不同天气形势下首都机场雷雨的发展演变规律

Development and Evolution Rule of Thunderstorm in Different Weather Situations at Beijing Capital International Airport

对2013年首都机场不同天气形势下32个雷雨日的雷达回波进行分型研究、对比分析,发现不同类型雷雨的雷达回波有不同的发生、发展和演变特征。高空槽过境雷雨、冷涡前部雷雨、锋面雷雨均有明显冷空气入侵,雷雨回波为大片强对流回波带,自西北向东南（或自西向东）过境,雷雨多持续1~2 h,有时伴有雷雨大风、冰雹等强对流天气;冷涡底部雷雨、冷涡后部雷雨为零散的片状或块状对流单体或多单体雷暴云团有组织移动,并在移动中发展合并,逐渐形成较大的线状或带状多单体雷暴群,沿高空引导气流向南或向东南移动,其中各组成单体或多单体雷暴生成、发展及衰减十分迅速,能造成一段或多段雷雨过程;副高边缘雷雨、切变线雷雨均发生在低层高温、高湿及偏南或偏东气流中,大气中储存有大量不稳定能量,微小的触发抬升条件就会激发出新的对流单体或多单体,此类雷雨回波多突发产生,生消演变频繁,一次过程可造成多段雷雨。

By classification and comparative analysis on radar echo data of 32 thunderstorm days in different weather situations at Beijing Capital International Airport（BCIA） in 2013, it was found that different types of thunderstorm have different radar echo characteristics in the processes of its occurrence, development and evolution. The results show that the upper trough passing thunderstorm, the thunderstorm in the forepart of cold vortex and the frontal thunderstorm are usually with obvious cold air intrusion. The radar echo of these aforementioned thunderstorm is a large strong convection echo band that moves from NW to SE （or from W to E）. Most of these thunderstorms lasted for 1-2 hours and sometimes accompanied by strong convective gale or hail. Moreover, the thunderstorm echoes occurs in cold vortex bottom or its rear are scattered flake or block convective cell or multicell storm which can organized move, collide and merge, and then gradually form a large linear or zonal multicell thunderstorm group. Then the thunderstorm group echo will move to the southeast or to the south along the upper guide flow. In this period, the formation, development and decay of thunderstorm group echoes are very quickly and often cause BCIA in thunderstorm several times. It is investigated that thunderstorms happened at edge of west pacific subtropical high or caused by shear line are occurred in high temperature and high humidity condition and within south or east airflow in the lower level. Because there is a large number of unstable energy stored in the atmosphere, tiny lifting condition will inspire new convection cell or multicell. These kind of thunderstorms are occurred accidentally and evolved frequently. In addition, they would cause multistage thunderstorms.