Effects of Black Carbon on East Asian Spring Climate

The climate effects of black carbon ( BC) aerosol due to anthropogenic and biomass burning emission over East Asia in spring time from year 2000 to 2004 have been simulated. the net downward radiative flux at top of atmosphere (TOA) in both clear and all sky are increased by BC, but it is decreased at the surface (SRF). The changes of radiation in the Si Chuan basin can reach 4W/m2 at TOA, and -5.5W/m(2) at SRF, which are distinct in the model domain. Cloud coverage change is one the important way to change radiation, and BC affects the cloud water path distinctly in convective clouds than in stratiform clouds. The surface temperature in Chinese mainland is decreased about 0.4K, and it is increased in the eastern and southern India, Tibet plateau and the Indo-China peninsula. The net surface sensible heat flux and temperature difference between surface and lower atmosphere are reduced by BC.