摘要
本文利用原始方程五层模式,采用粗细网格单向嵌套的方法,初始场资料用GFDL10年(1963—1973)平均7月份的高度场和湿度场,对我国西部沙漠地区的大气环流进行了模拟计算,并在我国沙漠地区作了两种不同下垫面时大气响应的对比试验。结果表明,在青藏高原及其附近,存在三个系统:(ⅰ)青藏主体热低压,(ⅱ)帕米尔高原热低压(或新疆低压),(ⅲ)副高西伸到沙漠地区的高压脊。此外,沙漠与高原之间存在着地形性热力环流。当试验区下垫面改变为草原时,土壤及地表温室都会有所上升,有加强对流的作用,但是,由于试验区为地形性热力环流的下沉气流所控制,且处于闭塞的地形环境中,水汽来源不足,故植被的生长环境仍不能得到改善。
This paper used the five-layer primitive equation model with topography to simulate the atmospheric circulation over the desert region of North-western China. The results indicate that:1) The desert region is influenced by the systems of a) the thermal lows over Tibetan Plateau and Pamirs, and b) the ridge Of the westward spreading subtropical high.2) There is a topographically induced vertical circulation between the Plateau and the desert.The comparison of results of two tests with different underlying surfaces show that:1) The orairie surface can strengthen the tendency of updraft. restrain the downdraft and lead to accumulate upper air over the experimental area.2) The temperatures of surface layer, soil and humidity of upper air all increase, meanwhile the humidity of surface layer decreases in the experiment of prairie surface.3) The weakening of topographical circulation causes the decreasing of rainfall over the Tibetan Plateau.
出处
《气象科学》
CSCD
北大核心
1990年第3期248-258,共11页
Journal of the Meteorological Sciences
