Author: "Emmanuel Marcq" / Search Limiters: Full Text - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Emmanuel Marcq"' showing total 55 results

Start Over Author "Emmanuel Marcq" Search Limiters Full Text

55 results on '"Emmanuel Marcq"'

1. Impact of the Turbulent Vertical Mixing on Chemical and Cloud Species in the Venus Cloud Layer

Author: Maxence Lefèvre, Franck Lefèvre, Emmanuel Marcq, Anni Määttänen, Aurélien Stolzenbach, and Nicolas Streel
Subjects: Venus, numerical modeling, chemistry, clouds, turbulence, Geophysics. Cosmic physics, QC801-809
Abstract: Abstract The Venusian atmosphere hosts a 10 km deep convective layer that has been studied by various spacecrafts. However, the impact of the strong vertical mixing on the chemistry of this region is still unknown. This study presents the first realistic coupling between resolved small‐scale turbulence and a chemical network. The resulting vertical mixing is different for each species: those with longer chemical timescales will tend to be well‐mixed. Vertical eddy diffusion due to resolved convection motions was estimated, ranging from 102 to 104 m2/s for the 48–55 km convective layer, several orders of magnitude above the typically used value. In the 48–55 km convective layer, the impact of the small‐scale turbulence on the cloud layer boundaries was between 200 m and 1 km. The impact of turbulence on cloud chemistry is consistent with Venus Express/Visible and Infrared Thermal Imaging Spectrometer observations. The observability at the cloud‐top of small‐scale turbulence by VenSpec‐U spectrometer would be challenging.
Published: 2024
Full Text: View/download PDF

2. Sulfur monoxide dimer chemistry as a possible source of polysulfur in the upper atmosphere of Venus

Author: Joseph P. Pinto, Jiazheng Li, Franklin P. Mills, Emmanuel Marcq, Daria Evdokimova, Denis Belyaev, and Yuk L. Yung
Subjects: Science
Abstract: Photochemistry of sulfur species in the upper Venus atmosphere is not well understood and the identity of ultraviolet (UV) absorber(s) remain unknown. Here, the authors show that sulfur monoxide dimer chemistry is a possible source of polysulfur, which could be responsible for the UV absorption.
Published: 2021
Full Text: View/download PDF

3. No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations

Author: Michael Doyle Smith, Oleg Korablev, Ann Carine Vandaele, Franck Montmessin, Anna A. Fedorova, Alexander Trokhimovskiy, François Forget, Franck Lefèvre, Frank Daerden, Ian R. Thomas, Loïc Trompet, Justin T. Erwin, Shohei Aoki, Séverine Robert, Lori Neary, Sébastien Viscardy, Alexey V. Grigoriev, Nikolay I. Ignatiev, Alexey Shakun, Andrey Patrakeev, Denis A. Belyaev, Jean-Loup Bertaux, Kevin S. Olsen, Lucio Baggio, Juan Alday, Yuriy S. Ivanov, Bojan Ristic, Jon Mason, Yannick Willame, Cédric Depiesse, Laszlo Hetey, Sophie Berkenbosch, Roland Clairquin, Claudio Queirolo, Bram Beeckman, Eddy Neefs, Manish R. Patel, Giancarlo Bellucci, Jose-Juan López-Moreno, Colin F. Wilson, Giuseppe Etiope, Lev Zelenyi, Håkan Svedhem, Jorge L. Vago, Gustavo Alonso-Rodrigo, Francesca Altieri, Konstantin Anufreychik, Gabriele Arnold, Sophie Bauduin, David Bolsée, Giacomo Carrozzo, R. Todd Clancy, Edward Cloutis, Matteo Crismani, Fabiana Da Pieve, Emiliano D’Aversa, Natalia Duxbury, Therese Encrenaz, Thierry Fouchet, Bernd Funke, Didier Fussen, Maia Garcia-Comas, Jean-Claude Gérard, Marco Giuranna, Leo Gkouvelis, Francisco Gonzalez-Galindo, Davide Grassi, Sandrine Guerlet, Paul Hartogh, James Holmes, Benoît Hubert, Jacek Kaminski, Ozgur Karatekin, Yasumasa Kasaba, David Kass, Igor Khatuntsev, Armin Kleinböhl, Nikita Kokonkov, Vladimir Krasnopolsky, Ruslan Kuzmin, Gaétan Lacombe, Orietta Lanciano, Emmanuel Lellouch, Stephen Lewis, Mikhail Luginin, Giuliano Liuzzi, Manuel López-Puertas, Miguel López-Valverde, Anni Määttänen, Arnaud Mahieux, Emmanuel Marcq, Javier Martin-Torres, Igor Maslov, Alexander Medvedev, Ehouarn Millour, Boris Moshkin, Michael J. Mumma, Hiromu Nakagawa, Robert E. Novak, Fabrizio Oliva, Dmitry Patsaev, Arianna Piccialli, Cathy Quantin-Nataf, Etienne Renotte, Birgit Ritter, Alexander Rodin, Frédéric Schmidt, Nick Schneider, Valery Shematovich, Michael D. Smith, Nicholas A. Teanby, Ed Thiemann, Nicolas Thomas, Jean Vander Auwera, Luis Vazquez, Geronimo Villanueva, Matthieu Vincendon, James Whiteway, Valérie Wilquet, Michael J. Wolff, Paulina Wolkenberg, Roger Yelle, Roland Young, Ludmila Zasova, and Maria Paz Zorzano
Subjects: Geosciences (General)
Abstract: The detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere, which—given methane’s lifetime of several centuries—predicts an even, well mixed distribution of methane. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally.
Published: 2019
Full Text: View/download PDF

4. Ariel: Enabling planetary science across light-years

Author: Giovanna Tinetti, Paul Eccleston, Carole Haswell, Pierre-Olivier Lagage, Jérémy Leconte, Theresa Lüftinger, Giusi Micela, Michel Min, Göran Pilbratt, Ludovic Puig, Mark Swain, Leonardo Testi, Diego Turrini, Bart Vandenbussche, Maria Rosa Zapatero Osorio, Anna Aret, Jean-Philippe Beaulieu, Buchhave, Lars A., Martin Ferus, Matt Griffin, Manuel Guedel, Paul Hartogh, Pedro Machado, Giuseppe Malaguti, Enric Pallé, Mirek Rataj, Tom Ray, Ignasi Ribas, Robert Szabó, Jonathan Tan, Stephanie Werner, Francesco Ratti, Carsten Scharmberg, Jean-Christophe Salvignol, Nathalie Boudin, Jean-Philippe Halain, Martin Haag, Pierre-Elie Crouzet, Ralf Kohley, Kate Symonds, Florian Renk, Andrew Caldwell, Manuel Abreu, Gustavo Alonso, Jerome Amiaux, Michel Berthé, Georgia Bishop, Neil Bowles, Manuel Carmona, Deirdre Coffey, Josep Colomé, Martin Crook, Lucile Désjonqueres, Díaz, José J., Rachel Drummond, Mauro Focardi, Gómez, Jose M., Warren Holmes, Matthijs Krijger, Zsolt Kovacs, Tom Hunt, Richardo Machado, Gianluca Morgante, Marc Ollivier, Roland Ottensamer, Emanuele Pace, Teresa Pagano, Enzo Pascale, Chris Pearson, Søren Møller Pedersen, Moshe Pniel, Stéphane Roose, Giorgio Savini, Richard Stamper, Peter Szirovicza, Janos Szoke, Ian Tosh, Francesc Vilardell, Joanna Barstow, Luca Borsato, Sarah Casewell, Quentin Changeat, Benjamin Charnay, Svatopluk Civiš, Vincent Coudé du Foresto, Athena Coustenis, Nicolas Cowan, Camilla Danielski, Olivier Demangeon, Pierre Drossart, Edwards, Billy N., Gabriella Gilli, Therese Encrenaz, Csaba Kiss, Anastasia Kokori, Masahiro Ikoma, Juan Carlos Morales, Joao Mendonca, Andrea Moneti, Lorenzo Mugnai, Antonio García Muñoz, Ravit Helled, Mihkel Kama, Yamila Miguel, Nikos Nikolaou, Isabella Pagano, Olja Panic, Miriam Rengel, Hans Rickman, Marco Rocchetto, Subhajit Sarkar, Franck Selsis, Jonathan Tennyson, Angelos Tsiaras, Olivia Venot, Krisztián Vida, Waldmann, Ingo P., Sergey Yurchenko, Gyula Szabó, Rob Zellem, Ahmed Al-Refaie, Javier Perez Alvarez, Lara Anisman, Axel Arhancet, Jaume Ateca, Robin Baeyens, Barnes, John R., Taylor Bell, Serena Benatti, Katia Biazzo, Maria Błęcka, Aldo Stefano Bonomo, José Bosch, Diego Bossini, Jeremy Bourgalais, Daniele Brienza, Anna Brucalassi, Giovanni Bruno, Hamish Caines, Simon Calcutt, Tiago Campante, Rodolfo Canestrari, Nick Cann, Giada Casali, Albert Casas, Giuseppe Cassone, Christophe Cara, Ludmila Carone, Nathalie Carrasco, Paolo Chioetto, Fausto Cortecchia, Markus Czupalla, Chubb, Katy L., Angela Ciaravella, Antonio Claret, Riccardo Claudi, Claudio Codella, Maya Garcia Comas, Gianluca Cracchiolo, Patricio Cubillos, Vania Da Peppo, Leen Decin, Clemence Dejabrun, Elisa Delgado-Mena, Anna Di Giorgio, Emiliano Diolaiti, Caroline Dorn, Vanessa Doublier, Eric Doumayrou, Georgina Dransfield, Luc Dumaye, Emma Dunford, Antonio Jimenez Escobar, Vincent Van Eylen, Maria Farina, Davide Fedele, Alejandro Fernández, Benjamin Fleury, Sergio Fonte, Jean Fontignie, Luca Fossati, Bernd Funke, Camille Galy, Zoltán Garai, Andrés García, Alberto García-Rigo, Antonio Garufi, Giuseppe Germano Sacco, Paolo Giacobbe, Alejandro Gómez, Arturo Gonzalez, Francisco Gonzalez-Galindo, Davide Grassi, Caitlin Griffith, Mario Giuseppe Guarcello, Audrey Goujon, Amélie Gressier, Aleksandra Grzegorczyk, Tristan Guillot, Gloria Guilluy, Peter Hargrave, Marie-Laure Hellin, Enrique Herrero, Matt Hills, Benoit Horeau, Yuichi Ito, Niels Christian Jessen, Petr Kabath, Szilárd Kálmán, Yui Kawashima, Tadahiro Kimura, Antonín Knížek, Laura Kreidberg, Ronald Kruid, Kruijssen, Diederik J. M., Petr Kubelík, Luisa Lara, Sebastien Lebonnois, David Lee, Maxence Lefevre, Tim Lichtenberg, Daniele Locci, Matteo Lombini, Alejandro Sanchez Lopez, Andrea Lorenzani, Ryan MacDonald, Laura Magrini, Jesus Maldonado, Emmanuel Marcq, Alessandra Migliorini, Darius Modirrousta-Galian, Karan Molaverdikhani, Sergio Molinari, Paul Mollière, Vincent Moreau, Giuseppe Morello, Gilles Morinaud, Mario Morvan, Moses, Julianne I., Salima Mouzali, Nariman Nakhjiri, Luca Naponiello, Norio Narita, Valerio Nascimbeni, Athanasia Nikolaou, Vladimiro Noce, Fabrizio Oliva, Pietro Palladino, Andreas Papageorgiou, Vivien Parmentier, Giovanni Peres, Javier Pérez, Santiago Perez-Hoyos, Manuel Perger, Cesare Cecchi Pestellini, Antonino Petralia, Anne Philippon, Arianna Piccialli, Marco Pignatari, Giampaolo Piotto, Linda Podio, Gianluca Polenta, Giampaolo Preti, Theodor Pribulla, Manuel Lopez Puertas, Monica Rainer, Jean-Michel Reess, Paul Rimmer, Séverine Robert, Albert Rosich, Loic Rossi, Duncan Rust, Ayman Saleh, Nicoletta Sanna, Eugenio Schisano, Laura Schreiber, Victor Schwartz, Antonio Scippa, Bálint Seli, Sho Shibata, Caroline Simpson, Oliver Shorttle, Skaf, N., Konrad Skup, Mateusz Sobiecki, Sergio Sousa, Alessandro Sozzetti, Judit Šponer, Lukas Steiger, Paolo Tanga, Paul Tackley, Jake Taylor, Matthias Tecza, Luca Terenzi, Pascal Tremblin, Andrea Tozzi, Amaury Triaud, Loïc Trompet, Shang-Min Tsai, Maria Tsantaki, Diana Valencia, Ann Carine Vandaele, Mathieu Van der Swaelmen, Adibekyan Vardan, Gautam Vasisht, Allona Vazan, Ciro Del Vecchio, Dave Waltham, Piotr Wawer, Thomas Widemann, Paulina Wolkenberg, Gordon Hou Yip, Yuk Yung, Mantas Zilinskas, Tiziano Zingales, Paola Zuppella, University College of London [London] (UCL), Space Science and Technology Department [Didcot] (RAL Space), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Université de Bordeaux (UB), Agence Spatiale Européenne = European Space Agency (ESA), SRON Netherlands Institute for Space Research (SRON), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Bologna (OABO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), 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), 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), 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 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), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), European Space Agency, Agence Spatiale Européenne (ESA), European Space Agency (ESA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Giovanna Tinetti, Paul Eccleston, Carole Haswell, Pierre-Olivier Lagage, Jérémy Leconte, Theresa Lüftinger, Giusi Micela, Michel Min, Göran Pilbratt, Ludovic Puig, Mark Swain, Leonardo Testi, Diego Turrini, Bart Vandenbussche, Maria Rosa Zapatero Osorio, Anna Aret, Jean-Philippe Beaulieu, Lars Buchhave, Martin Feru, Matt Griffin, Manuel Guedel, Paul Hartogh, Pedro Machado, Giuseppe Malaguti, Enric Pallé, Mirek Rataj, Tom Ray, Ignasi Riba, Robert Szabó, Jonathan Tan, Stephanie Werner, Francesco Ratti, Carsten Scharmberg, Jean-Christophe Salvignol, Nathalie Boudin, Jean-Philippe Halain, Martin Haag, Pierre-Elie Crouzet, Ralf Kohley, Kate Symond, Florian Renk, Andrew Caldwell, Manuel Abreu, Gustavo Alonso, Jerome Amiaux, Michel Berthé, Georgia Bishop, Neil Bowle, Manuel Carmona, Deirdre Coffey, Josep Colomé, Martin Crook, Lucile Désjonquere, José J. Díaz, Rachel Drummond, Mauro Focardi, Jose M. Gómez, Warren Holme, Matthijs Krijger, Zsolt Kovac, Tom Hunt, Richardo Machado, Gianluca Morgante, Marc Ollivier, Roland Ottensamer, Emanuele Pace, Teresa Pagano, Enzo Pascale, Chris Pearson, Søren Møller Pedersen, Moshe Pniel, Stéphane Roose, Giorgio Savini, Richard Stamper, Peter Szirovicza, Janos Szoke, Ian Tosh, Francesc Vilardell, Joanna Barstow, Luca Borsato, Sarah Casewell, Quentin Changeat, Benjamin Charnay, Svatopluk Civiš, Vincent Coudé du Foresto, Athena Cousteni, Nicolas Cowan, Camilla Danielski, Olivier Demangeon, Pierre Drossart, Billy N. Edward, Gabriella Gilli, Therese Encrenaz, Csaba Ki, Anastasia Kokori, Masahiro Ikoma, Juan Carlos Morale, João Mendonça, Andrea Moneti, Lorenzo Mugnai, Antonio García Muñoz, Ravit Helled, Mihkel Kama, Yamila Miguel, Nikos Nikolaou, Isabella Pagano, Olja Panic, Miriam Rengel, Hans Rickman, Marco Rocchetto, Subhajit Sarkar, Franck Selsi, Jonathan Tennyson, Angelos Tsiara, Olivia Venot, Krisztián Vida, Ingo P. Waldmann, Sergey Yurchenko, Gyula Szabó, Rob Zellem, Ahmed Al-Refaie, Javier Perez Alvarez, Lara Anisman, Axel Arhancet, Jaume Ateca, Robin Baeyen, John R. Barne, Taylor Bell, Serena Benatti, Katia Biazzo, Maria Błęcka, Aldo Stefano Bonomo, José Bosch, Diego Bossini, Jeremy Bourgalai, Daniele Brienza, Anna Brucalassi, Giovanni Bruno, Hamish Caine, Simon Calcutt, Tiago Campante, Rodolfo Canestrari, Nick Cann, Giada Casali, Albert Casa, Giuseppe Cassone, Christophe Cara, Ludmila Carone, Nathalie Carrasco, Paolo Chioetto, Fausto Cortecchia, Markus Czupalla, Katy L. Chubb, Angela Ciaravella, Antonio Claret, Riccardo Claudi, Claudio Codella, Maya Garcia Coma, Gianluca Cracchiolo, Patricio Cubillo, Vania Da Peppo, Leen Decin, Clemence Dejabrun, Elisa Delgado-Mena, Anna Di Giorgio, Emiliano Diolaiti, Caroline Dorn, Vanessa Doublier, Eric Doumayrou, Georgina Dransfield, Luc Dumaye, Emma Dunford, Antonio Jimenez Escobar, Vincent Van Eylen, Maria Farina, Davide Fedele, Alejandro Fernández, Benjamin Fleury, Sergio Fonte, Jean Fontignie, Luca Fossati, Bernd Funke, Camille Galy, Zoltán Garai, Andrés García, Alberto García-Rigo, Antonio Garufi, Giuseppe Germano Sacco, Paolo Giacobbe, Alejandro Gómez, Arturo Gonzalez, Francisco Gonzalez-Galindo, Davide Grassi, Caitlin Griffith, Mario Giuseppe Guarcello, Audrey Goujon, Amélie Gressier, Aleksandra Grzegorczyk, Tristan Guillot, Gloria Guilluy, Peter Hargrave, Marie-Laure Hellin, Enrique Herrero, Matt Hill, Benoit Horeau, Yuichi Ito, Niels Christian Jessen, Petr Kabath, Szilárd Kálmán, Yui Kawashima, Tadahiro Kimura, Antonín Knížek, Laura Kreidberg, Ronald Kruid, Diederik J. M. Kruijssen, Petr Kubelík, Luisa Lara, Sebastien Lebonnoi, David Lee, Maxence Lefevre, Tim Lichtenberg, Daniele Locci, Matteo Lombini, Alejandro Sanchez Lopez, Andrea Lorenzani, Ryan MacDonald, Laura Magrini, Jesus Maldonado, Emmanuel Marcq, Alessandra Migliorini, Darius Modirrousta-Galian, Karan Molaverdikhani, Sergio Molinari, Paul Mollière, Vincent Moreau, Giuseppe Morello, Gilles Morinaud, Mario Morvan, Julianne I. Mose, Salima Mouzali, Nariman Nakhjiri, Luca Naponiello, Norio Narita, Valerio Nascimbeni, Athanasia Nikolaou, Vladimiro Noce, Fabrizio Oliva, Pietro Palladino, Andreas Papageorgiou, Vivien Parmentier, Giovanni Pere, Javier Pérez, Santiago Perez-Hoyo, Manuel Perger, Cesare Cecchi Pestellini, Antonino Petralia, Anne Philippon, Arianna Piccialli, Marco Pignatari, Giampaolo Piotto, Linda Podio, Gianluca Polenta, Giampaolo Preti, Theodor Pribulla, Manuel Lopez Puerta, Monica Rainer, Jean-Michel Ree, Paul Rimmer, Séverine Robert, Albert Rosich, Loic Rossi, Duncan Rust, Ayman Saleh, Nicoletta Sanna, Eugenio Schisano, Laura Schreiber, Victor Schwartz, Antonio Scippa, Bálint Seli, Sho Shibata, Caroline Simpson, Oliver Shorttle, N. Skaf, Konrad Skup, Mateusz Sobiecki, Sergio Sousa, Alessandro Sozzetti, Judit Šponer, Lukas Steiger, Paolo Tanga, Paul Tackley, Jake Taylor, Matthias Tecza, Luca Terenzi, Pascal Tremblin, Andrea Tozzi, Amaury Triaud, Loïc Trompet, Shang-Min Tsai, Maria Tsantaki, Diana Valencia, Ann Carine Vandaele, Mathieu Van der Swaelmen, Adibekyan Vardan, Gautam Vasisht, Allona Vazan, Ciro Del Vecchio, Dave Waltham, Piotr Wawer, Thomas Widemann, Paulina Wolkenberg, Gordon Hou Yip, Yuk Yung, Mantas Zilinska, Tiziano Zingale, Paola Zuppella, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), 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 de Paris (UP), 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), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Cardon, Catherine
Subjects: [SDU] Sciences of the Universe [physics], Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Settore FIS/05 - Astronomia E Astrofisica, [SDU]Sciences of the Universe [physics], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysic, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution., Comment: Ariel Definition Study Report, 147 pages. Reviewed by ESA Science Advisory Structure in November 2020. Original document available at: https://www.cosmos.esa.int/documents/1783156/3267291/Ariel_RedBook_Nov2020.pdf/
Published: 2021
Full Text: View/download PDF

