Characterization of released dust over open waters in the south of the Iran Plateau based on satellite and ground-based measurements

Abstract

Satellite recordings by CALIPSO and Aqua-MODIS, available data on the Aerosol Robotic Net-work (AERONET), and synoptic stations have been used to investigate dust storms over the Persian Gulf and the Oman Sea from January 2007 to December 2019. We found that the depo-larization of lidar signals by atmospheric dust particles is quite sensitive to their origins (deserts, or alluvial sediments). In the CALIPSO data set, the depolarization just over the thickness of an aerosol layer is called as the integrated depolarization ratio (IPDR). The IPDR and MODIS aerosol optical depth (AOD) over the mentioned waters are in correlation with the changes in the wind pattern over the region and activities of different dust sources in the neighborhoods of the waters. This investigation shows that the highest IPDR values belong to the dust particles which are originating from the Arabian Peninsula and impacting almost all regions in the south of the Iran Plateau from February to May. Also, these waters are under considerable influence of the Mesopotamian region and dust sources at the east side of the plateau. These sources are almost composed of alluvial sediments, and the IPDR for particles rising from them, is not high as those from the Arabian desert. Even though intense dust plumes raised from sources in the East of the Plateau impact these waters very frequently in summertime, but largest dust particles belong to the plumes originating from the Arabian desert in spring.