Author: "Aymeric Spiga" / Topic: 010303 astronomy & astrophysics - Searchworks@Jio Institute Digital Library Search Results

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76 results on '"Aymeric Spiga"'

1. The Mars system revealed by the Martian Moons eXploration mission

Author: Kazunori Ogohara, Hiromu Nakagawa, Shohei Aoki, Toru Kouyama, Tomohiro Usui, Naoki Terada, Takeshi Imamura, Franck Montmessin, David Brain, Alain Doressoundiram, Thomas Gautier, Takuya Hara, Yuki Harada, Hitoshi Ikeda, Mizuho Koike, François Leblanc, Ramses Ramirez, Eric Sawyer, Kanako Seki, Aymeric Spiga, Ann Carine Vandaele, Shoichiro Yokota, Antonella Barucci, Shingo Kameda, Kyoto Sangyo University, Graduate School of Science [Sendai], Tohoku University [Sendai], Laboratoire de Physique Atmosphérique et Planétaire (LPAP), Université de Liège, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Artificial Intelligence Research Center [Tokyo] (AIST), National Institute of Advanced Industrial Science and Technology [Tokyo] (AIST), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Graduate School of Frontier Sciences [Kashiwa], The University of Tokyo (UTokyo), 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), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], 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), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Graduate School of Science [Tokyo], Graduate School of Advanced Science and Engineering [Higashi-Hiroshima], Hiroshima University, Earth-Life Science Institute [Tokyo] (ELSI), Tokyo Institute of Technology [Tokyo] (TITECH), Space Science Institute [Boulder] (SSI), Department of Physics [Orlando] (UCF | Physics), University of Central Florida [Orlando] (UCF), Centre National d'Études Spatiales [Toulouse] (CNES), Department of Earth and Planetary Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Graduate School of Science [Toyonaka], Osaka University, and Rikkyo University [Tokyo]
Subjects: QB275-343, QE1-996.5, 010504 meteorology & atmospheric sciences, Paleoclimate, Dust cycle, Mars, Mars system, Geology, 01 natural sciences, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Geography. Anthropology. Recreation, Transport process, Atmospheric escape, Water cycle, 010303 astronomy & astrophysics, Geodesy, 0105 earth and related environmental sciences
Abstract: Japan Aerospace Exploration Agency (JAXA) plans a Phobos sample return mission (MMX: Martian Moons eXploration). In this study, we review the related works on the past climate of Mars, its evolution, and the present climate and weather to describe the scientific goals and strategies of the MMX mission regarding the evolution of the Martian surface environment. The MMX spacecraft will retrieve and return a sample of Phobos regolith back to Earth in 2029. Mars ejecta are expected to be accumulated on the surface of Phobos without being much shocked. Samples from Phobos probably contain all types of Martian rock from sedimentary to igneous covering all geological eras if ejecta from Mars could be accumulated on the Phobos surface. Therefore, the history of the surface environment of Mars can be restored by analyzing the returned samples. Remote sensing of the Martian atmosphere and monitoring ions escaping to space while the spacecraft is orbiting Mars in the equatorial orbit are also planned. The camera with multi-wavelength filters and the infrared spectrometer onboard the spacecraft can monitor rapid transport processes of water vapor, dust, ice clouds, and other species, which could not be traced by the previous satellites on the sun-synchronous polar orbit. Such time-resolved pictures of the atmospheric phenomena should be an important clue to understand both the processes of water exchange between the surface/underground reservoirs and the atmosphere and the drivers of efficient material transport to the upper atmosphere. The mass spectrometer with unprecedented mass resolution can observe ions escaping to space and monitor the atmospheric escape which has made the past Mars to evolve towards the cold and dry surface environment we know today. Together with the above two instruments, it can potentially reveal what kinds of atmospheric events can transport tracers (e.g., H2O) upward and enhance the atmospheric escape. Graphical Abstract
Published: 2022

2. Seasonal Variability of the Daytime and Nighttime Atmospheric Turbulence Experienced by InSight on Mars

Author: Audrey Chatain, François Forget, Don Banfield, Aymeric Spiga, and Naomi Murdoch
Subjects: Daytime, 010504 meteorology & atmospheric sciences, Planetary boundary layer, FOS: Physical sciences, Atmospheric sciences, 01 natural sciences, Physics::Geophysics, Physics::Fluid Dynamics, Diurnal cycle, 0103 physical sciences, Atmospheric instability, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Convection cell, Earth and Planetary Astrophysics (astro-ph.EP), Turbulence, Mars Exploration Program, Vortex, Physics - Atmospheric and Oceanic Physics, Geophysics, 13. Climate action, Atmospheric and Oceanic Physics (physics.ao-ph), Physics::Space Physics, General Earth and Planetary Sciences, Environmental science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: The InSight mission, featuring continuous high-frequency high-sensitivity pressure measurements, is in ideal position to study the active atmospheric turbulence of Mars. Data acquired during 1.25 Martian year allows us to study the seasonal evolution of turbulence and its diurnal cycle. We investigate vortices (abrupt pressure drops), local turbulence (frequency range 0.01-2 Hz) and non-local turbulence often caused by convection cells and plumes (frequency range 0.002-0.01 Hz). Contrary to non-local turbulence, local turbulence is strongly sensitive at all local times and seasons to the ambient wind. We report many remarkable events with the arrival of northern autumn at the InSight landing site: a spectacular burst of daytime vortices, the appearance of nighttime vortices, and the development of nighttime local turbulence as intense as its daytime counterpart. Nighttime turbulence at this dusty season appears as a result of the combination of a stronger low-level jet, producing shear-driven turbulence, and a weaker stability., 15 pages, 5 figures, accepted version of the manuscript published in GRL
Published: 2021

3. Soil Thermophysical Properties Near the InSight Lander Derived From 50 Sols of Radiometer Measurements

Author: John A. Grant, Veronique Ansan, Nicholas H. Warner, Matthew P. Golombek, Bruce Banerdt, Nils Müller, Justin N. Maki, Matthias Grott, Tilman Spohn, Mark T. Lemmon, Susan Smrekar, Nathan R. Williams, François Forget, Ehouarn Millour, Ingrid Daubar, Matthew A. Siegler, Aymeric Spiga, Don Banfield, Jörg Knollenberg, Sylvain Piqueux, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Planetary Science Institute [Tucson] (PSI), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), and Texas A&M University [College Station]
Subjects: Radiometer, 010504 meteorology & atmospheric sciences, Temperature, Mars, Mars Exploration Program, 01 natural sciences, Duricrust, Soil, Geophysics, Space and Planetary Science, Geochemistry and Petrology, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Thermophysics, Earth and Planetary Sciences (miscellaneous), 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Remote sensing, InSight
Abstract: Measurements from the InSight lander radiometer acquired after landing are used to characterize the thermophysical properties of the Martian soil in Homestead hollow. This data set is unique as it stems from a high measurement cadence fixed platform studying a simple well-characterized surface, and it benefits from the environmental characterization provided by other instruments. We focus on observations acquired before the arrival of a regional dust storm (near Sol 50), on the furthest observed patch of soil (i.e., ∼3.5 m away from the edge of the lander deck) where temperatures are least impacted by the presence of the lander and where the soil has been least disrupted during landing. Diurnal temperature cycles are fit using a homogenous soil configuration with a thermal inertia of 183 ± 25 J m
Published: 2021

4. Vortex‐Dominated Aeolian Activity at InSight's Landing Site, Part 1: Multi‐Instrument Observations, Analysis, and Implications

Author: Alexander E. Stott, L. M. Sotomayor, Constantinos Charalambous, John A. Grant, Sebastien Rodriguez, Nicholas H. Warner, Veronique Ansan, Don Banfield, William T. Pike, Naomi Murdoch, Aymeric Spiga, Maria E. Banks, Daniel Viúdez-Moreiras, William B. Banerdt, P. H. Lognonné, Ernst Hauber, Jorge Pla-Garcia, Matthew P. Golombek, Clément Perrin, Ralph D. Lorenz, Justin N. Maki, T. Warren, Anna Mittelholz, Claire E. Newman, Antoine Lucas, Matthew E. Baker, Catherine L. Johnson, J. B. Garvin, Ingrid Daubar, Mark T. Lemmon, Sara Navarro, Catherine M. Weitz, J. B. McClean, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Department of Electrical and Electronic Engineering [London] (DEEE), Imperial College London, MIT Haystack Observatory, Massachusetts Institute of Technology (MIT), Johns Hopkins University (JHU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Space Science Institute [Boulder] (SSI), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Institut de Physique du Globe de Paris (IPG Paris), 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), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), NASA Goddard Space Flight Center (GSFC), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Planetary Science Institute [Tucson] (PSI), Smithsonian Institution, State University of New York at Geneseo (SUNY Geneseo), State University of New York (SUNY), Brown University, German Aerospace Center (DLR), University of British Columbia (UBC), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), University of Oxford, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Cornell University [New York], Aeolis Research, ANR-19-CE31-0008,MAGIS,MArs Geophysical InSight(2019), Rodriguez, Sébastien, and MArs Geophysical InSight - - MAGIS2019 - ANR-19-CE31-0008 - AAPG2019 - VALID
Subjects: Convection, Seismometer, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars, 01 natural sciences, Wind speed, Physics::Geophysics, aeolian changes at the InSight landing site on Mars, convective vortices as a primary driver of particle motion, dust lifting and saltation, multi-instrument measurements constrain the timing and atmospheric conditions of aeolian changes, passing vortices lifting dust are correlated with magnetic signatures, surface creep, surface tracks, particle transport, Geochemistry and Petrology, Planet, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), wind, 14. Life underwater, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, InSight, 0105 earth and related environmental sciences, Mars landing, Mars Exploration Program, Geophysics, Vortex, Planetengeologie, [PHYS.ASTR.EP] Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 13. Climate action, Space and Planetary Science, Aeolian processes, Astrophysics::Earth and Planetary Astrophysics, Geology, camera
Abstract: International audience; We report the aeolian changes observed in situ by NASA's InSight lander during the first 400 sols of operations: Granule creep, saltation, dust removal, and the formation of dark surface tracks. Aeolian changes are infrequent and sporadic. However, on sols, when they do occur, they consistently appear between noon to 3 p.m., and are associated with the passage of convective vortices during periods of high vortex activity. Aeolian changes are more frequent at elevated locations, such as the top surfaces of rocks and lander footpads. InSight observed these changes using, for the first time, simultaneous insitu and orbital imaging and high-frequency meteorological, seismological, and magnetic measurements. Seismometer measurements of ground acceleration constrain the timing and trajectory of convective vortex encounters, linking surface changes to source vortices. Magnetometer measurements show perturbations in magnetic field strength during the passage of convective vortices consistent with chargedparticle motion. Detachment of sand-scale particles occurs when high background winds and vortexinduced turbulence provide a peak surface friction wind speed above the classic saltation fluid threshold. However, detachment of dust-and granule-scale particles also occurred when the surface friction wind speed remained below this threshold. This may be explained by local enhancement of the surface roughness and other effects described here and further studied in Part 2 (Baker et al., 2021). The lack of saltation and bright dust-coated surfaces at the InSight landing site implies surface stability and the onset of particle motion may be suppressed by dust "cushioning." This differentiates the InSight landing site from other areas on Mars that exhibit more aeolian activity. Plain Language Summary Aeolian activity, the movement of dust and sand by the wind, is common on Earth and has been observed on other planets, including Mars. A new Mars lander, InSight, has for the first time monitored aeolian changes by combining imaging with weather, seismic and CHARALAMBOUS ET AL.
Published: 2021

5. Listening for the Landing: Seismic Detections of Perseverance's Arrival at Mars With InSight

Author: Foivos Karakostas, N. Wójcicka, Tarje Nissen-Meyer, Nicholas A Teanby, Eleanor K. Sansom, Carene Larmat, Gareth S. Collins, Ross Maguire, Bruce Banerdt, Kuangdai Leng, Marouchka Froment, Benjamin Fernando, Aymeric Spiga, Özgür Karatekin, Philippe Lognonné, Taichi Kawamura, Lucie Rolland, Ingrid Daubar, Simon Stähler, Domenico Giardini, University of Oxford, Imperial College London, Los Alamos National Laboratory (LANL), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Maryland [College Park], University of Maryland System, Michigan State University [East Lansing], Michigan State University System, Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Royal Observatory of Belgium [Brussels] (ROB), Curtin University [Perth], Planning and Transport Research Centre (PATREC), University of Bristol [Bristol], 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), California Institute of Technology (CALTECH), Brown University, ANR-19-CE31-0008,MAGIS,MArs Geophysical InSight(2019), University of Oxford [Oxford], 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), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris)
Subjects: QE1-996.5, 010504 meteorology & atmospheric sciences, seismoacoustics, Astronomy, Mars, QB1-991, Geology, Mars Exploration Program, Environmental Science (miscellaneous), seismology, 01 natural sciences, impacts, InSight, 13. Climate action, [SDU]Sciences of the Universe [physics], 0103 physical sciences, General Earth and Planetary Sciences, Active listening, 010303 astronomy & astrophysics, Seismology, 0105 earth and related environmental sciences
Abstract: International audience; The entry, descent, and landing (EDL) sequence of NASA's Mars 2020 Perseverance Rover will act as a seismic source of known temporal and spatial localization. We evaluate whether the signals produced by this event will be detectable by the InSight lander (3,452 km away), comparing expected signal amplitudes to noise levels at the instrument. Modeling is undertaken to predict the propagation of the acoustic signal (purely in the atmosphere), the seismoacoustic signal (atmosphere-to-ground coupled), and the elastodynamic seismic signal (in the ground only). Our results suggest that the acoustic and seismoacoustic signals, produced by the atmospheric shock wave from the EDL, are unlikely to be detectable due to the pattern of winds in the martian atmosphere and the weak air-to-ground coupling, respectively. However, the elastodynamic seismic signal produced by the impact of the spacecraft's cruise balance masses on the surface may be detected by InSight. The upper and lower bounds on predicted ground velocity at InSight are 2.0 × 10 −14 and 1.3 × 10 −10 m s −1. The upper value is above the noise floor at the time of landing 40% of the time on average. The large range of possible values reflects uncertainties in the current understanding of impact-generated seismic waves and their subsequent propagation and attenuation through Mars. Uncertainty in the detectability also stems from the indeterminate instrument noise level at the time of this future event. A positive detection would be of enormous value in constraining the seismic properties of Mars, and in improving our understanding of impact-generated seismic waves.
Published: 2021

