiruna] (IRF), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), 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), Johns Hopkins University (JHU), University of Maryland [Baltimore County] (UMBC), University of Maryland System, University of New Hampshire (UNH), St Petersburg State University (SPbU), International Space Science Institute [Bern] (ISSI), and Boston University [Boston] (BU)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics::High Energy Astrophysical Phenomena, Solar wind, Planets, Astronomy and Astrophysics, Magnetosheath, Cusp, 7. Clean energy, 01 natural sciences, 13. Climate action, Space and Planetary Science, Physics::Space Physics, X-rays, 0103 physical sciences, Comets, Astrophysics::Solar and Stellar Astrophysics, X-ray background, Astrophysics::Earth and Planetary Astrophysics, Charge exchange, Instrumentation, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; Both heliophysics and planetary physics seek to understand the complex nature of the solar wind’s interaction with solar system obstacles like Earth’s magnetosphere, the ionospheres of Venus and Mars, and comets. Studies with this objective are frequently conducted with the help of single or multipoint in situ electromagnetic field and particle observations, guided by the predictions of both local and global numerical simulations, and placed in context by observations from far and extreme ultraviolet (FUV, EUV), hard X-ray, and energetic neutral atom imagers (ENA). Each proposed interaction mechanism (e.g., steady or transient magnetic reconnection, local or global magnetic reconnection, ion pick-up, or the Kelvin-Helmholtz instability) generates diagnostic plasma density structures. The significance of each mechanism to the overall interaction (as measured in terms of atmospheric/ionospheric loss at comets, Venus, and Mars or global magnetospheric/ionospheric convection at Earth) remains to be determined but can be evaluated on the basis of how often the density signatures that it generates are observed as a function of solar wind conditions. This paper reviews efforts to image the diagnostic plasma density structures in the soft (low energy, 0.1–2.0 keV) X-rays produced when high charge state solar wind ions exchange electrons with the exospheric neutrals surrounding solar system obstacles.The introduction notes that theory, local, and global simulations predict the characteristics of plasma boundaries such the bow shock and magnetopause (including location, density gradient, and motion) and regions such as the magnetosheath (including density and width) as a function of location, solar wind conditions, and the particular mechanism operating. In situ measurements confirm the existence of time- and spatial-dependent plasma density structures like the bow shock, magnetosheath, and magnetopause/ionopause at Venus, Mars, comets, and the Earth. However, in situ measurements rarely suffice to determine the global extent of these density structures or their global variation as a function of solar wind conditions, except in the form of empirical studies based on observations from many different times and solar wind conditions. Remote sensing observations provide global information about auroral ovals (FUV and hard X-ray), the terrestrial plasmasphere (EUV), and the terrestrial ring current (ENA). ENA instruments with low energy thresholds (∼1 keV) have recently been used to obtain important information concerning the magnetosheaths of Venus, Mars, and the Earth. Recent technological developments make these magnetosheaths valuable potential targets for high-cadence wide-field-of-view soft X-ray imagers.Section 2 describes proposed dayside interaction mechanisms, including reconnection, the Kelvin-Helmholtz instability, and other processes in greater detail with an emphasis on the plasma density structures that they generate. It focuses upon the questions that remain as yet unanswered, such as the significance of each proposed interaction mode, which can be determined from its occurrence pattern as a function of location and solar wind conditions. Section 3 outlines the physics underlying the charge exchange generation of soft X-rays. Section 4 lists the background sources (helium focusing cone, planetary, and cosmic) of soft X-rays from which the charge exchange emissions generated by solar wind exchange must be distinguished. With the help of simulations employing state-of-the-art magnetohydrodynamic models for the solar wind-magnetosphere interaction, models for Earth’s exosphere, and knowledge concerning these background emissions, Sect. 5 demonstrates that boundaries and regions such as the bow shock, magnetosheath, magnetopause, and cusps can readily be identified in images of charge exchange emissions. Section 6 reviews observations by (generally narrow) field of view (FOV) astrophysical telescopes that confirm the presence of these emissions at the intensities predicted by the simulations. Section 7 describes the design of a notional wide FOV “lobster-eye” telescope capable of imaging the global interactions and shows how it might be used to extract information concerning the global interaction of the solar wind with solar system obstacles. The conclusion outlines prospects for missions employing such wide FOV imagers.
Published: 2018

13. Operations of the Sample Analysis at Mars instrument suite onboard the Curiosity rover

Author: Caroline Freissinet, Arnaud Buch, Samuel Teinturier, Micah Johnson, Jean-Yves Bonnet, Eric Lorigny, Cyril Szopa, Michel Cabane, Paul R. Mahaffy, Mehdi Benna, Charles Malespin, Stephen Indyk, David Coscia, B. D. Prats, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Telespazio France, IMPEC - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), CentraleSupélec, Honeybee Robotics Ltd, NASA Goddard Space Flight Center ( GSFC ), eINFORMe inc., Centre National d'Etudes Spatiales ( CNES ), Goddard Earth Sciences and Technology and Research ( GESTAR ), Universities Space Research Association ( USRA ) -NASA, 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), 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), Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), NASA Goddard Space Flight Center (GSFC), Centre National d'Études Spatiales [Toulouse] (CNES), Goddard Earth Sciences and Technology and Research (GESTAR), and Universities Space Research Association (USRA)-NASA
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Martian, Scientific instrument, Engineering, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Spectrometer, business.industry, Payload, Suite, Mars Exploration Program, 01 natural sciences, Workflow, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 0103 physical sciences, Sample Analysis at Mars, Aerospace engineering, business, 010303 astronomy & astrophysics, [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], 0105 earth and related environmental sciences
Abstract: The Sample Analysis at Mars instrument suite, onboard the Curiosity rover, has been analyzing the martian environment since August 05th 2012, as one of the main tools of the Mars Science Laboratory mission. This suite is composed of three independent but interoperable instruments, namely a Quadrupole Mass Spectrometer, a Tunable Laser Spectrometer and a Gas Chromatograph, plus a sophisticated Sample Manipulation System. SAM is used to analyze soils, rocks and atmosphere. For instance, it detected in situ martian complex organics for the first time, provide us with a several years survey of the atmospheric composition and helped understand how the martian environment evolved through the planet history. At 40 kg, it represents half of the scientific payload weight of Curiosity and is one of the two analytical instruments of the mission. This instrument suite is the result of an international collaboration between the NASA Goddard Space Flight Center, the NASA Jet Propulsion Laboratory and a consortium of French laboratories supported by the Center National d’Etudes Spatiales (the French space agency). This contribution will present the organization of the SAM operational workflow from the ground infrastructure, to flight operations and laboratory supporting work. It will also describe how the CNES hosts and supports the SAM team during this exciting mission.
Published: 2018

14. Statistical Analysis of Solar Events Associated with Storm Sudden Commencements over One Year of Solar Maximum During Cycle 23: Propagation from the Sun to the Earth and Effects

Author: F. Pitout, Stephane Regnier, Benjamin Grison, Brigitte Schmieder, Dominique Fontaine, Aurélie Marchaudon, Aude Chambodut, Karine Bocchialini, I. Zouganelis, Michel Menvielle, N. Cornilleau-Wehrlin, Monique Pick, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (ASCR), HEPPI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Département des sciences de la Terre, Université Paris-Sud - Paris 11 (UP11), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-École polytechnique (X)-Sorbonne Universités-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Department of Mathematics, Physics and Electrical Engineering [Newcastle], University of Northumbria at Newcastle [United Kingdom], European Space Astronomy Centre (ESAC), European Space Agency (ESA), Czech Academy of Sciences [Prague] (CAS), HELIOS - 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), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Sorbonne Université (SU)-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), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), 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 d'astrophysique spatiale ( IAS ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institute of Atmospheric Physics [Prague] ( IAP ), Czech Academy of Sciences [Prague] ( ASCR ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Université Paris-Sud - Paris 11 ( UP11 ), Institut de physique du globe de Strasbourg ( IPGS ), Université de Strasbourg ( UNISTRA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique des Plasmas ( LPP ), Université Paris-Sud - Paris 11 ( UP11 ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Observatoire de Paris-École polytechnique ( X ) -Sorbonne Universités-PSL Research University ( PSL ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), European Space Astronomy Center ( ESAC ), and European Space Agency ( ESA )
Subjects: 010504 meteorology & atmospheric sciences, Interplanetary medium, FOS: Physical sciences, Auroral kilometric radiation, F500, Astrophysics, 01 natural sciences, Physics - Space Physics, 0103 physical sciences, Coronal mass ejection, Earth: SSC, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Geomagnetic storm, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Solar maximum, Space Physics (physics.space-ph), Earth's magnetic field, Astrophysics - Solar and Stellar Astrophysics, Sun: CME, 13. Climate action, Space and Planetary Science, geoeffectiveness, Solar wind: ICME, Ionosphere, Thermosphere, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Abstract: Taking the 32 storm sudden commencements (SSCs) listed by ISGI during 2002 as a starting point, we performed a multi-criterion analysis based on observations (propagation time, velocity comparisons, sense of the magnetic field rotation, radio waves) to associate them with solar sources. We identified their effects in the interplanetary medium, and looked at the response of the terrestrial ionized and neutral environment. We find that 28 SSCs can be related to 44 coronal mass ejections (CMEs), 15 with a unique CME and 13 with a series of multiple CMEs, among which 19 involved halo CMEs; 12 of the 19 fastest CMEs with speeds greater than 1000 km/s are halo CMEs. The probability for an SSC to occur is 75% if the CME is a halo CME. The complex interactions between two CMEs and the modification of their trajectories have been examined using joint white-light and multiple-wavelength radio observations. The solar-wind structures at L1 after the shocks leading the 32 SSCs are 12 magnetic clouds (MCs), 6 interplanetary CMEs (ICMEs) without an MC structure, 4 miscellaneous structures, which cannot unambiguously be classified as ICMEs, 5 corotating or stream interaction regions (CIRs/SIRs), and 4 isolated shock events; note than one CIR caused two SSCs. The 11 MCs listed in 3 or more MC catalogs covering the year 2002 are associated with SSCs. For the 3 most intense geomagnetic storms related to MCs, we note 2 sudden increases of the Dst, at the arrival of the sheath and the arrival of the MC itself. The most geoeffective events are MCs, since 92% of them trigger moderate or intense storms, followed by ICMEs (33%). At best, CIRs/SIRs only cause weak storms. We show that these geoeffective events (ICMEs or MCs) trigger or reinforce terrestrial radiowave activity in the magnetosphere, an enhanced convection in the ionosphere, and a stronger response in the thermosphere., Comment: Solar Physics, in press
Published: 2018

15. Disagreement among global cloud distributions from CALIOP, passive satellite sensors and general circulation models

Author: Noel, Vincent, Chepfer, Helene, Chiriaco, Marjolaine, Winker, David, Okamoto, Hajime, Hagihara, Yuichiro, Cesana, Gregory, Lacour, Adrien, Laboratoire d'aérologie - LA ( LA ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Météorologie Dynamique (UMR 8539) ( LMD ), 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 Paris ) -École normale supérieure - Paris ( ENS Paris ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), NASA Langley Research Center [Hampton] ( LaRC ), Research Institute for Applied Mechanics, Kyushu University [Fukuoka], Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-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)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, 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), SPACE - 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), NASA Langley Research Center [Hampton] (LaRC), Research Institute for Applied Mechanics [Fukuoka] (RIAM), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-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), 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 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), and Kyushu University
Subjects: bepress|Physical Sciences and Mathematics, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], EarthArXiv|Physical Sciences and Mathematics|Oceanography and Atmospheric Sciences and Meteorology, 010504 meteorology & atmospheric sciences, 0211 other engineering and technologies, CALIPSO, FOS: Physical sciences, climatologies, 02 engineering and technology, Oceanography and Atmospheric Sciences and Meteorology, clouds, 01 natural sciences, EarthArXiv|Physical Sciences and Mathematics, Physics - Atmospheric and Oceanic Physics, remote sensing, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 13. Climate action, GEWEX, bepress|Physical Sciences and Mathematics|Oceanography and Atmospheric Sciences and Meteorology, Atmospheric and Oceanic Physics (physics.ao-ph), Physical Sciences and Mathematics, lidar, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences
Abstract: Cloud detection is the first step of any complex satellite-based cloud retrieval. No instrument detects all clouds, and analyses that use a given satellite climatology can only discuss a specific subset of clouds. We attempt to clarify which subsets of clouds are detected in a robust way by passive sensors, and which require active sensors. To do so, we identify where retrievals of Cloud Amounts (CAs), based on numerous sensors and algorithms, differ the most. We investigate large uncertainties, and confront retrievals from the CALIOP lidar, which detects semitransparent clouds and directly measures their vertical distribution, whatever the surface below. We document the cloud vertical distribution, opacity and seasonal variability where CAs from passive sensors disagree most. CALIOP CAs are larger than the passive average by +0.05 (AM) and +0.07 (PM). Over land, the +0.1 average difference rises to +0.2 over the African desert, Antarctica and Greenland, where large passive disagreements are traced to unfavorable surface conditions. Over oceans, CALIOP retrievals are closer to the average of passive retrievals except over the ITCZ (+0.1). Passive CAs disagree more in tropical areas associated with large-scale subsidence, where CALIOP observes a specific multi-layer cloud population: optically thin, high-level clouds and opaque (z>7km), shallow boundary layer clouds (z
Published: 2018

16. Tensile strength of 67P/Churyumov–Gerasimenko nucleus material from overhangs

Author: Attree, N., Groussin, O., Jorda, L., Nébouy, D., Thomas, N., Brouet, Y., Kührt, Ekkehard, Preusker, Frank, Scholten, Frank, Knollenberg, Jörg, Hartogh, P., Sierks, H., Barbieri, C., Lamy, P., Rodrigo, R., Koschny, D., Rickman, H., Keller, H. U., A’Hearn, M. F., Auger, A.-T., Barucci, Antonella, Bertaux, J.-L., Bertini, I., Bodewits, Dennis, Boudreault, S., Cremonese, G., Deppo, Vania Da, Davidsson, B., Debei, S., De Cecco, M., Deller, J., El-Maarry, M. R., Fornasier, S., Fulle, M., Gutierrez, P.J., Güttler, C., Hviid, Stubbe, Ip, W-H., Kovacs, G., Kramm, J. R., Küppers, M., Lara López, Luisa M., Lazzarin, M., Lopez Moreno, J., Lowry, S., Marchi, S., Marzari, F., Mottola, S., Naletto, G., Oklay, Nilda, Pajola, M., Toth, I., Tubiana, C., Vincent, Jean-Baptiste, Shi, X., Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Physikalisches Institut [Bern], Universität Bern [Bern], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, 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), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Agency Advanced Concepts and Science Payloads Office (ESA ESTEC), European Space Agency (ESA), ESA Scientific Support Office, Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Laboratory for Ultraviolet and X-ray Optical Research [Padova] (LUXOR), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR)-Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Industrial Engineering [Padova], University of Trento [Trento], Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Operations Department (ESAC), European Space Astronomy Centre (ESAC), European Space Agency (ESA)-European Space Agency (ESA), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), University of Kent [Canterbury], Solar System Exploration Research Virtual Institute (SSERVI), Southwest Research Institute [Boulder] (SwRI), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), NASA Ames Research Center (ARC), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Laboratoire d'Astrophysique de Marseille ( LAM ), Aix Marseille Université ( AMU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] ( DLR ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Centro de Astrobiologia [Madrid] ( CAB ), Instituto Nacional de Técnica Aeroespacial ( INTA ) -Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), International Space Science Institute ( ISSI ), Space Research Centre [Warsaw] ( CBK ), Polska Akademia Nauk ( PAN ), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] ( IGEP ), Technische Universität Braunschweig [Braunschweig], Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), INAF - Osservatorio Astronomico di Trieste ( OAT ), Istituto Nazionale di Astrofisica ( INAF ), Laboratory for Ultraviolet and X-ray Optical Research [Padova] ( LUXOR ), CNR Institute for Photonics and Nanotechnologies ( IFN ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ) -Consiglio Nazionale delle Ricerche [Roma] ( CNR ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), National Central University [Taiwan] ( NCU ), European Space Astronomy Center ( ESAC ), European Space Agency ( ESA ) -European Space Agency ( ESA ), Centre for Astrophysics and Planetary Science [Canterbury] ( CAPS ), Solar System Exploration Research Virtual Institute ( SSERVI ), Southwest Research Institute [Boulder] ( SwRI ), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' ( CISAS ), NASA Ames Research Center ( ARC ), Hungarian Academy of Sciences [Budapest], Universität Bern [Bern] (UNIBE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), 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), Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)-National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), ITA, USA, GBR, FRA, DEU, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Polska Akademia Nauk (PAN), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Consejo Superior de Investigaciones Científicas [Spain] (CSIC)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Comets: individual: Churyumov-Gerasimenko, FOS: Physical sciences, general [comets], Comets: general, Methods: observational, es, individual: Churyumov-Gerasimenko [comets], Astronomi, astrofysik och kosmologi, [SDU]Sciences of the Universe [physics], Astronomy, Astrophysics and Cosmology, observational [Methods], addenda, errata, ComputingMilieux_MISCELLANEOUS, [ SDU ] Sciences of the Universe [physics], Astrophysics - Earth and Planetary Astrophysics
Abstract: We directly measure twenty overhanging cliffs on the surface of comet 67P/Churyumov-Gerasimenko extracted from the latest shape model and estimate the minimum tensile strengths needed to support them against collapse under the comet's gravity. We find extremely low strengths of around one Pa or less (one to five Pa, when scaled to a metre length). The presence of eroded material at the base of most overhangs, as well as the observed collapse of two features and implied previous collapse of another, suggests that they are prone to failure and that true material strengths are close to these lower limits (although we only consider static stresses and not dynamic stress from, for example, cometary activity). Thus, a tensile strength of a few pascals is a good approximation for the tensile strength of 67P's nucleus material, which is in agreement with previous work. We find no particular trends in overhang properties with size, over the $\sim10-100$ m range studied here, or location on the nucleus. There are no obvious differences, in terms of strength, height or evidence of collapse, between the populations of overhangs on the two cometary lobes, suggesting that 67P is relatively homogenous in terms of tensile strength. Low material strengths are supportive of cometary formation as a primordial rubble pile or by collisional fragmentation of a small (tens of km) body., 13 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics
Published: 2018

