为研究边界层过程中地表阻曳系数对短期数值预报(特别是降水)的影响,利用复杂地形条件下有限区域数值预报模式,根据青藏高原及其北侧部分地区已有的观测结果,改变了不同地区地面阻曳系数及其组合,设计出４种不同的数值试验方案,对1991年6月11-15日的一次典型江淮梅雨天气过程进行了24-96h数值预报试验。结果表明:(1)地表阻曳系数对雨量中心强度的短期预报有一定影响;(2)4个方案中以修改了青藏高原及其北侧地区阻曳系数值的方案2更好些;(3)随积分时间延长,边界层过程对降水和形势场的影响将更显著。

In this paper,the limite-area numerical weather forecasting model suitable for complex topography and the observation data over Tibetan Plateau and part area of its north-side are used to study the influences of surface dray coefficients in boundary process on numerical weather forecasting (especially precipitation forecasting) Firstly,dray coefficients of different underlying surface are altered and combined Secondly,4 groups of different numerical experiment schemes are designed At last,24 96h numerical forecasting experiments about a typical Jianghuai Meiyu heavy rain weather process during 11 15 June,1991 have been carried out The results show: (1) Surface dray coefficients has some influences on short-range forecasting of center intensity of rainfall (2) Among 4 schemes,scheme 2,in which the drag coefficients over Tibetan Plateau and part area of its north-side are modified,has a better result (3) With integration time prolonging,the influences about boundary process on rainfall and weather situation are more notable.