下垫面特征对一次短期天气过程影响的数值试验(Ⅱ)

A NUMERICAL EXPERIMENT OF THE INFLUENCE OF UNDERLYING SURFACE ON A SHORT-RANGE SYNOPTIC PROCESS(Ⅱ)

在文献工作的基础上,利用文献的个例和模式,研究了局地区域下垫面特征的变化对自身及其邻域短期降水和环流的影响,并探讨了可能的影响机理;最后比较了局地区域与大区域下垫面特征相同变化所致的影响差异.

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.