Primary Assessment of the Simulated Climatic State Using a Coupled Aerosol-Climate Model BCC_AGCM2.0.1_CAM

Using the coupled model system of the second generation Global Circulation Model of the National Climate Center (BCC_AGCM2.0.1) and Canadian Aerosol Model (CAM), the simulation of five typical aerosols (sulfate, black carbon, organic carbon, soil dust, and sea salt) and possible effects on the modeled climate are discussed in this paper. The results show that in general, the coupled system simulates the five aerosols reasonably well, and there are obvious improvements in sulfate, dust, and sea salt aerosols compared to the original monthly mean aerosol data used in BCC_AGCM2.0.1. The climatic statistics simulated by the coupled system mainly agree well with observational/reanalyzed data, and are a little better than the monthly mean aerosol data in terms of the total cloud amount, land surface temperature, and precipitation rate. The enhanced representation of dust and sea salt improves the simulation of net solar radiation at the top of the atmosphere in the Sahara Desert and mid-latitude ocean in the Southern Hemisphere and also affects the land surface temperature. The cloud feedback above the tropical ocean caused by the change in aerosol scheme not only alters radiation but also markedly influences precipitation.