MSL - SAM and CHEMIN, Discussion of the science/results from these instruments Options

[bugs_]

https://mars.nasa.gov/news/8548/with-mars-m...xygen/?site=msl

Seasonal variations in Oxygen levels

[marsophile]

https://mars.nasa.gov/news/8548/with-mars-m...xygen/?site=msl

Seasonal variations in Oxygen levels

Quantitatively, the relative increase in spring and summer of oxygen seems to be roughly double the increase of methane (from eyeballing the diagram). Then in fall and winter the changes are reversed. This seems consistent with a

CO₂ + 2H₂O --> CH₄ + 2O₂

atmospheric reaction that can be reversed. Although a straight H2O dissociation has been ruled out, perhaps there is some condition or catalyst that promotes the interaction of the two gasses. The paper mentions the possibility of a soil release but then a particular quantitative correlation would seem coincidental.

It might be interesting to see if there is any correlation with deviations from predicted atmospheric water vapour.

[serpens]

There does seem to be a tentative correlation between the observed oxygen mixing ratio and the annual variation in both atmospheric pressure and water content. The thing that caught my eye is the data points in winter dropping well below predictions, but consistent with the atmospheric pressure during southern ice cap winters being lower than for northern winters. Gale has already thrown a few surprises and the conundrum for those struggling to develop hypotheses is the inability to determine whether the variations are global or a feature of Gale or perhaps craters in general.