Atmospheric analysis of dust storms in Sistan region

Abstract

The Sistan Basin in Southwest Asia has been identified as one of the most active sources of dust and windiest terrestrial environments in the world. In this paper, atmospheric analysis of 7 severe dust storms in the Sistan and the Hamoun Lake Basin region during the past two decades was performed. The national center for environmental protection and national center for atmospheric research (NCEP-NCAR) data were used for synoptic analysis of dust events. The locations of low and high pressure systems which were responsible for occurring the dust events were identified and dust plumes routes were presented. The atmospheric analysis results demonstrated that the high-pressure systems over the Caspian Sea and surrounding areas and low-pressure systems over the Indian subcontinent and surrounding areas interactions result in northerly, westerly, and northwesterly winds over the Sistan region, and caused the dust events in this area and transport of dust plumes to east and southeast area. Hamoun Lake Basin in Iran, located in southern and southwestern parts of Afghanistan, and western, northwestern, and central Pakistan are more affected by dust events than other parts of Sistan. An investigation of the areas that were affected by dust plumes showed that southern and southwestern parts of Afghanistan and western Pakistan have the highest AODs and dust load at the surveyed events. The most intense dust activity in Sistan occurs during summertime and based on the results, the maximum amount of dust load reaches 5 gm−2 in the region in some cases.