6. Three-Dimensional Turbulence-Resolving Modeling of the Venusian Cloud Layer and Induced Gravity Waves: Inclusion of Complete Radiative Transfer and Wind Shear

Author: Aymeric Spiga, Sébastien Lebonnois, Maxence Lefèvre, 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: Convection, 010504 meteorology & atmospheric sciences, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Venus, 01 natural sciences, Geochemistry and Petrology, Wind shear, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Radiative transfer, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, biology, Gravitational wave, Turbulence, Mechanics, biology.organism_classification, Geophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Inclusion (mineral), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, Induced gravity
Abstract: International audience; Venus' convective cloud layers and associated gravity waves strongly impact the local and global budget of heat, momentum and chemical species. Here we use for the first time three-dimensional turbulence-resolving dynamical integrations of Venus' atmosphere from the surface to 100 km altitude, coupled with fully interactive radiative transfer computations. We show that this enables to correctly reproduce the vertical position (46-55 km altitude) and thickness (9 km) of the main convective cloud layer measured by Venus Express and Akatsuki radio-occultations, as well as the intensity of convective plumes (3 m/s) measured by VeGa balloons. Both the radiative forcing in the visible and the large-scale dynamical impact play a role in the variability of the cloud convective activity with local time and latitude. Our model reproduces the diurnal cycle in cloud convection observed by Akatsuki at the low-latitudes, and the lack thereof observed by Venus Express at the equator. The observed enhancement of cloud convection at high latitudes is simulated by our model, although underestimated compared to observations. We show that the influence of the vertical shear of horizontal super-rotating winds must be accounted for in our model to allow for gravity waves of the observed intensity (> 1 K) and horizontal wavelength (up to 20 km) to be generated through the "obstacle effect" mechanism. The vertical extent of our model also allows us to predict for the first time a 7-km-thick convective layer at the cloud top (70 km altitude) caused by the solar absorption of the unknown UV absorber.
Published: 2018

7. Mars Perihelion Cloud Trails as revealed by MARCI: Mesoscale Topographically Focussed Updrafts and Gravity Wave Forcing of High Altitude Clouds

Author: Nicholas G. Heavens, Bruce A. Cantor, R. Todd Clancy, Steven W. Lee, Michael C. Malin, Daniel Tyler, Michael J. Wolff, Aymeric Spiga, P. B. James, and Brad J. Sandor
Subjects: 010504 meteorology & atmospheric sciences, Mesoscale meteorology, Astronomy and Astrophysics, Mars Exploration Program, Albedo, Atmospheric sciences, 01 natural sciences, Article, Latitude, Atmosphere, Space and Planetary Science, Dust storm, 0103 physical sciences, Gravity wave, 010303 astronomy & astrophysics, Water vapor, Geology, 0105 earth and related environmental sciences
Abstract: Daily, global wide angle imaging of Mars clouds in MARCI (MARs Color Imager, (Malin et al., 2008)) ultraviolet and visible bands reveals the spatial/seasonal distributions and physical characteristics of perihelion cloud trails (PCT); a class of high altitude (40–50 km), horizontally extended (200–1000 km, trending W to WSW) water ice clouds formed over specific southern low-to-mid latitude (5S-40S), mesoscale ( ∼ 50 km) locations during the Mars perihelion, southern summer season. PCT were first reported in association with rim regions of Valles Marineris (Clancy et al., 2009). The current study employs MARCI 2007–2011 imaging to sample the broader distributions and properties of PCT; and indicates several distinct locations of peak occurrences, including SW Arsia Mons, elevated regions of Syria, Solis, and Thaumasia Planitia, along Valles Marineris margins, and the NE rim of Hellas Basin. PCT are present over Mars solar longitudes ( L S ) of 210–310 ° , in late morning to mid afternoon hours (10 am–3 pm), and are among the brightest and most distinctive clouds exhibited during the perihelion portion of the Mars orbit. Their locations ( i.e. , eastern margin origins) correspond to strong local elevation gradients, and their timing to peak solar heating conditions (perihelion, subsolar latitudes and midday local times). They occur approximately on a daily basis among all locations identified ( i.e. , not daily at a single location). Based on cloud surface shadow analyses, PCT form at 40–50 km aeroid altitudes, where water vapor is generally at near-saturation conditions in this perihelion period (e.g. Millour et al., 2014). They exhibited notable absences during periods of planet encircling and regional dust storm activity in 2007 and 2009, respectively, presumably due to reduced water saturation conditions above 35–40 km altitudes associated with increased dust heating over the vertically extended atmosphere (e.g. Neary et al., 2019). PCT exhibit smaller particle sizes (R e f f =0.2-0.5 μ m ) than typically exhibited in the lower atmosphere, and incorporate significant fractions of available water vapor at these altitudes. PCT ice particles are inferred to form continuously (over ∼ 4 h) at their PCT eastern origins, associated with localized updrafts, and are entrained in upper level zonal/meridional winds (towards W or WSW with ∼ 50 m/s speeds at 40–50 km altitudes) to create long, linear cloud trails. PCT cloud formation is apparently forced in the lower atmosphere ( ≤ 10–15 km) by strong updrafts associated with distinctive topographic gradients, such as simulated in mesoscale studies (e.g., Tyler and Barnes, 2015) and indicated by the surface-specific PCT locations. These lower scale height updrafts are proposed to generate vertically propagating gravity waves (GW), leading to PCT formation above ∼ 40 km altitudes where water vapor saturation conditions promote vigorous cloud ice formation. Recent mapping of GW amplitudes at ∼ 25 km altitudes, from Mars Climate Sounder 15 μ m radiance variations (Heavens et al., 2020) in fact demonstrates close correspondences to the detailed spatial distributions of observed PCT, relative to other potential factors such as surface albedo and surface elevation (or related boundary layer depths).
Published: 2021

8. The whirlwinds of Elysium: A catalog and meteorological characteristics of 'dust devil' vortices observed by InSight on Mars

Author: Constantinos Charalambous, Claire E. Newman, Matthieu Plasman, Ralph D. Lorenz, Aymeric Spiga, Philippe Lognonné, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), 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), 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), Aeolis Research, and Imperial College London
Subjects: education.field_of_study, Peak ground acceleration, 010504 meteorology & atmospheric sciences, Meteorology, Advection, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Population, Astronomy and Astrophysics, Mars Exploration Program, Atmosphere of Mars, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, 01 natural sciences, Wind speed, Vortex, Physics::Geophysics, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 13. Climate action, Space and Planetary Science, 0103 physical sciences, education, 010303 astronomy & astrophysics, Dust devil, Geology, 0105 earth and related environmental sciences
Abstract: International audience; A catalog of convective vortex encounters recorded by InSight on the Martian surface is presented, through Sol 390 of the mission. The catalog summarizes key meteorological parameters such as wind speed and direction before the event, peak wind, the duration and magnitude of the pressure excursion, temperatures and solar array data where present. Additional seismic parameters are also provided on seismometer-detected ground acceleration. The catalog is intended as a resource for vortex population studies, and as an index for examining these meteorological events in detail and to assess possible geophysical (seismic or magnetic) signatures. Whereas it is difficult to evaluate 'anecdotal' results in small surveys, the large number of events (853 with a pressure drop exceeding 0.8 Pa) in this work permits robust statistical evaluation. For example, it is found that three times as many pressure profiles have slower onsets than decays than vice versa, indicating an asymmetry in the surface pressure field due to the tilted advection of the vortex by ambient wind. A vortex area fraction of 0.07% during the most active six hours of the day is deduced.
Published: 2021

9. Lander and rover histories of dust accumulation on and removal from solar arrays on Mars

Author: Naomi Murdoch, François Forget, Thomas Pierron, Ehouarn Millour, Aymeric Spiga, Álvaro Vicente-Retortillo, Claire E. Newman, German Martinez, Ralph D. Lorenz, Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, National Aeronautics and Space Administration (NASA), Agence Nationale de la Recherche (ANR), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), University of Michigan [Ann Arbor], University of Michigan System, Lunar and Planetary Institute [Houston] (LPI), 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), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Aeolis Research, and Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)
Subjects: 010504 meteorology & atmospheric sciences, Planetary boundary layer, Boundary layer meteorology, Mars, 01 natural sciences, Astrobiology, Martian surface, 0103 physical sciences, 010303 astronomy & astrophysics, Dust devil, Solar power, 0105 earth and related environmental sciences, Dust devils, business.industry, Photovoltaic system, Mars landing, Astronomy and Astrophysics, Dust, Mars Exploration Program, Deposition (aerosol physics), 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Environmental science, business
Abstract: Highlights Presents solar array dust factor evolution for 6 landed missions. Evaluates statistics of solar array output decline, typically 0.2%/Sol but ranging 0.05–2%/Sol. Determines statistics of cleaning events. Compares evolution with meteorological predictions at the different landing sites. The degradation in electrical output of solar arrays on Mars landers and rovers is reviewed. A loss of 0.2% per Sol is typical, although observed rates of decrease in ‘dust factor’ vary between 0.05% and 2% per Sol. 0.2%/Sol has been observed throughout the first 800 Sols of the ongoing InSight mission, as well as the shorter Mars Pathfinder and Phoenix missions. This rate was also evident for much of the Spirit and Opportunity missions, but the degradation there was episodically reversed by cleaning events due to dust devils and gusts. The enduring success of those rover missions may have given an impression of the long-term viability of solar power on the Martian surface that is not globally-applicable: the occurrence of cleaning events with an operationally-useful frequency seems contingent upon local meteorological circumstances. The conditions for significant cleaning events have apparently not been realized at the InSight landing site, where, notably, dust devils have not been detected in imaging. Optical obscuration by dust deposition and removal has also been observed by ultraviolet sensors on Curiosity, with a similar (but slightly higher) degradation rate. The observations are compared with global circulation model (GCM) results: these predict a geographically somewhat uniform dust deposition rate, while there is some indication that the locations where cleaning events were more frequent may be associated with weaker background winds and a deeper planetary boundary layer. The conventional Dust Devil Activity metric in GCMs does not effectively predict the different dust histories. We thank the InSight science and engineering teams for useful discussions. RL and CEN acknowledge the support of the NASA InSight Participating Scientist Program via Grants 80NSSC18K1626 and 80NSSC18K1630, respectively. AVR is supported by AEI Project No. MDM-2017-0737 Unidad de Excelencia “María de Maeztu”- Centro de Astrobiología (INTA-CSIC)". AS, FF, EM, TP acknowledge the support of CNES, ESA and of ANR (MAGIS, ANR-19-CE31-0008-08). This is InSight Contribution Number 193. We thank Matt Golombek and Veronique Ansan for useful comments. Peerreview
Published: 2021

10. Mapping the zonal winds of Jupiter’s stratospheric equatorial oscillation

Author: Rohini Giles, R. Cosentino, Vincent Hue, Sandrine Guerlet, B. Benmahi, Thomas K. Greathouse, Thibault Cavalié, Aymeric Spiga, 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), 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), ASP 2021, 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 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), Department of Astronomy [College Park], University of Maryland [College Park], and University of Maryland System-University of Maryland System
Subjects: 010504 meteorology & atmospheric sciences, Equator, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics, planets and satellites: individual: Jupiter, Atmospheric sciences, 01 natural sciences, 7. Clean energy, Wind speed, Troposphere, Jupiter, Saturn, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Stratosphere, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), planets and satellites: atmospheres, Astronomy and Astrophysics, Thermal wind, planets and satellites: gaseous planets, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geostrophic wind, Astrophysics - Earth and Planetary Astrophysics
Abstract: Since the 1950s, quasi-periodic oscillations have been studied in the terrestrial equatorial stratosphere. Other planets of the solar system present (or are expected to present) such oscillations, like the Jupiter Equatorial Oscillation(JEO) and the Saturn Semi-Annual Oscillation (SSAO). In Jupiter's stratosphere, the equatorial oscillation of its relative temperature structure about the equator, is characterized by a quasi-period of 4.4 years. The stratospheric wind field in Jupiter's equatorial zone has never been directly observed. In this paper, we aim at mapping the absolute wind speeds in Jupiter's equatorial stratosphere to quantify vertical and horizontal wind and temperature shear. Assuming geostrophic equilibrium, we apply the thermal wind balance using nearly simultaneous stratospheric temperature measurements between 0.1 and 30 mbar performed with Gemini/TEXES and direct zonal wind measurements derived at 1 mbar from ALMA observations, all carried out between March 14th and 22nd, 2017. We are thus able to calculate self-consistently the zonal wind field in Jupiter's stratosphere where the JEO occurs. We obtain stratospheric map of the zonal wind speeds as a function of latitude and pressure about Jupiter's equator for the first time. The winds are vertically layered with successive eastward and westward jets. We find a 200 m/s westward jet at 4 mbar at the equator, with a typical longitudinal variability on the order of ~50 m/s. By extending our wind calculations to the upper troposphere, we find a wind structure qualitatively close to the wind observed using cloud-tracking techniques. Nearly simultaneous temperature and wind measurements, both in the stratosphere, are a powerful tool for future investigations of the JEO (and other planetary equatorial oscillations) and its temporal evolution., Comment: the article was accepted on July 12, 2021
Published: 2021

