气候变化领域集成服务门户(CCPortal): A Satellite-Detected Terrestrial Gamma Ray Flash Produced by a Cloud-to-Ground Lightning Leader

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DOI	10.1029/2020GL089427
	A Satellite-Detected Terrestrial Gamma Ray Flash Produced by a Cloud-to-Ground Lightning Leader
	Pu Y.; Cummer S.A.; Huang A.; Briggs M.; Mailyan B.; Lesage S.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:15
英文摘要	We report measurements of a terrestrial gamma ray flash (TGF) detected by the Fermi Gamma-ray Burst Monitor that was produced during a negative cloud-to-ground (CG) lightning leader. This is the first report of a downward directed TGF occurring during a CG flash but detected by a space-based instrument. The gamma ray photons are produced 3 ms preceding a return stroke (−146 kA) and are essentially simultaneous with an isolated low frequency radio pulse. Based on timing, the pulse is estimated to initiate at approximately 6 km altitude, and its polarity indicates downward moving negative charge, the opposite of regular satellite-detected upward TGFs. A likely scenario is that the runaway electrons accelerate into the upper, positively charged end of the leader in a high field region, with the reverse positron beam generating upward gamma rays detectable from space. A search for similar waveform features indicates that this type of downward CG-TGF may occur prior to 1% of high peak current CG strokes. Extrapolating gives a global rate of 5–10% of previously known TGFs and potentially a significant fraction of global TGFs. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	Clouds; Lightning protection; Cloud-to-ground lightning; Gamma-ray photons; High-field regions; High-peak currents; Positively charged; Runaway electrons; Terrestrial gamma-ray flashes; Waveform features; Gamma rays; cloud to ground lightning; electron; gamma radiation; satellite data; waveform analysis
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170016
作者单位	Electrical and Computer Engineering Department, Duke University, Durham, NC, United States; Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL, United States; Center for Underground Physics, Institute for Basic Science (IBS), Daejeon, South Korea
推荐引用方式 GB/T 7714	Pu Y.,Cummer S.A.,Huang A.,et al. A Satellite-Detected Terrestrial Gamma Ray Flash Produced by a Cloud-to-Ground Lightning Leader[J],2020,47(15).
APA	Pu Y.,Cummer S.A.,Huang A.,Briggs M.,Mailyan B.,&Lesage S..(2020).A Satellite-Detected Terrestrial Gamma Ray Flash Produced by a Cloud-to-Ground Lightning Leader.Geophysical Research Letters,47(15).
MLA	Pu Y.,et al."A Satellite-Detected Terrestrial Gamma Ray Flash Produced by a Cloud-to-Ground Lightning Leader".Geophysical Research Letters 47.15(2020).