一次江淮大暴雨嵌套数值模拟试验

利用MM5非静力平衡模式，设计了未嵌套、两生和三重嵌套模式方案，对1999年6月23日一次江淮大暴雨过程进行了实际资料的降水个例试验，重点讨论了嵌套对数值模拟结果的影响。结果表明：嵌套后，随着水平分辩率的提高，模拟的降水量越来越大；三重嵌套的中间层细网格已经可以把雨区范围、降水中心位置、降水强度比较接近实况地模拟出来，最内层累网格中模拟出若干个β中等尺度降水中心；嵌套后内层细网格信息的外传会使外层粗网格的模拟结果有所改善。

Multi-nested Numerical Simulation Experiments of a Storm Rainfall over Yangtze River

The mult i-nested numerical simulat io n ex periment s o f a storm rainfall o ver Yang tze River o n 23 June 1999 are conducted by nonhy drostat ic mo del MM5. The effect s of mult i-nest to the r esult of simulatio n are discussed. T he result s of exper iment s show that : in nest-grid model, the amount o f pr ecipitation increases with the rise in hor izontal resolut ion; the middle g rid of thr ee-nested gr id can simulate rain area and the posit ion of rain center and rainfall density accur ately, some meso-Bscale rain centers appear in inner gr id; Mesoscale informat ion in f ine gr id improves the simulat io n result s in co arse grid; the f ine grid increases the rate of nonconvect ive precipitatio n in coarse gr id, but the ex tent o f increase is finite.