11. Polarimetry as a tool for observing orographic gravity waves on venus

Author: Daphne Stam, Gourav Mahapatra, Maxence Lefèvre, Aymeric Spiga, Loïc Rossi, Faculty of Aerospace Engineering [Delft], Delft University of Technology (TU Delft), Department of Physics [Oxford], University of Oxford [Oxford], 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), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)
Subjects: 010504 meteorology & atmospheric sciences, Polarimetry, Venus, 01 natural sciences, Planet, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Radiative transfer, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Physics, biology, Gravitational wave, Astronomy and Astrophysics, Polarization (waves), biology.organism_classification, Computational physics, Wavelength, Geophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Degree of polarization, Astrophysics::Earth and Planetary Astrophysics, Planetary atmospheres
Abstract: Planet-wide stationary gravity waves have been observed with the thermal camera on the Akatsuki spacecraft. These waves have been attributed to the underlying surface topography and have successfully been reproduced using the Institut Pierre Simon Laplace (IPSL) Venus Mesoscale Model (VMM). Here, we use numerical radiative transfer computations of the total and polarized fluxes of the sunlight that is reflected by Venus under the conditions of these gravity waves to show that the waves could also be observed in polarimetric observations. To model the waves, we use the density perturbations computed by the IPSL VMM. We show the computed wave signatures in the polarization for nadir-viewing geometries observed by a spacecraft in orbit around Venus and as they could be observed using an Earth-based telescope. We find that the strength of the signatures of the atmospheric density waves in the degree of polarization of the reflected sunlight depends not only on the density variations themselves, but also on the wavelength and the cloud top altitude. Observations of such wave signatures on the dayside of the planet would give insight into the occurrence of the waves and possibly into the conditions that govern their onset and development. The computed change in degree of polarization due to these atmospheric density waves is about 1000 ppm at a wavelength of 300 nm. This signal is large enough for an accurate polarimeter to detect.
Published: 2021

12. Multi-model Meteorological and Aeolian Predictions for Mars 2020 and the Jezero Crater Region

Author: Ryan C. Sullivan, Daniel Viúdez-Moreiras, M. de la Torre Juarez, B. Chide, R. J. Wilson, Tanguy Bertrand, Mark I. Richardson, Stephen R. Lewis, Frank Daerden, Jorge Pla-Garcia, Claire E. Newman, Lori Neary, Melinda A. Kahre, Aymeric Spiga, J. A. Rodriguez-Manfredi, François Forget, Agustín Sánchez-Lavega, Sánchez Lavega, Á. [0000-0001-7234-7634], Lewis, S. [0000-0001-7237-6494], National Aeronautics and Space Administration (NASA), European Space Agency (ESA), Centre National D'Etudes Spatiales (CNES), Aeolis Research, California Institute of Technology (CALTECH), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Space Science Institute [Boulder] (SSI), NASA Ames Research Center (ARC), The Open University [Milton Keynes] (OU), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), 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), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), 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), Cornell Center for Astrophysics and Planetary Science (CCAPS), Cornell University [New York], Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), 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)-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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Daytime, 010504 meteorology & atmospheric sciences, Aeolian, Atmospheric circulation, Mars, Atmospheric sciences, 01 natural sciences, Wind speed, Article, Jezero crater, Meteorology, Impact crater, 0103 physical sciences, Solstice, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Dust devils, Atmosphere, Dust Devils, Mars 2020, Astronomy and Astrophysics, Wind direction, Atmospheric temperature, 13. Climate action, Space and Planetary Science, Aeolian processes, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology
Abstract: Nine simulations are used to predict the meteorology and aeolian activity of the Mars 2020 landing site region. Predicted seasonal variations of pressure and surface and atmospheric temperature generally agree. Minimum and maximum pressure is predicted at Ls similar to 145 degrees and 250 degrees, respectively. Maximum and minimum surface and atmospheric temperature are predicted at Ls similar to 180 degrees and 270 degrees, respectively; i.e., are warmest at northern fall equinox not summer solstice. Daily pressure cycles vary more between simulations, possibly due to differences in atmospheric dust distributions. Jezero crater sits inside and close to the NW rim of the huge Isidis basin, whose daytime upslope (similar to east-southeasterly) and nighttime downslope (similar to northwesterly) winds are predicted to dominate except around summer solstice, when the global circulation produces more southerly wind directions. Wind predictions vary hugely, with annual maximum speeds varying from 11 to 19 ms(-1) and daily mean wind speeds peaking in the first half of summer for most simulations but in the second half of the year for two. Most simulations predict net annual sand transport toward the WNW, which is generally consistent with aeolian observations, and peak sand fluxes in the first half of summer, with the weakest fluxes around winter solstice due to opposition between the global circulation and daytime upslope winds. However, one simulation predicts transport toward the NW, while another predicts fluxes peaking later and transport toward the WSW. Vortex activity is predicted to peak in summer and dip around winter solstice, and to be greater than at InSight and much greater than in Gale crater. We are grateful to reviewers Lori Fenton and Mackenzie Day for their detailed and insightful comments that resulted in a greatly improved manuscript. C.E.N. and M.I.R. were supported in this work by NASA Mars 2020 funding under JPL grant number 1514618. C.E.N. would also like to acknowledge the companionship of her beloved cat Sparky and the support of her fantastic mother Brenda during the writing of this manuscript during the COVID-19 pandemic. LMD co-authors F.F. and A.S. acknowledge funding support from Centre National d'Etudes Spatiales (CNES) and European Space Agency (ESA) and technical support for the enclosed simulations by E. Millour and L. Montabone. T.B. was supported for this research by an appointment to the National Aeronautics and Space Administration (NASA) Post-doctoral Program at the Ames Research Center administered by Universities Space Research Association (USRA) through a contract with NASA. L.N. and F.D. acknowledge funding support from the European Space Agency (ESA) PROgramme de Developpement d'Experiences scientifiques (PRODEX) Office, contract no. Prodex_NOMADMarsScience_C4000121493_2017-2019. M.T.J.'s work was carried out at the Jet Propulsion Laboratory/California Institute of Technology under a NASA Mars 2020 grant. R.S.'s work was supported under NASA Mars 2020 grant number 80NM0018F0616. S.R.L. thanks the UK Space Agency for support under grants ST/R001405/1, ST/S00145X/1 and ST/T002913/1.
Published: 2021

13. Global climate modeling of Saturn’s atmosphere. Part IV: Stratospheric equatorial oscillation

Author: Aymeric Spiga, Alexandre Boissinot, Deborah Bardet, Sandrine Guerlet, Simon Cabanes, Ehouarn Millour, 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), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Dipartimento di Fisica [Roma La Sapienza], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), ANR-17-CE31-0007,EMERGIANT,Un modèle commun pour comprendre les atmosphères des géantes gazeuses(2017), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Department of Physics [Roma La Sapienza], and Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome]
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Atmospheric circulation, Equator, FOS: Physical sciences, Atmospheric sciences, 01 natural sciences, Troposphere, Saturn, 0103 physical sciences, 010303 astronomy & astrophysics, Stratosphere, ComputingMilieux_MISCELLANEOUS, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Oscillation, Astronomy and Astrophysics, Physics - Atmospheric and Oceanic Physics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Atmospheric and Oceanic Physics (physics.ao-ph), Astrophysics::Earth and Planetary Astrophysics, Tropopause, Longitude, Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: The Composite InfraRed Spectrometer (CIRS) on board Cassini revealed an equatorial oscillation of stratospheric temperature, reminiscent of the Earth's Quasi-Biennial Oscillation (QBO), as well as anomalously high temperatures under Saturn's rings. To better understand these predominant features of Saturn's atmospheric circulation in the stratosphere, we have extended towards higher altitudes the DYNAMICO-Saturn global climate model (GCM), already used in a previous publication to study the tropospheric dynamics, jets formation and planetary-scale waves activity. Firstly, we study the higher model top impact on the tropospheric zonal jets and kinetic energy distribution. Raising the model top prevents energy and enstrophy accumulation at tropopause levels. The reference GCM simulation with 1/2$^{\circ}$ latitude/longitude resolution and a raised model top exhibits a QBO-like oscillation produced by resolved planetary-scale waves. However, the period is more irregular and the downward propagation faster than observations. Furthermore, compared to the CIRS observation retrievals, the modeled QBO-like oscillation underestimates by half both the amplitude of temperature anomalies at the equator and the vertical characteristic length of this equatorial oscillation. This QBO-like oscillation is mainly driven by westward-propagating waves; a significant lack of eastward wave-forcing explains a fluctuating eastward phase of the QBO-like oscillation. At 20$^{\circ}$N and 20$^{\circ}$S latitudes, the DYNAMICO-Saturn GCM exhibits several strong seasonal eastward jets, alternatively in the northern and southern hemisphere. These jets are correlated with the rings' shadowing. Using a GCM simulation without rings' shadowing, we show its impact on Saturn's stratospheric dynamics. Both residual-mean circulation and eddy forcing are impacted by rings' shadowing., Comment: 54 pages, 23 figures, revised version submitted to Icarus
Published: 2021
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14. Radiative-equilibrium model of Jupiter’s atmosphere and application to estimating stratospheric circulations

Author: Sandrine Guerlet, Thierry Fouchet, Hugues Delattre, Aymeric Spiga, 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), 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: Haze, 010504 meteorology & atmospheric sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Atmospheric sciences, 01 natural sciences, 7. Clean energy, Atmosphere, Troposphere, Jupiter, 0103 physical sciences, Radiative transfer, 010303 astronomy & astrophysics, Stratosphere, Physics::Atmospheric and Oceanic Physics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Astronomy and Astrophysics, Radiative forcing, Radiative equilibrium, 13. Climate action, Space and Planetary Science, Environmental science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present a computationally efficient 1-D seasonal radiative model, with convective adjustment, of Jupiter's atmosphere. Our model takes into account radiative forcings from the main hydrocarbons (methane, ethane, acetylene), ammonia, collision-induced absorption, four cloud and haze layers (including a UV-absorbing "polar" stratospheric haze) and an internal heat flux. We detail sensitivity studies of the equilibrium temperature profile to several parameters. We discuss the expected seasonal, vertical and meridional thermal structure and compare it to that derived from Cassini and ground-based thermal infrared observations. We find that the equilibrium temperature in the 5-30 mbar pressure range is very sensitive to the chosen stratospheric haze optical properties, sizes and number of monomers. The polar haze can significantly warm the lower stratosphere (10-30 mbar) by up to 20K at latitudes 45-60{\deg}. At pressures lower than 3 mbar, our modeled temperatures systematically underestimate the observed ones by 5K. This might suggest that other processes, such as dynamical heating by wave breaking or by eddies, or a coupling with thermospheric circulation, play an important role. In the troposphere, we can only match the observed lack of meridional gradient of temperature by varying the internal heat flux with latitude. We then exploit knowledge of heating and cooling rates to diagnose the residual-mean circulation in Jupiter's stratosphere, under the assumption that the eddy heat flux convergence term is negligible. In the lower stratosphere (5-30 mbar), the residual-mean circulation strongly depends on the assumed properties of the stratospheric haze. Our main conclusion is that it is crucial to improve our knowledge on the radiative forcing terms to increase our confidence in the estimated circulation. By extension, this will also be crucial for future 3D GCM studies., Comment: 72 pages, 21 figures. Version accepted by Icarus in June, 2020
Published: 2020

15. The Origin of Observed Magnetic Variability for a Sol on Mars From InSight

Author: Catherine L. Johnson, E. Barrett, Christopher T. Russell, François Forget, Aymeric Spiga, Steven P. Joy, S. N. Thorne, William B. Banerdt, Sue Smrekar, Benoit Langlais, Anna Mittelholz, Matthew Fillingim, Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Mars Exploration Program, 01 natural sciences, Astrobiology, Geophysics, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Ionosphere, 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2020

16. Martian Infrasound: Numerical Modeling and Analysis of InSight's Data

Author: L. Martire, Philippe Lognonné, William B. Banerdt, Lucie Rolland, Don Banfield, Aymeric Spiga, Raphaël F. Garcia, Roland Martin, Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Cornell Center for Astrophysics and Planetary Science (CCAPS), Cornell University [New York], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Géosciences Environnement Toulouse (GET), 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)-Observatoire Midi-Pyrénées (OMP), 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), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), 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 national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-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), and Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Martian, Seismometer, Frequency response, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Infrasound, Mars Exploration Program, Acoustic wave, Geophysics, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, 01 natural sciences, Mars infrasounds, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Surface wave, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Traitement du signal et de l'image, Waveguide (acoustics), 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Acoustic waves in planetary atmospheres couple into the solid surface, producing ground displacements that can be measured using seismometers. On November 26 2018, the InSight mission successfully landed on Mars. Its objectives include studying Mars' interior using the seismometer SEIS (Seismic Experiment for Interior Structures) and the atmosphere through the weather station APSS (Auxiliary Payload Sensor Suite). Because InSight is the first mission capable of studying infrasound on Mars, we investigate the signature of infrasound both in terms of air pressure and ground velocities. Using numerical simulations, we characterize (1) the acoustic propagation pattern in Martian dusk, and (2) the mechanical atmosphere-to-ground coupling under acoustic waves. Then, using SEIS data, we demonstrate that two low-frequency monotone events (S0133a and S0189a) are in fact infrasound trapped in the atmospheric nocturnal surface waveguide. We base our demonstration on the following facts. (1) Seismic signals rarely produce, at a given station, a single frequency varying from one event to the other. (2) No clear seismic phases have been identified for such events. (3) The observed SEIS signals present the characteristics expected for trapped infrasound observed through their compliance effects (specific frequency response, more energy on the vertical component, ±90 • phase shift between vertical and horizontal components, no detection on pressure sensor at these low amplitude levels). Our simulations of the nocturnal waveguide's response is however subject to uncertainties because 1) it relies on the sol-to-sol variability of the atmosphere, and 2) sub-surface properties are not properly known at this time.
Published: 2020

