北京多频段闪电三维定位网及一次雷暴过程的闪电时空演化特征  

Beijing Broadband Lightning NETwork and the Spatiotemporal Evolution of Lightning Flashes during a Thunderstorm

作　　者：王东方[1,2] 孙竹玲 袁善锋 卢晶雨 郄秀书 刘明远[1,2] 徐燕 陆高鹏[1] 田野 WANG Dongfang;SUN Zhuling;YUAN Shanfeng;LU Jingyu;QIE Xiushu;LIU Mingyuan;XU Yan;LU Gaopeng;TIAN Ye(Key Laboratory of Middle Atmosphere and Global Environment Observation(LAGEO),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;School of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049;Jiangxi Provincial Artificial Weather Leading Group Office,Nanchang 330096;Meteorological Observation Center of Beijing Meteorological Administration,Beijing 100089)

机构地区：[1]中国科学院大气物理研究所中层大气和全球环境探测重点实验室,北京100029 [2]中国科学院大学地球与行星科学学院,北京100049 [3]江西省人工影响天气领导小组办公室,南昌330096 [4]北京市气象局气象探测中心,北京100089

出　　处：《大气科学》2020年第4期851-864,共14页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目41630425、41875008;国际(地区)合作与交流项目41761144074。

摘　　要：北京多频段闪电三维定位网(Beijing Broadband Lightning NETwork,简称BLNET)是一个研究和业务相结合的区域性全闪三维定位网。2015年,对BLNET硬件、站网布局及定位算法等方面进行了更新升级,提高了传感器的灵敏度,提升了软件的运算效率和站网的探测性能。升级后的BLNET不仅具备了对云闪、地闪脉冲类型的快速识别和电流峰值估算等功能,也实现了对闪电辐射源脉冲的三维实时定位,以及通道可分辨的闪电放电过程精细定位。对2017年7月7日一次雷暴过程的闪电辐射源脉冲实时三维定位结果分析表明,这次雷暴过程一共观测到11902次闪电,以云闪为主,地闪占总闪的28%,正地闪较少,仅占总地闪的5%,在雷暴成熟期,最大闪电频数高达927 flashes(6 min)^-1。通过对比分析闪电辐射源位置和对应时刻的雷达回波,发现辐射源基本集中在强回波范围内。对一次正地闪的精细定位表明,该正地闪初始阶段表现出明显的预击穿过程,闪电辐射源的始发位置位于海拔高度约5.4 km,随后通道向上发展,在约10 km高度,通道开始沿着水平发展。对一次负地闪的精细定位表明,初始阶段放电首先从约7.1 km高度处始发,通道向南水平发展,同时部分负先导分支向下发展,约38 ms后,通道短暂停止发展,17 ms后,通道始发处重新激发。以上结果表明,BLNET不仅具备对整个雷暴生命史闪电活动的三维实时定位和监测,而且可以实现对闪电三维放电通道的精细定位。The Beijing Broadband Lightning NETwork(BLNET)is a regional total flashes 3 D(three-dimensional)location network that combines research and business.In 2015,the BLNET hardware,station network layout,and location algorithm were updated and upgraded to improve the sensitivity of the sensor and improve computational efficiency and detection performance.BLNET features the functions of IC(Intra-Cloud)flashes,CG(Cloud-to-Ground)flash-pulse-type identification,and current peak estimation,as well as 3 D real-time location of lightning radiation pulses and the fine location of the channel-resolvable lightning discharge process.The analysis of the real-time 3 D location results for the lightning radiation source pulse during the thunderstorm that occurred on 7 July 2017 shows a total of11,902 lightning flashes during the thunderstorm process.Most of these flashes were dominated by IC flashes,with CG flashes accounting for just 28% of the total.PCG(Positive Cloud-to-Ground)flashes account for only 5% of the total number of CG flashes.During the mature period of the thunderstorm,the maximum lightning frequency was 927 flashes(6 min)-1.By comparing and analyzing the location of the lightning radiation source and the radar echo at the corresponding time,the radiation source was found to be basically concentrated in the strong echo range.The fine location results of the PCG flashes indicate that the initial stage involved a clear pre-breakdown process.The origin of the lightning radiation source was about 5.4 km above sea level,and then the channel developed upward.At about 10 km,the channel began to exhibit a horizontal development.The fine location results of the NCG(Negative Cloud-to-Ground)flashes indicate that the discharge first originated from a height of about 7.1 km,then the channel developed to the south,and some negative pilot branches developed downward.After about 38 ms,the channel stopped developing for a short time.After 17 ms,the channel development began again and the air was re-energized.The above results show

关 键 词：闪电三维定位 BLNET(Beijing Broadband Lightning NETwork) 雷暴 

分 类 号：P411[天文地球—大气科学及气象学]