双多普勒雷达反演强风暴三维风场的数值试验  

Numerical Experiments on Retrieving the Three-Dimensional Wind Field of a Strong Convective Storm from Dual-Doppler Radar

作　　者：何宇翔[1] 肖辉[2] 杜秉玉[1] 刘术艳[1] 

机构地区：[1]南京信息工程大学电子工程系,江苏南京210044 [2]中国科学院大气物理研究所云降水物理和强风暴实验室,北京100029

出　　处：《南京气象学院学报》2005年第4期461-467,共7页Journal of Nanjing Institute of Meteorology

基　　金：国家"十五"科技攻关计划(2001BA610A-06-052001BA904B09);国家自然科学基金资助项目(4033303340175001);中国科学院项目(Y2003002KACX1-02)

摘　　要：两部雷达测得的径向速度再加上质量连续方程可以求解大气风场,利用这一原理,以1996年6月29日发生在北京东北部京冀交界处的一次强风暴过程为例,用模式反演出风暴体的三维风场结构,误差分析表明和实况基本一致。利用模式输出的三维风场,先模拟两部多普勒雷达扫描的数据,在此基础上,进行三维风场反演,结果表明,反演得到的流场和模拟的流场总体趋势完全一致,风暴的中心位置吻合较好,上升气流和下沉气流的分布也很接近,水平速度分量反演的误差很小,基本上可以反映三维风场的真实情况。垂直速度的平均离差在各个高度上都较小,反演结果较好。A simple technique of retrieving three-dimensional wind fields is investigated from the dual-Doppler weather radar radial wind based on certain assumptions. The result provides all of the three wind components, and satisfies both the radial velocity equation system and the continuity equation. The strong convective storm that occurred on 29 June 1996 in the northeast of Beijing is chosen as the retrieving case and the errors are analyzed. Retrieved wind fields from the simulated radar data show that the general trends of the retrieved wind stream field are coincided very well with the simulated ones. The central positions are generally at the same altitude and the updraft as well as downdraft structures are almost the same. Analyses of average deviation, average squared error and relative deviation of the horizontal velocity, show that the errors are all very small, therefore, the retrieved wind field can reflect the real three-dimensional one by and large. At the same time, the average deviation of vertical velocity shows that it is very small on various heights, indicating that the retrieved results are satisfactory while the results of 27 min are even better than 36 min. The discrepancy might result from that the storm is at its robust phase with the strongest convective activity at 36 min, while at 27 min the cloud is at development stage with relative weaker convective activity. Since the retrieving results, especially the vertical velocity results are good enough to reflect real situations of three dimensional wind field and the results are much better at 5.5 km height while the centers of mesoscale convective systems are at about 4--6 km altitude, so the retrieving algorithm can be developed and utilized in future research works.

关 键 词：双多普勒雷达 三维风场反演 数值模拟 强风暴 

分 类 号：P425[天文地球—大气科学及气象学]