17. Geology of the InSight landing site on Mars

Author: Jeffery L. Hall, R. Hausmann, Claire E. Newman, Sharon A. Wilson, Nathan R. Williams, L. Berger, H. Abarca, Matthew P. Golombek, Constantinos Charalambous, Justin N. Maki, Paul M. Andres, Matthias Grott, Maria E. Banks, Sylvain Piqueux, A. DeMott, Philippe Lognonné, M. Kopp, François Forget, T. J. Parker, Ehouarn Millour, Niclas S. Mueller, M. M. Baker, Fred Calef, James B. Garvin, Aymeric Spiga, E. Hauber, Eloise Marteau, Veronique Ansan, William T. Pike, Christos Vrettos, John A. Grant, Clément Perrin, Sebastien Rodriguez, Naomi Murdoch, Nicholas H. Warner, N. Ruoff, William B. Banerdt, A. Trussell, Don Banfield, H. Lethcoe-Wilson, Suzanne E. Smrekar, Ingrid Daubar, Tilman Spohn, Robert G. Deen, S. Le Maistre, William M. Folkner, Catherine M. Weitz, Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), UCL - SST/ELI/ELIC - Earth & Climate, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), State University of New York at Geneseo (SUNY Geneseo), State University of New York (SUNY), Smithsonian Institution, DLR Institute of Planetary Research, German Aerospace Center (DLR), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Planetary Science Institute [Tucson] (PSI), Department of Mechanical Engineering [Imperial College London], Imperial College London, Technical University of Kaiserslautern (TU Kaiserslautern), Royal Observatory of Belgium [Brussels] (ROB), 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), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), 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), Johns Hopkins University (JHU), NASA Goddard Space Flight Center (GSFC), Cornell University [New York], and Aeolis Research
Subjects: geology, landing site, 010504 meteorology & atmospheric sciences, Science, General Physics and Astronomy, Mars, Genetics and Molecular Biology, Mass wasting, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, Elysium, Planetenphysik, Impact crater, 0103 physical sciences, Planetary science, Traitement du signal et de l'image, Petrology, lcsh:Science, 010303 astronomy & astrophysics, Duricrust, InSight, 0105 earth and related environmental sciences, Multidisciplinary, Geomorphology, Geology, Mars Exploration Program, General Chemistry, 15. Life on land, Regolith, Planetengeologie, General Biochemistry, Aeolian processes, lcsh:Q, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft landed successfully on Mars and imaged the surface to characterize the surficial geology. Here we report on the geology and subsurface structure of the landing site to aid in situ geophysical investigations. InSight landed in a degraded impact crater in Elysium Planitia on a smooth sandy, granule- and pebble-rich surface with few rocks. Superposed impact craters are common and eolian bedforms are sparse. During landing, pulsed retrorockets modified the surface to reveal a near surface stratigraphy of surficial dust, over thin unconsolidated sand, underlain by a variable thickness duricrust, with poorly sorted, unconsolidated sand with rocks beneath. Impact, eolian, and mass wasting processes have dominantly modified the surface. Surface observations are consistent with expectations made from remote sensing data prior to landing indicating a surface composed of an impact-fragmented regolith overlying basaltic lava flows., The InSight spacecraft landed on Mars on November 2018. Here, the authors characterize the surficial geology of the landing site and compare with observations and models derived from remote sensing data prior to landing and from ongoing in situ geophysical investigations of the subsurface.
Published: 2020

18. Diurnal Variations of Dust During the 2018 Global Dust Storm Observed by the Mars Climate Sounder

Author: David M. Kass, Luca Montabone, Armin Kleinböhl, James H. Shirley, François Forget, Ehouarn Millour, Aymeric Spiga, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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), 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 Space Science Institute [Boulder] (SSI)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 010504 meteorology & atmospheric sciences, Atmospheric circulation, Mars Exploration Program, Atmosphere of Mars, Atmospheric sciences, 01 natural sciences, Physics::Geophysics, Geophysics, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Dust storm, Physics::Space Physics, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Environmental science, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences
Abstract: International audience; We report observations by the Mars Climate Sounder showing strong diurnal variations in temperature and the vertical dust distribution during the 2018 (Mars Year 34) global dust event. The temperature field shows weak diurnal tidal activity at equatorial latitudes but a strong diurnal tide in middle to high latitudes with a maximum amplitude of 29 K in the lower atmosphere of the south polar region. The diurnal variability of dust is small in the equatorial region and increases toward higher latitudes. At middle and low latitudes, comparable dust amounts are found about 5–10 km higher in the atmosphere on the dayside than on the nightside. The dust reaches the highest altitudes in the late afternoon and is found at the lowest altitudes in the late night. In the southern high latitudes a persistent cold air mass with low dust content is identified on the nightside of the planet centered at 3–6 a.m. local time. The observed variations are well represented by model simulations with the Laboratoire de Météorologie Dynamique General Circulation Model. Comparisons between data and model results suggest that the diurnal variations in the dust are largely driven by the meridional circulation exhibiting diurnal tidal variations. The model results show that the compact air mass in the south polar region has a high potential vorticity, supporting its interpretation as a remnant of the southern polar vortex, which is forced toward the nightside of the planet due to the enhanced diurnal tide during the global dust event.
Published: 2020

19. Mars's Twilight Cloud Band: A New Cloud Feature Seen During the Mars Year 34 Global Dust Storm

Author: Sonal Jain, Michael J. Wolff, François Forget, Justin Deighan, Aymeric Spiga, Mohamed Alhosani, Kyle Connour, Zachariah Milby, Ehouarn Millour, Nicholas M. Schneider, Franck Lefèvre, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], 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), 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 Space Science Institute [Boulder] (SSI)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Twilight, 010504 meteorology & atmospheric sciences, Meteorology, business.industry, Cloud computing, Mars Exploration Program, 01 natural sciences, Geophysics, 13. Climate action, Feature (computer vision), Dust storm, 0103 physical sciences, General Earth and Planetary Sciences, Environmental science, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; We report a new water‐ice cloud feature observed during the Mars year 34 global dust storm: twilight cloud bands that routinely formed just past the evening terminator. We use images taken by the MAVEN/IUVS instrument. These bands were often latitudinally‐continuous, spanning over 6000~km and were present between 18:00 and 19:00 local time. They were present for nearly the entire time IUVS imaged the evening terminator and often reached altitudes of at least 40 to 50~km during the mature phase of the storm. We compare these observations to LMD global climate model simulations. The simulations generally contain the temporal and spatial extents of the bands seen in IUVS data throughout the storm, but there are some discrepancies. We infer these clouds formed as a result of semidiurnal thermal tides.
Published: 2020

20. Global climate modeling of Saturn's atmosphere. Part III: Global statistical picture of zonostrophic turbulence in high-resolution 3D-turbulent simulations

Author: Roland M. B. Young, Simon Cabanes, and Aymeric Spiga
Subjects: Length scale, Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Turbulence, Fluid Dynamics (physics.flu-dyn), FOS: Physical sciences, Astronomy and Astrophysics, Physics - Fluid Dynamics, Forcing (mathematics), Enstrophy, 7. Clean energy, 01 natural sciences, Computational physics, Atmosphere, 13. Climate action, Space and Planetary Science, Saturn, 0103 physical sciences, Spectral slope, Radiative transfer, 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: We conduct an in-depth analysis of statistical flow properties calculated from the reference high-resolution Saturn simulation obtained by global climate modelling in Part II. In the steady state of this reference simulation, strongly energetic, zonally dominated, large-scale structures emerge, which scale with the Rhines scale. Spectral analysis reveals a strong anisotropy in the kinetic energy spectra, consistent with the zonostrophic turbulent flow regime. By computing spectral energy and enstrophy fluxes we confirm the existence of a double cascade scenario related to 2D-turbulent theory. To diagnose the relevant 3D dynamical mechanisms in Saturn's turbulent atmosphere, we run a set of four simulations using an idealized version of our Global Climate Model devoid of radiative transfer, with a well-defined Taylor-Green forcing and over several rotation rates (4, 1, 0.5, and 0.25 times Saturn's rotation rate). This allows us to identify dynamics in three distinctive inertial ranges: (1) a “residual-dominated” range, in which non-axisymmetric structures dominate with a −5/3 spectral slope; (2) a “zonostrophic inertial” range, dominated by axisymmetric jets and characterized by the pile-up of strong zonal modes with a steeper, nearly −3, spectral slope; and (3) a “large-scale” range, beyond Rhines' typical length scale, in which the reference Saturn simulation and our idealized simulations differ. In the latter range, the dynamics is dominated by long-lived zonal modes 2 and 3 when a Saturn-like seasonal forcing is considered (reference simulation), and a steep energetic decrease with the idealized Taylor-Green forcing. Finally, instantaneous spectral fluxes show the coexistence of upscale and downscale enstrophy/energy transfers at large scales, specific to the regime of zonostrophic turbulence in a 3D atmosphere.
Published: 2020
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21. Global climate modeling of Saturn's atmosphere. Part II: Multi-annual high-resolution dynamical simulations

Author: Sébastien Lebonnois, Aymeric Spiga, Melody Sylvestre, Mikel Indurain, Yann Meurdesoif, Thomas Dubos, Alexandre Boissinot, Simon Cabanes, Sandrine Guerlet, Thierry Fouchet, Ehouarn Millour, Jérémy Leconte, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), ECLIPSE 2020, 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), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), 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), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Calcul Scientifique (CALCULS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), 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), ANR-17-CE31-0007,EMERGIANT,Un modèle commun pour comprendre les atmosphères des géantes gazeuses(2017), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: 010504 meteorology & atmospheric sciences, Baroclinity, Equator, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, 01 natural sciences, 7. Clean energy, symbols.namesake, Saturn, Barotropic fluid, 0103 physical sciences, 010303 astronomy & astrophysics, Stratosphere, Physics::Atmospheric and Oceanic Physics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Jet (fluid), Rossby wave, Astronomy and Astrophysics, Geophysics, Physics - Atmospheric and Oceanic Physics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Atmospheric and Oceanic Physics (physics.ao-ph), symbols, Astrophysics::Earth and Planetary Astrophysics, Kelvin wave, Astrophysics - Earth and Planetary Astrophysics
Abstract: The Cassini mission unveiled the intense and diverse activity in Saturn's atmosphere: banded jets, waves, vortices, equatorial oscillations. To set the path towards a better understanding of those phenomena, we performed high-resolution multi-annual numerical simulations of Saturn's atmospheric dynamics. We built a new Global Climate Model [GCM] for Saturn, named the Saturn DYNAMICO GCM, by combining a radiative-seasonal model tailored for Saturn to a hydrodynamical solver based on an icosahedral grid suitable for massively-parallel architectures. The impact of numerical dissipation, and the conservation of angular momentum, are examined in the model before a reference simulation employing the Saturn DYNAMICO GCM with a $1/2^{\circ}$ latitude-longitude resolution is considered for analysis. Mid-latitude banded jets showing similarity with observations are reproduced by our model. Those jets are accelerated and maintained by eddy momentum transfers to the mean flow, with the magnitude of momentum fluxes compliant with the observed values. The eddy activity is not regularly distributed with time, but appears as bursts; both barotropic and baroclinic instabilities could play a role in the eddy activity. The steady-state latitude of occurrence of jets is controlled by poleward migration during the spin-up of our model. At the equator, a weakly-superrotating tropospheric jet and vertically-stacked alternating stratospheric jets are obtained in our GCM simulations. The model produces Yanai (Rossby-gravity), Rossby and Kelvin waves at the equator, as well as extratropical Rossby waves, and large-scale vortices in polar regions. Challenges remain to reproduce Saturn's powerful superrotating jet and hexagon-shaped circumpolar jet in the troposphere, and downward-propagating equatorial oscillation in the stratosphere., Comment: 68 pages, 23 figures, published in Icarus https://doi.org/10.1016/j.icarus.2019.07.011
Published: 2020

22. Idealised simulations of the deep atmosphere of hot Jupiters

Author: Gilles Chabrier, F. Sainsbury-Martinez, Isabelle Baraffe, Nathan J. Mayne, Aymeric Spiga, Y. Meurdesoif, Pascal Tremblin, Benjamin Drummond, P. Wang, T. Dubos, Florian Debras, S. Fromang, Jérémy Leconte, Maison de la Simulation (MDLS), 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 Paris-Sud - Paris 11 (UP11)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-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), University of Exeter, School of Physics and Astronomy [Exeter], Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Horizon 2020 program project ATMO (ID:757858), European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 679030/WHIPLASH), Programme National de Planétologie (PNP) of CNRS-INSU cofunded by CNES., European Research Council (ERC) for funding under the H2020 research and innovation programme (grant agreement 787361 COBOM), European Research Council (ERC) for funding under the H2020 research and innovation programme (grant agreement 740651 NewWorlds)., 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), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, 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), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, 01 natural sciences, Isothermal process, 0103 physical sciences, Hot Jupiter, planets and satellites: individual: HD 209458b, Newtonian fluid, Potential temperature, Adiabatic process, planets and satellites: fundamental parameters, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, planets and satellites: atmospheres, Advection, Astronomy and Astrophysics, Mechanics, Radius, planets and satellites: interiors, 13. Climate action, Space and Planetary Science, hydrodynamics, Dissipative system, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: Context: The anomalously large radii of hot Jupiters has long been a mystery. However, by combining both theoretical arguments and 2D models, a recent study has suggested that the vertical advection of potential temperature leads to an adiabatic temperature profile in the deep atmosphere hotter than the profile obtained with standard 1D models. Aims: In order to confirm the viability of that scenario, we extend this investigation to three dimensional, time-dependent, models. Methods: We use a 3D GCM, DYNAMICO to perform a series of calculations designed to explore the formation and structure of the driving atmospheric circulations, and detail how it responds to changes in both upper and deep atmospheric forcing. Results: In agreement with the previous, 2D, study, we find that a hot adiabat is the natural outcome of the long-term evolution of the deep atmosphere. Integration times of order $1500$ years are needed for that adiabat to emerge from an isothermal atmosphere, explaining why it has not been found in previous hot Jupiter studies. Models initialised from a hotter deep atmosphere tend to evolve faster toward the same final state. We also find that the deep adiabat is stable against low-levels of deep heating and cooling, as long as the Newtonian cooling time-scale is longer than $\sim 3000$ years at $200$ bar. Conclusions: We conclude that the steady-state vertical advection of potential temperature by deep atmospheric circulations constitutes a robust mechanism to explain hot Jupiter inflated radii. We suggest that future studies of hot Jupiters are evolved for a longer time than currently done, and, when possible, include models initialised with a hot deep adiabat. We stress that this mechanism stems from the advection of entropy by irradiation induced mass flows and does not require (finely tuned) dissipative process, in contrast with most previously suggested scenarios., Comment: 13 pages, 12 figures. Accepted for publication in A&A
Published: 2019

