Spatio-Temporal Level Variations of the Martian Seasonal South Polar Cap From Co-Registration of MOLA Profiles

Abstract

The seasonal deposition and sublimation of CO2 represents a major element in the Martian volatile cycle. Here, co-registration strategies are applied to Mars Orbiter Laser Altimeter profiles to obtain spatio-temporal variations in snow/ice level of the Seasonal South Polar Cap (SSPC), in grid elements of 0.5° in latitude from 60° to 87°S and 10° in longitude. The maximum snow/ice level in the range of 2–2.5 m is observed over the Residual South Polar Cap. Peak level at the Residual South Polar Cap in Martian Year 25 (MY25) are found to be typically ∼0.5 m higher than those in MY24. The total volume is estimated to peak at approximately 9.4 × 1012 m3. In addition, a map of average bulk density of the SSPC during its recession is derived. It implies much more snowfall-like precipitation at the Residual South Polar Cap and its surroundings than elsewhere on Mars.