Identification of dust aerosols, their sources, and the effect of soil moisture in Central Asia

Abstract

Dust aerosols in Central Asia are an important factor in global climate change and attribution studies. Identifying the source of dust in Central Asia is crucial for understanding the ecological environment and climate, locally and globally. In this study, daily dust aerosol data were calculated and extracted for Central Asia from 2003 to 2018. The multi-year trends of dust aerosols were analyzed, dust sources were identified, the characteristics of dust aerosols in dust sources were analyzed, and the influence of soil moisture on sand initiation was explored. The results show that there are distinct seasonal characteristics in the spatial distribution of dust aerosols in Central Asia. The proportion of the area in the zone of high dust aerosols was the greatest in spring. Nearly half of the dust aerosol areas exhibited an increasing trend. A high incidence of dust sources was mainly distributed in the southern Xinjiang region. The trend of change in the dust area first increased and then decreased. With the increase in soil moisture under different wind speed conditions, the aerosols from dust sources all showed an exponentially decreasing trend, and the increase in soil moisture led to an increase in the wind speed threshold of sand initiation. This study provides basic data support for the study of dust aerosols, identifies dust sources, and provides a basis for studying the radiative forcing and climate effects of dust aerosols in Central Asia.