5. Modeling the structure of irradiated ocean planets - implications for mass-radius relationships

Author: Olivier Mousis, Emmanuel Marcq, Artyom Aguichine, M. Deleuil, 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), 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), 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: Physics, Planet, [SDU]Sciences of the Universe [physics], Radius, Irradiation, Astrophysics, ComputingMilieux_MISCELLANEOUS
Abstract: Water-rich planets should be ubiquitous in the universe. Among the current exoplanet populations, many of those worlds are subject to important irradiation from their host star. As a consequence, water-rich worlds display supercritical water layer surrounded by an extended steam atmosphere making them good candidates for matching the observed mass-radius distribution of sub-Neptunes [1]. Here we describe a model that computes a realistic structure for water-rich planets by combining an interior model with an updated equation of state (EoS) for water, and an atmospheric model that takes into account radiative transfer. Our model has been applied to the GJ 9827 system as a test case and indicates Earth- or Venus-like interiors for planets b and c, respectively. Planet d could be an irradiated ocean planet with a water mass fraction of ∼20 ± 10%. We also provide mass-radius relationships for water-rich planets and their analytical expression. This allows one to directly retrieve a wide range of planetary compositions, without the requirement to run the model. The possible existence of such planets is discussed in light of atmospheric loss processes, suggesting that some sub-Neptunes are the outcome of planets that lost their H/He reservoirs. Figure 1. Mass-radius relationships produced by our model (green, yellow and red thick lines) [2], compared to mass-radius relationships of planets with only condensed phases and no atmosphere (black, grey and light blue thin lines) [3,4]. A few planets of the solar system, the GJ-9827 system and the TOI-178 system are shown as well [5,6]. [1] Mousis, O., Deleuil, M., Aguichine, A., et al. 2020, ApJL, 896, L22.[2] Aguichine, A., Mousis, O., Deleuil, M., et al. 2021, accepted in ApJ.[3] Zeng, L., Sasselov, D. D., & Jacobsen, S. B. 2016, ApJ, 819, 127.[4] Brugger, B., Mousis, O., Deleuil, M., et al. 2017, ApJ, 850, 93.[5] Kosiarek, M. R., Berardo, D. A., Crossfield, I. J. M., et al. 2021, AJ, 161, 47.[6] Leleu, A., Alibert, Y., Hara, N. C., et al. 2021, A&A, 649, A26.
Published: 2021

6. HST WFC3 G141 data analysis: exploring the transition from Super-Earth to Sub-Neptune

Author: Emmanuel Marcq, Amélie Gressier, Jean-Philippe Beaulieu, Benjamin Charnay, 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), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Physics, Super-Earth, 13. Climate action, Neptune, [SDU]Sciences of the Universe [physics], Astronomy, ComputingMilieux_MISCELLANEOUS
Abstract: Exoplanets with size between the Earth and Neptune (1-4R⊕) do not have any equivalent in our Solar System and remain challenging to characterize. Yet, there are ubiquitous in the Galaxy and Fulton et al. (2017) showed that their distribution (number of planets per star vs radius) is bimodal highlighting a gap in the number of planets around 1.7R⊕. Planets with a radius below 1.7R⊕ are thought to be mostly rocky planets, and called Super-Earth, above this limit planets are most likely made of gas and called Sub-Neptune. We made use of the available data from the Hubble Space Telescope in Near-Infrared (HST WFC3 G141) and gathered 18 transmission spectra of planets with size below 6 R⊕ to study the transition between rocky and gaseous planets. First, we used TauREx3 (Al-Refaie et al. 2019), a Bayesian retrieval code, to rule out atmospheric scenarios. We proved that a primary clear atmosphere dominated by Hydrogen and Helium is rejected with more than 3σ for a large majority of planets in the sample. Then, we measured the amplitude of the spectra in the water absorption band (around 1.4μm) and compared observational values to simulated ones using a self-consistent modeling code ExoREM (Baudino et al. 2015; Charnay et al. 2018). We explored the connection between the water absorption amplitudes and the temperature by setting the stellar and planetary parameters to those of HD 3167 c (2.7 R⊕, 8.33 M⊕) and trying different metallicities (1, 10, 100 and 1000 x solar), cloud compositions and temperatures (300-1200K).
Published: 2021

7. Detecting Venus’ volcanic gas plumes with VenSpec-H

Author: Séverine Robert, Caterina Macovenco, Maxence Lefèvre, Colin Wilson, Emmanuel Marcq, Bruno Bézard, Jörn Helbert, and Ann Carine Vandaele
Subjects: 13. Climate action
Abstract: The VenSpec-H instrument is part of the EnVision payload which is currently being evaluated by ESA for mission selection. EnVision is a medium class mission to determine the nature and current state of geological activity on Venus, and its relationship with the atmosphere, to understand how Venus and Earth could have evolved so differently. VenSpec-H is part of the VenSpec suite [1], including also an IR mapper and a UV spectrometer [2] suite. The science objectives of this suite are to search for temporal variations in surface temperatures and tropospheric concentrations of volcanically emitted gases, indicative of volcanic eruptions; and study surface-atmosphere interactions and weathering by mapping surface emissivity and tropospheric gas abundances. Recent and perhaps ongoing volcanic activity has been inferred in data from both Venus Express and Magellan. Maintenance of the clouds requires a constant input of H2O and SO2. A large eruption would locally alter the composition by increasing abundances of H2O, SO2 and CO and perhaps decreasing D/H ratio. Observations of changes in lower atmospheric SO2, CO and H2O vapour levels, cloud level H2SO4 droplet concentration, and mesospheric SO2, are therefore required to link specific volcanic events with past and ongoing observations of the variable and dynamic mesosphere, to understand both the importance of volatiles in volcanic activity on Venus and their effect on cloud maintenance and dynamics. To contribute to this investigation, VenSpec-H is designed to measure H2O and HDO contents in the first scale height of Venus’ atmosphere and probe H2O, HDO, CO, OCS, SO2 in the 30 to 40 km altitude range [3-8]. To assess the performances of our instrument at detecting volcanic eruptions, we defined a couple of scenarios of plume releases and simulated the corresponding spectra. To simulate the vertical transport of the plume and the horizontal advection by the dynamics, the LMD Venus Mesoscale Model [9] is used, based on the WRF dynamical core and the Venus IPSL radiative transfer. The domain is focused on Imdr Regio, where VIRTIS observed a hotspot anomaly possibly linked to volcanic activity [10]. Tracers were added to the model representing H2O, CO and SO2. The chemistry and photodissociation sources and sinks are modelled by a linear relaxation of the tracer abundance toward a value representative of the deep atmosphere with a characteristic time. The deep atmosphere abundance is set to 130 ppm for SO2, 30 ppm for H2O and 20 ppm for CO. The relaxation time is set to 100 years for SO2, to 1000 years for CO and to 1 week, 1 month and 1 year for H2O representing the uncertainty of the chemistry timescale in that region. Several configurations are considered for the plume, an idealised set-up where the elevation height is fixed and the outgassing abundance is constant inside the plume and in time, and a more realistic set-up where a temperature and outgassing anomalies at the surface are prescribed is ongoing testing. The radiances of the nightside atmosphere of Venus originate from the thermal emission of the surface and atmosphere. The spectra were simulated from 1 to 2.5 microns, using ASIMUT-ALVL, a line-by-line radiative transfer code developed at BIRA-IASB [11]. CO2, H2O, HDO, CO, SO2, and OCS, as well as aerosols were included. The performances of the instrument will be described in terms of its capabilities to detect small variations in the atmosphere. References [1] J. Helbert et al., “The VenSpec suite on the ESA EnVision mission to Venus”, Proc. SPIE 11128, Infrared Remote Sensing and Instrumentation XXVII, 1112804 (2019). [2] E. Marcq et al., “Instrumental requirements for the study of Venus’ cloud top using the UV imaging spectrometer VeSUV”, Advances in Space Research, 68 (2021) 275-291. [3] B. Bézard et al., “Water vapor abundance near the surface of Venus from Venus Express/VIRTIS observations,” Journal of Geophysical Research, Planets, 114 (2009) E00B39. [4] B. Bézard et al., “The 1.10- and 1.18-μm nightside windows of Venus observed by SPICAV-IR aboard Venus Express,” Icarus, 216 (2011) 173–183. [5] A. Fedorova et al., “The CO2 continuum absorption in the 1.10-and 1.18-μm windows on Venus from Maxwell Montes transits by SPICAV IR onboard Venus Express,” Planetary and Space Science, 113 (2015) 66-77. [6] E. Marcq et al., “Remote sensing of Venus’ lower atmosphere from ground-based IR spectroscopy: latitudinal and vertical distribution of minor species,” Planetary and Space Science, 54 (2006) 1360-1370. [7] E. Marcq et al., “A latitudinal survey of CO, OCS, H2O,and SO2 in the lower atmosphere of Venus: spectroscopic studies using VIRTIS-H,” Journal of Geophysical Research, Planets, 113 (2008) E00B07. [8] E. Marcq et al., “Evidence for SO2 latitudinal variations below the clouds of Venus”, Astronomy & Astrophysics, 648 (2021) L8. [9] M. Lefèvre, A. Spiga and S. Lebonnois, “Mesoscale modeling of Venus' bow-shape waves”, Icarus, 335 (2019) 113376. [10] E. Smrekar, et al., “Recent Hotspot Volcanism on Venus from VIRTIS Emissivity”, Data. Science, 328 (2010) 605. [11] A.C. Vandaele, M. Kruglanski and M. De Mazière, “Modeling and retrieval of atmospheric spectra using ASIMUT”, Proc. of the First 'Atmospheric Science Conference', ESRIN, Frascati, Italy, 2006.
Published: 2021

8. Io’s dry body shaped by atmospheric instability

Author: Martin Turbet, Kathleen Mandt, Antoine Schneeberger, Olivier Mousis, Emmanuel Marcq, François Leblanc, and Artyom Aguichine
Subjects: Atmospheric instability, Environmental science, Atmospheric sciences
Published: 2021

9. Mass-Radius relationships of small, highly irradiated exoplanets with small water mass fractions

Author: Artem Aguichine, M. Deleuil, Hugo Vivien, Olivier Mousis, Emmanuel Marcq, 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), 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), 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 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), 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: Water mass, Materials science, [SDU]Sciences of the Universe [physics], 13. Climate action, Astrophysics, Irradiation, Radius, ComputingMilieux_MISCELLANEOUS, Exoplanet
Abstract: This work aims to determine the mass-radius rela-tionships of highly irradiated (500< Tirr We show that these planets, even with smallwater contents, can become strongly inflated andproduce large radii for small masses.We alsoshow that strongly irradiated small planets cannotsustain their atmospheres due to the lack of hy-drostatic stability, implying they cannot preserveany hydrosphere. The temperature and the watermass fraction are the key parameters controllingthe extent of inflation and the thickness of thesupercritical layer. An important amount of wateralso leads to the contraction of the rocky interior.However, the composition of the rocky interioronly has a limited impact on the final mass-radiusrelationship, and barely impacts the behavior of thehydrosphere.
Published: 2021

