STUDY OF THE DIRECT RADIATIVE FORCING IN EAST CHINA WITH MODIS-GOCART ASSIMILATED AEROSOL OPTICAL DEPTH

A Regional Climate Model(RegCM2) including modified radiation transport process was used to investigate the direct radiative forcing of aerosol in East China with MODIS-GOCART assimilated aerosol optical depth of 2001, and investigate the sensitivity of radiative forcing to aerosol vertical distribution. The results show that aerosol solar effects heat the atmosphere but cool the surface. Aerosol infrared effects cool the atmosphere and heat the surface. The annual average TOA net radiative forcing is -4.1 W/m2. The net direct radiative forcing is the largest in spring, becoming smaller in summer and smallest in winter. The maximum forcing is mainly in the northern, southern of China and Sichuan Basin. Aerosol vertical distribution is one of the most important factors influencing radiative forcing. The nearer to the surface aerosol layer, the larger TOA radiative forcing and the less surface forcing. Radiative forcing at the top of atmosphere is more sensible than that on the surface to aerosol vertical distribution. The climatic feedback magnifies the influence of aerosol vertical distribution on radiative and climatic effect.