A modeling study of the climate effects of sulfate and carbonaceous aerosols over China

In this paper, the RIEMS 2.0 model is used to simulate the distribution of sulfate, black carbon, and organic carbon aerosols over China (16.2°–44.1°N, 93.4°–132.4°E) in 1998. The climate effects of these three anthropogenic aerosols are also simulated. The results are summarized as follows: (1) The regional average column burdens of sulfate, BC, OC, and SOC were 5.9, 0.24, 2.4, and 0.49 mg m−2, with maxima of 33.9, 1.48, 7.3, and 1.1 mg m−2, respectively. The column burden and surface concentration of secondary organic carbon accounted for about 20% and 7%, respectively, of the total organic carbon in eastern China. (2) The radiative forcings of sulfate, organic carbon, and black carbon at the top of the atmosphere were −1.24, −0.6, and 0.16 W m−2, respectively, with extremes of −5.25, −2.6, and 0.91 W m−2. (3) The surface air temperature changes caused by sulfate, organic carbon, and black carbon were −0.07, −0.04, and 0.01 K, respectively. The air temperature increase caused by black carbon at 850 hPa was higher than that at the surface. The net effect of the three kinds of anthropogenic aerosols together decreased the annual average temperature by −0.075 K; the maximum value was −0.3 K. (4) Black carbon can reduce the precipitation in arid and semi-arid areas of northern China and increase the precipitation in wet and semi-wet areas of southern China. The average precipitation increase caused by black carbon in China was 0.003 mm d−1. The net effect of the three kinds of anthropogenic aerosols was to decrease the precipitation over China by 0.008 mm d−1.