Torrential rainfall east to the Tibetan Plateau

A case of torrential precipitation process in the Mei-Yu front, an Asian monsoon system east to the Tibetan Plateau, is studied with a coupled mesoscale atmospheric model MM5 and a land-surface model PLACE (Parameterization for Land-Atmosphere-Cloud Exchange). Local and Remote impacts of water vapor on the location and intensity of Mei-Yu precipitation are studied by sensitivity experiments. The precipitation-evaporation interaction acts to shift Mei-Yu rainbelt to the upstream direction of the moisture flux by about 100km, which can be intepreted by the theory of slantwise vorticity development (SVD) on isentropic surfaces. The water vapor resource for the heavy rainfall is proved majorly from the Bay of Bengle, transported by the southwesterly low level jet (LLJ) southeast to the plateau.