Numerical Simulations of the Effect of Black Carbon Aerosol on Regional Climate in China

Black carbon (BC) aerosol, as an important component of the atmospheric aerosols, has attracted much attention recently, due to its ability to absorbing solar radiation and the possible effect on climate. In this study, the Regional Climate Model version 3 (RegCM3) is used to investigate the temporal and spatial distribution of BC aerosol in East Asia and the possible effect on regional climate in China. The influence of BC aerosol on the atmospheric radiation transfer, air temperature, and rainfall are analyzed. It is revealed that three main heavy loading regions of BC exist in China, that is, Northern China, Southern China, and the Mid-lower reaches of the Yangtze River, and that the BC loading follows a clear seasonal cycle. The simulation results show that BC aerosol induces a positive radiative forcing at the top of the atmosphere, and a negative radiative forcing at the surface in this region. It is also found that the response of the climate system in summer to the radiative forcing due to BC aerosol is a decrease in the air temperature in the mid-lower reaches of the Yangtze River and Huanghe area, and an increase in the air temperature in some regions in northern China. Meanwhile, the total rainfall in Southeast China is increased, but it is decreased in some regions in northern China.