P94 The numerical experimentation study of the local underlying surface effect based on WRF

Li, Qiang, CQMS, China, Chongqing, and Fanyou Kong, University of Oklahoma

By simulating representative precipitation cases using WRF-ARW model in different regions with the Yangtze River water bodies added, and the local terrain modified in the inherent underlying surface, the local circulation features and different meteorological elements of the response for local surface changes are studied. The precipitation distribution change is not obvious with the Yangtze River Water bodies imbedding in the different regional rainfall cases and the impact on regional spatial precipitation from reducing terrain height in Three Gorges Reservoir Area is obvious, indicating the Yangtze River water bodies only weakly affects local precipitation. With the Yangtze River underlying surface imbedded and the terrain height modified simultaneously, greater influence on the spatial rainfall variation can be observed that is the same as modifying terrain height independently, suggesting that local topography is important to the precipitation distribution. The variation of 2 m relative humidity is different with different underlying surface water bodies and at different regional rainfall cases and the impact on local relative humidity was inconspicuous overall. The 2 m temperature, the surface upward moisture flux and the surface upward heat flux increase mostly, which are more obvious in the Yangtze River turn under the role of local terrain “bell”.