多普勒雷达径向散度在迎风坡降水中的应用  

An application of Doppler radar radial divergence to precipitation of windward slope

作　　者：王丽荣[1] 王立荣[1] 牛朝阳[1] 许宏利[1] 景华 

机构地区：[1]石家庄市气象局,石家庄050081 [2]河北省气象局,石家庄050021

出　　处：《气象科学》2010年第2期228-233,共6页Journal of the Meteorological Sciences

基　　金：国家自然科学基金(40875024);灾害天气国家重点实验室开放课题预报员专项(CMATG2006Y07)

摘　　要：以太行山东部3次迎风坡降水过程为例,分析了由多普勒雷达原始资料计算得到的径向辐合与迎风坡降水分布的关系:迎风坡降水大值区落在临近径向的辐合大值区的弱辐合区内,且降水中心落在正径向速度开始减小的边界同NE风急流相交的位置。连续分布的径向辐合越强,降水越强。同时以2004年7月11—12日过程为例说明单站径向辐合和降水率的关系:径向辐合越强,降水越强,且径向辐合变化超前于降水率变化1h以上;径向辐合持续减弱3h以上,降水率减小,直至结束。径向散度对迎风坡区域的降水预报有很好的指示作用:综合分析区域径向辐合分布和单站径向辐合随时间的变化,可以预测迎风坡降水的落区、发展及生消。The relationship between radial divergence calculated by Doppler radar base data and precipitation distribution in windward slope are analyzed according to three rainfall processes in the east of Taihang Mountains windward side, the results suggest that the large value area of windward precipitation is located in the right weak convergence area of strong radial convergence （RC） , and the center of precipitation is located in the intersection area between the boundary where positive radial speed began to decrease and the NE wind jet. The stronger the continuous distribution RC, the more intense the precipitation. The course of July 11--12, 2004 has been taken as an example to explain the relation between RC of a single station and rainrate： RC is directly proportional to precipitation intensity, and it is ahead of rainrate more than one hour. While RC continuously weakens more than 3h, the rainrate starts to decrease till over. Radial divergence is effective in precipitation forecast in windward slope, combining with region RC distribution and single-station RC change with time, the location, development, genesis as well as elimination of windward rainfall can be predicted.

关 键 词：多普勒雷达 径向散度 迎风坡降水 

分 类 号：P463.213[天文地球—大气科学及气象学]