23. 6th international conference on Mars polar science and exploration: Conference summary and five top questions

Author: Patricio Becerra, Stephen M. Clifford, Isaac B. Smith, Serina Diniega, David Beaty, Ali M. Bramson, Aymeric Spiga, Sylvain Piqueux, Christine S. Hvidberg, Ganna Portyankina, Timothy N. Titus, and Thorsteinn Thorsteinsson
Subjects: Engineering, 010504 meteorology & atmospheric sciences, business.industry, 520 Astronomy, Astronomy and Astrophysics, Context (language use), Mars Exploration Program, Scientific field, 620 Engineering, 01 natural sciences, Space and Planetary Science, 0103 physical sciences, TRIPS architecture, Engineering ethics, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: We provide a historical context of the International Conference on Mars Polar Science and Exploration and summarize the proceedings from the 6th iteration of this meeting. In particular, we identify five key Mars polar science questions based primarily on presentations and discussions at the conference and discuss the overlap between some of those questions. We briefly describe the seven scientific field trips that were offered at the conference, which greatly supplemented conference discussion of Mars polar processes and landforms. We end with suggestions for measurements, modeling, and laboratory and field work that were highlighted during conference discussion as necessary steps to address key knowledge gaps.
Published: 2018

24. Seasonal variability in winds in the north polar region of Mars

Author: Aymeric Spiga and Isaac B. Smith
Subjects: Katabatic wind, 010504 meteorology & atmospheric sciences, Global wind patterns, Mesoscale meteorology, Astronomy and Astrophysics, Mars Exploration Program, Seasonality, medicine.disease, Atmospheric sciences, 01 natural sciences, Prevailing winds, Space and Planetary Science, Martian surface, 0103 physical sciences, medicine, Solstice, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: Surface features near Mars’ polar regions are very active, suggesting that they are among the most dynamic places on the planet. Much of that activity is driven by seasonal winds that strongly influence the distribution of water ice and other particulates. Morphologic features such as the spiral troughs, Chasma Boreale, and prominent circumpolar dune fields have experienced persistent winds for several Myr. Therefore, detailing the pattern of winds throughout the year is an important step to understanding what processes affect the martian surface in contemporary and past epochs. In this study, we provide polar-focused mesoscale simulations from northern spring to summer to understand variability from the diurnal to the seasonal scales. We find that there is a strong seasonality to the diurnal surface wind speeds driven primarily by the retreat of the seasonal CO 2 until about summer solstice, when the CO 2 is gone. The fastest winds are found when the CO 2 cap boundary is on the slopes of the north polar layered deposits, providing a strong thermal gradient that enhances the season-long katabatic effect. Mid-summer winds, while not as fast as spring winds, may play a role in dune migration for some dune fields. Late summer wind speeds pick up as the seasonal cap returns.
Published: 2018

25. Parameterization of Rocket Dust Storms on Mars in the LMD Martian GCM: Modeling Details and Validation

Author: Aymeric Spiga, Tanguy Bertrand, François Forget, Thomas Navarro, Ehouarn Millour, and Chao Wang
Subjects: Martian, business.product_category, 010504 meteorology & atmospheric sciences, Storm, GCM transcription factors, Mars Exploration Program, Atmospheric sciences, 01 natural sciences, Geophysics, Rocket, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Environmental science, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Published: 2018

26. Preparing for InSight: An Invitation to Participate in a Blind Test for Martian Seismicity

Author: Mark P. Panning, M. van Driel, Naomi Murdoch, Philippe Lognonné, David Mimoun, B. Kenda, L. Perrin, Bruce Banerdt, Ingrid Daubar, Matthew P. Golombek, John Clinton, Jeroen Tromp, Mélanie Drilleau, Aymeric Spiga, Savas Ceylan, Maren Böse, Raphaël F. Garcia, Renee Weber, Amir Khan, Domenico Giardini, Centre National d'Études Spatiales - CNES (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), National Aeronautics and Space Administration - NASA (USA), Université de Paris Diderot - Paris 7 (FRANCE), Sorbonne Université (FRANCE), University of Florida (USA), California Institute of Technology - Caltech (USA), Princeton University (USA), and Eidgenössische Technische Hochschule Zürich - ETHZ (SWITZERLAND)
Subjects: Martian, 010504 meteorology & atmospheric sciences, Team plan, Seismicity, Mars, Single station, Mars Exploration Program, Induced seismicity, 01 natural sciences, Test (assessment), InSight seismology geophysics noise Mars, Geophysics, Autre, 13. Climate action, 0103 physical sciences, Insight, Routine analysis, 010303 astronomy & astrophysics, Astrophysique, Geology, Seismology, 0105 earth and related environmental sciences
Abstract: The InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) lander will deploy a seismic monitoring package on Mars in November 2018. In prepara- tion for the data return, we prepared a blind test in which we invite participants to detect and characterize seismicity included in a synthetic dataset of continuous waveforms from a single station that mimics both the streams of data that will be available from InSight, as well as expected tectonic and impact seismicity and noise conditions on Mars. We expect that the test will ultimately improve and extend the current set of methods that the InSight team plan to use in routine analysis of the Martian dataset.
Published: 2017

27. Unraveling the martian water cycle with high-resolution global climate simulations

Author: Jean-Baptiste Madeleine, François Forget, Ehouarn Millour, Aymeric Spiga, Thomas Navarro, Alizée Pottier, Franck Montmessin, Andre Szantai, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de 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), 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: Martian, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Atmosphere, Atmospheric circulation, Baroclinity, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars, Astronomy and Astrophysics, Mars Exploration Program, Atmosphere of Mars, Atmospheric sciences, 01 natural sciences, Dynamics, Latitude, Meteorology, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Water cycle, climate, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Global climate modeling of the Mars water cycle is usually performed at relatively coarse resolution (200– 300 km), which may not be sufficient to properly represent the impact of waves, fronts, topography effects on the detailed structure of clouds and surface ice deposits. Here, we present new numerical simulations of the annual water cycle performed at a resolution of 1° ×1° (∼ 60 km in latitude). The model includes the radiative effects of clouds, whose influence on the thermal structure and atmospheric dynamics is significant, thus we also examine simulations with inactive clouds to distinguish the direct impact of resolution on circulation and winds from the indirect impact of resolution via water ice clouds. To first order, we find that the high resolution does not dramatically change the behavior of the system, and that simulations performed at ∼ 200 km resolution capture well the behavior of the simulated water cycle and Mars climate. Nevertheless, a detailed comparison between high and low resolution simulations, with reference to observations, reveal several significant changes that impact our understanding of the water cycle active today on Mars. The key northern cap edge dynamics are affected by an increase in baroclinic wave strength, with a complication of northern summer dynamics. South polar frost deposition is modified, with a westward longitudinal shift, since southern dynamics are also influenced. Baroclinic wave mode transitions are observed. New transient phenomena appear, like spiral and streak clouds, already documented in the observations. Atmospheric circulation cells in the polar region exhibit a large variability and are fine structured, with slope winds. Most modeled phenomena affected by high resolution give a picture of a more turbulent planet, inducing further variability. This is challenging for long-period climate studies.
Published: 2017

28. Editorial: Topical Volume on Dust Devils

Author: Ralph D. Lorenz, Aymeric Spiga, Angelo Pio Rossi, Matthew R. Balme, Dennis Reiss, Lynn D. V. Neakrase, and John C. Zarnecki
Subjects: 010504 meteorology & atmospheric sciences, Volume (thermodynamics), Meteorology, Space and Planetary Science, 0103 physical sciences, Environmental science, Astronomy and Astrophysics, Atmospheric sciences, 010303 astronomy & astrophysics, 01 natural sciences, Dust devil, 0105 earth and related environmental sciences
Published: 2016

29. Mars’ Background Free Oscillations

Author: M. Schimmel, Yasuhiro Nishikawa, Tanguy Bertrand, Aymeric Spiga, Philippe Lognonné, François Forget, Taichi Kawamura, Kei Kurita, Eléonore Stutzmann, 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), 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), Institute of Earth Sciences Jaume Almera, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), NASA Ames Research Center (ARC), The University of Tokyo (UTokyo), Schimmel, Martin [0000-0003-2601-4462], and Schimmel, Martin
Subjects: Martian, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 010504 meteorology & atmospheric sciences, Atmospheric pressure, Atmospheric circulation, Planetary boundary layer, Planetary free oscillation, Normal mode, Mars, Astronomy and Astrophysics, Mars Exploration Program, Geophysics, Atmosphere of Mars, GCM, 01 natural sciences, Seismometer, Planetary science, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences, InSight
Abstract: Observations and inversion of the eigenfrequencies of free oscillations constitute powerful tools to investigate the internal structure of a planet. On Mars, such free oscillations can be excited by atmospheric pressure and wind stresses from the Martian atmosphere, analogous to what occurs on Earth. Over long periods and on a global scale, this phenomenon may continuously excite Mars' background free oscillations (MBFs), which constitute the so-called Martian hum. However, the source exciting MBFs is related both to the global-scale atmospheric circulation on Mars and to the variations in pressure and wind at the planetary boundary layer, for which no data are available.To overcome this drawback, we focus herein on a global-scale source and use results of simulations based on General Circular Models (GCMs). GCMs can predict and reproduce long-term, global-scale Martian pressure and wind variations and suggest that, contrary to what happens on Earth, daily correlations in the Martian hum might be generated by the solar-driven GCM. After recalling the excitation terms, we calculate MBFs by using GCM computations and estimate the contribution to the hum made by the global atmospheric circulation. Although we work at the lower limit of MBF signals, the results indicate that the signal is likely to be periodic, which would allow us to use more efficient stacking theories than can be applied to Earth's hum. We conclude by discussing the perspectives for the InSight SEIS instrument to detect the Martian hum. The amplitude of the MBF signal is on the order of nanogals and is therefore hidden by instrumental and thermal noise, which implies that, provided the predicted daily coherence in hum excitation is present, the InSight SEIS seismometer should be capable of detecting the Martian hum after monthly to yearly stacks.
Published: 2019

30. ExoMars Atmospheric Mars Entry and Landing Investigations and Analysis (AMELIA)

Author: Gian Gabriele Ori, Andrea Pacifici, T. Mäkinen, Stefano Debei, Martin C. Towner, Sami W. Asmar, Tetsuya Tokano, Mark Leese, François Forget, Ari-Matti Harri, Ehouarn Millour, T. Siili, Francesca Ferri, Alessio Aboudan, Dirk Plettemeier, Aymeric Spiga, Manish R. Patel, Véronique Dehant, Mark Schoenenberger, Carlo Bettanini, Paul Withers, Özgür Karatekin, Jeffrey A. Herath, Bart Van Hove, Ingo Müller-Wodarg, Sebastien Paris, Giacomo Colombatti, Stephen R. Lewis, UCL - SST/ELI/ELIC - Earth & Climate, 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: 010504 meteorology & atmospheric sciences, Atmospheric investigations, Attitude, Dynamical models, Entry Descent and Landing (EDL), Mars, Trajectory, Astronomy and Astrophysics, Space and Planetary Science, Exploration of Mars, 01 natural sciences, Astrobiology, Aeronautics, Range (aeronautics), 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Martian, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], dynamical models, Mars landing, Mars Exploration Program, atmospheric investigations, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Geography, Mars Orbiter Laser Altimeter, trajectory, attitude, Descent (aeronautics), Mars entry
Abstract: International audience; The entry, descent and landing of Schiaparelli, the ExoMars Entry, descent and landing Demonstrator Module (EDM), offered a rare (once-per-mission) opportunity for in situ investigations of the martian environment over a wide altitude range. The aim of the ExoMars AMELIA experiment was to exploit the Entry, Descent and Landing System (EDLS) engineering measurements for scientific investigations of Mars’ atmosphere and surface. Here we present the simulations, modelling and the planned investigations prior to the Entry, Descent and Landing (EDL) event that took place on 19th October 2016. Despite the unfortunate conclusion of the Schiaparelli mission, flight data recorded during the entry and the descent until the loss of signal, have been recovered. These flight data, although limited and affected by transmission interruptions and malfunctions, are essential for investigating the anomaly and validating the EDL operation, but can also contribute towards the partial achievement of AMELIA science objectives
Published: 2019