10. Characterising the interior structures and atmospheres of multiplanetary systems

Author: M. Deleuil, Alexandre Santerne, Olivier Mousis, L. Acuña, Emmanuel Marcq, Théo A. López, Thierry Morel, 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), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, 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), 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), A. Siebert, K. Baillié, E. Lagadec, N. Lagarde, J. Malzac, J.-B. Marquette, M. N'Diaye, J. Richard, O. Venot (eds), 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), 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: Materials science, [SDU]Sciences of the Universe [physics], 13. Climate action, Astrophysics::Earth and Planetary Astrophysics, Physics::Atmospheric and Oceanic Physics, ComputingMilieux_MISCELLANEOUS, Astrobiology
Abstract: The increasing number of well characterised low-mass planets, combined with the valuable informations from stellar and planetary spectroscopy, opens the way to the modeling of planetary structures and compositions, which can be obtained with theoretical and numerical works. This approach gives a valuable insight to understand the formation of planetary systems in the low-mass range. We present a 1D planetary model where the interior is coupled with the atmosphere in radiative-convective equilibirum within a Bayesian retrieval scheme. In addition to a Fe core and a silicate mantle, we take into account water in all its possible phases, including steam and supercritical phases, which is necessary for systems with a wide range of stellar irradiations. Our interior-atmosphere model calculates the compositional and atmospheric parameters, such as Fe and water content, surface pressures, scale heights and albedos. We analyse the multiplanetary systems K2-138 and TRAPPIST-1, which present six low-mass planets with different densities and irradiations. From the individual composition of their planets, we derive a similar trend for both systems: a global increase on the water content with increasing distance from the star in the inner region of the systems, while the planets in the outer region present a constant water mass fraction. This trend reveals the possible effects of migration, formation location and atmospheric mass loss during their formation history.
Published: 2021

11. Mass–Radius Relationships for Irradiated Ocean Planets

Author: Magali Deleuil, Artyom Aguichine, Olivier Mousis, Emmanuel Marcq, 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), 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), 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: Equation of state, 010504 meteorology & atmospheric sciences, Exoplanet astronomy, FOS: Physical sciences, Atmospheric model, Astrophysics, 01 natural sciences, Planet, 0103 physical sciences, Radiative transfer, Computational methods, Hydrosphere, Ocean planet, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Exoplanets, Astronomy and Astrophysics, Radius, Exoplanet, Exoplanet structure, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Planetary theory, Astrophysics::Earth and Planetary Astrophysics, Planetary interior, Astrophysics - Earth and Planetary Astrophysics
Abstract: Massive and water-rich planets should be ubiquitous in the universe. Many of those worlds are expected to be subject to important irradiation from their host star, and display supercritical water layers surrounded by extended steam atmospheres. Irradiated ocean planets with such inflated hydrospheres have been recently shown to be good candidates for matching the mass-radius distribution of sub-Neptunes. Here we describe a model that computes a realistic structure for water-rich planets by combining an interior model with an updated equation of state (EoS) for water, and an atmospheric model that takes into account radiative transfer. We find that the use of non appropriate EoSs can lead to the overestimation of the planetary radius by up to $\sim$10\%, depending on the planet size and composition. Our model has been applied to the GJ 9827 system as a test case and indicates Earth- or Venus-like interiors for planets b and c, respectively. Planet d could be an irradiated ocean planet with a water mass fraction of $\sim$$20\pm10\%$. We also provide fits for the mass-radius relationships, allowing one to directly retrieve a wide range of planetary compositions, without the requirement to run the model. Our calculations finally suggest that highly irradiated planets lost their H/He content through atmospheric loss processes, and that the leftover material led to either super-Earths or sub-Neptunes, depending on the water mass fraction., Accepted for publication in ApJ
Published: 2021

12. Evidence for SO2 latitudinal variations below the clouds of Venus

Author: Bruno Bézard, Ismaïl Amine, Emmanuel Marcq, Marc Duquesnoy, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: spectroscopy, 010504 meteorology & atmospheric sciences, Atmospheric circulation, Venus, Astrophysics, Atmospheric sciences, 01 natural sciences, Latitude, Troposphere, Atmospheric radiative transfer codes, Altitude, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, geography, geography.geographical_feature_category, biology, Astronomy and Astrophysics, biology.organism_classification, Outgassing, Volcano, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Planets and satellites
Abstract: Context. Sulphur dioxide (SO2) is highly variable above the clouds of Venus, yet no spatial or temporal variability below the clouds had been known until now. Aims. In order to constrain Venus’s atmospheric circulation and chemistry (including possible volcanic outgassing), more accurate SO2 measurements below the clouds are therefore needed. Methods. We used the high-resolution iSHELL spectrometer located at the NASA IRTF to record thermal night-side spectra, which we fitted using an updated forward radiative transfer model that was previously employed to process SpeX/IRTF and VIRTIS-H/Venus Express spectra. Results. We report, for the first time, an increase in SO2 with increasing latitude (+30% between the minimum near 15°S and > 35°N). This is consistent with the interaction between the Hadley-cell circulation and a postulated vertical profile in SO2 estimated to increase between 30 and 40 km in altitude, as previously suggested by in situ ISAV measurements. Conclusions. This SO2 variability challenges our current understanding of Venus’s tropospheric thermochemistry and underlines the high scientific return from high-resolution spectroscopy from, for example, future orbiters.
Published: 2021

13. The Need for Ground-Based Observations of Venus

Author: Thomas Navarro, Glenn S. Orton, Javier Peralta, Emilie Royer, Thomas Widemann, Brad J. Sandor, Yeon Joo Lee, Kevin McGouldrick, Candace Gray, Emmanuel Marcq, Arnaud Mahieux, Toru Kouyama, Kunio M. Sayanagi, and Eliot F. Young
Subjects: biology, Venus, biology.organism_classification, Geology, Astrobiology
Published: 2021

14. Instrumental requirements for the study of Venus’ cloud top using the UV imaging spectrometer VeSUV

Author: Gabriel Guignan, Colin Wilson, Benjamin Lustrement, Kandis Lea Jessup, Bruno Bézard, Nicolas Rouanet, Franck Montmessin, Jérémie Lasue, Emmanuel Marcq, Yeon Joo Lee, 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), 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), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Southwest Research Institute [Boulder] (SwRI), Zentrum für Astronomie und Astrophysik [Berlin] (ZAA), Technische Universität Berlin (TU), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], 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 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)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Technical University of Berlin / Technische Universität Berlin (TU), University of Oxford, 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)
Subjects: Atmospheric Science, medicine.medical_specialty, 010504 meteorology & atmospheric sciences, Imaging spectrometer, Aerospace Engineering, Venus, medicine.disease_cause, 01 natural sciences, Atmospheric radiative transfer codes, 0103 physical sciences, medicine, Spectral resolution, 010303 astronomy & astrophysics, Instrumentation, 0105 earth and related environmental sciences, Remote sensing, Ultraviolet, Physics, biology, Atmosphere, Cloud top, Hyperspectral imaging, Astronomy and Astrophysics, biology.organism_classification, Spectral imaging, Geophysics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], General Earth and Planetary Sciences, UV spectroscopy
Abstract: International audience; Ultraviolet spectral imaging has been a powerful tool to investigate the cloud top of Venus, allowing for measurement of several minor gases (especially SO2, SO, O3), of cloud top aerosol’s microphysical properties and of atmospheric dynamics through tracking of the unevenly distributed UV absorber. After a brief review of recent UV instruments that orbited around Venus, we present the results of a state-of-the-art radiative transfer model from Marcq et al. (2020) to derive the spectral resolution and Signal-to-Noise ratio (SNR) required to derive abundances of these gases, retrieve optical properties of the aerosols beyond our current knowledge. This leads us to propose a two-channel UV hyperspectral push-broom imager called VeSUV (standing for Venusian Spectroscopy in UV) whose technical characteristics will improve on existing measurements by a factor of at least 2, and which is well suited to the integration into the payload of future low Venus orbit platforms such as the proposed EnVision mission to ESA M5 call.
Published: 2021

15. Future Exploration of Venus: International Coordination and Collaborations

Author: Ludmilla Zasova, A. Martynov, Sanjay S. Limaye, James A. Cutts, Colin Wilson, Ann Carine Vandaele, Masato Nakamura, Tibor Kremic, Mark A. Bullock, Noam R. Izenberg, Richard Ghail, Joern Helbert, Anastasia Kosenkova, Emmanuel Marcq, Irina Kovalenko, and James W. Head
Subjects: 010504 meteorology & atmospheric sciences, biology, Planetare Labore, Venus, Internationale Kooperation, biology.organism_classification, 01 natural sciences, Missionskonzepte, Astrobiology, 0103 physical sciences, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: Understanding Venus will benefit from a dedicated effort through an international program of missions that are coordinated and offering opportunities for coooperation. The recent discovery of phosphene in the Venus clouds and possibility of life will increase the exploration missions and cooperation and coordination will be very benefical.
Published: 2021

16. The Spatial and Temporal Distribution of Nighttime Ozone and Sulfur Dioxide in the Venus Mesosphere as Deduced from SPICAV UV Stellar Occultations

Author: Franck Lefèvre, Jean-Loup Bertaux, Denis Belyaev, Oleg Korablev, Franck Montmessin, Daria Evdokimova, Loïc Verdier, Emmanuel Marcq, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), 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), 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: Ozone, 010504 meteorology & atmospheric sciences, Venus, Atmospheric sciences, 01 natural sciences, Occultation, Mesosphere, Atmosphere of Venus, chemistry.chemical_compound, Geochemistry and Petrology, 0103 physical sciences, Ozone layer, Earth and Planetary Sciences (miscellaneous), Mixing ratio, 010303 astronomy & astrophysics, Sulfur dioxide, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], biology, biology.organism_classification, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Environmental science
Abstract: International audience; The nighttime ozone and sulfur dioxide distributions were analyzed using the entire SPICAV‐UV/Venus Express stellar occultation dataset. After the discovery of an ozone layer at 100 km in the mesosphere reported by Montmessin et al. (2011), 132 other detections were made during the entire 8 years long observing period of the SPICAV UV instrument. In the rare detections the peak abundances of O3 accumulating in the mesosphere are observed with densities from 107 to 108 molecules⋅cm‐3 at 85‐110 km. The ozone layer is estimated to vary from 1 ppbv to 30 ppbv at 85‐95 km while at 95‐105 km the VMR is expected within an interval from 6 ppbv to 120 ppbv. Below 93 km, a puzzling decrease of mixing ratio is observed toward midnight at 30°N. Our work also provides an improved sequel to the analysis of the sulfur dioxide survey previously made in the upper mesosphere by Belyaev et al. (2017). On average, the SO2 content is found to remain constant throughout the vertical profile at a value of around 135±21 ppbv between 85 and 100 km. Rapid and large variations prevent to conclude firmly on any time or space pattern of SO2.
Published: 2021

17. ARES IV: Probing the Atmospheres of the Two Warm Small Planets HD 106315c and HD 3167c with the HST/WFC3 Camera

Author: Sam Wright, Emmanuel Marcq, Adam Yassin Jaziri, Amélie Gressier, Quentin Changeat, Doriann Blain, Michelle Fabienne Bieger, Alexandre Santerne, Jérémy Leconte, Ahmed Al-Refaie, Darius Modirrousta-Galian, Alessandro Sozzetti, Tiziano Tsingales, William Pluriel, Pierre Drossart, Jean-Philippe Beaulieu, Gloria Guilluy, Kai Hou Yip, Niall Whiteford, Olivia Venot, Lorenzo V. Mugnai, Ingo Waldmann, Mario Morvan, Robin Baeyens, Flavien Kiefer, Billy Edwards, Angelos Tsiaras, Mathilde Poveda, Nour Skaf, Benjamin Charnay, Dipartimento di Fisica [Torino], Università degli studi di Torino = University of Turin (UNITO), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), 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), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), 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), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Palermo (OAPa), Dipartimento di Fisica e Chimica [Palermo] (DiFC), Università degli studi di Palermo - University of Palermo, Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Dipartimento di Fisica [Roma La Sapienza], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), 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), Maison de la Simulation (MDLS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Centre for Exoplanet Science, School of Physical Sciences [Hobart], University of Tasmania [Hobart, Australia] (UTAS), ANR-16-CE31-0005,e-PYTHEAS,Etude des hydrocarbures en émission et absorption dasn les exoplanètes à haute température(2016), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Università degli studi di Torino (UNITO), 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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), 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), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Paris (UP)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
Subjects: astronomy data analysis, Exoplanets, Exoplanet atmospheres, Hubble Space Telescope, EXOPLANET, 010504 meteorology & atmospheric sciences, Infrared, MODELS, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, 7. Clean energy, Atmosphere, METHANE, Planet, Hubble space telescope, 0103 physical sciences, PHOTOMETRY, Absorption (logic), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, SPECTRUM, Science & Technology, SPECTROSCOPY, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Radius, FRAMEWORK, Exoplanet, LINE LISTS, TRANSITING PLANET, 13. Climate action, Space and Planetary Science, Physical Sciences, Wide Field Camera 3, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present an atmospheric characterization study of two medium sized planets bracketing the radius of Neptune: HD 106315 c (R$_{\rm{P}}$=4.98 $\pm$ 0.23 R$_{\oplus}$) and HD 3167 c (R$_{\rm{P}}$=2.740$_{-0.100}^{+0.106}$ R$_{\oplus}$). We analyse spatially scanned spectroscopic observations obtained with the G141 grism (1.125 - 1.650 $\mu$m) of the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope. We use the publicly available Iraclis pipeline and TauREx3 atmospheric retrieval code and we detect water vapor in the atmosphere of both planets with an abundance of $\log_{10}[\mathrm{H_2O}]=-2.1^{+0.7}_{-1.3}$ ($\sim$5.68$\sigma$) and $\log_{10}[\mathrm{H_2O}]=-4.1^{+0.9}_{-0.9}$ ($\sim$3.17$\sigma$) for HD 106315 c and HD 3167 c, respectively. The transmission spectrum of HD 106315 c shows also a possible evidence of ammonia absorption ($\log_{10}[\mathrm {NH_3}]=-4.3^{+0.7}_{-2.0}$, $\sim$1.97$\sigma$ -even if it is not significant-), whilst carbon dioxide absorption features may be present in the atmosphere of HD 3167 c in the $\sim$1.1-1.6~$\mu$m wavelength range ($\log_{10}[\mathrm{CO_{2}}]= -2.4^{+0.7}_{-1.0}$, $\sim$3.28$\sigma$). However the CO$_2$ detection appears significant, it must be considered carefully and put into perspective. Indeed, CO$_2$ presence is not explained by 1D equilibrium chemistry models, and it could be due to possible systematics. The additional contribution of clouds, CO and CH$_4$ are discussed. HD 106315 c and HD 3167 c will be interesting targets for upcoming telescopes such as the James Webb Space Telescope (JWST) and the Atmospheric Remote-Sensing Infrared Exoplanet Large-Survey (Ariel)., Comment: Accepted for publication in AJ
Published: 2021

