Study on the influence mechanism of aerosol on extreme precipitation over China based on satellite remote sensing data

With the intensification of climate change, the frequency and intensity of global extreme weather and climate events are increasing. Extreme precipitation events are typical cases, which will cause huge economic losses and casualties to human society. However, there are few studies on the mechanism of aerosol influence on extreme precipitation. Therefore, in this paper, the correlation between aerosol optical depth (AOD) and extreme precipitation in China was studied. Through the study of AOD in 2000-2020, it was found that the AOD in eastern China showed a linear decrease trend in summer and autumn, and an increase trend in northeast China in spring. In winter, the AOD in North China and Sichuan Basin showed an increase trend. The spatial distribution of AOD was related to the influence of population and industry density and topography. By calculating the correlation between precipitation and AOD, it can be found that in spring, the increase of AOD promoted extreme precipitation in northeast China, while the decrease of AOD promoted extreme precipitation in South China. In summer, except for some coastal areas in northeast China and South China, AOD in eastern China had a negative correlation with summer precipitation, and AOD promoted the occurrence of summer extreme precipitation in China. In autumn, the decrease of autumn AOD inhibited extreme precipitation in North China and promoted extreme precipitation in South China. In winter, the correlation between AOD and precipitation showed a "positive - negative - positive" spatial distribution from northeast to southwest, indicating that aerosols promoted precipitation in northeast and southwest China, while inhibited precipitation in North China and the middle and lower reaches of the Yangtze River.