31. Planetary boundary layer and slope winds on Venus

Author: Sébastien Lebonnois, Gerald Schubert, François Forget, Aymeric Spiga, 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), Department of Earth and Space Science (ESS-UCLA), University of California [Los Angeles] (UCLA), University of California-University of California, 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, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: Katabatic wind, 010504 meteorology & atmospheric sciences, biology, Planetary boundary layer, Astronomy and Astrophysics, Venus, biology.organism_classification, Atmospheric sciences, 01 natural sciences, Convective Boundary Layer, Atmosphere, Atmosphere of Venus, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 13. Climate action, Space and Planetary Science, Diurnal cycle, 0103 physical sciences, Anabatic wind, 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Few constraints are available to characterize the deep atmosphere of Venus, though this region is crucial to understand the interactions between surface and atmosphere on Venus. Based on simulations performed with the IPSL Venus Global Climate Model, the possible structure and characteristics of Venus’ planetary boundary layer (PBL) are investigated. The vertical profile of the potential temperature in the deepest 10 km above the surface and its diurnal variations are controlled by radiative and dynamical processes. The model predicts a diurnal cycle for the PBL activity, with a stable nocturnal PBL while convective activity develops during daytime. The diurnal convective PBL is strongly correlated with surface solar flux and is maximum around noon and in low latitude regions. It typically reaches less than 2 km above the surface, but its vertical extension is much higher over high elevations, and more precisely over the western flanks of elevated terrains. This correlation is explained by the impact of surface winds, which undergo a diurnal cycle with downward katabatic winds at night and upward anabatic winds during the day along the slopes of high-elevation terrains. The convergence of these daytime anabatic winds induces upward vertical winds, that are responsible for the correlation between height of the convective boundary layer and topography.
Published: 2018

32. Large-Eddy Simulations of Dust Devils and Convective Vortices

Author: Bradley Jemmett-Smith, Siegfried Raasch, Junshi Ito, Daniel Tyler, Seiya Nishizawa, Erika Barth, Scot Rafkin, Aymeric Spiga, Zhaolin Gu, Tetsuya Takemi, Wei Wei, Martina Klose, Fabian Hoffmann, 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), Southwest Research Institute [Boulder] (SwRI), Xi'an Jiaotong University (Xjtu), Leibniz Universität Hannover [Hannover] (LUH), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), University of Leeds, USDA-ARS, Jornada Experimental Range, New Mexico State University, RIKEN Center for Computational Science [Kobe] (RIKEN CCS), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Disaster Prevention Research Institute (DPRI), Kyoto University [Kyoto], Oregon State University (OSU), Wuhan University of Technology, 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), Leibniz Universität Hannover=Leibniz University Hannover, Kyoto University, and Wuhan University of Technology (WHUT)
Subjects: Martian, Physics, Convection, 010504 meteorology & atmospheric sciences, Mathematics::History and Overview, Astronomy and Astrophysics, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Atmospheric sciences, 01 natural sciences, Convective Boundary Layer, Physics::Geophysics, Vortex, Physics::Fluid Dynamics, Planetary science, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Dust devil, Whirlwind, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences
Abstract: International audience; In this review, we address the use of numerical computations called Large-Eddy Simulations (LES) to study dust devils, and the more general class of atmospheric phenomena they belong to (convec-tive vortices). We describe the main elements of the LES methodology. We review the properties, statistics, and variability of dust devils and convective vortices resolved by LES in both terrestrial and Martian environments. The current challenges faced by modelers using LES for dust devils are also discussed in
Published: 2016

33. Dust Devil Sediment Transport: From Lab to Field to Global Impact

Author: Martina Klose, Bradley Jemmett-Smith, Peter Knippertz, Dennis Reiss, Manish R. Patel, Ralph D. Lorenz, Aymeric Spiga, Claire E. Newman, Melinda A. Kahre, Lynn D. V. Neakrase, Mark T. Lemmon, Henrik Kahanpää, Stephen R. Lewis, Patrick L. Whelley, 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: 010504 meteorology & atmospheric sciences, Mars, Atmospheric sciences, 01 natural sciences, Dust emission, Field measurements, 0103 physical sciences, ddc:550, 010303 astronomy & astrophysics, Dust devil, Dust devils, 0105 earth and related environmental sciences, Dust environmental impact, Modeling, Earth, Astronomy and Astrophysics, Mars Exploration Program, Sediment transport, Entrainment (meteorology), Field (geography), Aerosol, Lab experiments, Earth sciences, Planetary science, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Environmental science, Planetary atmospheres
Abstract: International audience; The impact of dust aerosols on the climate and environment of Earth and Mars is complex and forms a major area of research. A difficulty arises in estimating the contribution of small-scale dust devils to the total dust aerosol. This difficulty is due to uncertainties in the amount of dust lifted by individual dust devils, the frequency of dust devil occurrence, and the lack of statistical generality of individual experiments and observations. In this paper, we review results of observational, laboratory, and modeling studies and provide an overview of dust devil dust transport on various spatio-temporal scales as obtained with the different research approaches. Methods used for the investigation of dust devils on Earth and Mars vary. For example, while the use of imagery for the investigation of dust devil occurrence frequency is common practice for Mars, this is less so the case for Earth. Modeling approaches for Earth and Mars are similar in that they are based on the same underlying theory, but they are applied in different ways. Insights into the benefits and limitations of each approach suggest potential future research focuses, which can further reduce the uncertainty associated with dust devil dust entrainment. The potential impacts of dust devils on the climates of Earth and Mars are discussed on the basis of the presented research results.
Published: 2016

34. Mesoscale modeling of Venus' bow-shape waves

Author: Sébastien Lebonnois, Aymeric Spiga, Maxence Lefèvre, 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), Department of Physics [Oxford], and University of Oxford [Oxford]
Subjects: Convection, 010504 meteorology & atmospheric sciences, Mixed layer, Mesoscale meteorology, FOS: Physical sciences, Venus, 01 natural sciences, Standing wave, Atmosphere, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 0103 physical sciences, Radiative transfer, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), biology, Cloud top, Astronomy and Astrophysics, Geophysics, biology.organism_classification, 13. Climate action, Space and Planetary Science, Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: The Akatsuki instrument LIR measured an unprecedented wave feature at the top of Venusian cloud layer. Stationary bow-shape waves of thousands of kilometers large lasting several Earth days have been observed over the main equatorial mountains. Here we use for the first time a mesoscale model of the Venus's atmosphere with high-resolution topography and fully coupled interactive radiative transfer computations. Mountain waves resolved by the model form large-scale bow shape waves with an amplitude of about 1.5 K and a size up to several decades of latitude similar to the ones measured by the Akatsuki spacecraft. The maximum amplitude of the waves appears in the afternoon due to an increase of the near-surface stability. Propagating vertically the waves encounter two regions of low static stability, the mixed layer between approximately 18 and 30 km and the convective layer between 50 and 55 km. Some part of the wave energy can pass through these regions via wave tunneling. These two layers act as wave filter, especially the deep atmosphere layer. The encounter with these layers generates trapped lee waves propagating horizontally. No stationary waves is resolved at cloud top over the polar regions because of strong circumpolar transient waves, and a thicker deep atmosphere mixed layer that filters most the mountain waves, 25 pages and 16 figures
Published: 2020

35. The DREAMS Experiment Onboard the Schiaparelli Module of the ExoMars 2016 Mission: Design, Performances and Expected Results

Author: F. Valero, Giacomo Colombatti, François Forget, Maria Genzer, J. J. Jiménez, Ernesto Palomba, Alessio Aboudan, T. Nikkanen, Ralph D. Lorenz, John Robert Brucato, Nilton O. Renno, F. J. Álvarez, J. Martinez-Oter, Daniel Toledo, Ciprian Ionut Popa, Ari-Matti Harri, I. Arruego Rodríguez, Vito Mennella, Simone Silvestro, Maria Hieta, Jean-Pierre Pommereau, Giancarlo Bellucci, Simone Pirrotta, Pietro Schipani, Franck Montmessin, Luis Vázquez, R. Molinaro, Francesca Esposito, Harri Haukka, G. Landis, G. Déprez, D. Moirin, Francesca Ferri, Jean-Jacques Berthelier, Stefano Debei, Natalia Deniskina, L. Lapauw, O. Karatekin, Fausto Cortecchia, F. Cucciarrè, G. Di Achille, Gabriele Franzese, Aymeric Spiga, Sebastiano Chiodini, Raffaele Mugnuolo, Cesare Molfese, E. Marchetti, Olivier Witasse, Jean-Luc Josset, S. B. Calcutt, Colin Wilson, V. Apestigue, Margarita Yela, F. Vivat, Pascal Rannou, Enrico Friso, D. Möhlmann, Laurent Marty, R. Hassen-Kodja, S. Rafkin, Manish R. Patel, J. Rivas, Walter Schmidt, Fabio Cozzolino, E. Segato, Roland Trautner, Henrik Kahanpää, Carlo Bettanini, INAF - Osservatorio Astronomico di Capodimonte (OAC), Istituto Nazionale di Astrofisica (INAF), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Instituto Nacional de Técnica Aeroespacial (INTA), Finnish Meteorological Institute (FMI), 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), University of Oxford [Oxford], Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), INAF - Osservatorio Astrofisico di Arcetri (OAA), INAF - Osservatorio Astronomico di Bologna (OABO), Osservatorio Astronomico d'Abruzzo, 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), Dipartimento di Fisica 'Ettore Pancini', Università degli studi di Napoli Federico II, 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 Exploration Institute [Neuchâtel] (SPACE - X), Royal Observatory of Belgium [Brussels] (ROB), NASA Glenn Research Center, NASA, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), The Open University [Milton Keynes] (OU), STRATO - LATMOS, Southwest Research Institute [San Antonio] (SwRI), Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), University of Michigan [Ann Arbor], University of Michigan System, Université de Reims Champagne-Ardenne (URCA), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Departamento de Astrofisica y Ciencias de la Atmósfera, Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Agenzia Spaziale Italiana (ASI), ITA, USA, GBR, FRA, DEU, ESP, BEL, FIN, NLD, and CHE
Subjects: Meridiani Planum, 010504 meteorology & atmospheric sciences, Computer science, Mars, 01 natural sciences, law.invention, Orbiter, law, Dust storm season, 0103 physical sciences, Aerospace engineering, 010303 astronomy & astrophysics, DREAMS, 0105 earth and related environmental sciences, Martian, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Payload, Atmospheric electric field, ExoMars, Meteorological station, Schiaparelli, Astronomy and Astrophysics, Space and Planetary Science, Touchdown, Atmosphere of Mars, Mars Exploration Program, Spare part, business
Abstract: International audience; The first of the two missions foreseen in the ExoMars program was successfully launched on 14th March 2016. It included the Trace Gas Orbiter and the Schiaparelli Entry descent and landing Demonstrator Module. Schiaparelli hosted the DREAMS instrument suite that was the only scientific payload designed to operate after the touchdown. DREAMS is a meteorological station with the capability of measuring the electric properties of the Martian atmosphere. It was a completely autonomous instrument, relying on its internal battery for the power supply. Even with low resources (mass, energy), DREAMS would be able to perform novel measurements on Mars (atmospheric electric field) and further our understanding of the Martian environment, including the dust cycle. DREAMS sensors were designed to operate in a very dusty environment, because the experiment was designed to operate on Mars during the dust storm season (October 2016 in Meridiani Planum). Unfortunately, the Schiaparelli module failed part of the descent and the landing and crashed onto the surface of Mars. Nevertheless, several seconds before the crash, the module central computer switched the DREAMS instrument on, and sent back housekeeping data indicating that the DREAMS sensors were performing nominally. This article describes the instrument in terms of scientific goals, design, working principle and performances, as well as the results of calibration and field tests. The spare model is mature and available to fly in a future mission.
Published: 2018

36. Geology and Physical Properties Investigations by the InSight Lander

Author: Sylvain Piqueux, Pierre Delage, William B. Banerdt, Ingrid Daubar, Nils Müller, Matthias Grott, Antoine Lucas, Tamara Gudkova, U. R. Christensen, Johan O. A. Robertsson, Don Banfield, Brigitte Knapmeyer-Endrun, T. Spohn, Suzanne E. Smrekar, Lucile Fayon, David Sollberger, Ralph D. Lorenz, Domenico Giardini, D. Kipp, G. Kargl, Matthew P. Golombek, Nicholas A Teanby, Sharon Kedar, B. Kenda, Ashitey Trebi-Ollennu, Raphaël F. Garcia, Ernst Hauber, Paul Morgan, Khaled Ali, Roy Lichtenheldt, Aymeric Spiga, Philippe Lognonné, Jason P. Marshall, Naomi Murdoch, David Mimoun, Cedric Schmelzbach, Joana Voigt, Constantinos Charalambous, Justin N. Maki, Veronique Ansan, William T. Pike, T. Nicollier, José E. Andrade, Mark P. Panning, Sebastien Rodriguez, Nicholas H. Warner, Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Département Electronique, Optronique et Signal (DEOS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), German Aerospace Center (DLR), Division of Engineering and Applied Science, California Institute of Technology, California Institute of Technology (CALTECH), School of Earth Sciences [Bristol], University of Bristol [Bristol], Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Jülich Centre for Neutron Science (JCNS - PGI, JARA-FIT), Peter Grünberg Institut, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Cornell University, Departments of Anesthesiology and Physiology and Biophysics, University of Alabama at Birmingham [ Birmingham] (UAB), UNS-CNRS-Observatoire de la Côte d'Azur, Géotechnique (cermes), Laboratoire Navier (navier umr 8205), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS), Department of Mechanical Engineering [Imperial College London], Imperial College London, University of Arizona, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), University of Florida [Gainesville], Schmidt United Institute of Physics of the Earth [Moscow] (IPE), Russian Academy of Sciences [Moscow] (RAS), Departamento de Ecologia (CEAMISH), Universidad Autonoma del Estado de Morelos (UAEM), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Institut National Polythechnique Houphouet Boigny, California Institute of Technology (CALTECH)-NASA, Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, and Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA)
Subjects: Seismometer, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Wind stress, Mars, 01 natural sciences, Wind speed, Seismic wave, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Planetenphysik, 0103 physical sciences, Traitement du signal et de l'image, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 010303 astronomy & astrophysics, Dust devil, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, InSight, Raumfahrt-Systemdynamik, Physical properties, Leitungsbereich PF, Astronomy and Astrophysics, Geology, Geophysics, Mars Exploration Program, Surface materials, InSight Mars Geology Physical properties Surface materials, Regolith, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Planetengeologie, Space and Planetary Science, Hesperian, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; Although not the prime focus of the InSight mission, the near-surface geology and physical properties investigations provide critical information for both placing the instruments (seismometer and heat flow probe with mole) on the surface and for understanding the nature of the shallow subsurface and its effect on recorded seismic waves. Two color cameras on the lander will obtain multiple stereo images of the surface and its interaction with the spacecraft. Images will be used to identify the geologic materials and features present, quantify their areal coverage, help determine the basic geologic evolution of the area, and provide ground truth for orbital remote sensing data. A radiometer will measure the hourly temperature of the surface in two spots, which will determine the thermal inertia of the surface materials present and their particle size and/or cohesion. Continuous measurements of wind speed and direction offer a unique opportunity to correlate dust devils and high winds with eolian changes imaged at the surface and to determine the threshold friction wind stress for grain motion on Mars. During the first two weeks after landing, these investigations will support the selection of instrument placement locations that are relatively smooth, flat, free of small rocks and load bearing. Soil mechanics parameters and elastic properties of near surface materials will be determined from mole penetration and thermal conductivity measurements from the surface to 3–5 m depth, the measurement of seismic waves during mole hammering, passive monitoring of seismic waves, and experiments with the arm and scoop of the lander (indentations, scraping and trenching). These investigations will determine and test the presence and mechanical properties of the expected 3–17 m thick fragmented regolith (and underlying fractured material) built up by impact and eolian processes on top of Hesperian lava flows and determine its seismic properties for the seismic investigation of Mars’ interior.
Published: 2018

