Atmospheric photochemistry above possible martian hot spots

International audienceConsidering the possibility of outgassing from some localized sources on Mars, we have developed a one-dimensional photochemical model that includes methane (CH4), sulfur dioxide (SO2) and hydrogen sulfide (H2S). Halogens were considered but were found to have no significant impact on the martian atmospheric chemistry. We find that the introduction of methane into the martian atmosphere results in the formation of mainly formaldehyde (CH2O), methyl alcohol (CH3OH) and ethane (C2H6), whereas the introduction of the sulfur species produces mainly sulfur monoxide (SO) and sulfuric acid (H2SO4). Depending upon the flux of the outgassed molecules from possible hot spots, some of these species and the resulting new molecules may be detectable locally, either by remote sensing (e.g., with the Planetary Fourier Spectrometer on Mars Express) or in situ measurements