Impacts of Surface Processes over Land and Ocean on Summer Precipitation and Subtropical High

Comparison experiments based upon the Global Ocean- Atmosphere- Land System model developed at LASG (IAP/LASG GOALS) were designed to study the impacts of sensible and latent heat flux over land and ocean surfaces on the mean July distributions of precipitation and subtropical high, and on the seasonal variation of the Asian circulation. Results show that, the strong surface sensible heat fluxes over North America and North Africa in summer are very important for the configurations of the subtropical anticyclones over the North Pacific and North Atlantic Oceans. Through changing the recycling precipitation ratio, the surface latent heat flux over land surface affects apparently the distribution of global precipitation. It is also shown that the surface sensible heat flux of the Tibetan Plateau is the basic factor that causes the abrupt seasonal transition from winter to summer of the circulation in the surrounding area.