37. Study of gravity waves distribution and propagation in the thermosphere of Mars based on MGS, ODY, MRO and MAVEN density measurements

Author: François Forget, Ehouarn Millour, M. Vals, Luca Montabone, Aymeric Spiga, François Lott, 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), 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 Space Science Institute [Boulder] (SSI)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010504 meteorology & atmospheric sciences, Gravitational wave, Longitudinal static stability, FOS: Physical sciences, Astronomy and Astrophysics, Geophysics, Mars Exploration Program, 01 natural sciences, Aerobraking, law.invention, Atmosphere, Orbiter, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, law, 0103 physical sciences, Thermosphere, Saturation (chemistry), 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: By measuring the regular oscillations of the density of CO$_{2}$ in the upper atmosphere (between 120 and 190~km), the mass spectrometer MAVEN/NGIMS (Atmosphere and Volatile EvolutioN/Neutral Gas Ion Mass Spectrometer) reveals the local impact of gravity waves (GWs). This yields precious information on the activity of GWs and the atmospheric conditions in which they propagate and break. The intensity of GWs measured by MAVEN in the upper atmosphere has been shown to be dictated by saturation processes in isothermal conditions. As a result, GWs activity is correlated to the evolution of the inverse of the background temperature. Previous data gathered at lower altitudes ($\sim$95 to $\sim$150~km) during aerobraking by the accelerometers on board MGS (Mars Global Surveyor), ODY (Mars Odyssey) and MRO (Mars Reconnaissance Orbiter) are analyzed in the light of those recent findings with MAVEN. The anti-correlation between GW-induced density perturbations and background temperature is plausibly found in the ODY data acquired in the polar regions, but not in he MGS and MRO data. MRO data in polar regions exhibit a correlation between the density perturbations and the Brunt-V\"{a}is\"{a}l\"{a} frequency, obtained from Global Climate Modeling. At lower altitude levels (between 100 and 120~km), although wave saturation might still be dominant, isothermal conditions are no longer verified. In this case, theory predicts that the intensity of GWs is no more correlated to background temperature, but to static stability. At other latitudes in the three aerobraking datasets, the GW-induced relative density perturbations are correlated with neither inverse temperature nor static stability; in this particular case, this means that the observed activity of GWs is not only controlled by saturation, but also by the effects of GWs sources and wind filtering through critical levels., Comment: 21 pages, 15 figures, version submitted to Planetary and Space Science on January 8th 2019 and accepted on July 31th 2019
Published: 2019

38. A seasonally recurrent annular cyclone in Mars northern latitudes and observations of a companion vortex

Author: T. del Río-Gaztelurrutia, Dima Titov, Miguel Almeida, François Forget, Augustin Sanchez-Lavega, Aymeric Spiga, Harald Hoffmann, Brigitte Gondet, A. Garro, Simon Wood, H. Chen Chen, Alejandro Cardesín-Moinelo, Anni Määttänen, I. Ordonez-Etxeberria, Ricardo Hueso, Departamento de Fisica Aplicada [Bilbao], Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), European Space Astronomy Centre (ESAC), European Space Agency (ESA), European Space Research and Technology Centre (ESTEC), European Space Operations Center (ESOC), Dias Almeida Data Processing and Systems, 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), 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), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: 010504 meteorology & atmospheric sciences, Atmospheric sciences, 01 natural sciences, double cyclonic vortex, law.invention, Latitude, Orbiter, Geochemistry and Petrology, law, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Mars Express, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Martian, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Atmosphere of Mars, Mars Exploration Program, water ice clouds, Martian clouds, Geophysics, 13. Climate action, Space and Planetary Science, Cyclone, Timekeeping on Mars, Longitude, Geology
Abstract: International audience; We study a seasonally recurrent cyclone and related cloud phenomena observed on Mars at Ls ~ 120°, latitude ~ 60°N and longitude 90°W from images obtained with cameras in different spacecraft between 1995 and 2018. A remarkable double cyclone formed in 2012 and we present a detailed study of its dynamics using images from Mars Express and Mars Reconnaissance Orbiter obtained between June 6 and July 9. A double cyclone was also observed in 2006 and 2008. In other Martian Years the primary cyclone showed an annular cloud morphology with a large water ice cloud observed eastward of it. The cyclones have a size of ~ 600‐800 km with a cloud‐free core of a radius ~ 100‐300 km. Tangential velocities measured from cloud tracking in 2012 images are ~ 5‐20 ms‐1 at 10 km altitude and DC moved eastwards with a velocity of 4 ms‐ 1 during its lifetime of one month. The vortices grow in the morning hours, but with the increasing insolation as the sol progresses, a part of the clouds evaporate, the winds weaken and the vortices lose coherence. This phenomenon forms under high temperature gradients in a region with a large north‐south topographic slope and has been recurrent each Martian year between 1995 and 2018. We argue the interest of studying its changing properties each Martian year in order to explore their possible relationship to the state of the Martian atmosphere at Ls ~ 120°.
Published: 2018

39. Equatorial Oscillation and Planetary Wave Activity in Saturn's Stratosphere Through the Cassini Epoch

Author: Nicolas Gorius, F. M. Flasar, Aymeric Spiga, Brigette E. Hesman, S. Guerlet, Thierry Fouchet, Leigh N. Fletcher, SRON Netherlands Institute for Space Research (SRON), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), NASA Goddard Space Flight Center (GSFC), 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), 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)
Subjects: [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Epoch (reference date), Oscillation, Infrared remote sensing, Astronomy, 01 natural sciences, Latitude, Atmosphere, Geophysics, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Saturn, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Stratosphere, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2018

40. Finite-Difference Modeling of Acoustic and Gravity Wave Propagation in Mars Atmosphere: Application to Infrasounds Emitted by Meteor Impacts

Author: Roland Martin, Bruce Banerdt, Quentin Brissaud, Aymeric Spiga, Philippe Lognonné, Lucie Rolland, Dimitri Komatitsch, Raphaël F. Garcia, Département Electronique, Optronique et Signal (DEOS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Géosciences Environnement Toulouse (GET), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Aix-Marseille Université - AMU (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut de Physique du Globe de Paris - IPGP (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), National Aeronautics and Space Administration - NASA (USA), Observatoire de la Côte d'Azur (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), California Institute of Technology - Caltech (USA), Ecole Centrale Marseille (FRANCE), Ecole Normale Supérieure de Paris - ENS Paris (FRANCE), Ecole Polytechnique (FRANCE), Ecole des Ponts ParisTech (FRANCE), Institut national des sciences de l'Univers - INSU (FRANCE), Géosciences Environnement Toulouse - GET (Toulouse, France), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), 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), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), and Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SPI.OTHER]Engineering Sciences [physics]/Other, 010504 meteorology & atmospheric sciences, Pressure sensor, Mars, Gravity waves, Atmospheric sciences, 01 natural sciences, Atmosphere, 0103 physical sciences, Numerical modeling, Traitement du signal et de l'image, Gravity wave, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Physics, Martian, Attenuation, Astronomy and Astrophysics, Geophysics, Mars Exploration Program, Acoustic wave, Atmosphere of Mars, Ray tracing (physics), Acoustic waves, 13. Climate action, Space and Planetary Science, Impacts, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, InSight mission
Abstract: International audience; The propagation of acoustic and gravity waves in planetary atmospheres is strongly dependent on both wind conditions and attenuation properties. This study presents a finite-difference modeling tool tailored for acoustic-gravity wave applications that takes into account the effect of background winds, attenuation phenomena (including relaxation effects specific to carbon dioxide atmospheres) and wave amplification by exponential density decrease with height. The simulation tool is implemented in 2D Cartesian coordinates and first validated by comparison with analytical solutions for benchmark problems. It is then applied to surface explosions simulating meteor impacts on Mars in various Martian atmospheric conditions inferred from global climate models. The acoustic wave travel times are validated by comparison with 2D ray tracing in a windy atmosphere. Our simulations predict that acoustic waves generated by impacts can refract back to the surface on wind ducts at high altitude. In addition, due to the strong nighttime near-surface temperature gradient on Mars, the acoustic waves are trapped in a waveguide close to the surface, which allows a night-side detection of impacts at large distances in Mars plains. Such theoretical predictions are directly applicable to future measurements by the INSIGHT NASA Discovery mission.
Published: 2017

41. Snow precipitation on Mars driven by cloud-induced night-time convection

Author: François Forget, Ehouarn Millour, David P. Hinson, Jean-Baptiste Madeleine, Franck Montmessin, Aymeric Spiga, Thomas Navarro, 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), Stanford University, Search for Extraterrestrial Intelligence Institute (SETI), 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), 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: Martian, Cryospheric science, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric dynamics, 010504 meteorology & atmospheric sciences, Mars Exploration Program, Atmosphere of Mars, Atmospheric sciences, Snow, 01 natural sciences, 13. Climate action, [SDU]Sciences of the Universe [physics], Inner planets, 0103 physical sciences, Atmospheric instability, General Earth and Planetary Sciences, Environmental science, Atmospheric science, Precipitation, Water cycle, 010303 astronomy & astrophysics, Water vapor, 0105 earth and related environmental sciences
Abstract: International audience; Although it contains less water vapour than Earth’s atmosphere, the Martian atmosphere hosts clouds. These clouds, composed of water-ice particles, influence the global transport of water vapour and the seasonal variations of ice deposits. However, the influence of water-ice clouds on local weather is unclear: it is thought that Martian clouds are devoid of moist convective motions, and snow precipitation occurs only by the slow sedimentation of individual particles. Here we present numerical simulations of the meteorology in Martian cloudy regions that demonstrate that localized convective snowstorms can occur on Mars. We show that such snowstorms—or ice microbursts—can explain deep night-time mixing layers detected from orbit and precipitation signatures detected below water-ice clouds by the Phoenix lander. In our simulations, convective snowstorms occur only during the Martian night, and result from atmospheric instability due to radiative cooling of water-ice cloud particles. This triggers strong convective plumes within and below clouds, with fast snow precipitation resulting from the vigorous descending currents. Night-time convection in Martian water-ice clouds and the associated snow precipitation lead to transport of water both above and below the mixing layers, and thus would affect Mars’ water cycle past and present, especially under the high-obliquity conditions associated with a more intense water cycle.
Published: 2017

42. Modeling of Ground Deformation and Shallow Surface Waves Generated by Martian Dust Devils and Perspectives for Near-Surface Structure Inversion

Author: Aymeric Spiga, William B. Banerdt, Ralph D. Lorenz, Don Banfield, Sharon Kedar, Matthew P. Golombek, Taichi Kawamura, Philippe Lognonné, Balthasar Kenda, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de 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), 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), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, CALTECH, Jet Prop Lab, M-S 321-B60,4800 Oak Grove Dr, Pasadena, CA 91109 USA, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Cornell University [New York], Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), and NASA-California Institute of Technology (CALTECH)
Subjects: Seismometer, 010504 meteorology & atmospheric sciences, MOTION, Author Keywords:Dust devils, FREQUENCY, 01 natural sciences, Physics::Geophysics, NOISE, RATIO, Large-eddy simulation, SEISMIC SIGNALS, Ground tilt, 0103 physical sciences, Subsurface, LARGE-EDDY SIMULATIONS, 010303 astronomy & astrophysics, Dust devil, 0105 earth and related environmental sciences, Remote sensing, Martian, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], MARS, Astronomy and Astrophysics, Geophysics, Mars Exploration Program, WIND, Regolith, Vortex, INFRASOUND, 13. Climate action, Space and Planetary Science, Surface wave, [SDU]Sciences of the Universe [physics], Astrophysics::Earth and Planetary Astrophysics, Noise (radio), Geology, Insight KeyWords Plus:CONVECTIVE BOUNDARY-LAYER
Abstract: International audience; We investigated the possible seismic signatures of dust devils on Mars, both at long and short period, based on the analysis of Earth data and on forward modeling for Mars. Seismic and meteorological data collected in the Mojave Desert, California, recorded the signals generated by dust devils. In the 10-100 s band, the quasi-static surface deformation triggered by pressure fluctuations resulted in detectable ground-tilt effects: these are in good agreement with our modeling based on Sorrells' theory. In addition, high-frequency records also exhibit a significant excitation in correspondence to dust devil episodes. Besides wind noise, this signal includes shallow surface waves due to the atmosphere-surface coupling and is used for a preliminary inversion of the near-surface S-wave profile down to 50 m depth. In the case of Mars, we modeled the long-period signals generated by the pressure field resulting from turbulence-resolving Large-Eddy Simulations. For typical dust-devil-like vortices with pressure drops of a couple Pascals, the corresponding horizontal acceleration is of a few nm/s(2) for rocky subsurface models and reaches 10-20 nm/s(2) for weak regolith models. In both cases, this signal can be detected by the Very-Broad Band seismometers of the InSight/SEIS experiment up to a distance of a few hundred meters from the vortex, the amplitude of the signal decreasing as the inverse of the distance. Atmospheric vortices are thus expected to be detected at the InSight landing site; the analysis of their seismic and atmospheric signals could lead to additional constraints on the near-surface structure, more precisely on the ground compliance and possibly on the seismic velocities
Published: 2017

