Search Publications
Observed seasonal changes in Martian hydrogen chloride explained by heterogeneous chemistry
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +7 more
Aims: The aim of this work is to show that the seasonal changes and vertical distribution profiles of hydrogen chloride (HCl) on Mars, as observed by the ExoMars Trace Gas Orbiter, are consistent with the production of gas-phase chlorine atoms from airborne dust and a subsequent rapid uptake of HCl onto water ice particles.
Methods: A 1D…
Climatology of gravity wave activity based on two Martian years from ACS/TGO observations
Montmessin, Franck; Starichenko, Ekaterina D.; Belyaev, Denis A. +6 more
Context. Gravity waves redistribute energy and momentum between the lower and upper atmosphere, thus providing vertical coupling between layers, and they affect the state, dynamics, and variability of the upper atmosphere. The statistics of gravity wave activity on Mars is poorly explored but is required in order to characterize the atmospheric ci…
No detection of SO2, H2S, or OCS in the atmosphere of Mars from the first two Martian years of observations from TGO/ACS
Forget, F.; Montmessin, F.; Fedorova, A. A. +13 more
Context. The detection of sulphur species in the Martian atmosphere would be a strong indicator of volcanic outgassing from the surface of Mars.
Aims: We wish to establish the presence of SO2, H2S, or OCS in the Martian atmosphere or determine upper limits on their concentration in the absence of a detection.
Method…
Seasonal reappearance of HCl in the atmosphere of Mars during the Mars year 35 dusty season
Forget, F.; Montmessin, F.; Irwin, P. G. J. +15 more
Hydrogen chloride was discovered in the atmosphere of Mars for the first time during the global dust storm in Mars year (MY) 34 (July 2018) using the Atmospheric Chemistry Suite mid-infrared channel (ACS MIR) on the ExoMars Trace Gas Orbiter. The simultaneity of variations in dust and HCl, and a correlation between water vapour and HCl, led to the…
Day-night differences in Mars methane suggest nighttime containment at Gale crater
Atreya, Sushil K.; Vasavada, Ashwin R.; Moores, John E. +10 more
We report new measurements of atmospheric methane by the Curiosity rover's Tunable Laser Spectrometer that is part of the Sample Analysis at Mars suite (TLS-SAM), finding nondetections during two daytime measurements of average value 0.05 ± 0.22 ppbv (95% confidence interval CI). These are in marked contrast with nighttime background levels of 0.5…
A stringent upper limit of 20 pptv for methane on Mars and constraints on its dispersion outside Gale crater
Daerden, F.; Forget, F.; Montmessin, F. +17 more
Context. Reports on the detection of methane in the Martian atmosphere have motivated numerous studies aiming to confirm or explain its presence on a planet where it might imply a biogenic or more likely a geophysical origin.
Aims: Our intent is to complement and improve on the previously reported detection attempts by the Atmospheric Chemist…
Isotopes of chlorine from HCl in the Martian atmosphere
Montmessin, F.; Korablev, O.; Fedorova, A. A. +7 more
Hydrogen chloride gas was recently discovered in the atmosphere of Mars during southern summer seasons. Its connection with potential chlorine reservoirs and the related atmospheric chemistry is now of particular interest and actively studied. Measurements by the Atmospheric Chemistry Suite mid-infrared channel (ACS MIR) on the ExoMars Trace Gas O…
Upper limits for phosphine (PH3) in the atmosphere of Mars
Patel, M. R.; Montmessin, F.; Irwin, P. G. J. +12 more
Phosphine (PH3) is proposed to be a possible biomarker in planetary atmospheres and has been claimed to have been observed in the atmosphere of Venus, sparking interest in the habitability of Venus's atmosphere. Observations of another biomarker, methane (CH4), have been reported several times in the atmosphere of Mars, hinti…
First observation of the magnetic dipole CO2 absorption band at 3.3 µm in the atmosphere of Mars by the ExoMars Trace Gas Orbiter ACS instrument
Montmessin, F.; Korablev, O.; Bertaux, J. -L. +8 more
The atmosphere of Mars is dominated by CO2, making it a natural laboratory for studying CO2 spectroscopy. The Atmospheric Chemistry Suite (ACS) on board the ExoMars Trace Gas Orbiter uses solar occultation geometry to search for minor atmospheric species. During the first year of ACS observations, the attention was focused on…
First detection of ozone in the mid-infrared at Mars: implications for methane detection
Montmessin, F.; Fedorova, A.; Korablev, O. +9 more
Aims: The ExoMars Trace Gas Orbiter was sent to Mars in March 2016 to search for trace gases diagnostic of active geological or biogenic processes.
Methods: We report the first observation of the spectral features of Martian ozone (O3) in the mid-infrared range using the Atmospheric Chemistry Suite Mid-InfaRed (MIR) channel, a…