殷启元,范祥鹏. 2019. 一次“晴天霹雳”致死事件分析[J]. 气象学报, (0):-, doi:10.11676/qxxb2019.004
一次“晴天霹雳”致死事件分析
Analysis of a bolt from the blue lethal event
投稿时间:2017-12-25  修订日期:2018-04-17
DOI:10.11676/qxxb2019.004
中文关键词:  雷灾事故,晴天霹雳,旁络闪击,跨步电压
英文关键词:Lightning  disaster, Bolt  from the  blue,Side  flash,Step  voltage
基金项目:国家自然科学基金,国家重点实验室
作者单位E-mail
殷启元 广东省气象公共安全技术支持中心 76806604@qq.com 
范祥鹏 中国气象科学研究院灾害天气国家重点实验室 yan-xia04@163.com 
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中文摘要:
      本文对2017年广州从化地区一次天气“晴朗”情况下的闪电致死事件进行调查分析,发现,这次事件是闪电首先击中一颗大树,然后击中附近人员头顶致死。根据目击者描述的时间和位置,利用闪电低频电场变化探测阵列的定位数据和广东电力等系统的雷电定位数据,结合广州番禺雷达观测资料,确定此事件是由一次含有7次回击的地闪过程的首次回击造成,其电流峰值强度为-30.9kA。闪电起始于13.0km高度云内,经历约600ms云内发展过程后闪电通道从云体延伸出来,云砧区边缘(0dBz)到回击点水平距离约0.3km,降水区边缘(18dBz)到回击点水平距离约1.8km。根据雷击现场等效电路模型,计算旁络闪击空气击穿场强可击穿空气与人头部连接为通路,根据电路分流原理,如果雷电流击中13m高的大树后流经到“跳点”(树干上方1/4)处后,则有13.2kA雷电流直接闪击到受害者身上,同时还承受了78.3kV跨步电压伤害,而距离雷击点10m远的目击者仅承受1.3kV跨步电压。
英文摘要:
      This paper investigation and analysis of a lethal event which caused by a" bolt from the blue " in a sunny weather, in Conghua, Guangzhou 2017,is presented in this paper. This event was as the following: the lightning strike first hit a big tree, and then hit the head of a nearby people to death. According to the occurrence time, surroundings and position of the thunder disaster described by the witness, and by using the location data of Low Frequency Electric field Detection Array (LFEDA) and Guangdong Lightning Location System (GDLLS)"s location data and Radar data from Guangzhou CINRAD-SA radar, the event could be identified as a lightning death incident caused by a "bolt from the blue". The accident discharge was found to be the first Return-Stroke (RS) with current peak of -30.9 kA which belonged to a Cloud-Ground (CG) lightning flash with 7 RSs. The flash initiated at a height of about 13km. After a cloud development process of about 600 ms, the lightning channel extends from the cloud, the horizontal distance from the edge of the cloud anvil ( 0 dbz ) to the return point is about 0.3 km, and the horizontal distance from the edge of the precipitation area ( 18 dbz ) to the return point is about 1.8 km According to the equivalent circuit model of lightning strike, we calculated the air breakdown voltage of side flash and found that the ‘jump point’ that between 1/3 and 1/4 above the trunk could form conductive path to the head of the victim. This paper assumes that the ‘jump point’ is at 1/4 above the 13m height trunk. Based on the Circuit Shunt Principle, the process of the event was inferred to be as: the flash hit the tree and the current flowed to the "jump point", then, 13.2kA lightning current blinked directly to the victim and the victim also withstood the injury of 78.3kV, while the witness who was 10m from the lightning strike point only withstood 1.3kV step voltage.
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