DOI: 10.1029/2018JA025450
Scopus记录号: 2-s2.0-85050822336
论文题名: Characteristics of Radio Emissions Associated With Terrestrial Gamma-Ray Flashes
作者: Mailyan B.G. ; Nag A. ; Murphy M.J. ; Briggs M.S. ; Dwyer J.R. ; Rison W. ; Krehbiel P.R. ; Boggs L. ; Bozarth A. ; Cramer E.S. ; Roberts O.J. ; Stanbro M. ; Rassoul H.K.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 7 起始页码: 5933
结束页码: 5948
语种: 英语
英文关键词: Fermi Gamma-ray Space Telescope
; GBM
; lightning
; NLDN
; radio frequency pulses
; terrestrial gamma-ray flashes
英文摘要: In this study, we analyze 44 terrestrial gamma-ray flashes (TGFs) detected by the Fermi Gamma-ray Burst Monitor (GBM) occurring in 2014–2016 in conjunction with data from the U.S. National Lightning Detection Network (NLDN). We examine the characteristics of magnetic field waveforms measured by NLDN sensors for 61 pulses that occurred within 5 ms of the start-time of the TGF photon flux. For 21 (out of 44) TGFs, the associated NLDN pulse occurred almost simultaneously with (that is, within 200 μs of) the TGF. One TGF had two NLDN pulses within 200 μs. The median absolute time interval between the beginning of these near-simultaneous pulses and the TGF flux start-time is 50 μs. We speculate that these RF pulses are signatures of either TGF-associated relativistic electron avalanches or currents traveling in conducting paths “preconditioned” by TGF-associated electron beams. Compared to pulses that were not simultaneous with TGFs (but within 5 ms of one), simultaneous pulses had higher median absolute peak current (26 kA versus 11 kA), longer median threshold-to-peak rise time (14 μs versus 2.8 μs), and longer median peak-to-zero time (15 μs versus 5.5 μs). A majority (77%) of our simultaneous RF pulses had NLDN-estimated peak currents less than 50 kA indicating that TGF emissions can be associated with moderate-peak-amplitude processes. The lightning flash associated with one of the TGFs in our data set was observed by a Lightning Mapping Array, which reported a relatively high-power source at an altitude of 25 km occurring 101 μs after the GBM-reported TGF discovery-bin start-time. ©2018. 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/113644
Appears in Collections: 气候减缓与适应
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作者单位: Florida Institute of Technology, Melbourne, FL, United States; The Center for Space Plasma and Aeronomic Research (CSPAR), The University of Alabama in Huntsville, Huntsville, AL, United States; Vaisala Inc., Louisville, CO, United States; Department of Physics and Space Science Center (EOS), University of New Hampshire, Durham, NH, United States; New Mexico Institute of Mining and Technology, Socorro, NM, United States; Universities Space Research Association, Huntsville, AL, United States
Recommended Citation:
Mailyan B.G.,Nag A.,Murphy M.J.,et al. Characteristics of Radio Emissions Associated With Terrestrial Gamma-Ray Flashes[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(7)