一次台风倒槽内诱生低压及其暴雨预报的数值试验

利用细网格五层原始方程模式,考虑了大尺度凝结、积云对流、辐射和感热输送等物理过程,对一次台风倒槽内诱生低压及其暴雨进行了数值预报试验,其结果与实际情况比较一致。 

A NUMERICAL EXPERIMENT FORECASTING THE INDUC-TION OF LOW PRESSURE AND RAINSTORM IN A TYPHOON INVERTED TROUGH

A typhoon moving inland on Aug. 29, 1980 induced a low in the Jiangxi and Hunan Provinces and brought heavy rains at the induced low. Using a 5-level sigma-coordinated primitive equation model, the occurrence of the induced low in the typhoon inverted trough and the resulted rainstorm are forecasted, with consideration of physical processes for large scale condensation, cumulus convection and momentum exchange, solar radiational heating, long-wave radiational cooling, turbulent transfer and diffusion of momentum, heat and specific humidity in vertical and horizontal directions, as well as the transfer of sensible heat.The results show that the horizontal circulation, vorticity field, divergence field, vertical velocity field and convective precipitation of the induced low correspond with reality in terms of their domains, diagnostic products and satellite cluster imageries. The rainfall is less in the simulation than in the observal-tion.