DOI: 10.1016/j.atmosres.2017.11.007
Scopus记录号: 2-s2.0-85037331461
论文题名: A case study of lightning attachment to flat ground showing multiple unconnected upward leaders
作者: Cummins K.L. ; Krider E.P. ; Olbinski M. ; Holle R.L.
刊名: Atmospheric Research
ISSN: 1698095
出版年: 2018
卷: 202 起始页码: 169
结束页码: 174
语种: 英语
英文关键词: Cloud-to-ground lightning
; Lightning attachment
; Lightning photograph
; Unconnected upward positive leaders
Scopus关键词: Cameras
; Clouds
; Lightning protection
; Photography
; Uncertainty analysis
; Cloud-to-ground lightning
; Lightning attachment
; Lightning strikes
; Natural lightning strikes
; Peak currents
; Positive leaders
; Two Dimensional (2 D)
; Upward positive leaders
; Lightning
; cloud to ground lightning
; image analysis
; photograph
; New Mexico
; United States
英文摘要: On 10 July 2015, a cloud-to-ground (CG) lightning flash that produced two ground terminations was photographed from inside the safety of a truck in southern New Mexico. An analysis of archived NLDN data verified that this was a two-stroke flash, and a close-up view of the first stroke shows that it also initiated at least 12 unconnected, upward leaders (or “streamers”) near the ground termination. No unconnected upward leaders were seen near the second ground attachment. After combining an analysis of the photograph with information provided by the NLDN, we infer that the first stroke was of negative (normal) polarity, had modest peak current, and struck about 460 m (± 24%) from the camera. Attachment occurred when an upward-propagating positive leader reached an inferred height of about 21 m above local ground. The second stroke struck ground about 740 m from the camera, and the height of its attachment leader is estimated to be 15 m. The estimated lengths of the unconnected upward leaders in the two-dimensional (2-D) plane of the first stroke range from 2 to 8 m, and all appear to be located within 15 m (2-D) of the main ground termination, with 24% uncertainty. Many of the unconnected upward leaders (inferred to be positive) exhibit multiple upward branches, and most of those branches have upward-directed forks or splits at their ends. This is the first report showing such extensive branching for positive upward leaders in natural lightning strikes to ground. None of the upward leaders can be seen to emanate from the tops of tall, isolated, or pointed objects on the ground, but they likely begin on small plants and rocks, or flat ground. In terms of lightning safety, this photo demonstrates that numerous upward leaders can be produced near a lightning strike point and have the potential to damage or cause injury at more than one specific point on the ground. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/108965
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ 85721, United States; Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, Florida, United States; Olbinski Photography, Phoenix, AZ 85013, United States; Holle Meteorology & Photography, Oro Valley, AZ 85737, United States
Recommended Citation:
Cummins K.L.,Krider E.P.,Olbinski M.,et al. A case study of lightning attachment to flat ground showing multiple unconnected upward leaders[J]. Atmospheric Research,2018-01-01,202