43. Special Issue on Dust Devils

Author: Lynn D. V. Neakrase, Angelo Pio Rossi, Aymeric Spiga, Dennis Reiss, Ralph D. Lorenz, John C. Zarnecki, and M. Balme
Subjects: 010504 meteorology & atmospheric sciences, 0103 physical sciences, Environmental science, 010303 astronomy & astrophysics, 01 natural sciences, Dust devil, 0105 earth and related environmental sciences
Published: 2017

44. Dust Devil Sediment Transport: From Lab to Field to Global Impact

Author: Martina Klose, Bradley C. Jemmett-Smith, Henrik Kahanpää, Melinda Kahre, Peter Knippertz, Mark T. Lemmon, Stephen R. Lewis, Ralph D. Lorenz, Lynn D. V. Neakrase, Claire Newman, Manish R. Patel, Dennis Reiss, Aymeric Spiga, and Patrick L. Whelley
Subjects: 010504 meteorology & atmospheric sciences, 0103 physical sciences, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences
Published: 2017

45. Estimations of the Seismic Pressure Noise on Mars Determined from Large Eddy Simulations and Demonstration of Pressure Decorrelation Techniques for the Insight Mission

Author: Taichi Kawamura, Balthasar Kenda, Philippe Lognonné, Aymeric Spiga, William B. Banerdt, Naomi Murdoch, David Mimoun, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut de Physique du Globe de Paris - IPGP (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), National Aeronautics and Space Administration - NASA (USA), Université de Paris Diderot - Paris 7 (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université de La Réunion (FRANCE), California Institute of Technology - Caltech (USA), Ecole Normale Supérieure de Paris - ENS Paris (FRANCE), Ecole Polytechnique (FRANCE), Ecole des Ponts ParisTech (FRANCE), Institut national des sciences de l'Univers - INSU (FRANCE), Département Electronique, Optronique et Signal (DEOS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), 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), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), and École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)
Subjects: Seismometer, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Mars, Surface pressure, 01 natural sciences, Regolith, Physics::Geophysics, Physics - Geophysics, 0103 physical sciences, Pressure, 010303 astronomy & astrophysics, Decorrelation, Astrophysique, Seismology, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Atmospheric pressure, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Atmosphere, Astronomy and Astrophysics, Mars Exploration Program, Geodesy, Pressure sensor, Geophysics (physics.geo-ph), Physics - Atmospheric and Oceanic Physics, Amplitude, Geophysics, 13. Climate action, Space and Planetary Science, Atmospheric and Oceanic Physics (physics.ao-ph), Geology, Noise (radio), Astrophysics - Earth and Planetary Astrophysics
Abstract: International audience; The atmospheric pressure fluctuations on Mars induce an elastic response in the ground that creates a ground tilt, detectable as a seismic signal on the InSight seismometer SEIS. The seismic pressure noise is modeled using Large Eddy Simulations (LES) of the wind and surface pressure at the InSight landing site and a Green’s function ground deformation approach that is subsequently validated via a detailed comparison with two other methods: a spectral approach, and an approach based on Sorrells’ theory (Sorrells,Geophys. J. Int. 26:71–82, 1971; Sorrells et al., Nat. Phys. Sci. 229:14–16, 1971). The horizontal accelerations as a result of the ground tilt due to the LES turbulence-induced pressure fluctuations are found to be typically ∼ 2–40 nm/s2 in amplitude, whereas the direct horizontal acceleration is two orders of magnitude smaller and is thus negligible in comparison. The vertical accelerations are found to be ∼ 0.1–6 nm/s2 in amplitude. These are expected to be worst-case estimates for the seismic noise as we use a half-space approximation; the presence at some (shallow) depth of a harder layer would significantly reduce quasi-static displacement and tilt effects. We show that under calm conditions, a single-pressure measurement is representative of the large-scale pressure field (to a distance of several kilometers), particularly in the prevailing wind direction. However, during windy conditions, small-scale turbulence results in a reduced correlation between the pressure signals, and the single-pressure measurement becomes less representative of the pressure field. The correlation between the seismic signal and the pressure signal is found to be higher for the windiest period because the seismic pressure noise reflects the atmospheric structure close to the seismometer. In the same way that we reduce the atmospheric seismic signal by making use of a pressure sensor that is part of the InSight Auxiliary Payload Sensor Suite, we also the use the synthetic noise data obtained from the LES pressure field to demonstrate a decorrelation strategy. We show that our decorrelation approach is efficient, resulting in a reduction by a factor of ∼ 5 in the observed horizontal tilt noise (in the wind direction) and the vertical noise. This technique can, therefore, be used to remove the pressure signal from the seismic data obtained on Mars during the InSight mission.
Published: 2017

46. On the dynamical nature of Saturn's North Polar hexagon

Author: Aymeric Spiga, Vladimir Zeitlin, Masoud Rostami, 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), 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: 010504 meteorology & atmospheric sciences, North polar vortex, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Rotating Shallow Water Model, Geometry, Barotropic Instability, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Atmospheric sciences, 01 natural sciences, Instability, NPV, Polar vortex, Saturn, Barotropic fluid, 0103 physical sciences, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], 010303 astronomy & astrophysics, Saturn's hexagon, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Physics, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Jet (fluid), Hexagon, Astronomy and Astrophysics, Vortex, Space and Planetary Science, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Polar, Saturn's Hexagon
Abstract: International audience; An explanation of long-lived Saturn's North Polar hexagonal circumpolar jet in terms of instability of the coupled system polar vortex - circumpolar jet is proposed in the framework of the rotating shallow water model, where scarcely known vertical structure of the Saturn's atmosphere is averaged out. The absence of a hexagonal structure at Saturn's South Pole is explained similarly. By using the latest state-of-the-art observed winds in Saturn's polar regions a detailed linear stability analysis of the circumpolar jet is performed (i) excluding (\jet-only" configuration), and (2) including ("jet+vortex" configuration) the north polar vortex in the system. A domain of parameters: latitude of the circumpolar jet and curvature of its azimuthal velocity profile, where the most unstable mode of the system has azimuthal wavenumber 6, is identified. Fully nonlinear simulations are then performed, initialized either with the most unstable mode of small amplitude, or with the random combination of unstable modes. It is shown that developing barotropic instability of the "jet+vortex" system produces a long-living structure akin to the observed hexagon, which is not the case of the "jet-only" system, which was studied in this context in a number of papers in literature. The north polar vortex, thus, plays a decisive dynamical role. The influence of moist convection, which was recently suggested to be at the origin of Saturn's north polar vortex system in the literature, is investigated in the framework of the model and does not alter the conclusions.
Published: 2017

47. Large-Eddy Simulations of Dust Devils and Convective Vortices

Author: Aymeric Spiga, Erika Barth, Zhaolin Gu, Fabian Hoffmann, Junshi Ito, Bradley Jemmett-Smith, Martina Klose, Seiya Nishizawa, Siegfried Raasch, Scot Rafkin, Tetsuya Takemi, Daniel Tyler, and Wei Wei
Subjects: 010504 meteorology & atmospheric sciences, 0103 physical sciences, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences
Published: 2017

48. Katabatic jumps in the Martian northern polar regions

Author: Aymeric Spiga, Isaac B. Smith, 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), Planetary Science Institute [Tucson] (PSI), 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: Martian, Katabatic wind, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Mesoscale meteorology, Astronomy and Astrophysics, Geophysics, Mars Exploration Program, 15. Life on land, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Atmospheric sciences, Snow, 01 natural sciences, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Polar, Martian polar ice caps, 010303 astronomy & astrophysics, Geology, Polar low, 0105 earth and related environmental sciences
Abstract: International audience; Martian polar regions host active regional wind circulations, such as the downslope katabatic winds which develop owing to near-surface radiative cooling and sloped topography. Many observations (stratigraphy from radar profiling, frost streaks, spectral analysis of ices) concur to show that aeolian processes play a key role in glacial processes in Martian polar regions. A spectacular manifestation of this resides in elongated clouds that forms within the polar spiral troughs, a series of geological depressions in Mars’ polar caps. Here we report mesoscale atmospheric modeling in Martian polar regions making use of five nested domains operating a model downscaling from horizontal resolutions of twenty kilometers to 200 m in a typical polar trough. We show that strong katabatic jumps form at the bottom of polar troughs with an horizontal morphology and location similar to trough clouds, large vertical velocity (up to +3 m/s) and temperature perturbations (up to 20 K) propitious to cloud formation. This strongly suggests that trough clouds on Mars are caused by katabatic jumps forming within polar troughs. This phenomena is analogous to the terrestrial Loewe phenomena over Antarctica’s slopes and coastlines, resulting in a distinctive “wall of snow” during katabatic events. Our mesoscale modeling results thereby suggest that trough clouds might be present manifestations of the ice migration processes that yielded the internal cap structure discovered by radar observations, as part of a “cyclic step” process. This has important implications for the stability and possible migration over geological timescales of water ice surface reservoirs—and, overall, for the evolution of Mars’ polar caps over geological timescales.
Published: 2017

49. The Mars Analysis Correction Data Assimilation (MACDA) Dataset V1.0

Author: Peter L. Read, D. Lowe, M. D. Smith, K. Marsh, Luca Montabone, James Holmes, Stephen R. Lewis, Aymeric Spiga, and A. Pamment
Subjects: Martian, Thermal Emission Spectrometer, 010504 meteorology & atmospheric sciences, Meteorology, Mars Exploration Program, Atmosphere of Mars, Atmospheric sciences, 01 natural sciences, Data assimilation, Geography, 13. Climate action, General Circulation Model, 0103 physical sciences, General Earth and Planetary Sciences, Timekeeping on Mars, Mars global surveyor, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: The Mars Analysis Correction Data Assimilation (MACDA) dataset version 1.0 contains the reanalysis of fundamental atmospheric and surface variables for the planet Mars covering a period of about three Martian years (a Martian year is about 1.88 terrestrial years). This has been produced by data assimilation of observations from NASA's Mars Global Surveyor (MGS) spacecraft during its science mapping phase (February 1999–August 2004). In particular, we have used retrieved thermal profiles and total dust optical depths from the Thermal Emission Spectrometer (TES) on board MGS. Data have been assimilated into a Mars global climate model (MGCM) using the Analysis Correction scheme developed at the UK Meteorological Office. The MGCM used is the UK spectral version of the Laboratoire de Météorologie Dynamique (LMD, Paris, France) MGCM. MACDA is a joint project of the University of Oxford and The Open University in the UK.
Published: 2014

50. An intercomparison of Large-Eddy Simulations of the Martian daytime convective boundary layer

Author: Scot Rafkin, Aymeric Spiga, Tanguy Bertrand, Arnaud Colaïtis, François Forget, and Ehouarn Millour
Subjects: Martian, Convection, Daytime, 010504 meteorology & atmospheric sciences, Meteorology, Planetary boundary layer, Context (language use), Mars Exploration Program, Radiative forcing, Atmospheric sciences, 01 natural sciences, Convective Boundary Layer, 0103 physical sciences, Environmental science, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Large-Eddy Simulations (LES) for Mars resolve the Planetary Boundary Layer (PBL) turbulent dynamics by using a very fine horizontal resolution of a few tens of meters. LES modeling is becoming a more and more useful tool to prepare the robotic exploration of Mars by providing means to evaluate the intensity of convective plumes and vortices, horizontal wind gustiness, and turbulent fluctuations of temperature in the Martian PBL. In such context, and given the relative paucity of turbulence-related measurements on Mars, an intercomparison of LES models is a fruitful way to evaluate the models' predictions and to indicate possible areas of improvement. Thus, to prepare the landing of the ExoMars Schiaparelli lander (also named ExoMars Demonstrator Module, EDM), scheduled for October 2016, the results of the Laboratoire de Météorologie Dynamique (LMD) and South-West Research Institute (SwRI) LES models have been compared. The objective of this study is to determine the range of uncertainties, and dispersions, of the two numerical models' predictions, for the critical phase of the spacecraft's descent in the Martian daytime turbulent PBL. First, a strategy is defined to ensure similar radiative forcing in both the LMD and SwRI models. Then, LES are performed over a flat terrain with and without large-scale ambient horizontal wind. The LMD and SwRI Martian LES models predict similar temporal evolution of the PBL and organization in the horizontal and vertical wind fields. However, the convective motions in the daytime PBL are more vigorous by a factor 1.5–2 in SwRI results than in LMD results, independently of the presence or not of ambient horizontal wind. This discrepancy is further investigated through sensitivity studies to surface conditions, ambient wind, and airborne dust loading.
Published: 2016

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