18. Planetary system LHS 1140 revisited with ESPRESSO and TESS

Author: L. Acuña, Nathan Hara, Nuno C. Santos, David Barrado, João P. Faria, Emmanuel Marcq, Nicola Astudillo-Defru, Stéphane Udry, Xavier Bonfils, Francesco Pepe, Pedro Figueira, A. Leleu, Philippe Robutel, Alexandre C. M. Correia, Jorge Lillo-Box, S. G. Sousa, C. Lovis, Magali Deleuil, O. Mousis, Jose-Manuel Almenara, Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Instituto de Astrofísica e Ciências do Espaço (IASTRO), Center for Space and Habitability (CSH), University of Bern, Space Research and Planetary Sciences [Bern) (WP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], National Centre of Competence in Research PlanetS (NCCR PlanetS), Universität Bern [Bern]-Universität Bern [Bern]-Swiss National Science Foundation (SNSF), 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), Departamento de Física e Astronomia [Porto] (DFA/FCUP), Faculdade de Ciências da Universidade do Porto (FCUP), Universidade do Porto-Universidade do Porto, Geneva Observatory, University of Geneva [Switzerland], Centro de Física da Universidade de Coimbra (CFisUC), Universidade de Coimbra [Coimbra], Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), 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 de Lille-Sorbonne Université (SU)-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)-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), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), 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), Spanish StateResearch Agency (AEI) Projects No.ESP2017-87676-C5-1-R and No. MDM-2017-0737 Unidad de Excelencia 'María de Maeztu' – Centro de Astrobiología(INTA-CSIC). This work was supported by FCT – Fundação para a Ciênciae a Tecnologia through national funds and by FEDER through COM-PETE2020 – Programa Operacional Competitividade e Internacionalizaçãoby these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER-032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953. N.A.-D. acknowledges thesupport of FONDECYT project 3180063. X.B. and J.M.A. acknowledge fundingfrom the European Research Council under the ERC Grant Agreement n. 337591-ExTrA. A.C. acknowledges support by CFisUC projects (UIDB/04564/2020and UIDP/04564/2020), ENGAGE SKA (POCI-01-0145-FEDER-022217), andPHOBOS (POCI-01-0145-FEDER-029932), funded by COMPETE 2020 andFCT, Portugal. J.P.F. is supported in the form of a work contract funded bynational funds through FCT with reference DL57/2016/CP1364/CT0005, European Project: 337591,EC:FP7:ERC,ERC-2013-StG,EXTRA(2014), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE)-Swiss National Science Foundation (SNSF), 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), Universidade do Porto = University of Porto-Universidade do Porto = University of Porto, Université de Genève = University of Geneva (UNIGE), 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, 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), Faria, J. [0000-0002-6728-244X], Correia, A. C. M. [0000-0002-8946-8579], Leleu, A. [0000-0003-2051-7974], Lillo Box, J. [0000-0003-3742-1987], Santos, N. [0000-0003-4422-2919], Agencia Estatal de Investigación (AEI), FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao, Comisión Nacional de Investigación Científica y Tecnológica (CONICYT), European Research Council (ERC), ENGAGE SKA, PHOBOS, Portuguese Foundation for Science and Technology, Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Fundacao para a Ciencia e a Tecnologia (FCT), Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), and European Commission (EC)
Subjects: 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Context (language use), Astrophysics, polarimetric [Techniques], 01 natural sciences, Photometry (optics), planets and satellites: terrestrial planets, Planet, 0103 physical sciences, techniques: radial velocities, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], radial velocities [Techniques], planets and satellites: composition, Astronomy and Astrophysics, Planetary system, Orbital period, interiors [Planets and satellites], Exoplanet, planets and satellites: interiors, planets and satellites: individual: LHS1140, Radial velocity, techniques: polarimetric, 13. Climate action, Space and Planetary Science, terrestrial planets [Planets and satellites], composition [Planets and satellites], individual: LHS1140 [Planets and satellites], [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Circumstellar habitable zone, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. LHS 1140 is an M dwarf known to host two transiting planets at orbital periods of 3.77 and 24.7 days. They were detected with HARPS and Spitzer. The external planet (LHS 1140 b) is a rocky super-Earth that is located in the middle of the habitable zone of this low-mass star. All these properties place this system at the forefront of the habitable exoplanet exploration, and it therefore constitutes a relevant case for further astrobiological studies, including atmospheric observations. Aims. We further characterize this system by improving the physical and orbital properties of the known planets, search for additional planetary-mass components in the system, and explore the possibility of co-orbitals. Methods. We collected 113 new high-precision radial velocity observations with ESPRESSO over a 1.5-yr time span with an average photon-noise precision of 1.07 m s-1. We performed an extensive analysis of the HARPS and ESPRESSO datasets and also analyzed them together with the new TESS photometry. We analyzed the Bayesian evidence of several models with different numbers of planets and orbital configurations. Results. We significantly improve our knowledge of the properties of the known planets LHS 1140 b (Pb ∼ 24.7 days) and LHS 1140 c (Pc ∼ 3.77 days). We determine new masses with a precision of 6% for LHS 1140 b (6.48 ± 0.46 Mpdbl) and 9% for LHS 1140 c (mc = 1.78 ± 0.17 Mpdbl). This reduces the uncertainties relative to previously published values by half. Although both planets have Earth-like bulk compositions, the internal structure analysis suggests that LHS 1140 b might be iron-enriched and LHS 1140 c might be a true Earth twin. In both cases, the water content is compatible to a maximum fraction of 10-12% in mass, which is equivalent to a deep ocean layer of 779 ± 650 km for the habitable-zone planet LHS 1140 b. Our results also provide evidence for a new planet candidate in the system (md = 4.8 ± 1.1Mpdbl) on a 78.9-day orbital period, which is detected through three independent methods. The analysis also allows us to discard other planets above 0.5 Mpdbl for periods shorter than 10 days and above 2 Mpdbl for periods up to one year. Finally, our co-orbital analysis discards co-orbital planets in the tadpole and horseshoe configurations of LHS 1140 b down to 1 Mpdbl with a 95% confidence level (twice better than with the previous HARPS dataset). Indications for a possible co-orbital signal in LHS 1140 c are detected in both radial velocity (alternatively explained by a high eccentricity) and photometric data (alternatively explained by systematics), however. Conclusions. The new precise measurements of the planet properties of the two transiting planets in LHS 1140 as well as the detection of the planet candidate LHS 1140 d make this system a key target for atmospheric studies of rocky worlds at different stellar irradiations., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)
Published: 2020

19. The Venus Emissivity Mapper – Obtaining Global Mineralogy of Venus from Orbit on the ESA EnVision and NASA VERITAS missions to Venus

Author: Nils Müller, Jörn Helbert, Yaquelin M. Rosas-Ortiz, Mario D'Amore, Suzanne E. Smrekar, Darby Dyar, Alessandro Maturilli, Richard Ghail, Jean-Michel Reess, Thomas Widemann, G. Alemanno, Conor Ryan, David Kappel, Emmanuel Marcq, Ingo Walter, and Gabriele Arnold
Subjects: biology, Emissivity, Astronomy, Venus, Orbit (control theory), biology.organism_classification, Geology
Abstract: Introduction: The Venus Emissivity Mapper is the first flight instrument designed to focus on mapping the surface of Venus using several atmospheric windows around 1 µm. After years of development, VEM now has a mature design. An existing laboratory prototype has verified an achievable instrument SNR of well above 1000, as well as predicted error in retrieval of relative emissivity of better than 1%, assuming the availability of improved Venus topography.VEM science goals: The instrument will provide a global map of rock type from orbit, assessing iron contents and the redox state of the surface by observing the surface with six narrow band filters, ranging from 0.86 to 1.18 µm. Three additional windows allow corrections for cloud composition and variability, two measure water abundance, and three compensate for stray light. Continuous observation of Venus’ thermal emission will also place tighter constraints on current volcanic activity. Eight channels provide measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamics, permitting accurate correction of atmospheric interference on the surface data.The instrument is currently part of two Phase A studies: is part of the payload of the NASA VERITAS mission as well as of the ESA EnVision mission, here as the VenSpec-M channel in the VenSpec spectrometer suite. Combining VEM with a high-resolution radar mapper will provide key insights into the divergent evolution of Venus and Earth. Flying VEM on more than one mission will enable a long timeline of monitoring for volcanic activity on Venus. Combined with the existing VenusExpress data, VEM enables detection and mapping of surface changes over decades.VEM Design: The VEM system design is a pushbroom multispectral imaging system. It leverages a proven measurement technique pioneered by VIRTIS on Venus Express (VEX). It also incorporates lessons learned from VIRTIS to achieve greatly improved sensitivity and spectral and spatial coverage:A filter array (rather than a grating) provides wavelength stability (band-center and width-scatter) ~5× more stable and maximizes signal to the focal-plane array (FPA). Spectral windows below 1µm are covered for the first time. A two-stage baffle decreases scattered light and improves sensitivity. Use of an InGaAs detector with an integrated thermal electric cooler (TEC) eliminates the need for cryogenic cooling. The design maturity, combined with a standard camera optical design, leads to low development risk.VEM prototyping: VEM has been under development for several years with significantly financial investment from DLR. Following creation of the first breadboard model in 2015 during Phase A for the NASA Discovery proposal VERITAS, a laboratory prototype (LP) of the VEM instrument has been developed. This prototype includes the development version of the VEM optics with a filter array with two active filter strips. The optics underwent a set of calibration measurements on sub-unit level at LATMOS prior to delivery to DLR. All key optical design parameters including transmission and wavelength coverage have been verified using the VEMO prototype.A first performance evaluation of the VEM prototype used two Venus analog samples heated to Venus surface temperatures. This was performed using the Venus simulations setup at the Planetary Spectroscopy Laboratory with the prototype mounted on the chamber. The retrieved emissivities match laboratory values, and uncertainty for a single unbinned exposure is VEM atmospheric correction: Methodology for retrieving surface emissivity is complex but well understood and demonstrated. To distinguish between surface and atmospheric contributions, VEM uses an updated version of the extensively tested pipeline developed to process VIRTIS data, combined with a radiative transfer model (RTM). Surface emissivity retrieval techniques were developed based on Galileo NIMS observations at 1700, 1800 and 2300 nm. VEM cloud bands occur at 1195, 1310, and 1510 nm, the first on the flank of the 1180‑nm surface windows. VEM’s cloud bands are close to surface bands, providing near-optimal correction. Only relative emissivity measurements are needed to calculate the spectral slope to meet our surface emissivity requirements. We do not have a requirement on the accuracy of the retrieved emissivity. However, we can now tie an emissivity retrieval to in situ measurements to assess accuracy. For this comparison, the Venera 9 and 10 landing sites (not observed by VIRTIS) will be observed by VEM both on EnVision and on VERITAS.VEM observes each spot on the surface multiple times. Therefore both atmospheric and instrument noise are reduced by averaging image swaths acquired at different times. Applying the updated analysis of atmospheric error for VEM parameters and taking multiple-look averaging into account, our capability for emissivity precision is better than 1.5% for all bands and better than 1% in most bands.Conclusion: VEM builds on recent advances in the laboratory analog spectroscopy at PSL at DLR. It is the first flight instrument designed to focus on mapping the surface of Venus using atmospheric windows around 1 µm. VEM has a mature design with an existing laboratory prototype that verifies an achievable instrument SNR of >1000, as well as a predicted error in the retrieval of relative emissivity of better than 1%.
Published: 2020

20. Monitoring Venus cloud top: the VenSpec-U spectrometer on board ESA EnVision

Author: Colin Wilson, Gabriel Guignan, Benjamin Lustrement, Franck Montmessin, Richard Ghail, Ann Carine Vandaele, Jörn Helbert, Bruno Bézard, Emmanuel Marcq, Jérémie Lasue, Thomas Widemann, 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), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], and Royal Holloway [University of London] (RHUL)
Subjects: biology, Spectrometer, Cloud top, Planetare Labore, VenSpec, Venus, Spektroskopie, biology.organism_classification, On board, [SDU]Sciences of the Universe [physics], Environmental science, ComputingMilieux_MISCELLANEOUS, Remote sensing
Abstract: Instrument description The VenSpec-U instrument is a dual channel UV spectral imager (low and high spectral resolution channels, “LR” and “HR” hereafter), part of the VenSpec spectrometer suite on board the proposed Venus orbiter EnVision. Each channel consists of an entrance baffle, an objective composed of two lenses and a stop diaphragm, and a spectrometer composed of a slit and a toroidal holographic grating. It also includes s shortpass filter to reject the wavelengths above the higher limit of both channel bands and a zero-order trap to avoid straylight due to internal reflexions of the grating zero-order. The optical layout is presented in Figure 1. Both LR and HR slits are parallel and the optical layout is such that both channels have the same instantaneous field of view (FoV), allowing simultaneous observations and calibrations. Each slit image is then spectrally dispersed by its respective toroidal holographic grating and is formed on a shared CMOS back-side illuminated detector. Figure 1: VenSpec-U optical layout overview, with the HR and LR channels respectively on the left and on the right. The narrow-slit axis of the detector contains the spectral information, whereas the long-slit axis contains the spatial information along the 22.5° FoV of each slit. The spectra of LR and HR channels are dispersed one above the other on the focal plane. The remaining spatial direction is provided through orbital scrolling (“pushbroom” strategy). Binning on the spatial axis is performed on the detector. The detector will be controlled such that the integration time and the binning scheme is adjusted independently (and simultaneously) for each channel giving high flexibility and providing parameters for the optimisation of each acquisition. Instrument Performance the HR channel (210-240 nm) at 0.2 nm spectral resolution and spatial sampling not coarser than 36 km (12 km target) should reach a SNR of at least 100; the LR channel (190-380 nm) at 2 nm spectral resolution and spatial sampling not coarser than 6 km (3 km target) should reach a SNR of at least 200. According to our forward model based on HST-STIS [Jessup et al., 2015] and SPICAV-UV heritage [Marcq et al., 2020], this shall be sufficient to measure the targeted species (SO, SO2, UV absorber) with a relative accuracy better than 25%. These measurements shall allow to characterize variability of Venus cloud top on temporal scales ranging from hours to years and spatial scales ranging from a few kilometers to planetary scale in relation to the climate and/or present day volcanic activity of Venus. Bibliography K. L. Jessup et al., Coordinated Hubble Space Telescope and Venus Express Observations of Venus’ upper cloud deck, Icarus 258, 2015 E. Marcq et al., Climatology of SO2 and UV absorber at Venus’ cloud top from SPICAV-UV nadir dataset, Icarus 335, 2020
Published: 2020

21. Irradiated ocean planets bridge super-Earth and sub-Neptune populations

Author: Joseph Naar, Emmanuel Marcq, Olivier Mousis, Artyom Aguichine, Thomas Goncalves, B. Brugger, Magali Deleuil, Lorena Acuña Aguirre, 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), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Department of Astronomy [Ithaca], Cornell University [New York], 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), 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL)
Subjects: 010504 meteorology & atmospheric sciences, Hydrogen, FOS: Physical sciences, chemistry.chemical_element, Astrophysics, 01 natural sciences, Neptune, Planet, 0103 physical sciences, 14. Life underwater, 010303 astronomy & astrophysics, Helium, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Super-Earth, Astronomy and Astrophysics, Exoplanet, Stars, chemistry, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics::Earth and Planetary Astrophysics, Planetary mass, Astrophysics - Earth and Planetary Astrophysics
Abstract: Small planets ($\sim$1--3.9 $\Rearth$) constitute more than half of the inventory of the 4000-plus exoplanets discovered so far. Smaller planets are sufficiently dense to be rocky, but those with radii larger than $\sim$1.6 $\Rearth$ are thought to display in many cases hydrogen/helium gaseous envelopes up to $\sim$30\% of the planetary mass. These low-mass planets are highly irradiated and the question of their origin, evolution, and possible links remains open. Here we show that close-in ocean planets affected by greenhouse effect display hydrospheres in supercritical state, which generate inflated atmospheres without invoking the presence of large hydrogen/helium gaseous envelopes. We present a new set of mass-radius relationships for ocean planets with different compositions and different equilibrium temperatures, which are found to be well adapted to low-density sub-Neptune planets. Our model suggests that super-Earths and water-rich sub-Neptunes could belong to the same family of planets, i.e. hydrogen/helium-free planets, with differences between their interiors simply resulting from the variation in the water content., Accepted for publication in The Astrophysical Journal Letters
Published: 2020

