Coupled atmosphere-land surface modeling over GAME-T region

The South China Sea Monsoon (SCSM) onset of 1998 has been studied by using a coupled mesoscale atmosphere-land surface model composed of NCAR/PSU MM5 and GSFC PLACE. A series of two-week numerical experiments have been carried out to study the effect of local land-cover change on the regional earth climate system. The modeling results were compared with the observations of a field campaign GEWEX GAME-Tropics over Thailand. The model correctly simulated the onset of SCSM, which was at May 19, with the build up of the westerly over the northern part of Indian ocean, and the moving of strong convection and precipitation from the Bay of Bangle to the south China sea. Water and energy budgets in various model domains have been analyzed to assess the role of atmosphere and land-surface components responsible for the monsoon development. Preliminary results shew that the land use is important in affecting the hydrological cycle in SCSM development. Moreover, the latent heat resulted from the convective precipitation of SCSM fueled up the formation of a low pressure belt which later tremendously contributed to the flood in Yantz river region in June.