17. 14 years of Mars’ atmosphere monitoring by SPICAM on Mars Express

Author: Lacombe , Gaetan, Montmessin , Franck, Korablev , Oleg, Lefèvre , Franck, Bertaux , Jean-Loup, Fedorova , Anna A., Trokhimovskiy , Alexander, Baggio , Lucio, Reberac , Aurélie, Chapron , Nicolas, Crepel , Mickael, David , L., Rougerie , Bruno, Maltagliati , Luca, Willame , Yannick, Guslyakova , Svetlana, Gérard , Jean-Claude, Stiepen , Arnaud, Fussen , Didier, Mateshvili , Nina, Määttänen , Anni, Forget , François, Witasse , Olivier, Leblanc , François, Vandaele , Ann Carine, Marcq , Emmanuel, Sandel , Bill R., Gondet , Brigitte, Schneider , Nicholas, Chaffin , Michael S., IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Space Research Institute of the Russian Academy of Sciences ( IKI ), Russian Academy of Sciences [Moscow] ( RAS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), CEA Paris Saclay, Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Laboratoire de Physique Atmosphérique et Planétaire ( LPAP ), Université de Liège, Laboratoire de Météorologie Dynamique (UMR 8539) ( LMD ), 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 Paris ) -École normale supérieure - Paris ( ENS Paris ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ), HEPPI - LATMOS, Lunar and Planetary Laboratory [Tucson], University of Arizona, Institut d'astrophysique spatiale ( IAS ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratory for Atmospheric and Space Physics [Boulder] ( LASP ), University of Colorado Boulder [Boulder], 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), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Laboratoire de Physique Atmosphérique et Planétaire (LPAP), 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), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), HELIOS - LATMOS, Lunar and Planetary Laboratory [Tucson] (LPL), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], 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), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Agence Spatiale Européenne = European Space Agency (ESA), and Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]
Abstract: International audience; SPICAM is entering his 8th Martian yeararound Mars and continues to collect measurementswith its infrared channel. This dataset is uniqueinsofar as it comes from the same calibratedinstrument, continuously over the course of 14 years.Hence, it allows to probe different physicalphenomena with multi-annual and seasonal timescale,as well as episodic events (e.g dust storms). SPICAMcontributed to the improvement of the understandingof Mars’s climate in several areas including loweratmosphere composition, chemical processes and thestructure of the atmosphere.
Published: 2018

18. Intercomparison of in situ water vapor balloon-borne measurements from Pico-SDLA H2O and FLASH-B in the tropical UTLS

Author: Ghysels, Mélanie, Rivière, Emmanuel D., Khaykin, Sergey, Stoeffler, Clara, Amarouche, Nadir, Pommereau, Jean-Pierre, Held, Gerhard, Durry, Georges, Groupe de spectrométrie moléculaire et atmosphérique - UMR 7331 ( GSMA ), Université de Reims Champagne-Ardenne ( URCA ) -Centre National de la Recherche Scientifique ( CNRS ), Chemical Science and Technology Laboratory, National Institute of Standards and Technology [Gaithersburg] ( NIST ), SHTI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Division technique INSU/SDU ( DTI ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Instituto de Pesquisas Meteorológicas ( IPMet ), Universidade Estadual Paulista, Agence Nationale de la Recherche (ANR), ANR-2010-BLAN-609-01,TRO-pico,TRO-pico project, Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), National Institute of Standards and Technology [Gaithersburg] (NIST), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Pesquisas Meteorológicas (IPMet), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), ANR-10-BLAN-0609,TRO-Pico,Bilan multiéchelle de l'eau dans la haute troposphère et la basse stratosphère des régions TROpicales.(2010), UFR Sciences Exactes et Naturelles, Université de Versailles St. Quentin, Division Technique de l'Institut National des Sciences de l'Univers, Universidade Estadual Paulista (Unesp), and National Institute of Standards and Technology
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], lcsh:TA715-787, lcsh:Earthwork. Foundations, lcsh:TA170-171, lcsh:Environmental engineering
Abstract: Made available in DSpace on 2018-12-11T17:02:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-03-21 Agence Nationale de la Recherche In this paper we compare water vapor mixing ratio measurements from two quasi-parallel flights of the Pico-SDLA H2O and FLASH-B hygrometers. The measurements were made on 10 February 2013 and 13 March 2012, respectively, in the tropics near Bauru, São Paulo state, Brazil during an intense convective period. Both flights were performed as part of a French scientific project, TRO-Pico, to study the impact of the deep-convection overshoot on the water budget. Only a few instruments that permit the frequent sounding of stratospheric water vapor can be flown within small-volume weather balloons. Technical difficulties preclude the accurate measurement of stratospheric water vapor with conventional in situ techniques. The instruments described here are simple and lightweight, which permits their low-cost deployment by non-specialists aboard a small weather balloon. We obtain mixing ratio retrievals which agree above the cold-point tropopause to within 1.9 and 0.5 % for the first and second flights, respectively. This level of agreement for balloon-borne measured stratospheric water mixing ratio constitutes one of the best agreement reported in the literature. Because both instruments show similar profiles within their combined uncertainties, we conclude that the Pico-SDLA H2O and FLASH-B data sets are mutually consistent. Groupe de Spectrométrie Moléculaire et Atmosphérique UMR CNRS 7331 UFR Sciences Exactes et Naturelles, Moulin de la Housse, BP 1039 LATMOS CNRS Université de Versailles St. Quentin Division Technique de l'Institut National des Sciences de l'Univers, Place Aristide Briand 92195 Instituto de Pesquisas Meteorológicas (IPMet) Universidad e Estadual Paulista (UNESP), CX Postal 281 National Institute of Standards and Technology Instituto de Pesquisas Meteorológicas (IPMet) Universidad e Estadual Paulista (UNESP), CX Postal 281 Agence Nationale de la Recherche: ANR-2010-BLAN-609-01
Published: 2018

19. Atmospheric CO2 measurements with a 2-μm DIAL instrument

Author: Jean-Michel Melkonian, Jacques Pelon, Antoine Godard, Erwan Cadiou, Myriam Raybaut, Guillaume Gorju, Jean-Baptiste Dherbecourt, ONERA, Université Paris Saclay ( ONERA, Université Paris Saclay (F-91123 Palaiseau - France) ), ONERA-Université Paris-Saclay, Centre National d'Etudes Spatiales ( CNES ), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), ONERA, Université Paris Saclay (COmUE) [Palaiseau], ONERA-Université Paris Saclay (COmUE), Centre National d'Études Spatiales [Toulouse] (CNES), 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: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, Range (particle radiation), 010504 meteorology & atmospheric sciences, business.industry, Physics, QC1-999, Transmitter, 01 natural sciences, Signal, Aerosol, 010309 optics, Dial, Optics, 0103 physical sciences, Differential absorption lidar, business, Energy (signal processing), 0105 earth and related environmental sciences
Abstract: International audience; We report on ground-based atmospheric concentration measurements of carbon dioxide, using a pulsed direct detection differential absorption lidar operating at 2051 nm. The transmitter is based on a tunable parametric source emitting 10-mJ energy, 10-ns duration Fourier-limited pulses. Range resolved concentration measurements have been carried out on the aerosol back-scattered signal. Cloud signals have been used to get long range integrated-path measurements.
Published: 2018

20. Modeling the TTL at continental scale for a wet season: An evaluation of the BRAMS mesoscale model using TRO-Pico campaign, and measurements from airborne and spaceborne sensors

Author: Jean-Pierre Pommereau, Mélanie Ghysels, Sergey Khaykin, Gerhard Held, Claud Chantal, Jean-François Rysman, Jérémie Burgalat, Emmanuel Rivière, Abhinna Behera, Georges Durry, Genevieve Seze, Nadir Amarouche, Virginie Marécal, Groupe de spectrométrie moléculaire et atmosphérique - UMR 7331 ( GSMA ), Université de Reims Champagne-Ardenne ( URCA ) -Centre National de la Recherche Scientifique ( CNRS ), Centre national de recherches météorologiques ( CNRM ), Météo France-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Météorologie Dynamique (UMR 8539) ( LMD ), 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 Paris ) -École normale supérieure - Paris ( ENS Paris ), Division technique INSU/SDU ( DTI ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), SHTI - LATMOS, Instituto de Pesquisas Meteorológicas ( IPMet ), Universidade Estadual Paulista, UFR Sci Exactes & Naturelles, CNRS, Universidade de São Paulo (USP), Ecole Polytech, INSU, UPMC Univ Paris 06, Universidade Estadual Paulista (Unesp), Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), 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), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), STRATO - LATMOS, Instituto de Pesquisas Meteorológicas (IPMet), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), 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)-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 -Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and 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)
Subjects: Convection, Tropical tropopause layer, Atmospheric Science, 010504 meteorology & atmospheric sciences, Mesoscale meteorology, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, 7. Clean energy, Water vapor budget, Earth and Planetary Sciences (miscellaneous), BRAMS, Stratosphere, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Stratospheric overshooting convection, Inertia-gravity waves, Microwave Limb Sounder, Geophysics, Microwave humidity sounder, Mesoscale Modeling, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 13. Climate action, Space and Planetary Science, Environmental science, Satellite, Tropopause, Water vapor
Abstract: Made available in DSpace on 2018-11-26T17:48:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-03-16 Agence Nationale de la Recherche (ANR) region Champagne-Ardenne in France Direction Generale de l'Armement (PRECIP-CLOUD project) European Union's Framework Program MUSIC project LEFE project Overshoots a grande echelle Centre National d'Etudes Spatiales (CNES) Centre de Calcul ROMEO In order to better understand the water vapor (WV) intrusion into the tropical stratosphere, a mesoscale simulation of the tropical tropopause layer using the BRAMS (Brazilian version of Regional Atmospheric Modeling System (RAMS)) model is evaluated for a wet season. This simulation with a horizontal grid point resolution of 20kmx20km cannot resolve the stratospheric overshooting convection (SOC). Its ability to reproduce other key parameters playing a role in the stratospheric WV abundance is investigated using the balloon-borne TRO-Pico campaign measurements, the upper-air soundings over Brazil, and the satellite observations by Aura Microwave Limb Sounder, Microwave Humidity Sounder, and Geostationary Operational Environmental Satellite 12. The BRAMS exhibits a good ability in simulating temperature, cold-point, WV variability around the tropopause. However, the simulation is typically observed to be warmer by approximate to 2.0 degrees C and wetter by approximate to 0.4 ppmv at the hygropause, which can be partly affiliated with the grid boundary nudging of the model by European Centre for Medium-Range Weather Forecasts operational analyses. The modeled cloud tops show a good correlation (maximum cross-correlation of approximate to 0.7) with Geostationary Operational Environmental Satellite 12. Furthermore, the overshooting cells detected by Microwave Humidity Sounder are observed at the locations, where 75% of the modeled cloud tops are higher than 11km. Finally, the modeled inertia-gravity wave periodicity and wavelength are comparable with those deduced from the radio sounding measurements during TRO-Pico campaign. The good behavior of BRAMS confirms the SOC contribution in the WV abundance, and variability is of lesser importance than the large-scale processes. This simulation can be used as a reference run for upscaling the impact of SOC at a continental scale for future studies. UFR Sci Exactes & Naturelles, GSMA, CNRS, UMR 7331, Reims, France CNRS, CNRM, Meteo France, UMR3589, Toulouse, France UPMC Univ Paris 06, Sorbonne Univ, PSL Res Univ,ENS, LMD,IPSL,CNRS,UMR 8539,Ecole Polytech,Univ Paris, Palaiseau, France Ecole Polytech, ENS, CNRS, LMD,IPSL,UPMC, Paris, France INSU, Div Tech, Pl Aristide Briand, Meudon, France UPMC Univ Paris 06, UVSQ Univ Paris Saclay, CNRS, LATMOS,IPSL, Guyancourt, France Univ Estadual Paulista, Inst Pesquisas Meteorol, Bauru, Brazil Univ Estadual Paulista, Inst Pesquisas Meteorol, Bauru, Brazil Agence Nationale de la Recherche (ANR): ANR-2010-BLAN-609-01 European Union's Framework Program: 603608 MUSIC project: ANR-14-CE01-0014 Centre de Calcul ROMEO: 669
Published: 2018

21. Photochemical activity of HCN-C4H2 ices in Titan's lower atmosphere

Author: Dubois , David, Gudipati , Murthy, Carrasco , Nathalie, Dubois, David, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), 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), Jet Propulsion Laboratory (JPL), and California Institute of Technology (CALTECH)-NASA
Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [ SDU.STU.PL ] Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology
Abstract: International audience; Revealed by the Cassini and Voyager Missions, a plethora of volatile species are formed in Titan's upper atmosphere from the initial N2/CH4 (~98/2%) composition. As they precipitate, most of the volatiles condense in the colder lower atmosphere where they can form icy clouds (e.g. C4N2 , HCN, C2H6) which have been detected above the poles. HCN is the most abundant nitrile in Titan's atmosphere and suspected to condensate in Titan's lower stratosphere (typically -1. These stratospheric ices may contribute as condensation nuclei for ices deeper down in the troposphere. Furthermore, C4H2 , a simple alkyne formed by the chemistry and relatively abundant in the stratosphere, condenses near 75 km, lower than HCN. C4H2 can also absorb the lesser energetic photos at these low altitudes, forming the radical C4H which then reacts with CH4 , causing the consumption of methane. Consequently, the loss mechanism for C4H2 is photo-chemistry. As soon as C4H2 condenses, small molecule and complex accretion with HCN may occur. The reactive state that these ices may undergo with long-UV radiation after they form is still largely unknown. We explore these conditions by studying HCN-C4H2 ice mixtures in the laboratory, by using the Titan Organic Aerosol Spectroscopy and chemisTry (TOAST) setup at JPL's Ice Spectroscopy Laboratory (ISL). These ices are then irradiated at long-UV wavelengths pertaining to these low-altitude regions at low-controlled temperatures. The residue is analyzed using long-IR absorption. Our results show a solid-state HCN consumption due to irradiation, to which C4H2 acts as a catalyst, indicating HCN ice particle ageing in the troposphere may be facilitated by more complex condensed nuclei.
Published: 2018

