江淮流域一次特大暴雨的数值模拟及动力分析

NUMERICAL MODELLING OF JULY 1991 RAINSTORM OVER THE CHANGJIANG-HUAIHE REACHES WITH DYNAMIC ANALYSIS

以周晓平研制的有限区域细网格数值模式为基础，编制成一个套网格模式，并对１９９１年７月２～３日发生在江淮流域的特大暴雨过程，进行了数值模拟和动力分析。结果表明：低空急流加强，输送了大量暖湿空气并激发强烈的上升运动是造成该区暴雨的主要原因；在该过程中，热成风平衡遭到破坏，其非热成风平衡部分伴随相应的二级环流，也有利于垂直运动的产生。

Developed on the basis of the limited-area fine mesh model of Zhou Xiaoping is a nest-ed-grid model by which numerical simulation and dynamic analysis are performed of an exception-ally heavy rain event over the Channgjiang-Huaihe basins during July 2～3 , 1991. Results showthat low-level jet is enhanced, transporting large quantities of warm , moist air into the system,which by exciting intense rising, is responsible mainly for the rainstorm , during which thermalwind equilibrium is destroyed and a secondary circulation related to the equilibrium portion of thenonthermal wind favors the occurrence of vertical motion.