Upper limits on volcanic gases in the Martian atmosphere from the ACS MIR instrument

Ashwin Braude (1) , Franck Montmessin (1) , Kevin Olsen (2) , Alexander Trokhimovskiy (3) , Oleg Korablev (3) , Franck Lefèvre (1) , Anna Fedorova (3) , Juan Alday (4, 2) , Lucio Baggio (1) , Abdanour Irbah (1) , Gaetan Lacombe (1) , François Forget (5) , Ehouarn Millour (5) , Colin Wilson (2) , Andrey Patrakeev (3) , Alexey Shakun (3)

1 PLANETO - LATMOS
2 AOPP - Department of Atmospheric, Oceanic and Planetary Physics [Oxford]
3 IKI - Space Research Institute of the Russian Academy of Sciences
4 Physical and Theoretical Chemistry Laboratory [Oxford]
5 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)

The geological record provides convincing evidence for very recent volcanic activity on Mars (e.g. Horvath et al. 2021, Icarus 365, 114499). In this talk we present the results of Braude et al. (2022, A&A 658, A86), in which a comprehensive analysis was performed of solar occultation observations from the ACS MIR instrument from MY 34 to 35, in search of three tracers of residual volcanic outgassing from the surface of Mars: SO 2 , H 2 S and OCS. We found no statistically significant detections of either of these three molecules, instead imposing upper limits of 20 ppbv of SO 2 , 15 ppbv of H 2 S, and 0.4 ppbv of OCS. We thereby estimated that volcanic outgassing from the surface of Mars must be below 2 ktons day-1 .

Domains: Atmospheric and Oceanic Physics [physics.ao-ph]

Ashwin Braude, Franck Montmessin, Kevin Olsen, Alexander Trokhimovskiy, Oleg Korablev, et al.. Upper limits on volcanic gases in the Martian atmosphere from the ACS MIR instrument. Europlanet Science Congress 2022, Sep 2022, Granada, Spain. pp.EPSC2022-642. ⟨insu-03775034⟩