22. Do SST gradients drive the monthly climatological surface wind convergence over the tropical Atlantic?

Author: Diakhaté , Moussa, Lazar , Alban, De Coëtlogon , Gaëlle, Gaye , Amadou, Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang (LPAO-SF), École Supérieure Polytechnique de Dakar (ESP), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-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)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Processus de la variabilité climatique tropicale et impacts (PARVATI), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), TROPO - 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), PDI-MSC, International Joint Laboratory LMI ECLAIRS, European Project: 603521,EC:FP7:ENV,FP7-ENV-2013-two-stage,PREFACE(2013), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), 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), Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang ( LPAO-SF ), Université Cheikh Anta Diop ( UCAD ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques ( LOCEAN ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Processus de la variabilité climatique tropicale et impacts ( PARVATI ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), and European Project : 603521,EC:FP7:ENV,FP7-ENV-2013-two-stage,PREFACE ( 2013 )
Subjects: surface convergence budget, tropical Atlantic, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, [ SDU.STU.CL ] Sciences of the Universe [physics]/Earth Sciences/Climatology, ITCZ, SST
Abstract: International audience; This article presents a climatological study of the tropical Atlantic surface wind convergence, one of the main drivers of the marine intertropical convergence zone (ITCZ) precipitations, including coastal northeastern Brazilian and West African rainfalls. Climatological monthly mean surface wind convergence budget, as well as that of their month-to-month variations, is analysed over the 2000–2009 decade, using ocean–atmosphere reanalyses and satellite-derived data sets. Sea surface temperature (SST) influence is particularly investigated via comparison of its Laplacian with that of sea level pressure. Results for monthly means reveal that the Lindzen-Nigam paradigm does hold in regions of deep convection but only on their flanks. In deep convection regions, the budget analysis suggests the entrainment due to elevated heating by cumulus convection as the leading term. Elsewhere, over the ‘open ocean ITCZ’ meridional flanks, as well as over the ‘coastal one’ (Gulf of Guinea and northeastern Brazilian coasts), the pressure contribution is positive and largely dominated by its component below the boundary layer closely related to the SST. Horizontal advection is also found important over these areas, but with the pressure as the first-order driver. Otherwise, month-to-month variations of ITCZ are controlled by the geostrophy within the pressure contribution tightly dominated by the free tropospheric component.
Published: 2018

23. Springtime aerosol load as observed from ground-based and airborne lidars over northern Norway

Author: Patrick Chazette, Jean-Christophe Raut, Julien Totems, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chimie Atmosphérique Expérimentale (CAE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] ( LSCE ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), 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: lcsh:Chemistry, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], lcsh:QD1-999, 13. Climate action, lcsh:Physics, lcsh:QC1-999
Abstract: To investigate the origin of springtime aerosols in the Arctic region we performed ground-based and airborne 355 nm Raman lidar observations in the north of Norway (Hammerfest). Two lidars were embedded (i) on an ultralight aircraft for vertical (nadir) or horizontal line-of-sight measurements and (ii) in an air-conditioned van on the ground for vertical (zenith) measurements. This field experiment was designed as part of the Pollution in the ARCtic System (PARCS) project of the French Arctic Initiative and took place from 13 to 26 May 2016. The consistency among lidar measurements is verified by comparing nadir, horizontal line of sight, and ground-based Raman lidar profiles. Dispersion of the order of 0.01 km−1 is obtained among lidar-derived aerosol extinction coefficients at 355 nm. The aerosol load measured in the first 3 km of the troposphere remains low throughout the campaign, with aerosol optical thickness (AOT) of 0.1 at 355 nm (∼0.05 at 550 nm). The main contributors to the evolution of the aerosol load at low altitude prove to be one of the flares of the nearby Melkøya gas processing facility, the oceanic source, and the transport of aerosols from industrial sites in Russia. Moreover, ground-based lidar measurements allowed us to identify three cases of long-range aerosol transport (between 3 and 8 km above the mean sea level). Using back trajectories computed with the Lagrangian model FLEXPART-WRF, these aerosol plumes are shown to be the result of the strong forest fires that occurred in the area of Fort McMurray, in Canada. They can at most double the AOT value over the Arctic area, with an anomaly of 0.1 on the AOT at 355 nm.
Published: 2018

24. The phase function and density of the dust observed at comet 67P/Churyumov-Gerasimenko

Author: P. J. Gutierrez, W-H. Ip, F. Moreno, Monica Lazzarin, F. La Forgia, Ivano Bertini, Xian Shi, V. Da Deppo, Cesare Barbieri, Stefano Mottola, Holger Sierks, Giampiero Naletto, Pasquale Palumbo, M. A. Barucci, Jakob Deller, Stavro Ivanovski, H. S. Hviid, J. Lasue, Giovanna Rinaldi, Marco Fulle, Michael Küppers, Philippe Lamy, Hans Rickman, Stefano Debei, Ekkehard Kührt, Alessandra Rotundi, Detlef Koschny, Nicolas Thomas, R. Rodrigo, M. De Cecco, J.-R. Kramm, Björn Davidsson, Cecilia Tubiana, Laurent Jorda, G. Cremonese, Carsten Güttler, J. L. Bertaux, Anny Chantal Levasseur-Regourd, M. L. Lara, Olivier Groussin, Sonia Fornasier, Jörg Knollenberg, V. Della Corte, J. J. López-Moreno, H. U. Keller, Francesco Marzari, Dennis Bodewits, Agenzia Spaziale Italiana, INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Helmholtz zentrum für Schwerionenforschung GmbH (GSI), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Dipartimento di Scienze e Tecnologie [Napoli] (DIST), Universita degli studi di Napoli 'Parthenope' [Napoli], Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, 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), 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), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), 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)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, INAF - Osservatorio Astronomico di Padova (OAPD), Laboratory for Ultraviolet and X-ray Optical Research [Padova] (LUXOR), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR)-Consiglio Nazionale delle Ricerche [Roma] (CNR), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Department of Industrial Engineering [Padova], University of Trento [Trento], Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], European Space Astronomy Centre (ESAC), Physikalisches Institut [Bern], Universität Bern [Bern], Università degli Studi di Padova = University of Padua (Unipd), Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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), 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), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)-National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), NASA-California Institute of Technology (CALTECH), Universität Bern [Bern] (UNIBE), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Polska Akademia Nauk (PAN), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Braunschweig [Braunschweig], INAF - Osservatorio Astronomico di Trieste ( OAT ), Istituto Nazionale di Astrofisica ( INAF ), Istituto di Astrofisica e Planetologia Spaziali ( IAPS ), Dipartimento di Scienze e Tecnologie [Napoli] ( DIST ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] ( DLR ), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' ( CISAS ), Laboratoire d'Astrophysique de Marseille ( LAM ), Aix Marseille Université ( AMU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Centro de Astrobiologia [Madrid] ( CAB ), Instituto Nacional de Técnica Aeroespacial ( INTA ) -Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), International Space Science Institute ( ISSI ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ), Space Research Centre [Warsaw] ( CBK ), Polska Akademia Nauk ( PAN ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), INAF - Osservatorio Astronomico di Padova ( OAPD ), Laboratory for Ultraviolet and X-ray Optical Research [Padova] ( LUXOR ), CNR Institute for Photonics and Nanotechnologies ( IFN ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ) -Consiglio Nazionale delle Ricerche [Roma] ( CNR ), Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), National Central University [Taiwan] ( NCU ), Space Science Institute [Macau] ( SSI ), Macau University of Science and Technology ( MUST ), Aix Marseille Université ( AMU ), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] ( IGEP ), and European Space Astronomy Center ( ESAC )
Subjects: 67P/Churyumov-Gerasimenko, Brightness, comets: individual: 67P/Churyumov- Gerasimenko, 010504 meteorology & atmospheric sciences, Comet, Dust particles, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, space vehicles, comets: general, comets: individual: 67P/Churyumov-Gerasimenko, 01 natural sciences, Astronomi, astrofysik och kosmologi, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Phase function, Astrophysics::Solar and Stellar Astrophysics, comets, Particle density, 010303 astronomy & astrophysics, [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Comets: individual: 67P/Churyumov, Gerasimenko, 0105 earth and related environmental sciences, Physics, 520 Astronomy, comets: general, comets: individual: 67P/Churyumov-Gerasimenko, general [Comets], Astronomy and Astrophysics, Space vehicles, 620 Engineering, Bulk density, space vehicles, comets: general, comets: individual: 67P/Churyumov- Gerasimenko, Density distribution, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], space vehicles, Astrophysics::Earth and Planetary Astrophysics, Mass fraction
Abstract: The OSIRIS camera onboard Rosetta measured the phase function of both the coma dust and the nucleus. The two functions have a very different slope versus the phase angle. Here, we show that the nucleus phase function should be adopted to convert the brightness to the size of dust particles larger than 2.5 mm only. This makes the dust bursts observed close to Rosetta by OSIRIS, occurring about every hour, consistent with the fragmentation on impact with Rosetta of parent particles, whose flux agrees with the dust flux observed by GIADA. OSIRIS also measured the antisunward acceleration of the fragments, thus providing the first direct measurement of the solar radiation force acting on the dust fragments and thus of their bulk density, excluding any measurable rocket effect by the ice sublimation from the dust. The obtained particle density distribution has a peak matching the bulk density of most COSIMA particles, and represents a subset of the density distribution measured by GIADA. This implies a bias in the elemental abundances measured by COSIMA, which thus are consistent with the 67P dust mass fractions inferred by GIADA, i.e. (38 ± 8) per cent of hydrocarbons versus the (62 ± 8) per cent of sulphides and silicates.© 2018 The Author(s).Published by Oxford University Press on behalf of the Royal Astronomical Society., We thank the anonymous referee for having significantly improved the paper; and the Rosetta Science Ground Segment at ESAC, the Rosetta Mission Operations Centre at ESOC, and the Rosetta Project at ESTEC for their outstanding work enabling the science return of the Rosetta Mission. All GIADA data presented here are available on request before archiving in the PSA. This research was supported by the Italian Space Agency (ASI) within the ASI-INAF agreements I/032/05/0 and I/024/12/0.
Published: 2018

25. Effects of the Crustal Magnetic Fields and Changes in the IMF Orientation on the Magnetosphere of Mars: MAVEN Observations and LatHyS Results

Author: Sebastien Hess, David Brain, Jean-Yves Chaufray, Bruce M. Jakosky, Ronan Modolo, James P. McFadden, François Leblanc, Norberto Romanelli, John E. P. Connerney, Jasper Halekas, HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], NASA Goddard Space Flight Center (GSFC), Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), ANR-17-CE31-0016,TEMPETE,Évolutions temporelles des environnements planétaires magnétisés pendant des tempêtes solaires(2017), 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), University of California [Berkeley], University of California-University of California, HEPPI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), ONERA - The French Aerospace Lab ( Toulouse ), ONERA, Laboratory for Atmospheric and Space Physics [Boulder] ( LASP ), University of Colorado Boulder [Boulder], NASA Goddard Space Flight Center ( GSFC ), University of Iowa [Iowa], and Space Sciences Laboratory [Berkeley] ( SSL )
Subjects: 010504 meteorology & atmospheric sciences, CRUSTAL MAGNETIC FIELD EFFECT, Magnetosphere, Astrophysics, 01 natural sciences, IMF ORIENTATION, MARTIAN MAGNETOSPHERE, 0103 physical sciences, Interplanetary magnetic field, 010303 astronomy & astrophysics, O+ ION LOSS RATE, [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], 0105 earth and related environmental sciences, RECOVERY TIMESCALE, Martian, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], MARS, Plasma, Atmosphere of Mars, Mars Exploration Program, H+ ION LOSS RATE, Magnetic field, Solar wind, Geophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics
Abstract: International audience; The Mars Atmosphere and Volatile EvolutioN Mission (MAVEN) is currently probing the complex Martian environment. Although main structures arising from the interaction between the solar wind (SW) and the induced magnetosphere of Mars can be described using a steady state picture, time‐dependent physical processes modify the response of this obstacle. These processes result from temporal variabilities in the internal and/or external electromagnetic fields and plasma properties. Indeed, the crustal magnetic fields (CF) rotation constantly modifies the intrinsic magnetic field topology relative to the SW. Moreover, the magnetosphere's state is also modified by changes in the interplanetary magnetic field (IMF). In this work we analyze MAVEN magnetic field and plasma measurements obtained on 23 December 2014, between 06:00 UT ‐ 14:15 UT. These measurements suggest the external conditions remained approximately constant when MAVEN was inside the magnetosphere during the first orbit. In contrast, MAVEN observed changes in the IMF orientation before visiting the magnetosphere during the second orbit. To investigate the response of the Martian plasma environment to the CF rotation and IMF variability, we also perform hybrid simulations, using MAVEN observations to set SW external conditions. Simulation results are compared with the MAVEN measurements and show good agreement. Associated recovery timescales of different magnetospheric regions are found to range between ∼ 10 s and ∼ 10 min. Finally, we do not observe large variability in the total planetary H+ and O+ escape rates at different times during this event, although a correlation between the latter and the CFs location is identified.
Published: 2018

26. VUV-absorption cross section of carbon dioxide from 150 to 800 K and applications to warm exoplanetary atmospheres

Author: Maxence Lefèvre, Olivia Venot, Nicolas Fray, Et-touhami Es-sebbar, Yves Bénilan, Franck Lefèvre, Marie-Claire Gazeau, Eric Hébrard, C. Bahrini, Martin Schwell, Ingo Waldmann, Franck Montmessin, Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Instituut voor Sterrenkunde [Leuven], Katholieke Universiteit Leuven ( KU Leuven ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Paul Scherrer Institute ( PSI ), School of Physics and Astronomy [Exeter], University of Exeter, Laboratoire de Météorologie Dynamique (UMR 8539) ( LMD ), 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 Paris ) -École normale supérieure - Paris ( ENS Paris ), Department of Physics and Astronomy [UCL London], University College of London [London] ( UCL ), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), 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), Paul Scherrer Institute (PSI), 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), University College of London [London] (UCL), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-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)-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), École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL)
Subjects: Atmospheres, 010504 meteorology & atmospheric sciences, Satellites, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], methods: laboratory: molecular, FOS: Physical sciences, Planets, Astrophysics, 7. Clean energy, 01 natural sciences, Molecular physics, Spectral line, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, planets and satellites: atmospheres, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Earth and Planetary Astrophysics (astro-ph.EP), Spectrometer, Atmospheric models, Molecular data, Photodissociation, Absorption cross section, Astronomy and Astrophysics, Atmosphere of Mars, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Wavelength, 13. Climate action, Space and Planetary Science, Ground state, Astrophysics - Earth and Planetary Astrophysics
Abstract: Most exoplanets detected so far have atmospheric T significantly higher than 300K. Often close to their star, they receive an intense UV photons flux that triggers important photodissociation processes. The T dependency of VUV absorption cross sections are poorly known, leading to an undefined uncertainty in atmospheric models. Similarly, data measured at low T similar to that of the high atmosphere of Mars, Venus, and Titan are often lacking. Our aim is to quantify the T dependency of the abs. cross section of important molecules in planetary atmospheres. We want to provide both high-resolution data at T prevailing in these media and a simple parameterization of the absorption in order to simplify its use in photochemical models. This study focuses on carbon dioxide. We performed experimental measurements of CO$_2$ absorption cross section with synchrotron radiation for the wavelength range (115--200nm). For longer wavelengths (195--230nm), we used a deuterium lamp and a 1.5m Jobin-Yvon spectrometer. We used these data in our 1D thermo-photochemical model in order to study their impact on the predicted atmospheric compositions. The cross section of CO$_2$ increases with T. It can be separated in two parts: a continuum and a fine structure superimposed on the continuum. The variation of the continuum of absorption can be represented by the sum of three gaussian functions. Using data at high T in thermo-photochemical models modifies significantly the abundance and the photodissociation rates of many species, in addition to CO$_2$, such as methane and ammonia. These deviations have an impact on synthetic transmission spectra, leading to variations of up to 5 ppm. We present a full set of HR ($\Delta \lambda$=0.03nm) absorption cross sections of CO$_2$ from 115 to 230nm for T ranging from 150 to 800K., Comment: 14 pages, 17 figures, accepted for pulication in A&A
Published: 2018

