The OMEGA/Mars Express Dust Storm Catalog

Abstract 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 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” ( 240–270) from high southern latitudes to mid northern latitudes (“B”‐storm season). Another active local storm season is during the “C” regional storm season ( 305–330) 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 ( 210–360) and on MY 28 ( 210–240), 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 ( 265–270) in both hemispheres, showing stronger and/or more efficient dust lifting and transport processes compared to other years.