The origin, evolution, and trajectory of large dust storms on Mars during Mars years 24-30 (1999-2011)

Distinct locations of preferred storm origination emerge from the dust storm image sequences, including Acidalia, Utopia, Arcadia and Hellas. A route (trajectory) 'graph' for the observed sequences is provided. The routes are highly asymmetric between the two hemispheres. In the south, for non-global dust storms, the main routes are primarily oriented eastwest, whereas in the north, the routes are primarily north-south and zonally-concentrated into meridional channels. In a few impressive cases, storms originating in the northern hemisphere are observed to “flush” through Acidalia and Utopia, across the equator, and then branch in the low- and mid-southern latitudes. The origin of the 2007 global dust storm is ambiguous from the imaging data. Immediately prior to the global storm, a dust storm sequence from Chryse is identified. This storm's connection to the explosive expansion observed to start from Noachis/West Hellas is unclear due to image coverage. This paper further identifies and describes three different styles of dust storm development, which we refer to as “consecutive dust storms”, “sequential activation” and “merging.” The evolution of a given dust storm sequence can exhibit different combinations of these growth styles at different stages of development. Dust storm sequences can overlap in time, which makes them good candidate to grow into larger scale.