DOI: 10.1002/jgrd.50261
论文题名: An "anomalous" triggered lightning flash in Florida
作者: Gamerota W.R. ; Uman M.A. ; Hill J.D. ; Pilkey J. ; Ngin T. ; Jordan D.M. ; Mata C.T.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 8 起始页码: 3402
结束页码: 3414
语种: 英语
英文关键词: Lightning
Scopus关键词: Electric fields
; Lightning
; Lightning protection
; Rockets
; Above ground level
; Channel-base currents
; Field derivatives
; High-speed video images
; Lightning mapping array
; Positively charged
; Triggered flashes
; Triggered lightning
; Wire
; atmospheric electricity
; frequency-magnitude distribution
; lightning
; trigger mechanism
; Florida [United States]
; United States
英文摘要: An "anomalous" rocket-and-wire triggered lightning flash, a flash whose leaders do not follow the triggering wire remnants to ground, is characterized via high-speed video images at 10 and 300 kilo-frames per second, still camera images, 66-72 MHz source locations from a Lightning Mapping Array, channel-base current, and electric field and electric field derivative (dE/dt) measurements. This is the first anomalous flash of about 410 classically triggered flashes in north-central Florida. The flash began with an upward positively charged leader (UPL) initiating from the tip of the upward-moving triggering wire about 280 m above ground level. All but the bottom 17 m of wire exploded (became luminous) 37.6 ms after UPL initiation. A stepped leader initiated, likely from the top of the wire remnants, 282 m above ground level about 1.3 ms after the wire explosion and propagated downward for 2.1 ms, attaching to the top of a grounded utility pole 117 m southwest of the launching facility. The line charge density on the stepped leader is estimated to be of the order of 10-3 C m-1. Contrary to previously reported "anomalous" flashes in France and New Mexico (roughly 16% and 31%, respectively, of their triggered flashes), in our event, there was not a tens of milliseconds current-zero period preceding the stepped leader, there was no observed downward dart leader in the UPL channel prior to the stepped leader to ground, and there was a failed attempt to reestablish current in the exploded-wire channel between the UPL and ground. Key points First Differences between the Florida Virgin air was the preferred path to ground ©2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63815
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Electrical and Computer Engineering, University of Florida, Gainesville FL, United States; Stinger Ghaffarian Technologies, Kennedy Space Center, FL, United States
Recommended Citation:
Gamerota W.R.,Uman M.A.,Hill J.D.,et al. An "anomalous" triggered lightning flash in Florida[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(8)