22. HDO and SO2 thermal mapping on Venus

Author: Shigeto Watanabe, Thomas K. Greathouse, Yeon Joo Lee, Carver J. Bierson, Xi Zhang, Wencheng D. Shao, Rohini Giles, Bruno Bézard, Hideo Sagawa, Therese Encrenaz, Sébastien Lebonnois, Thierry Fouchet, Thomas Widemann, Emmanuel Marcq, Franck Lefèvre, Sushil K. Atreya, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Southwest Research Institute [San Antonio] (SwRI), 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), Kyoto Sangyo University, STRATO - LATMOS, 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), Planetary Science Laboratory [Ann Arbor] (PSL), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Zentrum für Astronomie und Astrophysik [Berlin] (ZAA), Technische Universität Berlin (TU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Hokkaido Information University, Department of Earth and Planetary Sciences [Santa Cruz], University of California [Santa Cruz] (UCSC), University of California-University of California, and European Project: 606798,EC:FP7:SPA,FP7-SPACE-2013-1,EUROVENUS(2013)
Subjects: Physics, planets and satellites: atmospheres, 010504 meteorology & atmospheric sciences, biology, Correlation coefficient, Terminator (solar), Imaging spectrometer, Astronomy and Astrophysics, Venus, Astrophysics, biology.organism_classification, 01 natural sciences, planets and satellites: terrestrial planets, 13. Climate action, Space and Planetary Science, Local time, 0103 physical sciences, Mixing ratio, Longitude, infrared: planetary systems, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Line (formation)
Abstract: Since January 2012, we have been monitoring the behavior of sulfur dioxide and water on Venus, using the Texas Echelon Cross-Echelle Spectrograph imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF, Mauna Kea Observatory). Here, we present new data recorded in February and April 2019 in the 1345 cm−1(7.4μm) spectral range, where SO2, CO2, and HDO (used as a proxy for H2O) transitions were observed. The cloud top of Venus was probed at an altitude of about 64 km. As in our previous studies, the volume mixing ratio (vmr) of SO2was estimated using the SO2/CO2line depth ratio of weak transitions; the H2O volume mixing ratio was derived from the HDO/CO2line depth ratio, assuming a D/H ratio of 200 times the Vienna standard mean ocean water. As reported in our previous analyses, the SO2mixing ratio shows strong variations with time and also over the disk, showing evidence for the formation of SO2plumes with a lifetime of a few hours; in contrast, the H2O abundance is remarkably uniform over the disk and shows moderate variations as a function of time. We have used the 2019 data in addition to our previous dataset to study the long-term variations of SO2and H2O. The data reveal a long-term anti-correlation with a correlation coefficient of −0.80; this coefficient becomes −0.90 if the analysis is restricted to the 2014–2019 time period. The statistical analysis of the SO2plumes as a function of local time confirms our previous result with a minimum around 10:00 and two maxima near the terminators. The dependence of the SO2vmr with respect to local time shows a higher abundance at the evening terminator with respect to the morning. The dependence of the SO2vmr with respect to longitude exhibits a broad maximum at 120–200° east longitudes, near the region of Aphrodite Terra. However, this trend has not been observed by other measurements and has yet to be confirmed.
Published: 2020

23. Escape of rock-forming volatile elements and noble gases from planetary embryos

Author: Petra Odert, Markus Benedikt, Emmanuel Marcq, Martin Leitzinger, Manuel Scherf, Nikolai V. Erkaev, Helmut Lammer, Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Institute for Geophysics, Astrophysics and Meteorology [Graz] (IGAM), Karl-Franzens-Universität Graz, 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), Siberian Federal University (SibFU), P27256-N27, P30949-N36 Russian Science Foundation, RSF: 18-12-00080, and M.R. Benedikt and H. Lammer acknowledge support from the Austrian Forschungsförderungsgesellschaft FFG project RASEN. M. Leitzinger and P. Odert acknowledge support of the Austrian FWF projects P27256-N27 and P30949-N36 . N.V.E. acknowledges the Russian Science Foundation grant No 18-12-00080 . H. Lammer and M. Scherf thank B. Fegley and K. Lodders for discussions on magma ocean-related outgassing of rock-forming elements. Finally, we thank Paolo Sossi and an anonymous referee for their constructive comments which helped to improve the manuscript significantly.
Subjects: Martian, Physics, Planetesimal, 010504 meteorology & atmospheric sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Atmospheres evolution, Astronomy and Astrophysics, Mars Exploration Program, 01 natural sciences, Astrobiology, Physics::Geophysics, Atmosphere, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Solar radiation, Terrestrial planet, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Volatiles, Planetary formation, 0105 earth and related environmental sciences, Hydrodynamic escape
Abstract: International audience; Large planetesimals and planetary embryos ranging from several hundred to a few thousand kilometers can develop magma oceans through mutual collisions, gravitational energy, and the heating of short-lived radioactive elements. During their solidification after the dissipation of the disk a steam atmosphere will be catastrophically outgassed and may be lost efficiently via hydrodynamic escape, as long as it does not condense. The escaping H-atoms that originate from the dissociation of H2O and H2 will drag heavier trace elements like noble gases such as Ne and Ar and outgassed moderately volatile rock-forming elements such as K, Na, Si, Mg, etc. into space. Under consideration of various EUV flux evolution scenarios of young solar-type stars, we apply an upper atmosphere hydrodynamic escape model that includes the dragging of heavier species by escaping H-atoms. We investigate the atmospheric/elemental escape and fractionation from planetary embryos with masses of 1 MMoon, 0.5 MMars, 1 MMars, and 1.5 MMars at different orbital distances between the orbits of Venus and Mars. Our results indicate that the steam atmospheres and the embedded trace elements will be lost efficiently before they condense for masses ≤0.5 MMars and orbital distances up to 1 AU. For heavier embryos of up to 1.5 MMars almost all of the considered steam atmospheres can be lost within ≈12 Myr, which lies within the time frame of the formation of the first Martian protocrust after ≈20 Myr, i.e. for such steam atmospheres to be lost completely a shallow magma ocean must remain below the atmosphere, which might be achieved through frequent impacts onto the planetary embryo. The considered outgassed noble gases and rock-forming elements will be completely dragged away together with the steam atmospheres under the assumption that the trace elements will reach the thermosphere. For embryos with masses ≤MMoon the gravity is too weak for a dense atmosphere to build up for the high magma ocean related surface temperatures and all outgassed elements will escape immediately to space. For all considered planetary masses and orbits the loss rates of Ar and Ne are so high that there will be no fractionation of their isotopes. The studied planetary embryos, even though not isotopically fractionated, will therefore be severely depleted in noble gases and moderately volatile elements. Hydrodynamic escape might then also affect the final composition of terrestrial planets that accrete out of such planetary embryos, such as the volatile content and the Fe/Mg ratio of a planet.
Published: 2020

24. A stringent upper limit on the PH3 abundance at the cloud top of Venus

Author: Clara Sousa-Silva, T. Fouchet, Thomas K. Greathouse, Thérèse Encrenaz, Rohini Giles, Bruno Bézard, Thomas Widemann, Emmanuel Marcq, Hideo Sagawa, Jane S. Greaves, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Southwest Research Institute [San Antonio] (SwRI), 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), Kyoto Sangyo University, School of Physics and Astronomy [Cardiff], Cardiff University, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), European Project: 606798,EC:FP7:SPA,FP7-SPACE-2013-1,EUROVENUS(2013), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Sorbonne Université (SU), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), 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: spectroscopy, 010504 meteorology & atmospheric sciences, Infrared, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Planets, Venus, Astrophysics, 01 natural sciences, Mesosphere, Atmosphere, satellites, Planet, 0103 physical sciences, Mixing ratio, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], imaging, Astronomy and Astrophysics, biology.organism_classification, Wavelength, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], atmospheres, Millimeter, Astrophysics - Earth and Planetary Astrophysics
Abstract: Following the announcement of the detection of phosphine (PH$_3$) in the cloud deck of Venus at millimeter wavelengths, we have searched for other possible signatures of this molecule in the infrared range. Since 2012, we have been observing Venus in the thermal infrared at various wavelengths to monitor the behavior of SO$_2$ and H$_2$O at the cloud top. We have identified a spectral interval recorded in March 2015 around 950 cm$^{-1}$ where a PH$_3$ transition is present. From the absence of any feature at this frequency, we derive, on the disk-integrated spectrum, a 3-$\sigma$ upper limit of 5 ppbv for the PH$_3$ mixing ratio, assumed to be constant throughout the atmosphere. This limit is 4 times lower than the disk-integrated mixing ratio derived at millimeter wavelengths. Our result brings a strong constraint on the maximum PH$_3$ abundance at the cloud top and in the lower mesosphere of Venus., Comment: Astronomy & Astrophysics, in press
Published: 2020

25. Climatology of SO2 and UV absorber at Venus’ cloud top from SPICAV-UV nadir dataset

Author: Denis Belyaev, Kandis Lea Jessup, Franck Montmessin, Oleg Korablev, Emmanuel Marcq, Yeon Joo Lee, Jean-Loup Bertaux, Lucio Baggio, Thérèse Encrenaz, IMPEC - 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), Southwest Research Institute [Boulder] (SwRI), 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), University of Tokyo [Kashiwa Campus], Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Atmospheres, 010504 meteorology & atmospheric sciences, Venus, Ultraviolet observations, 01 natural sciences, Latitude, Atmosphere, 0103 physical sciences, Radiative transfer, Nadir, 010303 astronomy & astrophysics, Observations, 0105 earth and related environmental sciences, Ultraviolet, [PHYS]Physics [physics], biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Advection, Cloud top, Astronomy and Astrophysics, Scale height, biology.organism_classification, 13. Climate action, Space and Planetary Science, Climatology, atmosphere, Environmental science, Composition
Abstract: International audience; Following our previous work (Marcq et al., 2013, Marcq et al., 2011), we have updated our forward radiative transfer code and processed the whole SPICAV-UV/Venus Express nadir dataset (2006-2014) in order to retrieve SO2 abundance at cloud top – assuming a SO2 decreasing scale height of 3 km and a ratio SO/SO2 tied to 10% – as well as the imaginary index of scattering mode 1 particles, representative of the remaining UV absorption, since the OSSO vertical profile found by Frandsen et al. (2016) cannot account for our observations. Our main results mostly confirm and extend the validity of those discussed by Marcq et al. (2013), namely: (i) long-term variations of low latitude SO2 at 70 km between ∼ 100 ppbv (2007, 2009) and less than 10 ppbv (2014); (ii) in average, decreasing SO2 with increasing latitude and depletion near the sub-solar point, consistent with a competition between advection and photo-chemical destruction; (iii) secular increase of mode 1 imaginary index at 250 nm, from 10−2 to 5 ⋅ 10−2 between 2006 and 2010; (iv) if not related instead to long-term variability, a possible localized enrichment of SO2 and UV brightness increase above the western slopes of Aphrodite Terra, consistent with Bertaux et al. (2016) supply mechanism through orographic gravity waves. This spatial and temporal variability underlines the need for a long term monitoring of Venus SO2 and cloud top from ground-based facilities until the next generation of Venusian orbiters is operational.
Published: 2020

26. The relative influence of H2O and CO2on the primitive surface conditions and evolution of rocky planets

Author: Anne Davaille, Hélène Massol, Philippe Sarda, Eric Chassefière, Emmanuel Marcq, and Arnaud Salvador
Subjects: 010504 meteorology & atmospheric sciences, biology, Cloud cover, Ocean current, Steady State theory, Venus, Geophysics, biology.organism_classification, Atmospheric sciences, 01 natural sciences, 7. Clean energy, Mantle (geology), Heat flux, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Heat transfer, Earth and Planetary Sciences (miscellaneous), Terrestrial planet, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: How the volatile content influences the primordial surface conditions of terrestrial planets and, thus, their future geodynamic evolution is an important question to answer. We simulate the secular convective cooling of a 1-D magma ocean (MO) in interaction with its outgassed atmosphere. The heat transfer in the atmosphere is computed either using the grey approximation or using a k-correlated method. We vary the initial CO2 and H2O contents (respectively from 0.1 × 10−2 to 14 × 10−2 wt % and from 0.03 to 1.4 times the Earth Ocean current mass) and the solar distance—from 0.63 to 1.30 AU. A first rapid cooling stage, where efficient MO cooling and degassing take place, producing the atmosphere, is followed by a second quasi steady state where the heat flux balance is dominated by the solar flux. The end of the rapid cooling stage (ERCS) is reached when the mantle heat flux becomes negligible compared to the absorbed solar flux. The resulting surface conditions at ERCS, including water ocean's formation, strongly depend both on the initial volatile content and solar distance D. For D > DC, the “critical distance,” the volatile content controls water condensation and a new scaling law is derived for the water condensation limit. Although today's Venus is located beyond DC due to its high albedo, its high CO2/H2O ratio prevents any water ocean formation. Depending on the formation time of its cloud cover and resulting albedo, only 0.3 Earth ocean mass might be sufficient to form a water ocean on early Venus.
Published: 2017

27. Thermal radiation of magma ocean planets using a 1-D radiative-convective model of H2 O-CO2 atmospheres

Author: Anne Davaille, Hélène Massol, Emmanuel Marcq, and Arnaud Salvador
Subjects: Physics, Convection, 010504 meteorology & atmospheric sciences, Atmospheric model, Surface pressure, Atmospheric sciences, Blanketing effect, 01 natural sciences, Computational physics, Atmosphere, Geophysics, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Thermal radiation, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Radiative transfer, Outgoing longwave radiation, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: This paper presents an updated version of the simple 1D radiative-convective H2O-CO2 atmospheric model from Marcq [2012] and used by Lebrun et al. [2013] in their coupled interior-atmosphere model. This updated version includes a correction of a major miscalculation of the outgoing longwave radiation (OLR), and extends the validity of the model (P-coordinate system, possible inclusion of N2, improved numerical stability). It confirms the qualitative findings of Marcq [2012], namely (1) the existence of a blanketing effect in any H2O-dominated atmosphere: the outgoing longwave radiation (OLR) reaches an asymptotic value, also known as Nakajima's limit and first evidenced by Nakajima et al. [1992], around 280W/m2 neglecting clouds, significantly higher than our former estimate from Marcq[2012]. (2) The blanketing effect breaks down for a given threshold temperature Tϵ, with a fast increase of OLR with increasing surface temperature beyond this threshold, making extrasolar planets in such an early stage of their evolution easily detectable near 4μm provided they orbit a red dwarf. Tϵ
Published: 2017

28. Modeling the albedo of Earth-like magma ocean planets with H2O-CO2 atmospheres

Author: Emmanuel Marcq, Martin Turbet, William Pluriel, 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), ECLIPSE 2019, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-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), 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL)
Subjects: 010504 meteorology & atmospheric sciences, Mie scattering, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Atmospheric model, 01 natural sciences, Astrobiology, Atmosphere, symbols.namesake, Planet, Bond albedo, 0103 physical sciences, Rayleigh scattering, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Outgassing, 13. Climate action, Space and Planetary Science, symbols, Terrestrial planet, Astrophysics::Earth and Planetary Astrophysics, Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: During accretion, the young rocky planets are so hot that they become endowed with a magma ocean. From that moment, the mantle convective thermal flux control the cooling of the planet and an atmosphere is created by outgassing. This atmosphere will then play a key role during this cooling phase. Studying this cooling phase in details is a necessary step to explain the great diversity of the observed telluric planets and especially to assess the presence of surface liquid water. We used here a radiative-convective 1D atmospheric model (H2O, CO2) to study the impact of the Bond albedo on the evolution of magma ocean planets. We derived from this model the thermal emission spectrum and the spectral reflectance of these planets, from which we calculated their Bond albedos. Compared to Marcq et al. (2017), the model now includes a new module to compute the Rayleigh scattering, and state of the art CO2 and H2O gaseous opacities data in the visible and infrared spectral ranges. We show that the Bond albedo of these planets depends on their surface temperature and results from a competition between Rayleigh scattering from the gases and Mie scattering from the clouds. The colder the surface temperature is, the thicker the clouds are, and the higher the Bond albedo is. We also evidence that the relative abundances of CO2 and H2O in the atmosphere strongly impact the Bond albedo. The Bond albedo is higher for atmospheres dominated by the CO2, better Rayleigh scatterer than H2O. Finally, we provide the community with an empirical formula for the Bond albedo that could be useful for future studies of magma ocean planets., 16 pages, 10 figures, 5 tables. Accepted for publication in the Journal Icarus the 27 August 2018
Published: 2019
Full Text: View/download PDF

