Electric field values observed near lightning flash initiations
Electric field values observed near lightning flash initiations
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DOI：
10.1029/2006gl028777
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发表时间：
2007-02
影响因子：
5.2
通讯作者：
M. Stolzenburg;T. Marshall;W. D. Rust;E. Bruning;D. MacGorman;T. Hamlin
中科院分区：
文献类型：
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作者：
M. Stolzenburg;T. Marshall;W. D. Rust;E. Bruning;D. MacGorman;T. Hamlin
从大约250个电场（E）探测的数据集中，有9个受到闪电的不利影响。这些探测被解释为在闪电起始位置附近结束。按标准压力换算，观测到的最大E为626 kV m−1，估计的最大E为929 kV m−1。E超过失控击穿阈值，RBth，由1.1-3.3倍，每次闪光之前，和过电压为1.4-4.3。在闪光前的几秒钟内，有7个病例的E值迅速增加（速率为11-100 kV m-1 s-1），有3个病例的最大E值出现在闪光前3秒或更长时间。第十次探测E > RBth，持续38秒，随后闪电在距离气球2公里处开始;一个通道在400米以内，但闪光和大E没有对仪器产生不利影响。研究结果表明，E > RBth是闪电萌生的必要条件，但不是充分条件。
From a dataset of about 250 soundings of electric field (E), nine were adversely affected by lightning. These soundings are interpreted as ending near lightning initiation locations. Scaled to standard pressure, the largest observed E was 626 kV m−1 and the largest estimated E was 929 kV m−1. E exceeded runaway breakdown threshold, RBth, by factors of 1.1–3.3 before each flash, and overvoltages were 1.4–4.3. Seven cases had rapid E increases (rates of 11–100 kV m−1 s−1) in the few seconds before the flash, and in three the maximum E occurred 3 s or more before the flash. A tenth sounding with E > RBth for 38 s had subsequent lightning initiate 2 km from the balloon; one channel came within 400 m, but the flash and large E did not adversely affect the instruments. The findings suggest that E > RBth is a necessary condition for lightning initiation, but it is not sufficient.