【摘要】 利用复杂地形条件下嵌套细网格预报模式和 ECMWF 格点资料,对“81.7”四川大暴雨及西南涡过程进行了一系列48小时数值模拟。初步研究了大区域下垫面特征及其变化对局地区域短期降水和环流的影响。并从地表特征在地面热平衡与环流演变的相互影响中的作用这一角度去探讨了这种影响实现的可能物理途径。更多还原

【Abstract】 A nested fine mesh model over complex topograph and ECMWF’s grid data is usedto simulate a series of 48-hour processes of severe storm rainfall and the associated vor-tex on July 11—15,1981.The effect of characteristics of underlying surface for a widearea on a short-range precipitation and circulation of local regions is studied primarily.It is shown that as an important factor,characteristics of underlying surface will affectshort-range precipitation of local regions by changing the heat transfer and moisture cy-cle in the surface-atmosphere interaction,thus alterring the atmospheric structures oftemperature and humidity and vertical motion field.The short-range change in the cha-racteristics of underlying surface mainly affects their intensities of synoptic and meso-scale circulations (e.g.Lake Baykel trough and southwest China vortex,respectively),but plays no considerable role in their nature and central positions.更多还原