29. Discovery of cloud top ozone on Venus

Author: Jean-Loup Bertaux, Lucio Baggio, Franck Montmessin, Franck Lefèvre, Aurélien Stolzenbach, Oleg Korablev, Denis Belyaev, Emmanuel Marcq, 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), 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 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: Atmospheres, Ozone, 010504 meteorology & atmospheric sciences, Venus, Atmospheric sciences, 01 natural sciences, Atmosphere, chemistry.chemical_compound, 0103 physical sciences, Ozone layer, Nadir, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Ultraviolet, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Dobson unit, Cloud top, Astronomy and Astrophysics, Mars Exploration Program, biology.organism_classification, observations, chemistry, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, composition, [SDE]Environmental Sciences, atmosphere, Environmental science
Abstract: International audience; After the first sporadic detections of an ozone (O33 volume mixing ratio peaks in the 10 to 20 ppbv range, yielding observable column densities in the 0.1 to 0.5 Dobson units (DU), comparable to nominal values on Mars but much smaller than for Earth ( ∼ 300 DU). These measurements are supported by our 3D-photochemical model coupled with the LMD-IPSL GCM (Lebonnois et al., 2010), which indicates that the ozone layer identified by SPICAV results from downward transport of O2 ( ∼ 50 ppmv) molecules over the poles by the mean meridional circulation. Our findings do not contradict previous upper limits (
Published: 2019

30. HDO and SO2 thermal mapping on Venus. IV. Statistical analysis of the SO2 plumes

Author: Emmanuel Marcq, T. Encrenaz, Franck Lefèvre, T. Fouchet, Yeon Joo Lee, Shigeto Watanabe, Hideo Sagawa, Thomas Widemann, Rohini Giles, Sushil K. Atreya, Thomas K. Greathouse, B. Bézard, Sébastien Lebonnois, 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), Southwest Research Institute [San Antonio] (SwRI), 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), Kyoto Sangyo University, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), 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), Planetary Science Laboratory [Ann Arbor] (PSL), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, University of Tokyo [Kashiwa Campus], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Hokkaido Information University, 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), 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, and École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)
Subjects: Physics, planets and satellites: atmospheres, [PHYS]Physics [physics], Vienna Standard Mean Ocean Water, 010504 meteorology & atmospheric sciences, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Equator, Imaging spectrometer, Astronomy and Astrophysics, Venus, Astrophysics, Noon, biology.organism_classification, 01 natural sciences, planets and satellites: terrestrial planets, 13. Climate action, Space and Planetary Science, Local time, 0103 physical sciences, Mixing ratio, Longitude, infrared: planetary systems, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Since January 2012 we have been monitoring the behavior of sulfur dioxide and water on Venus, using the Texas Echelon Cross-Echelle Spectrograph (TEXES) imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF, Mauna Kea Observatory). We present here the observations obtained between January 2016 and September 2018. As in the case of our previous runs, data were recorded around 1345 cm−1 (7.4 μm). The molecules SO2, CO2, and HDO (used as a proxy for H2O) were observed, and the cloudtop of Venus was probed at an altitude of about 64 km. The volume mixing ratio of SO2 was estimated using the SO2/CO2 line depth ratios of weak transitions; the H2O volume mixing ratio was derived from the HDO/CO2 line depth ratio, assuming a D/H ratio of 200 times the Vienna Standard Mean Ocean Water (VSMOW). As reported in our previous analyses, the SO2 mixing ratio shows strong variations with time and also over the disk, showing evidence of the formation of SO2 plumes with a lifetime of a few hours; in contrast, the H2O abundance is remarkably uniform over the disk and shows moderate variations as a function of time. We performed a statistical analysis of the behavior of the SO2 plumes, using all TEXES data between 2012 and 2018. They appear mostly located around the equator. Their distribution as a function of local time seems to show a depletion around noon; we do not have enough data to confirm this feature definitely. The distribution of SO2 plumes as a function of longitude shows no clear feature, apart from a possible depletion around 100E–150E and around 300E–360E. There seems to be a tendency for the H2O volume mixing ratio to decrease after 2016, and for the SO2 mixing ratio to increase after 2014. However, we see no clear anti-correlation between the SO2 and H2O abundances at the cloudtop, neither on the individual maps nor over the long term. Finally, there is a good agreement between the TEXES results and those obtained in the UV range (SPICAV/Venus Express and UVI/Akatsuki) at a slightly higher altitude. This agreement shows that SO2 observations obtained in the thermal infrared can be used to extend the local time coverage of the SO2 measurements obtained in the UV range.
Published: 2019

31. Characterisation of the hydrospheres of TRAPPIST-1 planets

Author: Maëva Levesque, L. Acuña, Olivier Mousis, Emmanuel Marcq, Magali Deleuil, Artyom Aguichine, 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), 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), 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), IMPEC - 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: Earth and Planetary Astrophysics (astro-ph.EP), Physics, Water mass, 010504 meteorology & atmospheric sciences, Planetary surface, FOS: Physical sciences, Ice Ih, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Exoplanet, Ice VII, Astrobiology, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Planetary mass, Physics::Atmospheric and Oceanic Physics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences, Hydrosphere
Abstract: Context. Planetary mass and radius data are showing a wide variety in densities of low-mass exoplanets. This includes sub-Neptunes, whose low densities can be explained with the presence of a volatile-rich layer. Water is one of the most abundant volatiles, which can be in the form of different phases depending on the planetary surface conditions. To constrain their composition and interior structure, it is required to develop models that calculate accurately the properties of water at its different phases. Aims. We present an interior structure model that includes a multiphase water layer with steam, supercritical and condensed phases. We derive the constraints for planetary compositional parameters and their uncertainties, focusing on the multiplanetary system TRAPPIST-1, which presents both warm and temperate planets. Methods. We use a 1D steam atmosphere in radiative-convective equilibrium with an interior whose water layer is in supercritical phase self-consistently. For temperate surface conditions, we implement liquid and ice Ih to ice VII phases in the hydrosphere. We adopt a MCMC inversion scheme to derive the probability distributions of core and water compositional parameters Results. We refine the composition of all planets and derive atmospheric parameters for planets b and c. The latter would be in a post-runaway greenhouse state and could be extended enough to be probed by space mission such as JWST. Planets d to h present condensed ice phases, with maximum water mass fractions below 20%. Conclusions. The derived amounts of water for TRAPPIST-1 planets show a general increase with semi-major axis, with the exception of planet d. This deviation from the trend could be due to formation mechanisms, such as migration and an enrichment of water in the region where planet d formed, or an extended CO$_{2}$-rich atmosphere., 11 pages, 7 figures. Accepted by Astronomy & Astrophysics (in press)
Published: 2021

32. Influence of Venus topography on the zonal wind and UV albedo at cloud top level: The role of stationary gravity waves

Author: Emmanuel Marcq, W. J. Markiewicz, Igor Khatuntsev, Jean-Loup Bertaux, Sébastien Lebonnois, M. V. Patsaeva, Anna Fedorova, Alain Hauchecorne, and A. V. Turin
Subjects: 010504 meteorology & atmospheric sciences, biology, Cloud top, Equator, Venus, Geophysics, Albedo, biology.organism_classification, Atmospheric sciences, 01 natural sciences, Atmosphere of Venus, Atmosphere, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Zonal flow, Earth and Planetary Sciences (miscellaneous), Longitude, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: Based on the analysis of UV images (at 365 nm) of Venus cloud top (altitude 67 ± 2 km) collected with VMC (Venus Monitoring Camera) on board Venus Express (VEX), it is found that the zonal wind speed south of the equator (from 5°S to 15°S) shows a conspicuous variation (from -101 to -83 m/s) with geographic longitude of Venus, correlated with the underlying relief of Aphrodite Terra. We interpret this pattern as the result of stationary gravity waves produced at ground level by the up lift of air when the horizontal wind encounters a mountain slope. These waves can propagate up to the cloud top level, break there and transfer their momentum to the zonal flow. Such upward propagation of gravity waves and influence on the wind speed vertical profile was shown to play an important role in the middle atmosphere of the Earth by Lindzen [1981], but is not reproduced in the current GCM of Venus atmosphere from LMD. In the equatorial regions, the UV albedo at 365 nm varies also with longitude. We argue that this variation may be simply explained by the divergence of the horizontal wind field. In the longitude region (from 60° to -10°) where the horizontal wind speed is increasing in magnitude (stretch), it triggers air upwelling which brings the UV absorber at cloud top level and decreases the albedo, and vice-versa when the wind is decreasing in magnitude (compression). This picture is fully consistent with the classical view of Venus meridional circulation, with upwelling at equator revealed by horizontal air motions away from equator: the longitude effect is only an additional but important modulation of this effect. This interpretation is comforted by a recent map of cloud top H2O [Fedorova et al., 2015], showing that near the equator the lower UV albedo longitude region is correlated with increased H2O. We argue that H2O enhancement is the sign of upwelling, suggesting that the UV absorber is also brought to cloud top by upwelling.
Published: 2016

33. Variability of the nitric oxide nightglow at Venus during solar minimum

Author: Emmanuel Marcq, Franck Montmessin, and Emilie Royer
Subjects: Solar minimum, Brightness, 010504 meteorology & atmospheric sciences, biology, Airglow, Field of view, Scale height, Venus, Atmospheric sciences, biology.organism_classification, 01 natural sciences, Standard deviation, Geophysics, Altitude, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: We present results from a NO airglow inversion method based on Venus Express data acquired from 2006 to 2010, during the last solar minimum period. We retrieve an altitude of 114 ± 10 km for the emission peak of the NO layer, with an associated scale height of 20 ± 10 km and an average limb brightness of 59.3 kR with a standard deviation of 63 kR. The inversion method allows for the quantification of the horizontal homogeneity of the NO layer. Images of the SPICAV field of view show a great variability of airglow morphologies, with NO layers that can be horizontally homogenous and continuous over distances exceeding 100 km, as well as sporadic patches of NO on a smaller horizontal scale. Frequent secondary emissions seen at lower tangent altitudes are the signatures of the complex dynamics of the upper Venusian atmosphere.
Published: 2016

34. The Venus Emissivity Mapper (VEM): Obtaining global mineralogy of Venus from orbit

Author: Constantine Tsang, Dennis Wendler, Gabriel Guignan, Emmanuel Marcq, Joern Helbert, Judit Jaenchen, Gabriele Arnold, Nils Mueller, Darby Dyar, Anko Boerner, Mario D'Amore, Suzanne E. Smrekar, Ingo Walter, Alessandro Maturilli, David Kappel, Sabrina Ferrari, Thomas Widemann, DLR Institute of Planetary Research, German Aerospace Center (DLR), Mount Holyoke College, DLR Institute for Optical Sensorsystems, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), DLR Institut für Planetenforschung, 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), IMPEC - 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), Università di Pavia, Southwest Research Institute [Boulder] (SwRI), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Marija Strojnik, Maureen S. Kirk (eds.), 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), 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), 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), Università degli Studi di Pavia, California Institute of Technology (CALTECH)-NASA, Imperial College London, DLR Institute of Optical Sensor Systems, and Università degli Studi di Pavia = University of Pavia (UNIPV)
Subjects: Asteroiden und Kometen, spectroscopy, Weltrauminstrumente, 010504 meteorology & atmospheric sciences, Multispectral image, Venus, 01 natural sciences, law.invention, remote sensing, Planetenphysik, law, 0103 physical sciences, Emissivity, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Echtzeit-Datenprozessierung, Venus Emissivity Mapper, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Near-infrared spectroscopy, Leitungsbereich PF, Global Map, biology.organism_classification, Planetary science, 13. Climate action, composition, Orbit (dynamics), Environmental science, Planetare Sensorsysteme
Abstract: The Venus Emissivity Mapper is the first flight instrument designed to focus on mapping the surface of Venus using atmospheric windows around 1 micron. After several years of development, VEM has a mature design with an existing laboratory prototype verifying an achievable instrument SNR of well above 1000, as well as predicted error in retrieval of relative emissivity of better than 1%, assuming the availability of an improved Venus topography. It will provide a global map of rock type, iron contents and redox state of the surface by observing the surface with six narrow band filters, ranging from 0.86 to 1.18 micron. Three additional windows allow corrections for cloud composition and variability, two measure water abundance, and three compensate for stray light. Continuous observation of Venus' thermal emission will also place tighter constraints on current day volcanic activity. Eight of the channels provide measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamics and permit accurate correction of atmospheric interference on the surface data. Combining VEM with a high-resolution radar mapper, such as on the ESA EnVision or NASA VERITAS mission proposals, will provide key insights into the divergent evolution of Venus and Earth.
Published: 2018

35. Sulfur dioxide in the Venus atmosphere: I. Vertical distribution and variability

Author: Franklin P. Mills, Sanjay S. Limaye, Oleg Korablev, Tony Roman, Ann Carine Vandaele, Daria Evdokimova, Arnaud Mahieux, Franck Lefèvre, Kandis Lea Jessup, Valérie Wilquet, Christopher D. Parkinson, Emmanuel Marcq, Th. Encrenaz, Aurélien Stolzenbach, Brad J. Sandor, Colin Wilson, Séverine Robert, S. Chamberlain, Larry W. Esposito, Franck Montmessin, Denis Belyaev, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Moscow Institute of Physics and Technology [Moscow] (MIPT), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), 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), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Department of Space Studies [Boulder], Southwest Research Institute [Boulder] (SwRI), 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), Space Science and Engineering Center [Madison] (SSEC), University of Wisconsin-Madison, Fonds National de la Recherche Scientifique [Bruxelles] (FNRS), Fenner School of Environment and Society, Australian National University (ANU), Space Science Institute [Boulder] (SSI), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Space Telescope Science Institute (STSci), Clarendon Laboratory [Oxford], University of Oxford [Oxford], and University of Oxford
Subjects: Haze, 010504 meteorology & atmospheric sciences, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy and Astrophysics, Venus, Atmospheric model, biology.organism_classification, Atmospheric sciences, 01 natural sciences, Sulfur oxide, Mesosphere, Atmosphere, Atmosphere of Venus, Altitude, 13. Climate action, Space and Planetary Science, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; Recent observations of sulfur containing species (SO2, SO, OCS, and H2SO4) in Venus’ mesosphere have generated controversy and great interest in the scientific community. These observations revealed unexpected spatial patterns and spatial/temporal variability that have not been satisfactorily explained by models. Sulfur oxide chemistry on Venus is closely linked to the global-scale cloud and haze layers, which are composed primarily of concentrated sulfuric acid. Sulfur oxide observations provide therefore important insight into the on-going chemical evolution of Venus’ atmosphere, atmospheric dynamics, and possible volcanism.This paper is the first of a series of two investigating the SO2 and SO variability in the Venus atmosphere. This first part of the study will focus on the vertical distribution of SO2, considering mostly observations performed by instruments and techniques providing accurate vertical information. This comprises instruments in space (SPICAV/SOIR suite on board Venus Express) and Earth-based instruments (JCMT). The most noticeable feature of the vertical profile of the SO2 abundance in the Venus atmosphere is the presence of an inversion layer located at about 70–75 km, with VMRs increasing above. The observations presented in this compilation indicate that at least one other significant sulfur reservoir (in addition to SO2 and SO) must be present throughout the 70–100 km altitude region to explain the inversion in the SO2 vertical profile. No photochemical model has an explanation for this behaviour. GCM modelling indicates that dynamics may play an important role in generating an inflection point at 75 km altitude but does not provide a definitive explanation of the source of the inflection at all local times or latitudesThe current study has been carried out within the frame of the International Space Science Institute (ISSI) International Team entitled ‘SO2 variability in the Venus atmosphere’.
Published: 2018

