This study investigates the impact of aerosols on meteorology and fine particulate matter (PM2.5) during the August 2022 heatwaves in eastern China using a coupled regional climate-chemistry-aerosol model. Aerosols caused a net cooling effect, reducing surface air temperature, PBLH, precipitation, and increasing PM2.5 concentrations. Anthropogenic emission reductions since 2013 led to a decrease in the direct radiative effect (DRE) but little change in the indirect radiative effect (IRE), resulting in overall warming and increased precipitation, particularly in the Beijing-Tianjin-Hebei region. The study highlights the increasing relative importance of IRE compared to DRE with emission reduction and the potential for exacerbated heatwaves due to weakened aerosol cooling.

Mingjie Liang, Zhiwei Han, Jiawei Li, Yue Li, Lin Liang