1.Key Laboratory of Middle Atmosphere and Global Environment Observation,Institute of Atmospheric Physics,Chinese Academy of Sciences;2.Institute of Urban Meteorology,China Meteorological Administration;3.College of Atmospheric Science,Chengdu University of Information Technology
受东北冷涡和低层暖湿气流影响，2016年6月10日北京城区午后爆发了相继5次降冰雹的一次强烈雷暴天气过程。利用国家“973”项目“雷电重大灾害天气系统的动力-微物理-电过程和成灾机理（雷暴973）” 2016夏季协同观测期间获得的闪电全闪三维定位和多普勒天气雷达等资料，详细分析了此次雹暴的闪电活动和雷达回波特征。此次雹暴过程包括三个孤立的单体相继发展、并合，所分析的4次降雹过程中，总闪电频数在降雹期间都有明显增多，最高可达365 fl/min，云闪占全部闪电的80%以上，其中3次降雹前正地闪出现突增，比例升高，正地闪占全部地闪的比例最高达56%。降雹时雷达回波>45dBZ的面积增大，顶高超过13km。整个雹暴过程，闪电辐射源主要分布在6~10km的高度区域，与强回波具有一致性。全部4次降雹过程均出现明显的闪电频数跃增，并通过2б阈值检验，其中3次提前时间为8-18分钟，说明总闪频数对于降雹过程有一定的预警能力。
Influenced by the Northeast China cold vortex and warm-moist airflow in low level, a damaging thunderstorm with 5 hail-fall stages took place in Beijing on 10 June 2016. Based on the 3D-location results of total lightning from Beijing Lightning Network (BLNET) and Doppler radar data during the STORM 973 2016 campaign, the characteristics of lightning activity and radar reflectivity structure during this thunderstorm were analyzed. The thunderstorm consisted of three isolated cells triggered in sequence and merged together finally, total lightning frequency increased significantly during the 4 hail-falling stages analyzed, up to 365 fl/min. IC (intra-cloud) lightning flashes accounted for more than 80% of total lightning. The ratio of PCG/CG (positive CG to CG) increased sharply before 3 hail fall stages, up to 56%. During the developments of hailstorm, the area of radar echo greater than 45dBZ increased and echo top exceeded 13km. Lightning radiation sources mainly distributed in the altitude layer from 6 to 10 km throughout the hailstorm process, which was consistent with strong radar echo region. In addition, the total lightning flashes increased dramatically before the 4 analyzed processes, and passed 2б-threshold test. Three of them were 8-18 minutes ahead of the hail-fallings, which shows that the total lightning frequency has a certain early warning ability for hail fall process.