古环境研究室知识库

Although variations of atmospheric dust aerosols emitted from different sources within Asia have been studied separately in previous research, the characteristics and causes of these changes have not been fully explored. This study used the Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2) data set for 1980-2016 to compare seasonal and interannual variations of atmospheric dust aerosols between mid-and low-latitude sources of Asia and explore the reasons for these variations. The seasonal variation of atmospheric dust aerosols in mid-latitude sources was different from that of low-latitude sources. The column burden of dust aerosols in the mid-latitude sources (including East and Central Asia) reached their maximum in spring, and accounted for about 37% and 33% of their annual total load, respectively. The maximum dust aerosols in spring in the Central Asia sources resulted from multiple factors such as soil wetness, snow depth, and vertical wind shear, but they were negatively correlated with soil wetness on the interannual scale (r = - 0.65). The maximum dust aerosol burden in spring in the East Asia sources resulted from vertical wind shear in the lower troposphere, and showed a positive correlation with the interannual change of dust aerosols in this source region (r = 0.51). However, the column burden of dust aerosols in the low-latitude sources (including South and West Asia) reached their maximum in summer, and accounted for about 41% and 37% of their annual total load, respectively. The maximum dust aerosols of summer in the low-latitude sources also resulted from vertical wind shear in the lower troposphere with correlation coefficients of 0.50 and 0.73 in the South and West Asia sources, respectively. The present results may help in further understanding the formation and change of Asian dust aerosols.