36. Composition and Chemistry of the Neutral Atmosphere of Venus

Author: Franklin P. Mills, Christopher D. Parkinson, Ann Carine Vandaele, Emmanuel Marcq, 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), Australian National University (ANU), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, and Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB)
Subjects: 010504 meteorology & atmospheric sciences, biology, Atmospheric composition, Astronomy and Astrophysics, 3d model, Venus, biology.organism_classification, Atmospheric sciences, 01 natural sciences, Occultation, Atmosphere, Atmosphere of Venus, Venus atmosphere, Neutral atmosphere, Planetary science, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, 0103 physical sciences, Spatial variability, Chemical modeling, 010303 astronomy & astrophysics, Spectroscopy, 0105 earth and related environmental sciences
Abstract: International audience; This paper deals with the composition and chemical processes occurring in the neutral atmosphere of Venus. Since the last synthesis, observers as well as modellers have emphasised the spatial and temporal variability of minor species, going beyond a static and uniform picture that may have prevailed in the past. The outline of this paper acknowledges this situation and follows closely the different dimensions along which variability in composition can be observed: vertical, latitudinal, longitudinal, temporal. The strong differences between the atmosphere below and above the cloud layers also dictate the structure of this paper. Observational constraints, obtained from both Earth and Venus Express, as well as 1D, 2D and 3D models results obtained since 1997 are also extensively referred and commented by the authors. An non-exhaustive list of topics included follows: modelled and observed latitudinal and vertical profiles of CO and OCS below the clouds of Venus; vertical profiles of CO and SO2 above the clouds as observed by solar occultation and modelled; temporal and spatial variability of sulphur oxides above the clouds. As a conclusion, open questions and topics of interest for further studies are discussed.
Published: 2017

37. The Venus Emissivity Mapper concept

Author: Alessandro Maturilli, M. Darby Dyar, Gabriel Guignan, Nils Mueller, Mario D'Amore, Anko Boerner, Jörn Helbert, David Kappel, Thomas Widemann, Emmanuel Marcq, Judit Jaenchen, Suzanne E. Smrekar, Dennis Wendler, Gabriele Arnold, Sabrina Ferrari, Ingo Walter, Strojnik, Marija, Kirk, Maureen, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), DLR Institute for Optical Sensorsystems, 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), 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), 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), Università degli Studi di Pavia, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Department of Astronomy of the Mount Holyoke College, Mount Holyoke College, Marija Strojnik, Maureen S. Kirk (eds.), DLR Institute of Optical Sensor Systems, and Università degli Studi di Pavia = University of Pavia (UNIPV)
Subjects: Asteroiden und Kometen, spectroscopy, 010504 meteorology & atmospheric sciences, near infrared, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Venus, 01 natural sciences, law.invention, Hochgeschwindigkeitselektronik, Interference (communication), law, 0103 physical sciences, Emissivity, Circular orbit, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Echtzeit-Datenprozessierung, geography, geography.geographical_feature_category, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Leitungsbereich PF, Global Map, biology.organism_classification, Volcano, 13. Climate action, Planetare Sensorsysteme, Flight instruments
Abstract: International audience; The Venus Emissivity Mapper (VEM) is the first flight instrument specially designed with a sole focus on mapping the surface of Venus using the narrow atmospheric windows around 1μm. VEM will provide a global map of surface composition as well as redox state of the surface, providing a comprehensive picture of surface-atmosphere interaction on Venus. In addition, continuous observation of the thermal emission of the Venus will provide tight constraints on current day volcanic activity. These capabilities are complemented by measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamic. Atmospheric data will allow for the accurate correction of atmospheric interference on the surface measurements and represent highly valuable science on their own. A mission combining VEM with a high-resolution radar mapper such as the NASA VOX or the ESA EnVision mission proposals in a low circular orbit will provide key insights in the divergent evolution of Venus.
Published: 2017

38. Sulfur dioxide in the Venus Atmosphere: II. Spatial and temporal variability

Author: Daria Evdokimova, Sanjay S. Limaye, Denis Belyaev, Thérèse Encrenaz, Valérie Wilquet, Colin Wilson, Arnaud Mahieux, Emmanuel Marcq, Aurélien Stolzenbach, Brad Sandor, Larry W. Esposito, Christopher D. Parkinson, Franck Lefèvre, Oleg Korablev, Ann Carine Vandaele, Frank Mills, Kandis Lea Jessup, Séverine Robert, S. Chamberlain, Tony Roman, Franck Montmessin, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Moscow Institute of Physics and Technology [Moscow] (MIPT), 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), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Department of Space Studies [Boulder], Southwest Research Institute [Boulder] (SwRI), Fenner School of Environment and Society, Australian National University (ANU), 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), Space Science and Engineering Center [Madison] (SSEC), University of Wisconsin-Madison, Fonds National de la Recherche Scientifique [Bruxelles] (FNRS), Space Science Institute [Boulder] (SSI), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Space Telescope Science Institute (STSci), Clarendon Laboratory [Oxford], University of Oxford [Oxford], and University of Oxford
Subjects: 010504 meteorology & atmospheric sciences, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Sulfur cycle, Astronomy and Astrophysics, Venus, Atmospheric model, Atmospheric sciences, biology.organism_classification, 01 natural sciences, Atmosphere of Venus, chemistry.chemical_compound, Amplitude, chemistry, 13. Climate action, Space and Planetary Science, Abundance (ecology), 0103 physical sciences, Nadir, Environmental science, 010303 astronomy & astrophysics, Sulfur dioxide, 0105 earth and related environmental sciences
Abstract: International audience; The vertical distribution of sulfur species in the Venus atmosphere has been investigated and discussed in Part I of this series of papers dealing with the variability of SO2 on Venus. In this second part, we focus our attention on the spatial (horizontal) and temporal variability exhibited by SO2. Appropriate data sets – SPICAV/UV nadir observations from Venus Express, ground-based ALMA and TEXES, as well as UV observation on the Hubble Space Telescope – have been considered for this analysis. High variability both on short-term and short-scale are observed. The long-term trend observed by these instruments shows a succession of rapid increases followed by slow decreases in the SO2 abundance at the cloud top level, implying that the transport of air from lower altitudes plays an important role. The origins of the larger amplitude short-scale, short-term variability observed at the cloud tops are not yet known but are likely also connected to variations in vertical transport of SO2 and possibly to variations in the abundance and production and loss of H2O, H2SO4, and Sx.
Published: 2017

39. Simulations of the latitudinal variability of CO-like and OCS-like passive tracers below the clouds of Venus using the Laboratoire de Météorologie Dynamique GCM

Author: Emmanuel Marcq and Sébastien Lebonnois
Subjects: 010504 meteorology & atmospheric sciences, biology, Venus, Scale height, biology.organism_classification, Atmospheric sciences, 01 natural sciences, Latitude, Atmosphere of Venus, Atmosphere, chemistry.chemical_compound, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Environmental science, Relaxation (physics), Chemical equilibrium, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Carbonyl sulfide
Abstract: The lower atmosphere of Venus below the clouds is a transitional region between the relatively calm lowermost scale height and the super-rotating atmosphere in the cloud region and above. Any observational constraint is then welcome to help in the development of general circulation models of Venus, a difficult task considering the thickness of its atmosphere. Starting from a state-of-the-art 3D Venus GCM [Lebonnois et al., 2010], we have included passive tracers in order to investigate the latitudinal variability of two minor gaseous species, carbonyl sulfide (OCS) and carbon monoxide (CO), whose vertical profiles and mixing ratios are known to vary with latitude between 30 and 40 km [Marcq et al., 2008]. The relaxation to chemical equilibrium is crudely parametrized through a vertically uniform timescale τ. A satisfactory agreement with available observations is obtained with 108 s ≲ τCO ≲ 5 * 108 s and 107 s ≲ τOCS ≲ 10 s. These results, in addition to validating the general circulation below the clouds, are also helpful in characterizing the chemical kinetics of Venus' atmosphere. This complements the much more sophisticated chemical models which focus more on thermodynamical equilibrium [Yung et al., 2009; Krasnopolsky, 2007].
Published: 2013

40. Thermal evolution of an early magma ocean in interaction with the atmosphere

Author: T. Lebrun, Anne Davaille, Emmanuel Marcq, François Leblanc, Philippe Sarda, G. Brandeis, Eric Chassefière, and Hélène Massol
Subjects: 010504 meteorology & atmospheric sciences, Venus, 01 natural sciences, Physics::Geophysics, Astrobiology, Atmosphere, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Astrophysics::Solar and Stellar Astrophysics, Ocean planet, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Secondary atmosphere, Accretion (meteorology), biology, Mars Exploration Program, Geophysics, biology.organism_classification, Lunar magma ocean, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Magma, Astrophysics::Earth and Planetary Astrophysics, Geology
Abstract: [1] The thermal evolution of magma oceans produced by collision with giant impactors late in accretion is expected to depend on the composition and structure of the atmosphere through the greenhouse effect of CO2 and H2O released from the magma during its crystallization. In order to constrain the various cooling timescales of the system, we developed a 1-D parameterized convection model of a magma ocean coupled with a 1-D radiative-convective model of the atmosphere. We conducted a parametric study and described the influences of the initial volatile inventories, the initial depth of the magma ocean, and the Sun-planet distance. Our results suggest that a steam atmosphere delays the end of the magma ocean phase by typically 1 Myr. Water vapor condenses to an ocean after 0.1, 1.5, and 10 Myr for, respectively, Mars, Earth, and Venus. This time would be virtually infinite for an Earth-sized planet located at less than 0.66 AU from the Sun. Using a more accurate calculation of opacities, we show that Venus is much closer to this threshold distance than in previous models. So there are conditions such as no water ocean is formed on Venus. Moreover, for Mars and Earth, water ocean formation timescales are shorter than typical time gaps between major impacts. This implies that successive water oceans may have developed during accretion, making easier the loss of their atmospheres by impact erosion. On the other hand, Venus could have remained in the magma ocean stage for most of its accretion.
Published: 2013

41. A layer of ozone detected in the nightside upper atmosphere of Venus

Author: Denis Belyaev, Emmanuel Marcq, Vincent Sarago, Jean-Loup Bertaux, Jean-Claude Gérard, Franck Montmessin, Franck Lefèvre, Anna Fedorova, Ann Carine Vandaele, Oleg Korablev, 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), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Laboratoire de Physique Atmosphérique et Planétaire (LPAP), Université de Liège, and Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB)
Subjects: Ozone, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Venus, Atmospheric sciences, 01 natural sciences, Astrobiology, Atmosphere of Venus, Atmosphere, chemistry.chemical_compound, 0103 physical sciences, 010303 astronomy & astrophysics, Stratosphere, Spectroscopy, 0105 earth and related environmental sciences, Secondary atmosphere, biology, Atmospheric composition, Astronomy and Astrophysics, biology.organism_classification, chemistry, 13. Climate action, Space and Planetary Science, Atmospheric Chemistry, Atmospheric chemistry, Environmental science, Occultations, Thermosphere
Abstract: International audience; To date, ozone has only been identified in the atmospheres of Earth and Mars. This study reports the first detection of ozone in the atmosphere of Venus by the SPICAV ultraviolet instrument onboard the Venus Express spacecraft. Venusian ozone is characterized by a vertically confined and horizontally variable layer residing in the thermosphere at a mean altitude of 100 km, with local concentrations of the order of 107-108 molecules.cm-3. The observed ozone concentrations are consistent with values expected for a chlorine-catalyzed destruction scheme, indicating that the key chemical reactions operating in Earth's upper stratosphere may also operate on Venus.
Published: 2011

42. Coordinated Hubble Space Telescope and Venus Express Observations of Venus’ upper cloud deck

Author: Colin Wilson, Franklin P. Mills, Sanjay S. Limaye, Mark Allen, Emmanuel Marcq, Jean-Loup Bertaux, Kandis Lea Jessup, Arnaud Mahieux, Yuk Yung, Wojciech J. Markiewicz, Ann Carine Vandaele, Valérie Wilquet, Tony Roman, Research School of Physics and Engineering [Canberra} (RSPE), Australian National University (ANU), Southwest Research Institute [Boulder] (SwRI), 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), Space Science Institute [Boulder] (SSI), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Department of Atmospheric Oceanic and Space Sciences [Madison], University of Wisconsin-Madison, University of Oxford [Oxford], California Institute of Technology (CALTECH), Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Space Telescope Science Institute (STSci), University of Oxford, and Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS)
Subjects: 010504 meteorology & atmospheric sciences, biology, Atmosphere, Cloud top, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy, Astronomy and Astrophysics, Venus, biology.organism_classification, 01 natural sciences, Occultation, Mesosphere, Atmosphere of Venus, Chemistry, 13. Climate action, Space and Planetary Science, 0103 physical sciences, 010303 astronomy & astrophysics, James Clerk Maxwell Telescope, Zenith, 0105 earth and related environmental sciences
Abstract: Hubble Space Telescope Imaging Spectrograph (HST/STIS) UV observations of Venus' upper cloud tops were obtained between 20N and 40S latitude on December 28, 2010; January 22, 2011 and January 27, 2011 in coordination with the Venus Express (VEx) mission. The high spectral (0.27nm) and spatial (40-60km/pixel) resolution HST/STIS data provide the first direct and simultaneous record of the latitude and local time distribution of Venus' 70-80km SO and SO2 (SOx) gas density on Venus' morning quadrant. These data were obtained simultaneously with (a) VEx/SOIR occultation and/or ground-based James Clerk Maxwell Telescope sub-mm observations that record respectively, Venus' near-terminator SO2 and dayside SOx vertical profiles between ~75 and 100km; and (b) 0.36μm VEx/VMC images of Venus' cloud-tops. Updating the (Marcq, E. et al. [2011]. Icarus 211, 58-69) radiative transfer model SO2 gas column densities of ~2-10μm-atm and ~0.4-1.8μm-atm are retrieved from the December 2010 and January 2011 HST observations, respectively on Venus' dayside (i.e., at solar zenith angles (SZA)x gas densities. On December 28, 2010 SO2 VMR values ~280-290ppb are retrieved between 74 and 81km from the HST and SOIR data obtained near Venus' morning terminator (at SZAs equal to 70° and 90°, respectively); these values are 10× higher than the HST-retrieved January 2011 near terminator values. Thus, the cloud top SO2 gas abundance declined at all local times between the three HST observing dates. On all dates the average dayside SO2/SO ratio inferred from HST between 70 and 80km is higher than that inferred from the sub-mm the JCMT data above 84km confirming that SOx photolysis is more efficient at higher altitudes. The direct correlation of the SOx gases provides the first clear evidence that SOx photolysis is not the only source for Venus' 70-80km sulfur reservoir. The cloud top SO2 gas density is dependent in part on the vertical transport of the gas from the lower atmosphere; and the 0.24μm cloud top brightness levels are linked to the density of the sub-micron haze. Thus, the new results may suggest a correlation between Venus' cloud-top sub-micron haze density and the vertical transport rate. These new results must be considered in models designed to simulate and explore the relationship between Venus' sulfur chemistry cycle, H2SO4 cloud formation rate and climate evolution. Additionally, we present the first photochemical model that uniquely tracks the transition of the SO2 atmosphere from steady to non-steady state with increasing SZA, as function of altitude within Venus' mesosphere, showing the photochemical and dynamical basis for the factor of ~2 enhancements in the SOx gas densities observed by HST near the terminator above that observed at smaller SZA. These results must also be considered when modeling the long-term evolution of Venus' atmospheric chemistry and dynamics.
Published: 2015

43. Thermal evolution of an early magma ocean in interaction with the atmosphere: conditions for the condensation of a water ocean