27. Exposed bright features on the comet 67P/Churyumov-Gerasimenko: distribution and evolution

Author: J. L. Bertaux, L. Jorda, Carsten Güttler, Francesco Marzari, Monica Lazzarin, D. Bodewits, Holger Sierks, V. Da Deppo, Jörg Knollenberg, Nafiseh Masoumzadeh, Giampiero Naletto, Maurizio Pajola, H. U. Keller, Björn Davidsson, Ivano Bertini, Philippe Lamy, Steve Boudreault, O. Groussin, Detlef Koschny, Michael Küppers, Nicolas Thomas, Cecilia Tubiana, J. D. P. Deshapriya, Stefano Debei, M. De Cecco, J. J. Lopez Moreno, Sonia Fornasier, Xian Shi, J. B. Vincent, Stefano Mottola, Pedro J. Gutiérrez, L. M. Lara, Alice Lucchetti, M. A. Barucci, J. Rainer Kramm, R. Rodrigo, N. Oklay, Gabriele Cremonese, Stubbe F. Hviid, Pedro Hasselmann, H. V. Hoang, Marco Fulle, Hans Rickman, F. Preusker, W-H. Ip, Clement Feller, Ekkehard Kührt, Cesare Barbieri, Jakob Deller, 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)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, NASA Ames Research Center (ARC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), 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), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Laboratory for Ultraviolet and X-ray Optical Research [Padova] (LUXOR), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR)-Consiglio Nazionale delle Ricerche [Roma] (CNR), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], European Space Astronomy Centre (ESAC), Physikalisches Institut [Bern], Universität Bern [Bern], German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Ministerio de Educación y Ciencia (España), European Space Agency, Swedish National Space Board, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, 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), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Polska Akademia Nauk (PAN), NASA-California Institute of Technology (CALTECH), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Technische Universität Braunschweig [Braunschweig], Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)-National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Universität Bern [Bern] (UNIBE), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), INAF - Osservatorio Astronomico di Padova ( OAPD ), Istituto Nazionale di Astrofisica ( INAF ), NASA Ames Research Center ( ARC ), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] ( DLR ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Centro de Astrobiologia [Madrid] ( CAB ), Instituto Nacional de Técnica Aeroespacial ( INTA ) -Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), International Space Science Institute ( ISSI ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ), Space Research Centre [Warsaw] ( CBK ), Polska Akademia Nauk ( PAN ), Laboratory for Ultraviolet and X-ray Optical Research [Padova] ( LUXOR ), CNR Institute for Photonics and Nanotechnologies ( IFN ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ) -Consiglio Nazionale delle Ricerche [Roma] ( CNR ), Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), INAF - Osservatorio Astronomico di Trieste ( OAT ), Laboratoire d'Astrophysique de Marseille ( LAM ), Aix Marseille Université ( AMU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), National Central University [Taiwan] ( NCU ), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] ( IGEP ), European Space Astronomy Center ( ESAC ), and Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' ( CISAS )
Subjects: 010504 meteorology & atmospheric sciences, Comet, Data analysis, 67P/Churyumov–Gerasimenko, Context (language use), Astrophysics, 01 natural sciences, individual: 67P/Churyumov-Gerasimenko [Comets], Methods: data analysis, 0103 physical sciences, Comets: individual: 67P/Churyumov-Gerasimenko, Techniques: photometric, Photometric techniques, data analysis [Methods], 010303 astronomy & astrophysics, [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], 0105 earth and related environmental sciences, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], biology, photometric [Techniques], Astronomy, Astronomy and Astrophysics, Albedo, biology.organism_classification, Reflectivity, On board, 13. Climate action, Space and Planetary Science, Osiris
Abstract: Context. Since its arrival at the comet 67P/Churyumov-Gerasimenko in August 2014, the Rosetta spacecraft followed the comet as it went past the perihelion and beyond until September 2016. During this time there were many scientific instruments operating on board Rosetta to study the comet and its evolution in unprecedented detail. In this context, our study focusses on the distribution and evolution of exposed bright features that have been observed by OSIRIS, which is the scientific imaging instrument aboard Rosetta. Aims. We envisage investigating various morphologies of exposed bright features and the mechanisms that triggered their appearance. Methods. We co-registered multi-filter observations of OSIRIS images that are available in reflectance. The Lommel-Seeliger disk function was used to correct for the illumination conditions and the resulting colour cubes were used to perform spectrophotometric analyses on regions of interest. Results. We present a catalogue of 57 exposed bright features observed on the nucleus of the comet, all of which are attributed to the presence of HO ice on the comet. Furthermore, we categorise these patches under four different morphologies and present geometric albedos for each category. Conclusions. Although the nucleus of 67P/Churyumov-Gerasimenko appears to be dark in general, there are localised HO ice sources on the comet. Cometary activity escalates towards the perihelion passage and reveals such volatile ices. We propose that isolated HO ice patches found in smooth terrains in regions, such as Imhotep, Bes, and Hapi, result from frost as an aftermath of the cessation of the diurnal water cycle on the comet as it recedes from perihelion. Upon the comet's return to perihelion, such patches are revealed when sublimation-driven erosion removes the thin dust layers that got deposited earlier. More powerful activity sources such as cometary outbursts are capable of revealing much fresher, less contaminated HO ice that is preserved with consolidated cometary material, as observed on exposed patches resting on boulders. This is corroborated by our albedo calculations that attribute higher albedos for bright features with formations related to outbursts.© ESO 2018., The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged.
Published: 2018

28. Two-year operation of the lidar 1200: from fine-scale tropospheric structures to lower stratospheric water vapor detection

Author: Françoise Posny, Franck Gabarrot, Guillaume Payen, Valentin Duflot, Jimmy Leclair de Bellevue, Holger Vömel, Nicolas Marquestaut, Philippe Keckhut, Jean-Marc Metzger, Hélène Vérèmes, Susanne Meier, Jean-Luc Baray, Jean-Pierre Cammas, Stephanie Evan, Ruud Dirksen, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, STRATO - 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 Météorologie Physique (LaMP), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lindenberg Meteorological Observatory - Richard Assmann Observatory (MOL-RAO), Deutscher Wetterdienst [Offenbach] (DWD), Earth Observing Laboratory [Boulder] (EOL), National Center for Atmospheric Research [Boulder] (NCAR)-University Corporation for Atmospheric Research (UCAR), Observatoire des Sciences de l'Univers de La Réunion ( OSU-Réunion ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de la Réunion ( UR ), Laboratoire de l'Atmosphère et des Cyclones ( LACy ), Météo France-Université de la Réunion ( UR ) -Centre National de la Recherche Scientifique ( CNRS ), SHTI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Météorologie Physique - Clermont Auvergne ( LaMP ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Lindenberg Meteorological Observatory - Richard Assmann Observatory ( MOL-RAO ), Deutscher Wetterdienst [Offenbach] ( DWD ), Earth Observing Laboratory [Boulder] ( EOL ), National Center for Atmospheric Research [Boulder] ( NCAR ) -University Corporation for Atmospheric Research ( UCAR ), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-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), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Time delay and integration, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, Meteorology, Hygrometer, QC1-999, 0211 other engineering and technologies, 02 engineering and technology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Atmospheric sciences, 01 natural sciences, Troposphere, Lidar, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 13. Climate action, Observatory, Scale (map), Stratosphere, Water vapor, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences
Abstract: International audience; The 2-year lidar water vapor database (November 2013 - October 2015) of the Maïdo Observatory (Reunion Island / 21°S,55.5°E) is now calibrated. The performance of the lidar to provide accurate vertical structures are shown to be good. The ability of measuring quantities of a few ppmv in the lower stratosphere is demonstrated up to 22 km (based on Cryogenic Frostpoint Hygrometer sondes/lidar profiles comparisons) for an integration time period of 48 hours and a vertical resolution of 1.3 km.
Published: 2018

29. Evaluation of the two-moment scheme LIMA based on microphysical observations from the HyMeX campaign

Author: Marie Taufour, Christine Lac, Gaëlle Delautier, Benoît Vié, Véronique Ducrocq, Clotilde Augros, Julien Delanoë, Brice Boudevillain, Jean-Pierre Pinty, Alfons Schwarzenböck, Centre national de recherches météorologiques ( CNRM ), Météo France-Centre National de la Recherche Scientifique ( CNRS ), Institut des Géosciences de l’Environnement ( IGE ), Institut de Recherche pour le Développement ( IRD ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Centre d'étude des environnements terrestre et planétaires ( CETP ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'aérologie - LA ( LA ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Météorologie Physique - Clermont Auvergne ( LaMP ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), 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 d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-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)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), 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)-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 -Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), 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), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), 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: Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, Population, 0211 other engineering and technologies, 02 engineering and technology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, 01 natural sciences, Precipitation, Water cycle, education, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 021110 strategic, defence & security studies, education.field_of_study, Microphysics, Ice crystals, Lead (sea ice), [ SDU.STU.ME ] Sciences of the Universe [physics]/Earth Sciences/Meteorology, Snow, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Environmental science, [ SDU.STU.CL ] Sciences of the Universe [physics]/Earth Sciences/Climatology, Graupel
Abstract: International audience; The goal of this paper is to present and evaluate the new LIMA (Liquid Ice Multiple Aerosols) microphysical scheme, which predicts six water species (water vapor, cloud water, rainwater, primary ice crystals, snow aggregates, and graupel). LIMA uses a two‐moment parameterization for three hydrometeor species (ice crystals, cloud droplets, and raindrops), and is derived from the one‐moment scheme ICE3 used daily in the AROME cloud resolvingoperational model at Météo‐France. In addition, it integrates a prognostic representation of the aerosol population. To evaluate the scheme, we simulate two well‐documented Heavy Precipitation Events from the HyMeX (Hydrological cycle in Mediterranean Experiment) campaign. The LIMA simulations are compared to ICE3 simulations and to a large variety of observations, such as rainfall accumulation from rain gauges, particle size distributions from disdrometers, airborne in‐situ measurements of ice particles and Dual‐Polarization radar variables. The evaluation suggests that the rain mixing ratio prognosed by LIMA is more realistic than that prognosed by ICE3. Comparisons with disdrometers and dual‐polarization radars highlight the better representation of the rain microphysical variability when using LIMA but lead to overpredict raindrops with large diameter. The vertical composition of the convective cells is also improved by the two‐moment ice parameterization in the LIMA scheme, which impacts the contents of the one‐moment parameterized snow and graupel species. This evaluation of LIMA suggests ways to improve the hydrometeors representation, focusing especially on the description of the Particle Size Distributions (PSD) for different water species.
Published: 2018

30. Ultraviolet Radiation modelling using output from the Chemistry Climate Model Initiative

Author: Slimane Bekki, Daniele Visioni, Hassan Bencherif, Laura E. Revell, Kohei Yoshida, Martyn P. Chipperfield, John A. Pyle, Andrea Stenke, Kengo Sudo, N. Butchart, Béatrice Josse, Thierry Portafaix, Alexander T. Archibald, Colette Brogniez, Patrick Jöckel, Eugene Rozanov, Makoto Deushi, Giovanni Pitari, Martine Michou, Luke D. Oman, Sophie Godin-Beekmann, Michaela I. Hegglin, Glauco Di Genova, Taichu Tanaka, Fiona M. O'Connor, Oliver Kirner, Olaf Morgenstern, David Saint-Martin, Guang Zeng, Rong-Ming Hu, Douglas E. Kinnison, Kévin Lamy, David A. Plummer, N. Luke Abraham, Hideharu Akiyoshi, Virginie Marécal, Sandip Dhomse, Laboratoire de l'Atmosphère et des Cyclones ( LACy ), Météo France-Université de la Réunion ( UR ) -Centre National de la Recherche Scientifique ( CNRS ), Centre national de recherches météorologiques ( CNRM ), Météo France-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d’Optique Atmosphérique - UMR 8518 ( LOA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), SHTI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), School of Chemistry and Physics [Durban], University of KwaZulu-Natal ( UKZN ), Institute for Atmospheric and Climate Science [Zürich] ( IAC ), Swiss Federal Institute of Technology in Zürich ( ETH Zürich ), Bodeker Scientific, School of Physical Chemical Sciences [Christchurch], University of Canterbury [Christchurch], National Institute for Environmental Studies ( NIES ), Department of Meteorology [Reading], University of Reading ( UOR ), DLR Institut für Physik der Atmosphäre ( IPA ), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] ( DLR ), Steinbuch Centre for Computing [Karlsruhe] ( SCC ), Karlsruher Institut für Technologie ( KIT ), National Institute of Water and Atmospheric Research [Wellington] ( NIWA ), Department of Chemistry [Cambridge, UK], University of Cambridge [UK] ( CAM ), National Centre for Atmospheric Science [Leeds] ( NCAS ), Natural Environment Research Council ( NERC ), Met Office Hadley Centre ( MOHC ), United Kingdom Met Office [Exeter], School of Earth and Environment [Leeds] ( SEE ), University of Leeds, Department of Physical and Chemical Sciences [L'Aquila] ( DSFC ), Università degli Studi dell'Aquila [L'Aquila] ( UNIVAQ.IT ), Meteorological Research Institute [Tsukuba] ( MRI ), Japan Meteorological Agency ( JMA ), National Center for Atmospheric Research [Boulder] ( NCAR ), NASA Goddard Space Flight Center ( GSFC ), Canadian Centre for Climate Modelling and Analysis ( CCCma ), Environment and Climate Change Canada, Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center ( PMOD/WRC ), Graduate School of Environmental Studies [Nagoya], Nagoya University, Laboratoire de l'Atmosphère et des Cyclones (LACy), Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), 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 -Institut national des sciences de l'Univers (INSU - CNRS)-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 -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, STRATO - 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), University of KwaZulu-Natal (UKZN), Institute for Atmospheric and Climate Science [Zürich] (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), National Institute for Environmental Studies (NIES), University of Reading (UOR), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Steinbuch Centre for Computing [Karlsruhe] (SCC), Karlsruher Institut für Technologie (KIT), National Institute of Water and Atmospheric Research [Wellington] (NIWA), University of Cambridge [UK] (CAM), National Centre for Atmospheric Science [Leeds] (NCAS), Natural Environment Research Council (NERC), Met Office Hadley Centre for Climate Change (MOHC), School of Earth and Environment [Leeds] (SEE), Department of Physical and Chemical Sciences [L'Aquila] (DSFC), Università degli Studi dell'Aquila (UNIVAQ), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), National Center for Atmospheric Research [Boulder] (NCAR), NASA Goddard Space Flight Center (GSFC), Canadian Centre for Climate Modelling and Analysis (CCCma), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Ozone, 010504 meteorology & atmospheric sciences, Northern Hemisphere, Noon, 010502 geochemistry & geophysics, Atmospheric sciences, 7. Clean energy, 01 natural sciences, Article, Aerosol, Latitude, Troposphere, chemistry.chemical_compound, chemistry, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 13. Climate action, Environmental science, Ultraviolet index, [ SDU.STU.CL ] Sciences of the Universe [physics]/Earth Sciences/Climatology, Southern Hemisphere, 0105 earth and related environmental sciences
Abstract: We have derived values of the Ultraviolet Index (UVI) at solar noon using the Tropospheric Ultraviolet Model (TUV) driven by ozone, temperature and aerosol fields from climate simulations of the first phase of the Chemistry-Climate Model Initiative (CCMI-1). Since clouds remain one of the largest uncertainties in climate projections, we simulated only the clear-sky UVI. We compared the modelled UVI climatologies against present-day climatological values of UVI derived from both satellite data (the OMI-Aura OMUVBd product) and ground-based measurements (from the NDACC network). Depending on the region, relative differences between the UVI obtained from CCMI/TUV calculations and the ground-based measurements ranged between −5.9% and 10.6%. We then calculated the UVI evolution throughout the 21st century for the four Representative Concentration Pathways (RCPs 2.6, 4.5, 6.0 and 8.5). Compared to 1960s values, we found an average increase in the UVI in 2100 (of 2–4%) in the tropical belt (30°N-30°S). For the mid-latitudes, we observed a 1.8 to 3.4 % increase in the Southern Hemisphere for RCP 2.6, 4.5 and 6.0, and found a 2.3% decrease in RCP 8.5. Higher increases in UVI are projected in the Northern Hemisphere except for RCP 8.5. At high latitudes, ozone recovery is well identified and induces a complete return of mean UVI levels to 1960 values for RCP 8.5 in the Southern Hemisphere. In the Northern Hemisphere, UVI levels in 2100 are higher by 0.5 to 5.5% for RCP 2.6, 4.5 and 6.0 and they are lower by 7.9% for RCP 8.5. We analysed the impacts of greenhouse gases (GHGs) and ozone-depleting substances (ODSs) on UVI from 1960 by comparing CCMI sensitivity simulations (1960–2100) with fixed GHGs or ODSs at their respective 1960 levels. As expected with ODS fixed at their 1960 levels, there is no large decrease in ozone levels and consequently no sudden increase in UVI levels. With fixed GHG, we observed a delayed return of ozone to 1960 values, with a corresponding pattern of change observed on UVI, and looking at the UVI difference between 2090s values and 1960s values, we found an 8 % increase in the tropical belt during the summer of each hemisphere. Finally we show that, while in the Southern Hemisphere the UVI is mainly driven by total ozone column, in the Northern Hemisphere both total ozone column and aerosol optical depth drive UVI levels, with aerosol optical depth having twice as much influence on the UVI as total ozone column does.
Published: 2018

