DOI: 10.1016/j.atmosres.2017.12.014
Scopus记录号: 2-s2.0-85044303485
论文题名: Characteristics of downward leaders in a cloud-to-ground lightning strike on a lightning rod
作者: Wang C. ; Sun Z. ; Jiang R. ; Tian Y. ; Qie X.
刊名: Atmospheric Research
ISSN: 1698095
出版年: 2018
卷: 203 起始页码: 246
结束页码: 253
语种: 英语
英文关键词: Grounding point
; Leader
; Lightning rod
; Natural lightning
Scopus关键词: Aluminum
; Clouds
; Digital subscriber lines
; DSL
; Electric fields
; High speed cameras
; Roofs
; Cloud-to-ground lightning
; Downward leaders
; Electric field change
; Frames per seconds
; Leader
; Lightning rods
; Return stroke
; Stepped leader
; Lightning
; cloud to ground lightning
; electric field
; lightning
; Beijing [Beijing (ADS)]
; Beijing [China]
; China
英文摘要: A natural downward negative cloud-to-ground (CG) lightning was observed at a close distance of 370 m by using electric field change measurements and a high-speed camera at 5400 frames per second (fps). Two subsequent leader-return strokes of the lightning hit a lightning rod installed on the top of a seven-story building in Beijing city, while the grounding point for the stepped leader-first return stroke was 12 m away, on the roof of the building. The 2-D average speed of the downward stepped leader (L1) before the first return stroke (R1) was approximately 5.1 × 104 m/s during its propagation over the 306 m above the building, and those before the subsequent strokes (R2 and R3) ranged from 1.1 × 106 m/s to 2.2 × 106 m/s. An attempted leader (AL) occurred 201 ms after R1 and 10 ms before R2 reached approximately 99 m above the roof and failed to connect to the ground. The 2-D average speed of the AL was approximately 7.4 × 104 m/s. The luminosity at tip of the leader was brighter than the channel behind it. The leader inducing the R2 with an alteration of terminating point was a dart-stepped leader (DSL), which propagated through the channel of AL and continued to develop downward with new branches at about 17 m above the roof. The 2-D speed of the DSL at the bottom 99 m was 6.6 × 105 m/s. The average time interval between the stepped pulses of the DSL was approximately 10 μs, smaller than that of L1 with value of about 17 μs. The average step lengths of the DSL were approximately 6.6 m. The study shows that the stepped leader-first return stroke of lightning will not always hit the tip of a tall metal rod due to the significant branching property of the leader. However, under certain conditions, the subsequent return strokes may alter the grounding point to the tip of a tall metal rod. For the lightning rod, the protection against subsequent return strokes may be better than that against the first return stroke. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/108949
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: College of Science, Beijing Information Science and Technology University, Beijing, 100192, China; Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Science, Beijing, 100029, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of information Science & Technology, Nanjing, 210044, China; University of Chinese Academy of Sciences, Beijing, 100049, China
Recommended Citation:
Wang C.,Sun Z.,Jiang R.,et al. Characteristics of downward leaders in a cloud-to-ground lightning strike on a lightning rod[J]. Atmospheric Research,2018-01-01,203