Dust activity over the Hellas basin of Mars during the period of southern spring equinox

Abstract

Dust storms that last for more than one Martian day frequently occur in Hellas basin of Mars around southern spring equinox. The dynamics behind the formation of these “Hellas storms”, however, is still unclear. In this study, a ten-year climatology of Martian atmospheric dust is simulated with the MarsWRF global climate model. Results suggest that occurrence of Hellas storms during southern spring equinox is related to the abrupt increase in the surface temperature contrast between the southern edge of the Hellas basin and the carbon dioxide ice covered south polar cap. Significant dust lifting over the southern edge of the Hellas basin occurs mainly during night time, due to the particular strength of the prevailing downslope flows at the site.