Association of anthropogenic aerosols with subtropical drought in East Asia

摘要

Anthropogenic aerosols play an important role in altering the radiation budget and Earth's climate. In this study, the association of anthropogenic aerosols with subtropical drought in East Asia is investigated with multisource data and simulations of Coupled Model Intercomparison Project Phase 5 (CMIP5) models. The result shows that the increase in anthropogenic aerosols partially contributes to the zonal drought at subtropical latitudes in East Asia from 1970. In East Asia, sulphate is the dominant type of anthropogenic aerosol and is mainly distributed over the southeastern China. Due to the sulphate aerosols, the geopotential height decreases/increases significantly at the upper-/lower-level atmosphere in the subtropical region, with a maximum variation at approximately 30 degrees N. Consequently, the downward motion of air is intensified in the subtropical region. Ultimately, the precipitation amount in the vicinity of the subtropical region is significantly diminished, with a maximum decrease at approximately 30 degrees N. In contrast, the sulphate aerosols could induce more precipitation over the tropical region. In conclusion, the anthropogenic aerosols have an important impact on precipitation in East Asia. In the future, with the intensification of human activities, the contribution of anthropogenic aerosols to aridification is an inevitable question.