Northward movement of Martian dust localized in the region of the Hellas Basin

Abstract

Transportation of dust in and around the Hellas Basin is simulated using a Martian atmospheric general circulation model. Results of numerical experiments show that dust, originally localized near the southwestern rim of the Hellas Basin, moves northward by the southerly wind along the west inner rim of the Hellas Basin. The southerly wind is on average approximately 5 m s-1 and is significantly stronger at nighttime. It is indicated that the time-averaged southerly wind is associated with a steady barotropic structure of meridional wind in and above the Hellas Basin. It is also suggested that baroclinic waves and downslope wind on the southern slope of the Hellas Basin enhance the southerly wind. The relevance of the movement of local dust storms near the Hellas Basin to the early phase of the global dust storm in 2001 is also discussed. Copyright 2008 by the American Geophysical Union.