Distinct Aerosol Impacts on Local Scale Convective Rainfall Between Sichuan Basin and North China Plain Regions in China
Jiefeng Li, Chuanfeng Zhao, Yue Sun, Xin Zhao, Jie Yang, Yikun Yang, Annan Chen, Yue Zhou
Abstract
Abstract Aerosols modulate cloud and precipitation processes through complex aerosol‐radiation interactions (ARI) and aerosol‐cloud interactions (ACI). The influence of aerosols on precipitation varies regionally due to many factors, including aerosol characteristics, precipitation types, and meteorological conditions. Using high‐resolution precipitation data from the hourly China merged precipitation analysis (CMPA) Version 1.0 and aerosol mixing ratio data from the Modern‐Era Retrospective Analysis for Research and Application Version 2 (MERRA‐2) during the warm seasons of 2015–2020, this study employs sulfate mixing ratio () as a CCN proxy to investigate the distinct impacts of aerosols on warm‐topped and cold‐topped rainfall across the Sichuan Basin (SCB) and the North China Plain (NCP) regions in China. Our findings reveal that in SCB, aerosols suppress warm‐topped rain by stabilizing the atmosphere, reducing the cloud effective radius ( r e ) and potentially weakening collision‐coalescence processes. Conversely, in cold‐topped rain events, aerosols initially enhance rainfall, but subsequently suppress it at higher concentrations. In NCP, suspended dust increases with rising acting as both giant cloud condensation (GCCNs) and ice nuclei (INs). This enhances cloud r e and promotes rainfall across both cloud types. Furthermore, the aerosol radiative effect destabilizes the atmosphere, amplifying these processes. Despite variations in meteorological conditions, aerosols consistently exert a significant influence on rainfall. This research highlights the distinct aerosol impacts on rainfall in the two regions and underscores the need for further study to improve climate predictions.