Search Publications
Global Vertical Distribution of Water Vapor on Mars: Results From 3.5 Years of ExoMars-TGO/NOMAD Science Operations
Aoki, S.; Vandaele, A. C.; Daerden, F. +20 more
We present water vapor vertical distributions on Mars retrieved from 3.5 years of solar occultation measurements by Nadir and Occultation for Mars Discovery onboard the ExoMars Trace Gas Orbiter, which reveal a strong contrast between aphelion and perihelion water climates. In equinox periods, most of water vapor is confined into the low-middle la…
Explaining NOMAD D/H Observations by Cloud-Induced Fractionation of Water Vapor on Mars
Aoki, S.; Vandaele, A. C.; Daerden, F. +25 more
The vertical profiles of water vapor and its semi-heavy hydrogen isotope HDO provided by instruments on ExoMars Trace Gas Orbiter constitute a unique new data set to understand the Martian water cycle including its isotopic composition. As water vapor undergoes hydrogen isotopic fractionation upon deposition (but not sublimation), the D/H isotopic…
A Two Martian Years Survey of Water Ice Clouds on Mars With ACS Onboard TGO
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +7 more
The middle infrared (MIR) channel of the atmospheric chemistry suite (ACS) instrument onboard the ExoMars Trace Gas Orbiter ESA-Roscosmos mission has performed Solar occultation measurements of the Martian atmosphere in the 2.3-4.2 µm spectral range since March 2018, which now covers two Martian years (MY). We use the methodology previously …
Martian Dust Storms and Gravity Waves: Disentangling Water Transport to the Upper Atmosphere
Medvedev, Alexander S.; Yiǧit, Erdal; Hartogh, Paul +2 more
Simulations with the Max Planck Institute Martian general circulation model for Martian years 28 and 34 reveal details of the water "pump" mechanism and the role of gravity wave (GW) forcing. Water is advected to the upper atmosphere mainly by upward branches of the meridional circulation: in low latitudes during equinoxes and over the south pole …
Thermal Structure and Aerosols in Mars' Atmosphere From TIRVIM/ACS Onboard the ExoMars Trace Gas Orbiter: Validation of the Retrieval Algorithm
Grigoriev, A.; Forget, F.; Montmessin, F. +12 more
The Atmospheric Chemistry Suite (ACS) onboard the ExoMars Trace Gas Orbiter monitors the Martian atmosphere through different spectral intervals in the infrared light. We present a retrieval algorithm tailored to the analysis of spectra acquired in nadir geometry by Thermal InfraRed channel in honor of professor Vassilii Ivanovich Moroz (TIRVIM), …
Density and Temperature of the Upper Mesosphere and Lower Thermosphere of Mars Retrieved From the OI 557.7 nm Dayglow Measured by TGO/NOMAD
Aoki, S.; Vandaele, A. C.; Daerden, F. +15 more
The upper mesosphere and lower thermosphere of Mars (70-150 km) is of high interest because it is a region affected by climatological/meteorological events in the lower atmosphere and external solar forcing. However, only a few measurements are available at this altitude range. OI 557.7 nm dayglow emission has been detected at these altitudes by t…
Improved Modeling of Mars' HDO Cycle Using a Mars' Global Climate Model
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +11 more
HDO and the D/H ratio are essential to understand Mars past and present climate, in particular with regard to the evolution through ages of the Martian water cycle. We present here new modeling developments of the HDO cycle with the Laboratoire de Météorologie Dynamique Mars Global Climate Model (GCM). The present study aims at exploring the behav…
Impacts of Heterogeneous Chemistry on Vertical Profiles of Martian Ozone
Vandaele, A. C.; Villanueva, G. L.; Liuzzi, G. +7 more
We show a positive vertical correlation between ozone and water ice using a vertical cross-correlation analysis with observations from the ExoMars Trace Gas Orbiter's Nadir and Occultation for Mars Discovery instrument. This is particularly apparent during LS = 0°-180°, Mars Year 35 at high southern latitudes, when the water vapor abund…
Seasonal Changes in the Vertical Structure of Ozone in the Martian Lower Atmosphere and Its Relationship to Water Vapor
Forget, F.; Montmessin, F.; Korablev, O. +13 more
The mid-infrared channel of the Atmospheric Chemistry Suite (ACS MIR) onboard the ExoMars Trace Gas Orbiter is capable of observing the infrared absorption of ozone (O3) in the atmosphere of Mars. During solar occulations, the 003←000 band (3,000-3,060 cm−1) is observed with spectral sampling of ∼0.045 cm−1. Around…
Reappraising the Production and Transfer of Hydrogen Atoms From the Middle to the Upper Atmosphere of Mars at Times of Elevated Water Vapor
Montmessin, F.; Fedorova, A. A.; Lefèvre, F. +7 more
Water escape on Mars has recently undergone a paradigm shift with the discovery of unexpected seasonal variations in the population of hydrogen atoms in the exosphere where thermal escape occurs and results in water lost to space. This discovery led to the hypothesis that, contradicting the accepted pathway, atomic hydrogen in the exosphere was no…