Numerical experiment of the influence of the Bohai Sea on Liaodong Peninsula torrential rain

By using M M5V3.5 mesoscale model,at orrential rain event caused by mesoscale depression over Liaodong Peninsula on 3 August 2004 was successfully simulated.Numerical experiment compared the influence of Bohai Sea,desert,city and Liao dong Peninsula on surface temperature,humidity,horizontal velocity at different levels and vertical velocity,and investigated the effects of different underlying surface in the local thermal and dynamical structure of the PBL and corresponding circulation.Therefore,it revealed that Bohai Sea and Liaodong Peninsula topo graphy increased the rainfall remarkably.Diagnostic analysis of moist potential vorticity showed that the torrential rain occurred in strong convective instability and baroclinic instability conditions.Changing the underlying surface and lowering the terrainaltitude weakened the instability of low troposphere and resulted in the decrease of rainfall.