Aphelion Cloud Formation and Swiss Cheese Sublimation: Martian Atmospheric Water Vapour Processes

This thesis studies the behaviour of atmospheric water vapour at two points in the Martian water cycle: the formation of the Aphelion Cloud Belt (ACB) in Northern spring and summer and the sublimation of the south polar cap in Northern autumn and winter. Firstly, comparing the phase functions of ACB clouds before and after the global dust storm (GDS) of Mars year 34 finds little difference between the two, indicating the dominant ice crystal habit was not impacted by the GDS. The exact nature of this geometry is still not known. Secondly, we mapped the current extent of Swiss cheese features and determined a range of temperatures of exposed water ice within them. From this we estimated a current sublimation rate and found the water vapour contribution from them is negligible. We also determined the area of exposed water ice needed to sublimate 30 precipitable microns of water vapour.