31. Using digital elevation models and image processing to follow clod evolution under rainfall

Author: Vannier, Edwige, Taconet, Odile, Dusséaux, Richard, Darboux, Frédéric, SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Unité de recherche Science du Sol (USS), Institut National de la Recherche Agronomique (INRA), 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 Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Unité de Recherche de Science du Sol d'Orléans ( UR SOLS ), Institut national de la recherche agronomique [Val de Loire] ( INRA Val de Loire ), 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), Unité de Science du Sol (Orléans) (URSols), and Cardon, Catherine
Subjects: [SDU.STU.ME] Sciences of the Universe [physics]/Earth Sciences/Meteorology, [ SDV ] Life Sciences [q-bio], Monitoring, Rainfall impact, [SDE.IE]Environmental Sciences/Environmental Engineering, [SDV]Life Sciences [q-bio], Cloddiness, Modeling, modèle d'élévation digitale, motte de terre, [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Soil surface roughness, précipitation au sol, Erosion, interaction sol environnement, Digital elevation model, impact de la pluie, soil clods, rugosité du sol
Abstract: Soil surface roughness plays an important role in determining how the soil will interact with its environment. Analysis of soil roughness at small scale matters both for preparation of soil in order to allow for plant emergence, and for decisions to favor soil conservation. Indeed, soil roughness may be shaped by tillage operations and then changes with time, under rainfall impact.Soil surface roughness is usually estimated by various indices, computed on measured profiles or images of elevations. Another approach is focusing on soil cloddiness, either by sieving or by image segmentation. The objective of this study is to monitor the evolution of clods under rainfall with Digital Elevation Model (DEM) recording and image processing.We prepared two trays of artificial soil surfaces in the laboratory with silt loam soil topped by pre-sieved clods. They were designed to look like a seedbed. Soil surface evolution was achieved by subjecting the trays to controlled artificial rainfalls, and DEM were recorded at each stage. We performed automatic clod segmentation and measurement of the volume of individual clods. Under rainfall impact, we could see smoothing and leveling of clods until disappearance of the smaller ones. We focused on the larger clods greater than 12 mm in diameter that remained till the last rainfall. They showed swelling (volume increase) followed by erosion (volume decrease), these two phenomena being size dependent. Clod volume decrease was modeled by an exponential function.Now, the slope and the amplitude parameters decreased according to a power law, as a function of mean volume of clods. Monitoring of clod volume with cumulated precipitation with the help of DEM measurements is able to differentiate the dynamics of clod depending on their size. This technique improves the usual roughness description and allows for a better understanding of the processes.
Published: 2017

32. ICE GENESIS: Synergetic Aircraft and Ground-Based Remote Sensing and In Situ Measurements of Snowfall Microphysical Properties

Author: Billault-Roux, Anne-Claire, Grazioli, Jacopo, Delanoë, Julien, Jorquera, Susana, Pauwels, Nicolas, Viltard, Nicolas, Martini, Audrey, Mariage, Vincent, Le Gac, Christophe, Caudoux, Christophe, Aubry, Clémantyne, Bertrand, Fabrice, Schwarzenboeck, Alfons, Jaffeux, Louis, Coutris, Pierre, Febvre, Guy, Pichon, Jean Marc, Dezitter, Fabien, Gehring, Josué, Untersee, Aude, Calas, Christophe, Figueras I Ventura, Jordi, Vie, Benoit, Peyrat, Adrien, Curat, Valentin, Rebouissoux, Simon, Berne, Alexis, Environmental Remote Sensing Laboratory [Lausanne], Ecole Polytechnique Fédérale de Lausanne (EPFL), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), 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), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Airbus Helicopters, Aeroport International de Marseille-Provence, Federal Office of Meteorology and Climatology MeteoSwiss, and Météo-France
Subjects: Snowfall, Atmospheric Science, Cloud microphysics, Precipitation, Radars/Radar observations, Remote sensing, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Icing
Abstract: An international field experiment took place in the Swiss Jura in January 2021 as a milestone of the European ICE GENESIS project (www.ice-genesis.eu/), which aims to better measure, understand, and model the ice/snow particle properties and mechanisms responsible for icing of rotor-craft and aircraft. The field campaign was designed to collect observations of clouds and snowfall at a prescribed range of temperatures (−10° to +2°C). The suite of in situ and remote sensing instruments included airborne probes and imagers on board a SAFIRE ATR-42 aircraft, able to sample liquid and ice particles from the micron to the millimeter size range, as well as icing sensors and cameras. Two 95 GHz Doppler cloud radars were installed on the SAFIRE ATR-42, while six Doppler weather radars operating at frequencies ranging from 10 to 95 GHz (and one lidar) were ground based. An operational polarimetric weather radar in nearby France (Montancy) complements the coverage. Finally, observations of standard meteorological variables as well as high-resolution pictures of falling snowflakes from a multiangle snowflake camera were collected at the ground level. The campaign showed its full potential during five (multihourly) flights where precipitation was monitored from cloud to ground. The originality of this campaign resides in the targeted specific temperature range for snowfall and in the synchronization between the ground-based remote sensing and the aircraft trajectories designed to maximize the collection of in situ observations within the column above the radar systems.
Published: 2023

33. ROSINA/DFMS and IES observations of 67P: Ion-neutral chemistry in the coma of a weakly outgassing comet

Author: André Bieler, M. Rinaldi, Martin Rubin, Michael R. Combi, Thierry Sémon, Kathrin Altwegg, J. H. Waite, Hans Balsiger, Jean-Jacques Berthelier, Stephen A. Fuselier, J. De Keyser, Myrtha Hässig, Chia-Yu Tzou, C. Briois, Peter Wurz, Herbert Gunell, Henri Rème, Kirk C. Hansen, Susarla Raghuram, Ulrich Mall, Gaël Cessateur, M. Galand, S. M. Petrinec, Annette Jäckel, A. Korth, James L. Burch, K. J. Trattner, E. Vigren, B. Fiethe, Tamas I. Gombosi, Kathleen Mandt, Léna Le Roy, T. W. Broiles, Ursina Calmonte, Sébastien Gasc, Space Science Division [San Antonio], Southwest Research Institute [San Antonio] ( SwRI ), UTSA Department of Physics and Astronomy [San Antonio], The University of Texas at San Antonio ( UTSA ), Physikalisches Institut [Bern], Universität Bern [Bern], IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), University of Michigan [Ann Arbor], Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Centre National de la Recherche Scientifique ( CNRS ) -Université d'Orléans ( UO ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], Imperial College London, Max Planck Institute for Solar System Research ( MPS ), Lockheed Martin Advanced Technology Center ( ATC ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratory for Atmospheric and Space Physics [Boulder] ( LASP ), University of Colorado Boulder [Boulder], Swedish Institute of Space Physics [Uppsala] ( IRF ), Southwest Research Institute [San Antonio] (SwRI), The University of Texas at San Antonio (UTSA), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan System-University of Michigan System, 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), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Lockheed Martin Advanced Technology Center (ATC), 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], Swedish Institute of Space Physics [Uppsala] (IRF), Universität Bern [Bern] (UNIBE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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: 67P/Churyumov-Gerasimenko, DYNAMICS, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Data analysis, Coma (optics), Astrophysics, Astronomy & Astrophysics, MASS, Mass spectrometry, Chemical reaction, Ion, METHANE, Comet nucleus, SPECTROMETER, comets, RATES, HALLEY, AMMONIA, Science & Technology, Chemistry, comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, SENSOR, plasmas, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], methods: data analysis, Outgassing, Solar wind, molecular processes, 0201 Astronomical And Space Sciences, solar wind, INNER COMA, 13. Climate action, Space and Planetary Science, Physical Sciences, P/HALLEY
Abstract: International audience; The Rosetta encounter with comet 67P/Churyumov-Gerasimenko provides a unique opportunity for an in situ, up-close investigation of ion-neutral chemistry in the coma of a weakly outgassing comet far from the Sun.Observations of primary and secondary ions and modeling are used to investigate the role of ion-neutral chemistry within the thin coma.Methods. Observations from late October through mid-December 2014 show the continuous presence of the solar wind 30 km from the comet nucleus. These and other observations indicate that there is no contact surface and the solar wind has direct access to the nucleus. On several occasions during this time period, the Rosetta/ROSINA/Double Focusing Mass Spectrometer measured the low-energy ion composition in the coma. Organic volatiles and water group ions and their breakup products (masses 14 through 19), CO2+ (masses 28 and 44) another mass peaks (at masses 26, 27 , and possibly 30) were observed. Secondary ions include H3O+ and HCO+ (masses 19 and 29). These secondary ions indicate ion-neutral chemistry in the thin coma of the comet. A relatively simple model is constructed to account for the low H3O+/H2O+ and HCO+/CO+ ratios observed in a water dominated coma. Results from this simple model are compared with results from models that include a more detailed chemical reaction network.At low outgassing rates, predictions from the simple model agree with observations and with results from more complex models that include much more chemistry. At higher outgassing rates, the ion-neutral chemistry is still limited and high HCO+/CO+ ratios are predicted and observed. However, at higher outgassing rates, the model predicts high H3O+/H2O+ ratios and the observed ratios are often low. These low ratios may be the result of the highly heterogeneous nature of the coma, where CO and CO2 number densities can exceed that of water.
Published: 2015
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34. Sulphur isotope mass-independent fractionation observed in comet 67P/Churyumov–Gerasimenko by Rosetta/ROSINA

Author: Sébastien Gasc, B. Fiethe, Tamas I. Gombosi, Chia-Yu Tzou, Ursina Calmonte, Thierry Sémon, Hans Balsiger, Martin Rubin, André Bieler, Susanne F. Wampfler, Kathrin Altwegg, Léna Le Roy, J-J Berthelier, J. De Keyser, Stephen A. Fuselier, Physikalisches Institut [Bern], Universität Bern [Bern], Center for Space and Habitability (CSH), University of Bern, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), UTSA Department of Physics and Astronomy [San Antonio], The University of Texas at San Antonio (UTSA), Center for Space and Habitability ( CSH ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], Southwest Research Institute [San Antonio] ( SwRI ), The University of Texas at San Antonio ( UTSA ), and Universität Bern [Bern] (UNIBE)
Subjects: 010504 meteorology & atmospheric sciences, 530 Physics, Comet, Analytical chemistry, chemistry.chemical_element, Fractionation, Mass spectrometry, 01 natural sciences, Astrobiology, Xenon, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Nebula, Isotope, 520 Astronomy, Astronomy and Astrophysics, 620 Engineering, Mass-independent fractionation, Troilite, chemistry, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], [ SDU ] Sciences of the Universe [physics]
Abstract: International audience; The knowledge about sulphur isotopic fractionation in volatile cometary species is limited as only measurements in five comets have been done and only for 34S/32S. The lack of information about the fractionation of 33S/32S makes it impossible to compare them with what is known from refractories. We present results of 34S/32S and for the first time 33S/32S isotopic ratio in H2S, OCS, and CS2 in the coma of comet 67P/Churyumov-Gerasimenko. Observations used for this study were performed with Rosetta Orbiter Spectrometer for Ion and Neutral Analysis/Double Focusing Mass Spectrometer during October 2014 and May 2016. Bulk isotopic 33S/32S and 34S/32S ratio derived from these three species yield δ33S = (-302 ± 29)‰ and δ34S = (-41 ± 17)‰ respectively. The observed isotopic fractionation is significantly different from the solar system standard (V-CDT) and all other reported values for solar system objects, except other comets. Furthermore we show that neither mass dependent nor mass-independent fractionation due to photo dissociation as it has been observed in recent laboratory studies can be the cause of the significant depletion compared to solar system standard. In addition, we conclude that there seems to be an intrinsic difference in sulphur isotopic fractionation in cometary volatiles and refractories while the difference between molecules is most likely due to different chemical pathways. The significant fractionation of sulphur isotopes together with a high D2O/HDO vs. HDO/H2O and non-solar isotopic ratio for xenon (Marty 2017) as well as for Si (Marty 2017) point towards a non-homogeneously mixed protosolar nebula.
Published: 2017

35. Thermal dependency of CO2 VUV absorption cross section and application to warm exoplanetary atmospheres

Author: Venot, O., Bénilan, Yves, Fray, Nicolas, Gazeau, Marie-Claire, Montmessin, Franck, Lefèvre, Franck, Bahrini, C., Es-Sebbar, Et-Touhami, Schwell, Martin, Hébrard, Eric, Lefevre, M., Waldmann, I. P., Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), STRATO - LATMOS, School of Physics and Astronomy [Exeter], University of Exeter, Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), SHTI - LATMOS, University College of London [London] ( UCL ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU]Sciences of the Universe [physics], [ SDU ] Sciences of the Universe [physics]
Abstract: International audience; Most of exoplanets detected so far have atmospheric temperatures significantly higher than 300 K. These exoplanets are often close to their star and thus receive an intense UV photons flux, triggering important pho-todissociation processes. However, the temperature dependency of VUV absorption cross sections, which are essential data to model photolyses in atmospheric models, are barely known. Thus, by lack of appropriate data, absorption cross sections at room temperature are used in photochemical models of extrasolar planets , leading to a non-measurable uncertainty. With the future space-or ground-based telescopes that will be developed in the coming years (JWST, E-ELT.. .) investigating these research fields becomes urgent [1]. In this context, we quantified the temperature dependency of the VUV absorption cross section of carbon dioxide (CO 2). We performed experimental measurements on the range (115-230 nm) between 150 and 800 K. The absorption cross section of CO 2 increases with the temperature (Fig. 1). At 200 nm, there are more than four orders of magnitude between the one at 300 K and the one at 800 K. We also determined a parametrisation to calculate the continuum of the absorption cross section on this wavelength range. We used these new data in our photo-thermochemical model for exoplanets [2] and studied the impact on the results (photolyses rates and chemical composition) as well as on the observables (synthetic transmission spectra) [3, 4]. We will present these experimental results and their consequences on the modelling of exo-planet atmospheres.
Published: 2017

36. Multi-model comparison of the volcanic sulfate deposition from the 1815 eruption of Mt. Tambora

Author: Lauren Marshall, Anja Schmidt, Matthew Toohey, Ken S. Carslaw, Graham W. Mann, Michael Sigl, Myriam Khodri, Claudia Timmreck, Davide Zanchettin, William Ball, Slimane Bekki, James S. A. Brooke, Sandip Dhomse, Colin Johnson, Jean-Francois Lamarque, Allegra LeGrande, Michael J. Mills, Ulrike Niemeier, Virginie Poulain, Alan Robock, Eugene Rozanov, Andrea Stenke, Timofei Sukhodolov, Simone Tilmes, Kostas Tsigaridis, Fiona Tummon, Institute for Climate and Atmospheric Science [Leeds] (ICAS), School of Earth and Environment [Leeds] (SEE), University of Leeds-University of Leeds, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Max-Planck-Institut für Meteorologie (MPI-M), Max-Planck-Gesellschaft, National Centre for Atmospheric Science [Leeds] (NCAS), Natural Environment Research Council (NERC), Laboratory of Environmental Chemistry [Villigen] (LUC), Paul Scherrer Institute (PSI), Processus de la variabilité climatique tropicale et impacts (PARVATI), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Meteorology (MPI-M), Department of Environmental Sciences, Informatics and Statistics [Venezia], University of Ca’ Foscari [Venice, Italy], Institute for Atmospheric and Climate Science [Zürich] (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Chemistry [Leeds], University of Leeds, Met Office Hadley Centre (MOHC), United Kingdom Met Office [Exeter], Atmospheric Chemistry Observations and Modeling Laboratory (ACOML), National Center for Atmospheric Research [Boulder] (NCAR), NASA Goddard Space Flight Center (GSFC), Center for Climate Systems Research [New York] (CCSR), Columbia University [New York], Department of Environmental Sciences [New Brunswick], School of Environmental and Biological Sciences [New Brunswick], Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers)-Rutgers University System (Rutgers)-Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers)-Rutgers University System (Rutgers), Institute for Climate and Atmospheric Science [Leeds] ( ICAS ), Leibniz-Institut für Meereswissenschaften ( IFM-GEOMAR ), Max-Planck-Institut für Meteorologie ( MPI-M ), National Centre for Atmospheric Science [Leeds] ( NCAS ), Natural Environment Research Council ( NERC ), Laboratory of Environmental Chemistry [Villigen] ( LUC ), Paul Scherrer Institute ( PSI ), Processus de la variabilité climatique tropicale et impacts ( PARVATI ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques ( LOCEAN ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Max Planck Institute for Meteorology ( MPI-M ), Institute for Atmospheric and Climate Science [Zürich] ( IAC ), Swiss Federal Institute of Technology in Zürich ( ETH Zürich ), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center ( PMOD/WRC ), SHTI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Met Office Hadley Centre ( MOHC ), Atmospheric Chemistry Observations and Modeling Laboratory ( ACOML ), National Center for Atmospheric Research [Boulder] ( NCAR ), NASA Goddard Space Flight Center ( GSFC ), Center for Climate Systems Research [New York] ( CCSR ), and Rutgers, The State University of New Jersey [New Brunswick] ( RUTGERS )
Subjects: [ PHYS.PHYS.PHYS-GEO-PH ] Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 010504 meteorology & atmospheric sciences, 13. Climate action, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 01 natural sciences, 0105 earth and related environmental sciences
Abstract: The eruption of Mt. Tambora in 1815 was the largest volcanic eruption of the past 500 years. The eruption had significant climatic impacts, leading to the 1816 “year without a summer”, and remains a valuable event from which to understand the climatic effects of large stratospheric volcanic sulfur dioxide injections. The eruption also resulted in one of the strongest and most easily identifiable volcanic sulfate signals in polar ice cores, which are widely used to reconstruct the timing and atmospheric sulfate loading of past eruptions. As part of the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), five state-of-the-art global aerosol models simulated this eruption. We analyse both simulated background (no Tambora) and volcanic (with Tambora) sulfate deposition to polar regions and compare to ice core records. The models simulate overall similar patterns of background sulfate deposition, although there are differences in regional details and magnitude. However, the volcanic sulfate deposition varies considerably between the models with differences in timing, spatial pattern and magnitude. Mean simulated deposited sulfate on Antarctica ranges from 19 to 264 kg km−2 and on Greenland from 31 to 194 kg km−2, as compared to the mean ice-core-derived estimates of roughly 50 kg km−2 for both Greenland and Antarctica. The ratio of the hemispheric atmospheric sulfate aerosol burden after the eruption to the average ice sheet deposited sulfate varies between models by up to a factor of 15. Sources of this inter-model variability include differences in both the formation and the transport of sulfate aerosol. Our results suggest that deriving relationships between sulfate deposited on ice sheets and atmospheric sulfate burdens from model simulations may be associated with greater uncertainties than previously thought. ISSN:1680-7375 ISSN:1680-7367
Published: 2017

