我国中东部雷暴活动特征分析

基于2010—2014年国家闪电监测网的云-地闪电定位数据,利用雷暴识别与追踪算法获得了505 257个雷暴系统,进而统计分析了我国中东部地区的雷暴发生发展特征。考虑地形和气候差异,将我国中东部划分为东北、华北、华中与华东、西南、华南五个区域,对比了上述区域的雷暴中地闪活动持续时间、移动距离、移动速度等特征,并进一步对雷暴发生的环境物理量特征进行了统计分析,最后讨论了雷暴发生与地形的相关关系。结果显示:雷暴具有局地性强、快速生消的特性,超过70%的雷暴移动速度低于60 km·h~(-1),超过80%的雷暴持续时间低于2 h,超过90%的雷暴移动距离低于60 km;东北地区雷暴移动速度相对更快,西南地区移速较慢且雷暴移动距离更短。华中与华东、华南地区雷暴发生的整层可降水量与对流有效位能值最高,西南次之,东北与华北地区最低,而0～6 km垂直风切变则反之;广东、海南等地为雷暴发生最活跃区域,江南、西南地区东部、华南地区西部、华北地区太行山一带等地为雷暴发生较为活跃的地区;雷暴发生与地形密切相关,四川盆地西麓与珠江三角洲地区明显呈现出随地形抬升而导致雷暴触发的情况。

Statistic Analysis of Thunderstorm Characteristics in Central and Eastern China

Based on the cloud-ground lightning location data of the National Lightning Monitoring Network from 2010 to 2014, 505257 thunderstorm systems were obtained by using the thunderstorm identifying and tracking algorithm, and then the occurrence and development characteristics of thunderstorms in central and eastern China were statistically analyzed. Due to the differences in topography and climate, in this paper, we divided the central and eastern part of China into five regions: Northeast China, North China, Central China and East China, Southwest China and South China. We compared the thunderstorm characteristic parameters, including duration, covering range and speed, etc., analyzed the characteristics of environmental physical quantities of thunderstorms, and also discussed the correlation between thunderstorms and topography. The results showed that thunderstorms have the characteristics of strong localization and rapid development. The moving speed of more than 70% thunderstorms is slower than 60 km·h-1, the duration of more than 80% thunderstorms is less than 2 h, and the covering range of more than 90% of thunderstorms is less than 60 km. The thunderstorms in Northeast China tend to move faster, whereas those in Southwest China travel slower and the covering range is even less. The thunderstorms in Central China, East China, and South China have the highest levels of CAPE (convective available potential energy), followed by the Southwest, and the lowest CAPE is found in Northeast China and North China. In comparison, the situation for the vertical wind shear of 0-6 km is on the contrary. Guangdong and Hai nan Provinces are the regions where thunderstorms are most frequently generated. South of Yangtze River, east of Southwest China, west of South China and the Taihang Mountain regions are prone to have more active thunderstorms. In addition, the generation of thunderstorms is closely related to terrain, thus, the west foot of Sichuan Basin and the Pearl River Delta often see the thunderstorm triggered by the obvious lift of terrain.