Climate Effects of Black Carbon Aerosol from the Mainland of China and India in East Asia in Winter

Aerosols containing black carbon (BC) have a significant impact on regional and global climate change. The latest version of the regional climate and chemistry model RegCM4 is used to explore the direct influence of BC emissions from India and mainland China on East Asian climate in winter to determine the direct impact of aerosols in Asian regions. The results demonstrate that the total BC column burden, as well as the top and bottom of atmospheric and surface effective radiative forcing, are 1.78 mg m⁻², +1.98 W m⁻² and −2.17 W m⁻², respectively, in East Asia. The ways in which the mechanisms of the Chinese mainland and Indian BC affect regional climate change differ. The Indian BC will have an impact on the East Asian winter climate by altering the dynamic processes of the atmosphere, resulting in a cooling effect at lower layers with increasing scattering aerosol loadings. In contrast, the BC from the mainland of China can have an immediate impact on the East Asian climate. Its solar radiation absorption can produce a warming effect at 850 hPa in most parts of East Asia. Furthermore, because of its higher loadings in this region, BC from the mainland of China may have a significantly larger impact on East Asian winter climate changes than Indian BC. In general, the Chinese mainland and Indian BCs will reduce cloud cover and increase air temperature near 850 hPa, as well as induce decreases in sunshine duration, air temperature, sensible heat flux, and surface evaporation. As a result, the boundary layer height falls and scattering aerosol loadings rise. The findings also indicate that the direct response of the East Asian winter climate to various BC emissions is nonlinear.