Effects of Global Dust Storms on Water Vapor in the Southern Polar Region of Mars

Martian Global Dust Storms (GDS) can significantly affect the water cycle in the lower atmosphere (040 km). We compare evolution of water vapor abundances, dust opacity and surface temperatures in the Southern Polar Region (SPR) during GDS years of MY25, MY28 and MY34 relative to years without GDS. During all GDS years, the vapor abundances decrease in the lower atmosphere in the SPR following the storm. Our results suggest that this decrease could be the result of disruption of the southward transport of vapor by atmospheric circulation. Alternatively, the decrease in vapor abundances could be caused by decreased desorption of vapor from the subsurface.