Aerosol Forcing Dominating Late-Summer Precipitation Change Over East Asia's Transitional Climatic Zone in CMIP6 Model Simulation

Utilizing the historical simulations from the Coupled Model inter-comparison Project Phase 6 (CMIP6), the contributions of greenhouse gasses, anthropogenic aerosols, and natural forcing to the declining trend in late summer precipitation over East Asia's transitional climatic zone (TCZ) were evaluated. Late summer precipitation across the TCZ has decreased significantly between the period of 1951 and 2013, as agreed upon by the gridded dataset utilized. CESM2, ACCESS-ESM1-5, GFDL-ESM4, and HadGEM2-GC31 out of the 13 estimated models capture the amplitude of the observed trend. Our results show that the decrease in precipitation across the TCZ is mainly attributable to the influence of aerosol forcing, which has a relative contribution of 139%. In comparison, greenhouse gases show an increasing trend in precipitation with a relative contribution of − 77%. We further examine the long-term trend in consecutive dry days during JAS and find that anthropogenic aerosol emissions significantly influence their occurrence. Our findings suggest that aerosols play a significant role in the observed changes in precipitation over the TCZ.