一次强烈雹暴的三维结构和形成机制的单、双多普勒雷达分析  

Analysis on the Three-Dimensional Structure and Formation Mechanism of a Severe Hailstorm with Single- and Dual-Doppler Radar Data

作　　者：王俊[1] 俞小鼎[2] 邰庆国[3] 盛日锋[1] 周黎明[1] 

机构地区：[1]山东省人民政府人工影响天气办公室,济南250031 [2]中国气象局培训中心,北京100081 [3]山东省气象局,济南250031

出　　处：《大气科学》2011年第2期247-258,共12页Chinese Journal of Atmospheric Sciences

基　　金：山东省自然基金项目Y2006E08;山东省科技发展计划项目2010GSF10805;山东省气象局攻关项目2006sdqxg14

摘　　要：利用单多普勒天气雷达的反射率因子、径向速度数据和双多普勒雷达反演的三维风场,分析了一次强烈雹暴的产生、发展和维持机制。主要结果为:该雹暴是产生于中等偏上垂直风切变和较大的对流有效位能条件下的右移风暴,它在旧无序多单体风暴的右侧产生。旧的多单体风暴和雹暴初始阶段主要雷达回波区域负的径向速度(向着雷达的速度)占主导地位,随着风暴的发展,特别是地面出现小冰雹后,雹暴中出现正径向速度(远离雷达的速度)区并且迅速增强,正径向速度与环境的负径向速度在强回波附近形成强烈辐合,促使雹暴发展和维持;旧多单体风暴低层的水平辐合风场主要是弱东北—东南风转西北—西南风,雹暴的水平辐合风场是由东北风和西南风组成,邻近雹暴的雷暴单体和雹暴自身在低层的风场形成半圆形的反气旋性环流。垂直风场结构表明,雹暴在高层的辐散气流与邻近雷暴单体高层气流结合后形成的下沉辐散气流,是该雹暴北风入流的主要产生原因;雹暴与邻近雷暴间通过高层和低层风场间的相互作用,促进了雹暴的产生、发展和维持。Using the data of radar reflectivity,radial velocity from a single Doppler radar and three-dimensional wind data retrieved from dual-Doppler radar,the formation,development,and maintenance mechanisms of a severe hailstorm were analyzed.The results showed that the hailstorm formed on the right side of an old disordered multi-cell storm and moved rightward,with moderate or higher vertical wind shear and large convective available potential energy（CAPE）.In the old disordered multi-cell storm and at the initial stage of this hailstorm,negative radial velocity（toward the radar） was dominant.With the development of the hailstorm,positive radial velocity（outward the radar） appeared and increased rapidly,especially after the occurrence of small-size hail.When the two airmasses,showing positive and negative radial velocities,respectively,met near the strong echo,strong convergence formed and promoted the development and maintenance of the hailstorm.At the low level of the old multi-cell storm,the wind convergence was mainly caused by the weak wind direction change from northeast-southeast to northwest-southwest.The convergence in the severe hailstorm was formed by the northeast and southwest airmasses.A semicircular anticyclonic circulation formed at the lower level between the hailstorm and thunderstorms which were close to the hailstorm.Vertical wind field structure showed that the sinking divergent flow,which formed as a result of the combination of high-level divergent flow in the hailstorm and the high-level flow in the nearby thunderstorm cell,was the main reason for northerly inflow in the hailstorm.The interaction between high- and low-level wind in the hailstorm and the nearby thunderstorms was the cause that the hailstorm formed,developed,and maintained.

关 键 词：强烈雹暴 双多普勒雷达 三维结构 单多普勒雷达 

分 类 号：P406[天文地球—大气科学及气象学]