Impact of aerosols on tropical cyclone-induced precipitation over the mainland of China

Abstract

In this study, we investigate the impacts of aerosols on tropical cyclone (TC) precipitation that occurred from 1980 to 2014 over China mainland. The TC-induced precipitation is objectively identified based on Western North Pacific (WNP) TC historical track data and daily precipitation data from meteorological stations. Aerosol optical depth (AOD) from the Second Modern-Era Retrospective Analysis for Research and Applications (MERRA-2) is used to represent the amount of aerosol pollution. The long-term variations in AOD and TC precipitation from the past 35 years are analyzed. A significant increasing trend is found for both the relative percentage of TC rainstorm days and the amount of aerosol loading. Together with the decreasing trend in the annual number of TCs affecting China, this indicates that aerosols are invigorating TC precipitation. For the TC precipitation during the study period, the relative occurrence of light rain shows a decreasing trend, while the proportion of heavy rain and rainstorms shows an increasing trend. Meanwhile, the intensity of the TC daily precipitation increases with the elevated pollution level, particularly during the TC initial period and for heavy TC rainfall. These statistical results based on long-term observations suggest that aerosols have a substantial impact on TC precipitation through microphysical effects and have the potential to impact the track, intensity, size, and lifespan of TCs over Southeast Asia.