37. Organics in comet 67P – a first comparative analysis of mass spectra from ROSINA–DFMS, COSAC and Ptolemy

Author: Andrew Morse, Markus Schuhmann, Martin Rubin, J. De Keyser, André Bieler, Tamas I. Gombosi, Jean-Jacques Berthelier, Léna Le Roy, Matthew Taylor, Ian Wright, Ursina Calmonte, Kathrin Altwegg, Stephen A. Fuselier, Sébastien Gasc, Chia-Yu Tzou, Hans Balsiger, Fred Goesmann, Physikalisches Institut [Bern], Universität Bern [Bern], Center for Space and Habitability ( CSH ), University of Bern, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] ( SwRI ), The University of Texas at San Antonio ( UTSA ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), University of Michigan [Ann Arbor], Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), School of Physical Sciences [Milton Keynes], The Open University [Milton Keynes] ( OU ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ), Universität Bern [Bern] (UNIBE), Center for Space and Habitability (CSH), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Southwest Research Institute [San Antonio] (SwRI), The University of Texas at San Antonio (UTSA), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan System-University of Michigan System, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Max-Planck-Institut für Sonnensystemforschung (MPS), and European Space Agency (ESA)
Subjects: Physics, 010504 meteorology & atmospheric sciences, 530 Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy, Astronomy and Astrophysics, 620 Engineering, Mass spectrometry, 01 natural sciences, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrobiology, 13. Climate action, Space and Planetary Science, Ptolemy's table of chords, 0103 physical sciences, Mass spectrum, 010303 astronomy & astrophysics, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 0105 earth and related environmental sciences
Abstract: International audience; The ESA Rosetta spacecraft followed comet 67P at a close distance for more than 2 yr. In addition, it deployed the lander Philae on to the surface of the comet. The (surface) composition of the comet is of great interest to understand the origin and evolution of comets. By combining measurements made on the comet itself and in the coma, we probe the nature of this surface material and compare it to remote sensing observations. We compare data from the double focusing mass spectrometer (DFMS) of the ROSINA experiment on ESA's Rosetta mission and previously published data from the two mass spectrometers COSAC (COmetary Sampling And Composition) and Ptolemy on the lander. The mass spectra of all three instruments show very similar patterns of mainly CHO-bearing molecules that sublimate at temperatures of 275 K. The DFMS data also show a great variety of CH-, CHN-, CHS-, CHO2- and CHNO-bearing saturated and unsaturated species. Methyl isocyanate, propanal and glycol aldehyde suggested by the earlier analysis of the measured COSAC spectrum could not be confirmed. The presence of polyoxymethylene in the Ptolemy spectrum was found to be unlikely. However, the signature of the aromatic compound toluene was identified in DFMS and Ptolemy data. Comparison with remote sensing instruments confirms the complex nature of the organics on the surface of 67P, which is much more diverse than anticipated.
Published: 2017

38. The influence of synoptic circulations and local processes on temperature anomalies at three French observatories

Author: Aurélie Colomb, Marie Lothon, Cheikh Dione, Marjolaine Chiriaco, Jean-Luc Baray, Fabienne Lohou, Sophie Bastin, Pascal Yiou, Laboratoire d'aérologie (LAERO), 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), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de météorologie physique (LaMP), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Extrèmes : Statistiques, Impacts et Régionalisation (ESTIMR), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Toulouse (UT)-Université de Toulouse (UT)-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), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie - LA ( LA ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de météorologie physique ( LaMP ), Centre National de la Recherche Scientifique ( CNRS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] ( LSCE ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Centre National de la Recherche Scientifique (CNRS)-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)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Atmospheric circulation, Cloud cover, Mesoscale meteorology, [ SDU.STU.ME ] Sciences of the Universe [physics]/Earth Sciences/Meteorology, Geopotential height, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Mediterranean sea, 13. Climate action, Climatology, Middle latitudes, Radiative transfer, Environmental science, 0105 earth and related environmental sciences, Orographic lift
Abstract: The relative contribution of the synoptic-scale circulations to local and mesoscale processes was quantified in terms of the variability of midlatitude temperature anomalies from 2003 to 2013 using meteorological variables collected from three French observatories and reanalyses. Four weather regimes were defined from sea level pressure anomalies using National Centers for Environmental Prediction reanalyses with a K-means algorithm. No correlation was found between daily temperature anomalies and weather regimes, and the variability of temperature anomalies within each regime was large. It was therefore not possible to evaluate the effect of large scales on temperature anomalies by this method. An alternative approach was found with the use of the analogs method: the principle being that for each day of the considered time series, a set of days that had a similar large-scale 500-hPa geopotential height field within a fixed domain was considered. The observed temperature anomalies were then compared with those observed during the analog days: the closer the two types of series are to each other, the greater is the influence of the large scale. This method highlights a widely predominant influence of the large-scale atmospheric circulation on the temperature anomalies. It showed a potentially larger influence of the Mediterranean Sea and orographic flow on the two southern observatories. Low-level cloud radiative effects substantially modulated the variability of the daily temperature anomalies.
Published: 2017

39. Halogens as tracers of protosolar nebula material in comet 67P/Churyumov-Gerasimenko

Author: Martin Hilchenbach, Johan De Keyser, Peter Wurz, Myrtha Hässig, Henri Rème, Stephen A. Fuselier, Jean-Jacques Berthelier, Nicolas Fray, Tamas I. Gombosi, Sébastien Gasc, Frederik Dhooghe, Martin Rubin, Léna Le Roy, Urs Mall, Michael R. Combi, Thierry Sémon, Romain Maggiolo, Bernard Marty, Andrew Gibbons, Kathrin Altwegg, Chia-Yu Tzou, Herbert Gunell, Eddy Equeter, Björn Fiethe, Christelle Briois, Hans Balsiger, Gaël Cessateur, Ursina Calmonte, Eddy Neefs, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Centre for Mathematical Plasma-Astrophysics [Leuven] (CmPA), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Physikalisches Institut [Bern], Universität Bern [Bern], Center for Space and Habitability (CSH), University of Bern, 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), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), The University of Texas at San Antonio (UTSA), Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Université de Lorraine (UL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Centre for Mathematical Plasma-Astrophysics [Leuven] ( CmPA ), Katholieke Universiteit Leuven ( KU Leuven ), Center for Space and Habitability ( CSH ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Climate and Space Sciences and Engineering ( CLaSP ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Southwest Research Institute [San Antonio] ( SwRI ), The University of Texas at San Antonio ( UTSA ), Université Libre de Bruxelles [Bruxelles] ( ULB ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Centre de Recherches Pétrographiques et Géochimiques ( CRPG ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Libre de Bruxelles [Bruxelles] (ULB), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)
Subjects: Solar System, 010504 meteorology & atmospheric sciences, Hydrogen, 530 Physics, Comet, Analytical chemistry, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Halide, chemistry.chemical_element, 01 natural sciences, Astrobiology, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Nebula, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Molecular cloud, Astronomy and Astrophysics, 620 Engineering, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry, 13. Climate action, Space and Planetary Science, Halogen, Mass spectrum, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Abstract: International audience; We report the first in situ detection of halogens in a cometary coma, that of 67P/Churyumov-Gerasimenko. Neutral gas mass spectra collected by the European Space Agencys Rosetta spacecraft during four periods of interest from the first comet encounter up to perihelion indicate that the main halogen-bearing compounds are HF, HCl and HBr. The bulk elemental abundances relative to oxygen are ∼8.9 × 10−5 for F/O, ∼1.2 × 10−4 for Cl/O, and ∼2.5 × 10−6 for Br/O, for the volatile fraction of the comet. The cometary isotopic ratios for 37Cl/35Cl and 81Br/79Br match the solar system values within the error margins. The observations point to an origin of the hydrogen halides in molecular cloud chemistry, with frozen hydrogen halides on dust grains, and a subsequent incorporation into comets as the cloud condensed and the solar system formed.
Published: 2017

40. Change of outgassing pattern of 67P/Churyumov–Gerasimenko during the March 2016 equinox as seen by ROSINA

Author: Hans Balsiger, André Bieler, Sébastien Gasc, Martin Rubin, Thierry Sémon, Chia-Yu Tzou, André Galli, Henri Rème, Peter Wurz, A. Korth, Jack H. Waite, Stephen A. Fuselier, Tamas I. Gombosi, Johan De Keyser, M. Hoang, Léna Le Roy, Ursina Calmonte, Kathrin Altwegg, Jean-Jacques Berthelier, Björn Fiethe, Urs Mall, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Center for Space and Habitability (CSH), University of Bern, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), 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), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Universität Bern [Bern], Center for Space and Habitability ( CSH ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Climate and Space Sciences and Engineering ( CLaSP ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], Southwest Research Institute [San Antonio] ( SwRI ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), 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), and Max-Planck-Institut für Sonnensystemforschung (MPS)
Subjects: Orbital plane, 010504 meteorology & atmospheric sciences, 530 Physics, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Equinox, 01 natural sciences, law.invention, Orbiter, law, 0103 physical sciences, 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Astronomy, Astronomy and Astrophysics, Spin axis, 620 Engineering, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Outgassing, 13. Climate action, Space and Planetary Science, Sublimation (phase transition), Water ice, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Abstract: International audience; As the spin axis of comet 67P/Churyumov–Gerasimenko (67P) is not normal to the orbital plane, 67P has strong seasonal changes in the illumination conditions on the nucleus’ surface, with a short and intense summer in the Southern hemisphere. We have been monitoring these seasonal variations in the gas coma with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument suite aboard the ESA's Rosetta spacecraft. Rosetta followed 67P from its rendezvous in 2014 August, from a distance of almost 3.5 au to Sun, through perihelion at 1.24 au, and away from Sun again. In this study, we present the change of outgassing pattern during the 2016 March equinox based on measurements acquired with the ROSINA instruments: while H2O, O2 and NH3 abundances rapidly decreased during this period, CO2, CO, H2S, CH4 and HCN abundances decreased much less and showed a strong south–north heterogeneity for the whole period, thus not following Sun. Sublimation temperatures of the pure ices are found to be uncorrelated with the slope of the decrease for the minor species. This can be interpreted as a consequence of two different ice phases, water ice and CO2 ice, in which the minor species are embedded in different relative abundances.
Published: 2017

41. Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko

Author: Sébastien Gasc, Martin Rubin, André Bieler, Jean-Jacques Berthelier, Michael R. Combi, Cécile Engrand, Hans Balsiger, Klaus Mezger, Chia-Yu Tzou, Kenneth C. Hansen, Björn Fiethe, Myrtha Hässig, Peter Wurz, Ursina Calmonte, Kathrin Altwegg, S. A. Fuselier, Léna Le Roy, Tamas I. Gombosi, J. De Keyser, Susanne F. Wampfler, Physikalisches Institut [Bern], Universität Bern [Bern], Center for Space and Habitability (CSH), University of Bern, HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Department of Climate and Space Sciences and Engineering (CLaSP), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], UTSA Department of Physics and Astronomy [San Antonio], The University of Texas at San Antonio (UTSA), Southwest Research Institute [San Antonio] (SwRI), Institut für Geologie [Bern], Center for Space and Habitability ( CSH ), HEPPI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Department of Climate and Space Sciences and Engineering ( CLaSP ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Centre de Sciences Nucléaires et de Sciences de la Matière ( CSNSM AS ), Université Paris-Saclay-Univ. Paris-Sud-CNRS/IN2P3, Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], The University of Texas at San Antonio ( UTSA ), Southwest Research Institute [San Antonio] ( SwRI ), Universität Bern [Bern] (UNIBE), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Solar System, Astrochemistry, 010504 meteorology & atmospheric sciences, Comet, Analytical chemistry, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, 0103 physical sciences, Isotopes of silicon, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Spectrometer, Astronomy and Astrophysics, Solar wind, Meteorite, Astrophysics - Solar and Stellar Astrophysics, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 13. Climate action, Space and Planetary Science, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) was designed to measure the composition of the gas in the coma of comet 67P/Churyumov-Gerasimenko, the target of the European Space Agency's Rosetta mission. In addition to the volatiles, ROSINA measured refractories sputtered off the comet by the interaction of solar wind protons with the surface of the comet. Aims. The origin of different solar system materials is still heavily debated. Isotopic ratios can be used to distinguish between different reservoirs and investigate processes occurring during the formation of the solar system. Methods. ROSINA consisted of two mass spectrometers and a pressure sensor. In the ROSINA Double Focusing Mass Spectrometer (DFMS), the neutral gas of cometary origin was ionized and then deflected in an electric and a magnetic field that separated the ions based on their mass-to-charge ratio. The DFMS had a high mass resolution, dynamic range, and sensitivity that allowed detection of rare species and the known major volatiles. Results. We measured the relative abundance of all three stable silicon isotopes with the ROSINA instrument on board the Rosetta spacecraft. Furthermore, we measured $^{13}$C/$^{12}$C in C$_2$H$_4$, C$_2$H$_5$, and CO. The DFMS in situ measurements indicate that the average silicon isotopic composition shows depletion in the heavy isotopes $^{29}$Si and $^{30}$Si with respect to $^{28}$Si and solar abundances, while $^{13}$C to $^{12}$C is analytically indistinguishable from bulk planetary and meteorite compositions. Although the origin of the deficiency of the heavy silicon isotopes cannot be explained unambiguously, we discuss mechanisms that could have contributed to the measured depletion of the isotopes $^{29}$Si and $^{30}$Si., Accepted for publication in Astronomy & Astrophysics
Published: 2017

