Aeolian dust in Central Asia: Spatial distribution and temporal variability

Abstract

Abstract Aeolian dust is a significant factor influencing the atmospheric environment in arid and semi-arid areas, and one which deeply involves biogeochemical cycling, energy exchange, and the global carbon balance. In this study, we investigated the synoptic features of atmospheric dust in the inland region of Central Asia and analyzed its spatiotemporal variation using meteorological observation records, satellite products from the Multi-angle Imagine SpectroRadiometer (MISR), and land use and land cover (LULC) data. Results showed that aeolian dust in Central Asia is particularly significant in the arid Aral Sea region where annual average dust event frequency reached 56 d during 1984–2018. Blowing dust and intense dust storms dominated the aeolian dust weather in Central Asia, which may severely affect the regional atmospheric environment and local inhabitants' health. Dust events occurred frequently in the Aralkum Desert, Kyzylkum Desert, Caspian Depression, Kara-Bogaz-Gol and, generally, along the southern and southeastern borders of Central Asia in spring, summer and autumn seasons; such events resulted in both high particulate matter (PM) concentrations and high dust deposition rates. Meanwhile, aeolian dust event frequency around the Aralkum Desert area, Caspian Depression, and Kara-Bogaz-Gol region increased gradually from the 1980s–2010s. The Aral Sea region's Aralkum Desert is the chief dust source in the Central Asian region, emitting vast quantities of saliferous mineral dusts that are then transported into East Asia by strong westerly jets.