Electrostatic Conditions That Produce Fast Breakdown in Thunderstorms
Electrostatic Conditions That Produce Fast Breakdown in Thunderstorms
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DOI：
10.1029/2021jd034829
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
A. Attanasio;C. Silva;P. Krehbiel
中科院分区：
文献类型：
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作者：
A. Attanasio;C. Silva;P. Krehbiel
快速击穿（FB）是由高速流光系统组成的击穿过程，已被观察到先于闪电先导形成，并在闪电引发中起关键作用。强烈的FB事件是地球上最强大的自然无线电发射的原因，被称为窄双极事件（NBE）。在本文中，Griffiths和Phelps（1976，https：//doi.org/10.1029/jc081i021p03671）流光击穿模型的改进版本与监督机器学习技术一起使用，以探测雷暴内产生FB和NBE所需的电场和电位。我们的研究结果表明，在新墨西哥州9 km高度观测到的+ FB和在佛罗里达14 km高度观测到的− FB所需的静电条件大致相同，每一个都需要大约100 MV的电势差才能传播500 m。此外，该模型说明了如何电场增强传播FB之前可以启动反弹FB的相反极性。
Fast breakdown (FB), a breakdown process composed of systems of high‐velocity streamers, has been observed to precede lightning leader formation and play a critical role in lightning initiation. Vigorous FB events are responsible for the most powerful natural radio emissions on Earth, known as narrow bipolar events (NBEs). In this paper, an improved version of the Griffiths and Phelps (1976, https://doi.org/10.1029/jc081i021p03671) model of streamer breakdown is used alongside supervised machine learning techniques to probe the required electric fields and potentials inside thunderstorms to produce FB and NBEs. Our results show that the electrostatic conditions needed to produce + FB observed in New Mexico at 9 km altitude and − FB in Florida at 14 km altitude are about the same, each requiring about 100 MV potential difference to propagate 500 m. Additionally, the model illustrates how electric field enhancement ahead of propagating FB can initiate rebounding FB of the opposite polarity.