42. Bidirectional reflectance and VIS-NIR spectroscopy of cometary analogues under simulated space conditions

Author: Bernhard Jost, Nicolas Thomas, Nathalie Carrasco, Sonia Fornasier, Clement Feller, Zurine Yoldi, Olivier Poch, Pedro Hasselmann, Cyril Szopa, Antoine Pommerol, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), National Centre of Competence in Research PlanetS (NCCR PlanetS), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE)-Swiss National Science Foundation (SNSF), Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-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 Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatorio Nacional [Rio de Janeiro], Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern], National Centre of Competence in Research PlanetS ( NCCR PlanetS ), Swiss National Science Foundation ( SNSF ), Université Paris Diderot - Paris 7 ( UPD7 ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Universitaire de France ( IUF ), Ministère de l'Éducation nationale, de l’Enseignement supérieur et de la Recherche ( M.E.N.E.S.R. ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), and Universität Bern [Bern]-Universität Bern [Bern]-Swiss National Science Foundation (SNSF)
Subjects: Materials science, 010504 meteorology & atmospheric sciences, Hyperspectral imaging, Comet, Analytical chemistry, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, Mantle (geology), Optics, Organics, 0103 physical sciences, Thermal, Comets, Surface layer, Porosity, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, business.industry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Tholin, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Water ice, 13. Climate action, Space and Planetary Science, Sublimation (phase transition), business, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Abstract: International audience; This work is intended to be the second publication in a series of papers reporting on the spectro-photometric properties of cometary analogues measured in the laboratory. Herein, we provide in-situ hyperspectral imaging data in the 0.40–2.35 μm range from three sublimation experiments under simulated space conditions in thermal vacuum from samples made of water ice, carbonaceous compounds and complex organic molecules. The dataset is complemented by measurements of the bidirectional reflectance in the visible (750 nm) spectral range before and after sublimation. A qualitative characterization of surface evolution processes is provided as well as a description of morphological changes during the simulation experiment.The aim of these experiments is to mimic the spectrum of comet 67P/Churyumov-Gerasimenko (67P) as acquired by the Rosetta mission by applying sublimation experiments on the mixtures of water ice with a complex organic material (tholins) and carbonaceous compounds (carbon black; activated charcoal) studied in our companion publication (Jost et al., submitted). Sublimation experiments are needed to develop the particular texture (high porosity), expected on the nucleus' surface, which might have a strong influence on spectro-photometric properties. The spectrally best matching mixtures of non volatile organic molecules from Jost et al. (submitted) are mixed with fine grained water ice particles and evolved in a thermal vacuum chamber, in order to monitor the influence of the sublimation process on their spectro-photometric properties.We demonstrate that the way the water ice and the non-volatile constituents are mixed, plays a major role in the formation and evolution of a surface residue mantle as well as having influence on the consolidation processes of the underlying ice. Additionally it results in different activity patterns under simulated insolation cycles. Further we show that the phase curves of samples having a porous surface mantle layer display higher coincidence with data of 67P than the phase curves of the samples having a more compact surface layer with smooth texture.The analysis of spectral absorption bands of water ice in the near-infrared (NIR) range, similar to those acquired by the VIRTIS instrument onboard Rosetta, allows to link compositional considerations with surface activity and texture.
Published: 2017

43. The 67P/Churyumov-Gerasimenko observation campaign in support of the Rosetta mission

Author: Benoit Carry, M. F. A'Hearn, Sebastien Besse, Michaël Gillon, M. J. Mumma, Galin Borisov, B. Rajkumar, Janet E. Drew, Olga Muñoz, Viktor Afanasiev, Tarik Zegmott, Lucas Paganini, D. Bodewits, Rita Schulz, Emily Kramer, Adam J. McKay, Diane H. Wooden, J. de León, Michael Schmidt, Geraint H. Jones, S. Haque, Andrew McNeill, Fernando Moreno, Sara Faggi, P. J. Gutiérrez, Jérémie Lasue, Aurélie Guilbert-Lepoutre, J. M. Sunshine, Javier Licandro, Zhong-Yi Lin, Pedro Lacerda, Philippe Rousselot, Jose Luis Ortiz, Nicolas Biver, Marco Micheli, J. J. López-Moreno, Matthew M. Knight, Jon Marchant, Detlef Koschny, Dominik R. G. Schleicher, F. Aceituno, Michael S. P. Kelley, Colin Snodgrass, G. P. Tozzi, Michael A. DiSanti, Karen J. Meech, Olivier Hainaut, Alfredo Sota, Niklas J. T. Edberg, Edith Hadamcik, Rene Duffard, Rosita Kokotanekova, Erika L. Gibb, Damien Hutsemekers, E. Ramos, Y. Ramanjooloo, A. Guijarro, Ulrich Hopp, Luisa Lara, Stephen C. Lowry, Tim Lister, Anita L. Cochran, V. Casanova, Pablo Santos-Sanz, J. Kleyna, R. Hedrosa, M. Pajuelo, A. K. Sen, Cyrielle Opitom, Emmanuel Jehin, A. Thompson, Alan Fitzsimmons, Geronimo L. Villanueva, E. J. W. de Mooij, Stefano Bagnulo, C. Ries, Boncho P. Bonev, O. Ivanova, Amy Mainzer, John K. Davies, Blair C. Conn, Anny Chantal Levasseur-Regourd, P. Nikolov, Auni Somero, Nikolai Kiselev, Lori M. Feaga, Maria Monguió, Francisco J. Pozuelos, A. Stinson, M. Delacruz, Björn Davidsson, Jacqueline V. Keane, M. Kluge, Dean C. Hines, Simon F. Green, Jean Manfroid, James Bauer, Silvia Protopapa, M. de Val-Borro, T. Pursimo, Xiaobin Wang, Cecilia Tubiana, Hermann Boehnhardt, Masafumi Yagi, I. Mohammed, Vera Rosenbush, F. Hoyo, Harry Lehto, G. Bergond, B. Yang, Méabh Hyland, Arno Riffeser, Hideaki Fujiwara, Erin L. Ryan, B. Zaprudin, School of Physical Sciences [Milton Keynes], The Open University [Milton Keynes] ( OU ), Department of Astronomy [College Park], University of Maryland [College Park], Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Special Astrophysical Observatory of the Russian Academy of Sciences ( SAO ), Russian Academy of Sciences [Moscow] ( RAS ), Armagh Observatory [Armagh], Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), Centro Astronómico Hispano Alemán, European Space Astronomy Center ( ESAC ), European Space Agency ( ESA ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Department of Physics [Washington], American University Washington D.C. ( AU ), Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, Joseph Louis LAGRANGE ( LAGRANGE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Mécanique Céleste et de Calcul des Ephémérides ( IMCCE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), McDonald Observatory, University of Texas at Austin [Austin], Research School of Astronomy and Astrophysics [Canberra] ( RSAA ), Australian National University ( ANU ), Gemini Observatory [Southern Operations Center], Association of Universities for Research in Astronomy ( AURA ), UK Astronomy Technology Centre ( UK ATC ), Science and Technology Facilities Council ( STFC ), Universidad de La Laguna ( ULL ), Instituto de Astrofisica de Canarias ( IAC ), Astrophysics Research Centre [Belfast] ( ARC ), Queen's University [Belfast] ( QUB ), Catholic University of America, Astrochemistry Laboratory [Greenbelt], NASA Goddard Space Flight Center ( GSFC ), Department of Astrophysical Sciences [Princeton], Princeton University, Institute for Astronomy [Honolulu], University of Hawaii at Manoa ( UHM ), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] ( UH ), Swedish Institute of Space Physics [Uppsala] ( IRF ), National Astronomical Observatory of Japan ( NAOJ ), Department of Physics and Astronomy [Columbia], University of Missouri-Columbia, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules ( UTINAM ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), European Southern Observatory ( ESO ), Department of Physics [Trinidad], The University of the West Indies, Space Telescope Science Institute ( STSci ), Ludwig-Maximilians University [Munich] ( LMU ), Astronomical Institute of the Slovak Academy of Sciences, Slovak Academy of Science [Bratislava] ( SAS ), Mullard Space Science Laboratory ( MSSL ), University College of London [London] ( UCL ), Centre for Planetary Sciences [UCL/Birkbeck] ( CPS ), Main Astronomical Observatory of NAS of Ukraine ( MAO ), National Academy of Sciences of Ukraine ( NASU ), Research and Scientific Support Department, ESTEC ( RSSD ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ) -European Space Agency ( ESA ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Tuorla Observatory, University of Turku, Institute of Astronomy [Taiwan] ( IANCU ), National Central University [Taiwan] ( NCU ), Las Cumbres Observatory ( LCO ), Centre for Astrophysics and Planetary Science [Canterbury] ( CAPS ), University of Kent [Canterbury], Astrophysics Research Institute [Liverpool] ( ARI ), Liverpool John Moores University ( LJMU ), ESA SSA-NEO Coordination Centre, Caribbean Institute of Astronomy ( CARINA ), Pontificia Universidad Católica del Perú ( PUCP ), Nordic Optical Telescope ( NOT ), SETI Institute, Lowell Observatory [Flagstaff], European Space Agency, Scientific Support Office, Assam University, INAF - Osservatorio Astrofisico di Arcetri ( OAA ), Istituto Nazionale di Astrofisica ( INAF ), Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences [Beijing] ( CAS ), Yunnan Observatories, Chinese Academy of Sciences [Changchun Branch] ( CAS ), NASA Ames Research Center ( ARC ), Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), University of Maryland System-University of Maryland System, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Special Astrophysical Observatory of the Russian Academy of Sciences (SAO), Russian Academy of Sciences [Moscow] (RAS), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Centro Astronómico Hispano Alemán, Observatorio de Calar Alto (CAHA), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-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 Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, American University Washington D.C. (AU), Institute of Astronomy of the Bulgarian Academy of Sciences, Bulgarian Academy of Sciences (BAS), 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, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Research School of Astronomy and Astrophysics [Canberra] (RSAA), Australian National University (ANU), Association of Universities for Research in Astronomy (AURA), UK Astronomy Technology Centre (UK ATC), Science and Technology Facilities Council (STFC), Universidad de La Laguna [Tenerife - SP] (ULL), Instituto de Astrofisica de Canarias (IAC), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), NASA Goddard Space Flight Center (GSFC), University of Hawai‘i [Mānoa] (UHM), University of Hertfordshire [Hatfield] (UH), Swedish Institute of Space Physics [Uppsala] (IRF), National Astronomical Observatory of Japan (NAOJ), Department of Physics and Astronomy [Columbia] (Mizzou Physics), University of Missouri [Columbia] (Mizzou), University of Missouri System-University of Missouri System, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Space Telescope Science Institute (STSci), Ludwig-Maximilians-Universität München (LMU), Slovak Academy of Science [Bratislava] (SAS), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Centre for Planetary Sciences [UCL/Birkbeck] (CPS), Main Astronomical Observatory of NAS of Ukraine (MAO), National Academy of Sciences of Ukraine (NASU), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), 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), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Las Cumbres Observatory (LCO), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), Astrophysics Research Institute [Liverpool] (ARI), Liverpool John Moores University (LJMU), Caribbean Institute of Astronomy (CARINA), Pontificia Universidad Católica del Perú (PUCP), Nordic Optical Telescope (NOT), ESA Scientific Support Office, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Chinese Academy of Sciences [Beijing] (CAS), Chinese Academy of Sciences [Changchun Branch] (CAS), NASA Ames Research Center (ARC), NASA-California Institute of Technology (CALTECH), Agence Spatiale Européenne = European Space Agency (ESA), Pôle Planétologie du LESIA, 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)-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), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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, 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), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), 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 Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP)
Subjects: Future studies, History, 010504 meteorology & atmospheric sciences, General Mathematics, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], General Physics and Astronomy, FOS: Physical sciences, Context (language use), 01 natural sciences, Astrobiology, Jupiter, 0103 physical sciences, 010303 astronomy & astrophysics, QC, 0105 earth and related environmental sciences, QB, Earth and Planetary Astrophysics (astro-ph.EP), comet 67P/Churyumov?Gerasimenko, Rosetta, solar system, observational astronomy, ta115, Spacecraft, business.industry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], General Engineering, Articles, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Early results, business, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Earth and Planetary Astrophysics
Abstract: We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft, and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively `well behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit-to-orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends -- in this paper we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies., Comment: Author prepared version; final published version available at journal. 22 pages
Published: 2017

44. Organic Aerosols in the Presence of CO2 in the Early Earth and Exoplanets: UV–Vis Refractive Indices of Oxidized Tholins

Author: Ludovic Vettier, Nathalie Carrasco, Laurent Broch, Lisseth Gavilan, Benjamin Fleury, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes (LCP-A2MC), Université de Lorraine (UL), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Project: 636829,H2020,ERC-2014-STG,PRIMCHEM(2015), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes ( LCP-A2MC ), Université de Lorraine ( UL ), Jet Propulsion Laboratory ( JPL ), and NASA-California Institute of Technology ( CALTECH )
Subjects: 010504 meteorology & atmospheric sciences, Band gap, Analytical chemistry, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Techniques: spectroscopic, medicine.disease_cause, 01 natural sciences, Ultraviolet visible spectroscopy, Optics, Ellipsometry, 0103 physical sciences, medicine, Planets and satellites: atmospheres, Thin film, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, business.industry, Methods: laboratory, Astronomy and Astrophysics, Tholin, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Planets and satellites: fundamental parameters, Aerosol, 13. Climate action, Space and Planetary Science, business, Refractive index, Ultraviolet
Abstract: International audience; The goal of this experimental study is to investigate how the presence of atmospheric CO2 affects the optical properties of organic photochemical aerosols. To this end, we add CO2 to a N2:CH4 gas mixture used in a plasma typically used for Titan studies. We produce organic thin films (tholins) in plasmas where the CO2 / CH4 ratio is increased from 0 to 4. We measure these films via spectrometric ellipsometry in the ultraviolet, visible and near-infrared (270 nm to 2 µm). The ellipsometry parameters are fitted with a Tauc-Lorentz model used for optically transparent materials, to obtain the thickness of the thin film, its optical band gap, and the refractive indices. According to this optical mode, oxidized organic aerosols are transparent in the visible up to the near ultraviolet (k = 0 from 900-400 nm), while the fully reduced organic aerosol absorbs in the visible as well as in the near UV (k = 0 from 900-500 nm). As the CO2 /CH4 ratio is quadrupled, the position of the UV absorption resonance is shifted from ∼177 nm to 264 nm, and its strength is also quadrupled: oxidized tholins absorb more efficiently in the middle UV with respect to the far UV for reduced tholins. Our laboratory wavelength-tabulated refractive indices provide further constraints to atmospheric models of the early Earth and Earth-like exoplanets including photochemical hazes formed under increasingly oxidizing conditions.
Published: 2017

45. Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth's atmosphere

Author: E. Kopp, Stephen A. Fuselier, Michael R. Combi, Chia-Yu Tzou, Thierry Sémon, André Bieler, Myrtha Hässig, Bernard Marty, David V. Bekaert, Martin Rubin, Sébastien Gasc, C. Briois, Peter Wurz, Annette Jäckel, Ulrich Mall, Akiva Bar-Nun, Kirk C. Hansen, J. De Keyser, Ursina Calmonte, Kathrin Altwegg, A. Korth, Hans Balsiger, T. C. Owen, Léna Le Roy, J. H. Waite, Jean-Jacques Berthelier, Olivier Mousis, Henri Rème, B. Fiethe, Tamas I. Gombosi, 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), Center for Space and Habitability (CSH), University of Bern, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Department of Geophysics [Tel Aviv] (TAU), Tel Aviv University (TAU), Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, 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), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), 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), European Space Agency (ESA) PRODEX program (Programme de Développement d’Expériences Scientifiques), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), European Project: 267255,EC:FP7:ERC,ERC-2010-AdG_20100224,NOGAT(2011), Universität Bern [Bern], Department of Geosciences [Tel Aviv], Tel Aviv University [Tel Aviv], Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Max-Planck-Institut für Sonnensystemforschung (MPS), 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), Centre de Recherches Pétrographiques et Géochimiques ( CRPG ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Center for Space and Habitability ( CSH ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Climate and Space Sciences and Engineering ( CLaSP ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Centre National de la Recherche Scientifique ( CNRS ) -Université d'Orléans ( UO ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], Southwest Research Institute [San Antonio] ( SwRI ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Laboratoire d'Astrophysique de Marseille ( LAM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Aix Marseille Université ( AMU ) -Centre National d'Etudes Spatiales ( CNES ), University of Hawaii at Manoa ( UHM ), Institut de recherche en astrophysique et planétologie ( IRAP ), and Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: 010504 meteorology & atmospheric sciences, 530 Physics, Physics::Instrumentation and Detectors, Comet, chemistry.chemical_element, 01 natural sciences, law.invention, Astrobiology, Atmosphere, Orbiter, Xenon, law, 540 Chemistry, 0103 physical sciences, Isotopes of xenon, Physics::Atomic and Molecular Clusters, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Multidisciplinary, Isotope, Spectrometer, 520 Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, 620 Engineering, Atmosphere of Earth, chemistry, 13. Climate action, [SDU]Sciences of the Universe [physics], Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, [ SDU ] Sciences of the Universe [physics]
Abstract: Comets contributed to Earth's atmosphere Models of xenon's origin in Earth's atmosphere require an additional, unknown source that has been a mystery for several decades. Marty et al. measured isotopic ratios of xenon released from comet 67P/Churyumov-Gerasimenko and found that they match the heretofore unknown source. The xenon appears to have been trapped in ice within the comet since before the solar system formed. Comets contributed about a quarter of the xenon on Earth, which constrains the amount of other materials (such as water) delivered to our planet by comets. Science , this issue p. 1069
Published: 2017

