The OMEGA/Mars Express Dust Storm Catalog

This paper describes the OMEGA Dust Storm Catalogue (ODSC), built over almost 4 Martian Years (end of MY 26 to mid MY 30d) from OMEGA/Mars Express hyperspectral observations. A storm detection method has been developed based on a pixel clustering algorithm applied to the OMEGA dust optical depth retrievals made at 0.9 (Formula presented.) m. The storm detections have been validated, both automatically and manually. This led to a total of 448 dust storms, of which 364 (∼81%) are local storms and 84 (∼19%) are regional ones. Some of these local dust storms are flagged as “dust lifting”, which corresponds to detections of strong atmospheric dust activities spatially localized above craters. A large increase of local dust storm activity has been noticed in MY 27 during the northern “solstitial pause” ((Formula presented.) 240–270 (Formula presented.)) from high southern latitudes to mid northern latitudes (“B”-storm season). Another active local storm season is during the “C” regional storm season ((Formula presented.) 305–330 (Formula presented.)) in MY 27 and 29. In general, most of the dust storm detections have been made between 10:00 and 18:00, with a detection peak from 14:00 to 16:00. These regional storms are concentrated on MY 29 ((Formula presented.) 210–360 (Formula presented.)) and on MY 28 ((Formula presented.) 210–240 (Formula presented.)), with only a few detections during the northern solstitial pause in both years. Many of these detections were made during the MY 28 Global Dust Storms formation period ((Formula presented.) 265–270 (Formula presented.)) in both hemispheres, showing stronger and/or more efficient dust lifting and transport processes compared to other years.