Preliminary Simulation Research of Direct Radiative Forcing of Mineral Dust Aerosol Over East Asia Region

To research the direct radiative effect of dust aerosols over East Asia region, a dust emission scheme, a transport model and a radiative scheme of dust aerosol have been added into Regional Climate Model Version 3(RegCM3). Based on the simulation between March 2001 to February 2002, it is found that Northwest China and Mongolia are the main dust sources of East Asia, where the emission rates exceed 1μg/(m2·s) with the maximum value of 90μg/(m2·s). The maximum column burden of dust aerosol is about 5g/m2, which emerges over Taklimakan desert and Qinling Mountains; The direct radiative forcing at TOA is positive over land and negative over sea, and its regional average values in Spring, Summer, Autumn, Winter are 1.08, 0.88, 0.37, 0.40W/m2 respectively. The solar radiative forcing is also positive over land and negative over sea, but the infrared radiative forcing is positive in all modeling region; The radiative forcing values at surface for four seasons are –5.64, –2.25, –1.37, –1.87W/m2 respectively. Radiative forcing can be affected deeply by the change of single scattering albedo of dust aerosol.