46. Direct Simulation Monte Carlo modelling of the major species in the coma of comet 67P/Churyumov-Gerasimenko

Author: Yinsi Shou, Giovanna Rinaldi, Michael R. Combi, Nicolas Fougere, Myrtha Hässig, Valeriy Tenishev, Stephen A. Fuselier, Martin Rubin, U. Fink, Gabor Toth, J. De Keyser, Jean-Jacques Berthelier, Chia-Yu Tzou, André Bieler, Stéphane Erard, Gianrico Filacchione, Dominique Bockelée-Morvan, Kirk C. Hansen, V. Debout, C. Leyrat, Zhenguang Huang, B. Fiethe, Tamas I. Gombosi, Alessandra Migliorini, Ursina Calmonte, Giuseppe Piccioni, Fabrizio Capaccioni, Léna Le Roy, Kathrin Altwegg, Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Space Research and Planetary Sciences [Bern) (WP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-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 Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Space Science Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), IMPEC - LATMOS, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Technische Universität Braunschweig [Braunschweig], Department of Climate and Space Sciences and Engineering ( CLaSP ), Space Research and Planetary Sciences ( WP ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Istituto di Astrofisica e Planetologia Spaziali ( IAPS ), Istituto Nazionale di Astrofisica ( INAF ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Lunar and Planetary Laboratory [Tucson], and Southwest Research Institute [San Antonio] ( SwRI )
Subjects: 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, 530 Physics, Comet, Equinox, Astrophysics, ROSINA, 01 natural sciences, 0103 physical sciences, Rosetta, medicine, Boundary value problem, comets, 010303 astronomy & astrophysics, Southern Hemisphere, [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], 0105 earth and related environmental sciences, Physics, Line-of-sight, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 520 Astronomy, Northern Hemisphere, Astronomy and Astrophysics, VIRTIS, 620 Engineering, medicine.anatomical_structure, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], space vehicles, Direct simulation Monte Carlo, Nucleus
Abstract: We analyse the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) - the Double Focusing Mass Spectrometer data between 2014 August and 2016 February to examine the effect of seasonal variations on the four major species within the coma of 67P/Churyumov-Gerasimenko (H2O, CO2, CO, and O2), resulting from the tilt in the orientation of the comet's spin axis. Using a numerical data inversion, we derive the non-uniform activity distribution at the surface of the nucleus for these species, suggesting that the activity distribution at the surface of the nucleus has not significantly been changed and that the differences observed in the coma are solely due to the variations in illumination conditions. A three-dimensional Direct Simulation Monte Carlo model is applied where the boundary conditions are computed with a coupling of the surface activity distributions and the local illumination. The model is able to reproduce the evolution of the densities observed by ROSINA including the changes happening at equinox. While O2 stays correlated with H2O as it was before equinox, CO2 and CO, which had a poor correlation with respect to H2O pre-equinox, also became well correlated with H2O post-equinox. The integration of the densities from the model along the line of sight results in column densities directly comparable to the VIRTIS-H observations. Also, the evolution of the volatiles' production rates is derived from the coma model showing a steepening in the production rate curves after equinox. The model/data comparison suggests that the seasonal effects result in the Northern hemisphere of 67P's nucleus being more processed with a layered structure while the Southern hemisphere constantly exposes new material.
Published: 2016

47. Low-albedo asteroids: analogues with a high polarization at large phase angles

Author: E Hadamcik, J-B Renard, J Lasue, A C Levasseur-Regourd, M Ishiguro, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), 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), 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 Physics and Astronomy [Seoul], Seoul National University [Seoul] (SNU), SNU Astronomy Research Center, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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: asteroids, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Polarimetry, minor planets, Astronomy and Astrophysics, meteors, meteroids, meteorites
Abstract: While remote observations of the linear polarization of five low-albedo near-Earth asteroids are available at large phase angles, space missions have collected materials from the surface of two of them and one of them is already back to Earth. The structure of the regolith on the surface may be different from that encountered on larger objects, because of their low gravity and thermal stress cycling. Dust particles crushed from low-albedo meteorites (i.e. Orgueil and Allende) are tentatively used as analogues to provide a better approach of such regoliths. The PROGRA2 experiment studies the light-scattering properties of dust particles of various size distributions under Earth’s gravity either deposited or with clouds lifted by an air-draught, as well as under μ-gravity conditions. Similar maximum in polarization (i.e. Pmax) values are obtained experimentally for dark particles deposited or in levitation, showing that multiple scattering is negligible. The increased sensitivity of PROGRA2 instruments, together with imaging techniques, makes it possible to study Pmax with increasing sizes of the lifted particles, up to mm-sizes and above. Our results confirm that particles constituting the regolith are mm-sized and may reach polarization values up to 50 per cent in good agreement with remote observations. Some materials are also suggested to be present on the surface of the particles. Also, huge agglomerates made by random ballistic deposition may be considered as relevant analogues e.g. for pebbles and boulders.
Published: 2022

48. An optimal estimation algorithm for the retrieval of fog and low cloud thermodynamic and micro-physical properties

Author: Alistair Bell, Pauline Martinet, Olivier Caumont, Frédéric Burnet, Julien Delanoë, Susana Jorquera, Yann Seity, Vinciane Unger, Centre national de recherches météorologiques (CNRM), 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)-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 -Centre National de la Recherche Scientifique (CNRS), Météo-France Direction Interrégionale Sud-Est (DIRSE), Météo-France, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), This research has been supported by the Agence Nationale de la Recherche (grant no. AAPG-2018-CE01-004.)., The instrumental data used in this study are part of the SOFOG-3D experiment. The SOFOG-3D field campaign was supported by METEO-FRANCE and ANR through grant AAPG-2018-CE01-004. Data are managed by the French National Centre for Atmospheric Data and Services (AERIS).The MWR network deployment was carried out thanks to support by IfU GmbH, the University of Cologne, the Met Office, Laboratoire d’Aérologie, MeteoSwiss, ONERA, and Radiometer Physics GmbH. MWR data have been made available and were quality-controlled and processed in the frame of CPEXLAB (Cloud and Precipitation Exploration LABoratory, http://www.cpex-lab.de/, last access: 8 September 2022), a competence centre within the Geoverbund ABC/J by acting support of Ulrich Löhnert, Rainer Haseneder-Lind and Arthur Kremer from the University of Cologne. This article is based upon work from COST action CA18235 PROBE, supported by COST (European Cooperation in Science and Technology, https://www.cost.eu/, 8 September 2022). Thibaut Montmerle and Yann Michel are thanked for their support on the use of the AROME EDA to compute background error covariance matrices. The authors also thank the two anonymous reviewers., Author contributions. AB and PM made developments to the 1DVar algorithm. AB performed the analysis documented in the paper, which was supervised by PM and OC. JD and SJ provided the radar data, which they also used to perform verification checks, and they also provided relevant assistance. FB provided the in situ data from the SOFOG-3D field campaign. YS provided the configuration to generate AROME forecasts. VU provided treatment for the microwave radiometer data., 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 -Institut national des sciences de l'Univers (INSU - CNRS)-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 -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), SPACE - 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), 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)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology
Abstract: The 1D-Var retrieval framework described hereused the NWPSAF 1D package. This can be downloaded fromthe NWPSAF website (https://nwp-saf.eumetsat.int/site/software/1d-var/download/, last access: 22 August 2022, Pavelin and Collard, 2009). The radiative transfer model RTTOV-gb v1.0 is available to licensed users free of charge. RTTOV-gb may be obtainedby registering (https://www.nwpsaf.eu/site/register/, last access: 22August 2022) and then selecting RTTOV-gb in your software preferences. Developments and updates of the RTTOV-gb code willbe published on the MWRnet website (http://cetemps.aquila.infn.it/rttovgb/rttovgb_updates.html, last access: 8 September 2022). Foraccess to the radar simulator and modified 1D-Var code, please contact pauline.martinet@meteo.fr; International audience; A new generation of cloud radars, with the ability to make observations close to the surface, presents the possibility of observing fog properties with better insight than was previously possible. The use of these instruments as part of an operational observation network could improve the prediction of fog events, something which is still a problem for even high-resolution Numerical Weather Prediction models. However, the retrieval of liquid water content (LWC) profiles from radar reflectivity alone is an under-determined problem, something which ground-based microwave radiometer observations can help to constrain. In fact, microwave radiometers are not only sensitive to temperature and humidity profiles but also known to be instruments of reference for the liquid water path. By providing the thermodynamic state of the atmosphere, to which the formation and evolution of fog events are highly sensitive, in addition to accurate liquid water path, which can be used to constrain the LWC retrieval from the cloud radar alone, combining microwave radiometers with cloud radars seems a natural next step to better understand and forecast fog events. To that end, a newly developed one dimensional variational (1D-Var) algorithm designed for the retrieval of temperature, specific humidity and liquid water content profiles with both cloud radar and microwave radiometer (MWR) observations is presented in this study. The algorithm was developed to evaluate the capability of cloud radar and MWR to provide accurate LWC profiles in addition to temperature and humidity in view of assimilating the retrieved profiles into a 3D/4D-Var operational assimilation system. The algorithm is firstly tested on a synthetic dataset, which allows the evaluation of the developed algorithm in idealised conditions. It is then tested with real data from the recent field campaign SOFOG-3D, carried out with the use of LWC measurements made from a tethered balloon platform. As expected, results from the synthetic dataset study were found to contain lower errors than that found from the retrievals on the dataset of real observations. It was found that retrieval of LWC can be obtained on idealised conditions with an uncertainty of less than 0.04 gm −3. With real data, as expected, retrievals with a good correlation (0.7) to in-situ measurements, but with a higher uncertainty than the synthetic dataset, of around 0.06 gm −3 , was found. This was reduced to 0.05 gm −3 when an accurate droplet number concentration could be prescribed to the algorithm. A sensitivity study was conducted to discuss the impact of different settings used in the 1D-Var algorithm and the for- ward operator. Additionally, retrievals of LWC from a real fog event observed during the SOFOG-3D field campaign were found to significantly improve the operational back- ground profiles of the AROME (Application of Research to Operations at MEsoscale) model, showing encouraging re- sults for future improvement of the AROME model initial state during fog conditions.
Published: 2022

49. Impact of present and future aircraft NOx and aerosol emissions on atmospheric composition and associated direct radiative forcing of climate

Author: Etienne Terrenoire, Didier A. Hauglustaine, Yann Cohen, Anne Cozic, Richard Valorso, Franck Lefèvre, Sigrun Matthes, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), DMPE, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), and European Project: 875036,ACACIA
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, Aircraft, Climate, Nitrogen Oxides, Aerosol, Atmospheric Composition, Radiative Forcing
Abstract: Aviation NOx emissions have not only an impact on global climate by changing ozone and methane levels but also contribute to deteriorate local air quality. In order to properly assess the co-benefit with air quality improvement and the trade-off with the climate change associated with CO2, it appears essential to better quantify the climate impact of aircraft NOx emissions. A new version of the LMDZ-INCA global model, including both tropospheric and stratospheric chemistry and the sulfate-nitrate-ammonium cycle, is applied to re-evaluate the impact of aircraft NOx and aerosol emissions on climate. The results confirm that the efficiency of NOx to produce ozone is very much dependent on the injection height. For the baseline simulation and reference scenario this efficiency is 6.6 TgO3/TgN. The efficiency increases with the background methane and NOx concentrations and with decreasing aircraft NOx emissions. The same findings translate to the associated ozone radiative forcing which exhibits a fairly constant value per ozone mass change of 3.4 mW/m2/TgO3. The methane lifetime variation is less sensitive to the aircraft NOx emission location than the ozone change. The change in CH4 mixing ratio itself represents 75 % of the total methane forcing. The indirect changes through long-term tropospheric ozone, stratospheric water vapour and methane oxidation to CO2 contribute for 19 %, 4 % and 1 %, respectively. The net NOx radiative forcing (O3 + CH4) is largely affected by the revised CH4 radiative forcing formula which increases the total CH4 negative forcing by 15 %. As a consequence, the ozone positive forcing and the methane negative forcing largely offset each other resulting in a slightly positive forcing for the present-day. However, in the future, the net forcing turns to negative due essentially to higher methane background concentrations. Additional radiative forcings involving particle formation arise from aircraft NOx emissions since the increased OH concentrations are responsible for an enhanced conversion of SO2 to sulfate particles. Aircraft NOx emissions also increase the formation of nitrate particles in the lower troposphere. However, in the upper-troposphere, increased sulfate concentrations favor the titration of ammonia leading to lower ammonium nitrate concentrations. The total forcing from sulfate and nitrate aerosols associated with NOx emissions is negative and is estimated to -3.0 mW/m2/TgN for the present-day. When these aerosol radiative forcings are considered, the total NOx forcing turns from a positive value to a negative value even for present-day conditions. Hence, total radiative forcing from aircraft emissions associated with changes in atmospheric chemistry and direct aerosols forcings is negative for both present-day and future (2050) conditions. NOx emissions only cause a negative forcing representing about 45 % of the total forcing. The negative forcing associated with sulfates largely dominates the effect of the other particles. The sulfate direct radiative forcing is estimated to be associated for about 50 % with the direct SO2 and SO4 aircraft emissions and for about 50 % with the increased conversion of SO2 to SO4 at higher OH concentrations, and hence related to the NOx emissions. The net effect of decreasing (resp. increasing) the flight altitude by 2000 ft (about 610 m) is to increase (resp. decrease) the total negative forcing by 57 % (resp. 65 %). The variation of the total forcing with flight altitude is dominated by the high sensitivity of the ozone positive forcing to the altitude of the perturbation. Several mitigation options involving flight aircraft operation and cruise altitude changes, traffic growth, engine technology, and fuel type, exist to reduce the climate impact of aircraft NOx emissions. However, the climate forcing of aircraft NOx emissions is likely to be small or even switch to negative (cooling) depending on atmospheric NOx or CH4 future background concentrations or when the NOx impact on sulfate and nitrate particles is considered. There remain large uncertainties on the NOx net impact on climate effect calculation. Nevertheless, the results suggest that reducing aircraft NOx emissions is primarily beneficial for improving air quality. For climate consideration, one option to reduce uncertainties in mitigation strategies might be to prioritize the reduction of CO2 aircraft emissions which have a well-established and long-term impact on climate, however this reduces the overall mitigation potential.
Published: 2022

50. High resolution assimilation of IASI ozone data with a global CTM

Author: B. Pajot, Sebastien Massart, Daniel Hurtmans, W. A. Lahoz, Andrea Piacentini, Cathy Clerbaux, Daniel Cariolle, P.-F. Coheur, Olivier Pannekoucke, Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique (CERFACS), Météo-France, Centre national de recherches météorologiques (CNRM), 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)-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 -Centre National de la Recherche Scientifique (CNRS), Norwegian Institute for Air Research (NILU), Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Ozone, Pixel, Meteorology, High resolution, Infrared atmospheric sounding interferometer, Standard deviation, Microwave Limb Sounder, chemistry.chemical_compound, symbols.namesake, Data assimilation, chemistry, [SDU]Sciences of the Universe [physics], symbols, Environmental science, Gaussian grid, Remote sensing
Abstract: The pixel size of the Infrared Atmospheric Sounding Interferometer (IASI) remote sensor is much smaller than the horizontal grid size of current Chemical Transport Models (CTMs). In order to assimilate the maximum of information from the IASI retrievals, we have increased the horizontal resolution of our model MOCAGE to be consistent with the IASI pixel size. Experiments are carried out with the Valentina data assimilation system using the standard and the high resolution versions of the model. Two resolutions of the horizontal Gaussian grid have been used for the model: with a T42 and a T170 triangular truncations. Our study is based on the combination of data from the IASI instrument and from the Microwave Limb Sounder (MLS), since this latter dataset allows the information to be spread through the whole atmospheric columns at a low computational cost. Two datasets of ozone super-observations have been constructed by averaging the IASI data on the two model grids. Direct model simulations without data assimilation first show that the increase of the horizontal resolution modifies the ozone smallest scale structures as well as the ozone meridional distribution. This modification results from a better representation of the vertical velocity with the T170 configuration. When the ozone assimilation is performed there is less influence of the horizontal resolution of the model. Nevertheless, in a general way, comparisons with independent data show large reductions of the ozone standard deviations when the resolution is increased. When the ozone assimilation is performed with the high resolution dataset, the high resolution model does not improve the ozone analysis compared to the one obtained with the same model resolution but with the low resolution IASI dataset. This result is due to the difficulty to combine IASI data and MLS data. For assimilating IASI data at high resolution the horizontal correlation length-scale has to be decreased to catch the small scale structures present in the dataset. By doing so the influence of the coarser resolution MLS data is decreased and part of the information brought on the vertical shape of the ozone profile is lost. It is concluded that it is essential to add information on the vertical distribution of ozone column when the IASI data is assimilated at a resolution close to the pixel size. Using IASI averaging kernels would likely improve the simulations, but the computational cost would be much higher. Alternatively, better results might be obtained by a careful tuning of the horizontal correlation length-scale.
Published: 2023

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