一次中尺度涡旋的成因分析

利用卫星云图、水汽图、常规天气图、物理量资料对2002年7月17日在华北地区上空出现的中尺度涡旋成因进行分析。分析表明：涡旋产生于斜压弱锋区中；涡旋的生成，是由多个对流单体组织起来的多尺度扰动相互作用的结果；该涡旋是一个浅薄的系统，仅在850hPa流场上有一个辐合点；涡旋的形成没有外来的水汽供应，因而强对流天气主要以大风、冰雹天气为主，在涡旋建立过程中，能量边形成边释放。

Analysis of a Mesoscale Vortex

Based on the satellite imagery and Meteorological Observation, a mesoscale vortex over North China on 17 July 2002 is analyzed. The results show that (1) The Vortex formed in weak baroclinic front zone, and caused by the interaction of muti scale disturbance of mutil cells. (2) The vortex was a shallow system, there was only a convergence area in 850hPa. (3) Without external vapour resource, the vortex weather was mainly high wind and hail. The energy released while it accumulated during the formation of vortex.