Author: Anne Davaille, François Leblanc, Philippe Sarda, Eric Chassefière, T. Lebrun, G. Brandeis, Emmanuel Marcq, Hélène Massol, Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Fluides, automatique, systèmes thermiques (FAST), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), 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), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Convection, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Environmental Engineering, Accretion (meteorology), lcsh:QP1-981, lcsh:QR1-502, Mars Exploration Program, Atmospheric sciences, Industrial and Manufacturing Engineering, lcsh:Microbiology, lcsh:Physiology, Physics::Geophysics, Atmosphere, Lunar magma ocean, 13. Climate action, Magma, Physics::Space Physics, lcsh:Zoology, Astrophysics::Solar and Stellar Astrophysics, Ocean planet, Astrophysics::Earth and Planetary Astrophysics, lcsh:QL1-991, Geology, Water vapor, Physics::Atmospheric and Oceanic Physics
Abstract: EPOV 2012: From Planets to Life – Colloquium of the CNRS Interdisciplinary Initiative “Planetary Environments and Origins of Life”; International audience; The thermal evolution of magma oceans produced by collision with giant impactors late in accretion is xpected to depend on the composition and structure of the atmosphere through the greenhouse effect of CO2 and H2O released from the magma during its crystallization. We developed a 1D parameterized convection model of a magma ocean coupled with a 1D radiative convective model of the atmosphere. We conducted a parametric study and described the influences of some important parameters such as the Sun-planet distance. Our results suggest that a steam atmosphere delays the end of the magma ocean phase by typically 1 Myr. Water vapor condenses to an ocean after 0.1 Myr, 1.5 Myr and 10 Myr for, respectively, Mars, Earth and Venus. This time would be virtually infinite for an Earth-sized planet located at less than 0.66 AU from the Sun. So there are conditions such as no water ocean is formed on Venus. Moreover, for Mars and Earth, water ocean formation time scales are shorter than typical time gaps between major impacts. This implies that successive water oceans may have developed during accretion, making easier the loss of their atmospheres by impact erosion.
Published: 2014

44. 3D modelling of the early martian climate under a denser CO2 atmosphere: Temperatures and CO2 ice clouds

Author: Robert M. Haberle, Laura Kerber, Robin Wordsworth, Emmanuel Marcq, Jean-Baptiste Madeleine, François Forget, Ehouarn Millour, Jérémy Leconte, Université Pierre et Marie Curie - Paris 6 (UPMC), 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-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Pierre-Simon-Laplace (IPSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), 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), NASA Ames Research Center (ARC), 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Atmospheres, 010504 meteorology & atmospheric sciences, Climate, FOS: Physical sciences, Mars, Atmospheric sciences, 01 natural sciences, Physics::Geophysics, Atmosphere, 0103 physical sciences, Greenhouse effect, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Martian, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Ice cloud, Secondary atmosphere, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Mars Exploration Program, 15. Life on land, 13. Climate action, Space and Planetary Science, Environmental science, Martian polar ice caps, Climate model, Astrophysics::Earth and Planetary Astrophysics, Polar caps, Astrophysics - Earth and Planetary Astrophysics
Abstract: On the basis of geological evidence, it is often stated that the early martian climate was warm enough for liquid water to flow on the surface thanks to the greenhouse effect of a thick atmosphere. We present 3D global climate simulations of the early martian climate performed assuming a faint young sun and a CO2 atmosphere with pressure between 0.1 and 7 bars. The model includes a detailed radiative transfer model using revised CO2 gas collision induced absorption properties, and a parameterisation of the CO2 ice cloud microphysical and radiative properties. A wide range of possible climates is explored by using various values of obliquities, orbital parameters, cloud microphysic parameters, atmospheric dust loading, and surface properties. Unlike on present day Mars, for pressures higher than a fraction of a bar, surface temperatures vary with altitude because of the adiabatic cooling and warming of the atmosphere when it moves vertically. In most simulations, CO2 ice clouds cover a major part of the planet but greenhouse effect does not exceed +15 K. We find that a CO2 atmosphere could not have raised the annual mean temperature above 0{\deg}C anywhere on the planet. The collapse of the atmosphere into permanent CO2 ice caps is predicted for pressures higher than 3 bar, or conversely at pressure lower than one bar if the obliquity is low enough. Summertime diurnal mean surface temperatures above 0{\deg}C (a condition which could have allowed rivers to form) are predicted for obliquity larger than 40{\deg} at high latitudes but not in locations where most valley networks are observed. In the absence of other warming mechanisms, our climate model results are thus consistent with a cold early Mars scenario in which non climatic mechanisms must occur to explain the evidence for liquid water. In a companion paper by Wordsworth et al., we simulate the hydrological cycle on such a planet., Comment: Icarus, In press. 23 pages, 18 figures
Published: 2013

45. Escape of the martian protoatmosphere and initial water inventory

Author: Kristina G. Kislyakova, Helmut Lammer, Martin Leitzinger, Manuel Güdel, Emmanuel Marcq, Alexander Stökl, Linda T. Elkins-Tanton, Nikolai V. Erkaev, Yu. N. Kulikov, Petra Odert, Ernst A. Dorfi, Institute of Computational Modelling of the Russian Academy of Sciences (ICM SB RAS), Siberian Branch of the Russian Academy of Sciences (SB RAS), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Department of Terrestrial Magnetism [Carnegie Institution], Carnegie Institution for Science, Institute for Astronomy [Vienna], University of Vienna [Vienna], Institute for Geophysics, Astrophysics and Meteorology [Graz] (IGAM), Karl-Franzens-Universität Graz, 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), Polar Geophysical Institute of Russian Academy of Sciences (PGI), Russian Academy of Sciences [Moscow] (RAS), and Carnegie Institution for Science [Washington]
Subjects: Planetesimal, Evolution, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Protoatmospheres, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Protoplanetary disk, Article, Protoplanetary nebula, Astrobiology, Atmosphere, Early mars, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics, Martian, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Atmospheric escape, Astronomy, Astronomy and Astrophysics, Mars Exploration Program, Accretion (astrophysics), 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Latest research in planet formation indicates that Mars formed within a few million years (Myr) and remained as a planetary embryo that never grew to a more massive planet. It can also be expected from dynamical models that most of Mars' building blocks consisted of material that formed in orbital locations just beyond the ice line which could have contained ~0.1–0.2wt.% of H2O. By using these constraints, we estimate the nebula-captured and catastrophically outgassed volatile contents during the solidification of Mars' magma ocean and apply a hydrodynamic upper atmosphere model for the study of the soft X-ray and extreme ultraviolet (XUV) driven thermal escape of the martian protoatmosphere during the early active epoch of the young Sun. The amount of gas that has been captured from the protoplanetary disk into the planetary atmosphere is calculated by solving the hydrostatic structure equations in the protoplanetary nebula. Depending on nebular properties such as the dust grain depletion factor, planetesimal accretion rates and luminosities, hydrogen envelopes with masses ≥3×1019g to ≤6.5×1022g could have been captured from the nebula around early Mars. Depending on the before mentioned parameters, due to the planets low gravity and a solar XUV flux that was ~100 times stronger compared to the present value, our results indicate that early Mars would have lost its nebular captured hydrogen envelope after the nebula gas evaporated, during a fast period of ~0.1–7.5Myr. After the solidification of early Mars' magma ocean, catastrophically outgassed volatiles with the amount of ~50–250bar H2O and ~10–55bar CO2 could have been lost during ~0.4–12Myr, if the impact related energy flux of large planetesimals and small embryos to the planet's surface lasted long enough, that the steam atmosphere could have been prevented from condensing. If this was not the case, then our results suggest that the timescales for H2O condensation and ocean formation may have been shorter compared to the atmosphere evaporation timescale, so that one can speculate that sporadically periods, where some amount of liquid water may have been present on the planet's surface. However, depending on the amount of the outgassed volatiles, because of impacts and the high XUV-driven atmospheric escape rates, such sporadically wet surface conditions may have also not lasted much longer than ~0.4–12Myr. After the loss of the captured hydrogen envelope and outgassed volatiles during the first 100 Myr period of the young Sun, a warmer and probably wetter period may have evolved by a combination of volcanic outgassing and impact delivered volatiles ~4.0±0.2Gyr ago, when the solar XUV flux decreased to values that have been, Highlights • Depending on nebula parameters Mars lost its nebula captured hydrogen envelope within ~0.1–7.5Myr by hydrodynamic escape. • Mars lost its outgassed steam atmosphere and initial water inventory during ~0.4–12Myr, years by hydrodynamic escape. • Liquid water could have been formed at the surface, sporadically during short time periods before it was lost. • Due to the strong early water loss efficient plate tectonics never began.
Published: 2013
Full Text: View/download PDF

46. A simple 1-D radiative-convective atmospheric model designed for integration into coupled models of magma ocean planets

Author: Emmanuel Marcq
Subjects: Convection, Atmospheric Science, 010504 meteorology & atmospheric sciences, Soil Science, Blanketing, Atmospheric model, Aquatic Science, Oceanography, Atmospheric sciences, 01 natural sciences, Atmosphere, Geochemistry and Petrology, 0103 physical sciences, Thermal, Earth and Planetary Sciences (miscellaneous), Radiative transfer, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Ecology, Paleontology, Forestry, Geophysics, Convection zone, Heat flux, 13. Climate action, Space and Planetary Science, Environmental science
Abstract: [1] In order to understand the early history of telluric interiors and atmospheres during the ocean magma stage, a coupled interior-atmosphere-escape model is being developed. This paper describes the atmospheric part and its first preliminary results. A unidimensional, radiative-convective, H2O-CO2 atmosphere is modeled following a vertical T(z) profile similar to Kasting (1988) and Abe and Matsui (1988). Opacities in the thermal IR are then computed using a k-correlated code (KSPECTRUM), tabulated continuum opacities for H2O-H2O and CO2-CO2 absorption, and water or sulphuric acid clouds in the moist convective zone (whenever present). The first results show the existence of two regimes depending on the relative value of the surface temperature Ts compared to a threshold temperature Tc depending on the total gaseous inventory. For Ts Tc, the blanketing is not efficient enough to prevent large radiative heat loss to space through a hot, cloudless atmosphere. Our current calculations may underestimate the thermal flux in the case of hot surfaces with little gaseous content in the atmosphere.
Published: 2012

47. Evidence for carbonyl sulfide (OCS) conversion to CO in the lower atmosphere of Venus

Author: Bruno Bézard, Mao-Chang Liang, Run-Lie Shia, Emmanuel Marcq, Yuk L. Yung, Xun Jiang, Christopher C. Lee, Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Research Center for Environmental Changes [Taipei], Academia Sinica, Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Department of Earth and Atmospheric Sciences [Houston], University of Houston, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, Soil Science, Model parameters, Venus, Aquatic Science, Oceanography, Atmospheric sciences, 01 natural sciences, Atmosphere of Venus, chemistry.chemical_compound, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Carbonyl sulfide, Thermal equilibrium, Ecology, biology, Paleontology, Forestry, biology.organism_classification, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], General Circulation Model, Environmental science
Abstract: International audience; The chemical regimes in the atmosphere of Venus vary from photochemistry in the middle atmosphere to thermal equilibrium chemistry in the lower atmosphere and the surface. Many chemical cycles have been proposed, but few details about these cycles are fully verified by comparison between observations and modeling. Recent high-quality data of carbonyl sulfide (OCS) and CO from ground-based and Venus Express observations provide a unique opportunity to test our understanding of chemistry and transport in the lower atmosphere of Venus. The spatial distributions of OCS and CO in the atmosphere reflect a sensitive balance between chemistry and transport. On the basis of our updated photochemical model and winds from Lee et al.'s (2007) general circulation model, we study the chemistry and transport in a simplified two-dimensional chemistry-transport model. OCS is produced by heterogeneous reactions on the surface; the middle atmosphere is a net sink for OCS. The combination of data and modeling provides strong evidence for the loss of OCS by conversion to CO. The detailed chemical mechanism is currently unknown, although a number of speculations have been proposed. The sensitivity of the distributions of OCS and CO to model parameters is reported.
Published: 2009

48. A latitudinal survey of CO, OCS, H2O, and SO2 in the lower atmosphere of Venus: Spectroscopic studies using VIRTIS-H

Author: P. Drossart, Florence Henry, Bruno Bézard, Emmanuel Marcq, Jean-Michel Reess, Giuseppe Piccioni, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), 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 Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: Atmospheric Science, Planetary Sciences: Solid Surface Planets: Composition (1060, 010504 meteorology & atmospheric sciences, Infrared, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Planetary Sciences: Solar System Objects: Venus, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Soil Science, Mineralogy, Venus, Aquatic Science, Oceanography, Atmospheric sciences, 01 natural sciences, Troposphere, Atmosphere, Atmosphere of Venus, chemistry.chemical_compound, Geochemistry and Petrology, 3672), 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Mixing ratio, Planetary Sciences: Solid Surface Planets: Atmospheres (0343, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Carbonyl sulfide, Ecology, biology, Paleontology, Forestry, biology.organism_classification, Planetary Sciences: Solid Surface Planets: Remote sensing, 1060), Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Environmental science, Water vapor
Abstract: International audience; The high-resolution channel (R $\simeq$ 2000) of the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument (VIRTIS-H) aboard Venus Express has provided numerous spectra of the nightside infrared thermal emission in the 2.3-μm window. Mixing ratios of various minor species in the 30-40 km range could therefore be inferred using this spectral window at higher latitudes accessible to the spacecraft but which cannot be observed from Earth. The previously known enhancement in carbon monoxide (CO) toward high latitudes is confirmed and extended up to 60° with a mixing ratio varying from 24 +/- 3 to 31 +/- 2 ppmv at 36 km. Measurements of carbonyl sulfide (OCS) also agree with the previously suspected latitudinal variations that are anticorrelated with those of CO, ranging between 2.5 +/- 1 and 4 +/- 1 ppmv at 33 km. New constraints were also derived on the mean abundance of water vapor (H2O, 31 +/- 2 ppmv) and sulfur dioxide (SO2, 130 +/- 50 ppmv) in the probed altitude range. CO and OCS variations are interpreted as caused by large-scale vertical motions, an explanation under current testing by various chemical and dynamical modeling. In such a case, these variations may help constrain the chemical time scale of those species in the lower troposphere.
Published: 2008

49. WATER FORMATION IN THE UPPER ATMOSPHERE OF THE EARLY EARTH

Author: Nathalie Carrasco, Emmanuel Marcq, Benjamin Fleury, Ludovic Vettier, Anni Määttänen, 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), 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)
Subjects: planets and satellites: atmospheres, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Physics, Astrochemistry, astrochemistry, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry.chemical_element, Earth, Astronomy and Astrophysics, Context (language use), Early Earth, Atmospheric sciences, Nitrogen, Trace gas, Troposphere, Atmosphere, chemistry.chemical_compound, chemistry, 13. Climate action, Space and Planetary Science, Carbon dioxide, Astrophysics::Earth and Planetary Astrophysics, Physics::Atmospheric and Oceanic Physics
Abstract: International audience; The water concentration and distribution in the early Earth's atmosphere are important parameters that contribute to the chemistry and the radiative budget of the atmosphere. If the atmosphere above the troposphere is generally considered as dry, photochemistry is known to be responsible for the production of numerous minor species. Here we used an experimental setup to study the production of water in conditions simulating the chemistry above the troposphere of the early Earth with an atmospheric composition based on three major molecules: N2, CO2, and H2. The formation of gaseous products was monitored using infrared spectroscopy. Water was found as the major product, with approximately 10% of the gas products detected. This important water formation is discussed in the context of the early Earth.
Published: 2015

50. Gyromagnetic ratio of rapidly rotating compact stars in general relativity

Author: Emmanuel Marcq, Jérôme Novak, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Equation of state, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, General relativity, Gyromagnetic ratio, FOS: Physical sciences, Perfect fluid, Angular velocity, General Relativity and Quantum Cosmology (gr-qc), Rotation, 01 natural sciences, General Relativity and Quantum Cosmology, Einstein-Maxwell equations, neutron stars, numerical simulations, Neutron star, Quantum electrodynamics, 0103 physical sciences, Compressibility, gyromagnetic ratio, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], 010303 astronomy & astrophysics, 04.40.Dg, 04.40.Nr, 02.70.Hm
Abstract: We numerically calculate equilibrium configurations of uniformly rotating and charged neutron stars, in the case of insulating material and neglecting the electromagnetic forces acting on the equilibrium of the fluid. This allows us to study the behaviour of the gyromagnetic ratio for those objects, when varying rotation rate and equation of state for the matter. Under the assumption of low charge and incompressible fluid, we find that the gyromagnetic ratio is directly proportional to the compaction parameter M/R of the star, and very little dependent on its angular velocity. Nevertheless, it seems impossible to have g=2 for these models with low charge-to-mass ratio, where matter consists of a perfect fluid and where the collapse limit is never reached., Comment: 11 pages, 6 figures, accepted for publication in Classical and Quantum Gravity
Published: 2003

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Database

Publisher

55 results on '"Emmanuel Marcq"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources