A5051099357- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Spaceflight effects on biology
- Scientific Research and Discoveries
- Atmospheric and Environmental Gas Dynamics
- Geology and Paleoclimatology Research
- Atmospheric Ozone and Climate
- Methane Hydrates and Related Phenomena
- Stellar, planetary, and galactic studies
- Aeolian processes and effects
- Space exploration and regulation
- Spacecraft Design and Technology
- Spacecraft and Cryogenic Technologies
- Geophysics and Gravity Measurements
- Atmospheric aerosols and clouds
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Isotope Analysis in Ecology
- Geomagnetism and Paleomagnetism Studies
- Cryospheric studies and observations
- Atmospheric chemistry and aerosols
- Meteorological Phenomena and Simulations
- Astronomy and Astrophysical Research
Centre National de la Recherche Scientifique
2016-2025
Sorbonne Université
2016-2025
École Polytechnique
2009-2025
École Normale Supérieure - PSL
2017-2025
Université Paris Sciences et Lettres
2015-2025
Laboratoire de Météorologie Dynamique
2015-2024
Institut Pierre-Simon Laplace
2015-2024
Université Paris Cité
2008-2024
Linares Medical Devices (United States)
2017-2023
University of Oxford
2022
Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument on European Space Agency's Express spacecraft provides new information Mars' geological and climatic history. Phyllosilicates formed aqueous alteration very early in planet's history (the “phyllocian” era) are found oldest terrains; sulfates were a second era “theiikian” an acidic environment. Beginning about 3.5 billion years ago, last “siderikian”) is dominated...
We describe a set of two “new generation” general circulation models the Martian atmosphere derived from we originally developed in early 1990s. The new share same physical parameterizations but use complementary numerical methods to solve atmospheric dynamic equations. vertical resolution near surface has been refined, and domain extended above 80 km. These changes are accompanied by inclusion state‐of‐the‐art better simulate dynamical processes (boundary layer scheme, subgrid‐scale...
Geomorphic evidence that Mars was warm enough to support flowing water about 3.8 billion years ago presents a continuing enigma cannot be explained by conventional greenhouse warming mechanisms. Model calculations show the surface of early could have been warmed through scattering variant effect, resulting from ability carbon dioxide ice clouds reflect outgoing thermal radiation back surface. This process also explain how Earth avoided an irreversible glaciation and extend size habitable...
Surface conditions on Mars are currently cold and dry, with water ice unstable the surface except near poles. However, geologically recent glacierlike landforms have been identified in tropics midlatitudes of Mars. The has proposed to originate from either a subsurface reservoir or atmosphere. We present high-resolution climate simulations performed model designed simulate present-day cycle but assuming 45 degrees obliquity as experienced by few million years ago. predicts accumulation...
The second ExoMars mission will be launched in 2020 to target an ancient location interpreted have strong potential for past habitability and preserving physical chemical biosignatures (as well as abiotic/prebiotic organics). deliver a lander with instruments atmospheric geophysical investigations rover tasked searching signs of extinct life. equipped drill collect material from outcrops at depth down 2 m. This subsurface sampling capability provide the best chance yet gain access...
The observation of small gullies associated with recent surface runoff on Mars has renewed the question liquid water stability at Mars. could be formed by groundwater seepage from underground aquifers; however, observations originating isolated peaks and dune crests this scenario. We show that these landforms may result melting ice in top few meters martian subsurface high obliquity. Our conclusions are based analogy between terrestrial debris flows observed Greenland numerical simulations...
In this paper, we present the results obtained by general circulation model developed at Laboratoire de Météorologie Dynamique which has been used to simulate Martian hydrological cycle. Our model, employs a simplified cloud scheme, reproduces observed water cycle with unprecedented agreement. The modeled seasonal evolution of cloudiness, also compares well data, is described in terms meteorological phenomena that control distribution. Whereas formation tropical region from changes...
The inner edge of the classical habitable zone is often defined by critical flux needed to trigger runaway greenhouse instability. This 1D notion a flux, however, may not be so relevant for inhomogeneously irradiated planets, or when water content limited (land planets). Here, based on results from our 3D global climate model, we find that circulation pattern can shift super-rotation stellar/anti stellar equatorial Rossby deformation radius significantly exceeds planetary radius. Using...
Radial velocity monitoring has found the signature of a $M \sin i = 1.3$~M$_\oplus$ planet located within Habitable Zone (HZ) Proxima Centauri \citep{Anglada16}. Despite hotter past and an active host star Proxima~b could have retained enough volatiles to sustain surface habitability \citep{Ribas2016}. Here we use 3D Global Climate Model (GCM) simulate b's atmosphere water cycle for its two likely rotation modes (1:1 3:2 spin-orbit resonances) while varying unconstrained inventory...
We have reconstructed longitude-latitude maps of column dust optical depth (CDOD) for Martian year (MY) 34 (May 5, 2017 --- March 23, 2019) using observations by the Mars Climate Sounder (MCS) aboard NASA's Reconnaissance Orbiter spacecraft. Our methodology works gridding standard and newly available estimates CDOD from MCS limb observations, "iterative weighted binning" methodology. In this work, we reconstruct four gridded per sol, at different Universal Times. Together with seasonal...
Proxima b is a planet with minimum mass of 1.3 MEarth orbiting within the habitable zone (HZ) Centauri, very low-mass, active star and Sun's closest neighbor. Here we investigate number factors related to potential habitability its ability maintain liquid water on surface. We set stage by estimating current high-energy irradiance show that currently receives 30 times more EUV radiation than Earth 250 X-rays. compute time evolution star's spectrum, which essential for modeling flux received...
We use a 3D general circulation model to compare the primitive Martian hydrological cycle in "warm and wet" "cold icy" scenarios. In warm wet scenario, an anomalously high solar flux or intense greenhouse warming artificially added climate are required maintain conditions ice-free northern ocean. Precipitation shows strong surface variations, with rates around Hellas basin west of Tharsis but low Margaritifer Sinus (where observed valley network drainage density is nonetheless high). cold...
The loss of water from Mars to space is thought result the transport upper atmosphere, where it dissociated hydrogen and escapes planet. Recent observations have suggested large, rapid seasonal intrusions into boosting abundance. We use Atmospheric Chemistry Suite on ExoMars Trace Gas Orbiter characterize distribution by altitude. Water profiles during 2018-2019 southern spring summer stormy seasons show that high-altitude preferentially supplied close perihelion, supersaturation occurs even...
Abstract The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft landed successfully on Mars imaged the surface to characterize surficial geology. Here we report geology subsurface structure of landing site aid in situ geophysical investigations. InSight a degraded impact crater Elysium Planitia smooth sandy, granule- pebble-rich with few rocks. Superposed craters are common eolian bedforms sparse. During landing, pulsed retrorockets modified...
The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission described herein has been selected for flight to as part the NASA Discovery Program. DAVINCI will be first incorporate science-driven flybys an instrumented descent sphere into a unified architecture. anticipated scientific outcome new understanding atmosphere, surface, evolutionary path possibly once-habitable planet analog hot terrestrial exoplanets. primary design features preferred launch in...
General introductionThe Mars Climate Database (MCD) is a database of meteorological fields derived from Circulation Model (GCM) numerical simulations the Martian atmosphere using Planetary (PCM) and validated available observational data. The MCD includes complementary post-processing schemes such as high spatial resolution interpolation environmental data means reconstructing variability thereof [1].The latest version MCD, 6.1, was released in December 2022. The PCM (formerly known...
A database of statistics which describe the climate and surface environment Mars has been constructed directly on basis output from multiannual integrations two general circulation models developed jointly at Laboratoire de Météorologie Dynamique du Centre National la Recherche Scientifique, France, University Oxford, United Kingdom, with support European Space Agency. The have validated to reproduce main features meteorology Mars, as observed by past spacecraft missions. As well more...
We present one Martian year of observations the density and temperature in upper atmosphere Mars (between 60 130 km) obtained by Express ultraviolet spectrometer Spectroscopy for Investigation Characteristics Atmosphere (SPICAM). Six hundred sixteen profiles were retrieved using stellar occultations technique at various latitude longitude. The atmospheric densities exhibit large seasonal fluctuations due to variations dust content lower which controls and, thus, scale height, below 50 km. In...