| 摘要: |
| 为了深入认识负地闪放电过程中光辐射信号的特性，对广州高建筑物雷电观测站所获得的回击光脉冲波形进行了分析。对观测到的88例负地闪事件中的184次回击（包括60次下行闪电首次回击、58次下行闪电继后回击、66次上行闪电继后回击）的光脉冲特征进行了统计分析，结果表明：下行闪电首次回击光脉冲10%~90%上升时间T1的算术平均值/中值为32.5/31.4 μs，20%~80%上升时间T2的算术平均值/中值为22.6/22.4 μs，半峰宽度T3的算术平均值/中值为131.1/117.0 μs。下行闪电继后回击光脉冲T1的算术平均值/中值为30.4/27.7 μs，T2的算术平均值/中值为19.5/17.6 μs，T3的算术平均值/中值为153.6/142.6 μs。在21例下行多回击负地闪事件中，光脉冲回击间隔时间在12.6~368.6 ms范围之间，算术平均值为78.7 ms，有14%闪电事件存在继后回击光脉冲峰值大于首次回击的情况。上行闪电继后回击光脉冲T1的算术平均值/中值为27.5/24.3 μs，T2的算术平均值/中值为17.0/15.7 μs，T3的算术平均值/中值为132.2/124.5 μs。总体上，下行闪电首次回击的光脉冲上升时间最长、下行闪电继后回击次之、上行闪电继后回击最小；下行闪电继后回击脉冲半峰宽度比下行闪电首次回击及上行闪电继后回击的更大。 |
| 关键词: 光脉冲 首次回击 继后回击 下行闪电 上行闪电 |
| DOI：10.16032/j.issn.1004-4965.2021.042 |
| 分类号: |
| 基金项目: |
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| CHARACTERISTICS OF OPTICAL PULSES INDUCED BY LIGHTNING RETURN STROKES TO TALL STRUCTURES IN GUANGZHOU |
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HUANG Xiaolei1,2, LYU Weitao3, WU Bin3, SUN Xiubin4, MA Ying3, CHEN Lyuwen5, QI Qi3, LIU Hengyi3
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1. State Key Laboratory of Severe Weather/ Laboratory of Lightning Physics and Protection Engineering,
Chinese Academy of Meteorological Sciences, Beijing 100081, China;2. Chengdu University of Information Technology, Chengdu 610225, China;3.State Key Laboratory of Severe Weather/ Laboratory of Lightning Physics and Protection Engineering, Chinese Academy of Meteorological Sciences, Beijing 100081, China;4.Chengdu University of Information Technology, Chengdu 610225, China;5.Guangzhou Institute of Tropical and Marine Meteorology, China Meteorological Administration, Guangzhou 510641, China
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| Abstract: |
| To understand the characteristics of lightning optical signals, this paper analyzes the return stroke optical pulse waveform obtained at the Tall-Object Lightning Observatory in Guangzhou. The optical pulse characteristics of 184 return strokes occurred in 88 negative cloud-to-ground lightning events are selected and analyzed. These return strokes consist of 60 first and 58 subsequent return strokes in 60 downward lightning flashes, and 66 subsequent return strokes in 28 upward lightning flashes. For the optical pulses of first return stroke in downward lightning, the average/median values of 10%~90% rise time (T1) are 32.5/31.4 μs, the average/median values of 20%~80% rise time (T2) are 22.6/22.4 μs and the average/median values of half-peak width (T3) are 131.1/117.0 μs. For the optical pulses of subsequent return stroke in downward lightning, the average/median values of T1, T2 and T3 are 30.4/27.7 μs, 19.5/17.6 μs, and 153.6/142.6 μs, respectively. Among 21 negative downward lightning events with multiple return strokes, the return stroke optical pulse interval varies from 12.6 ms to 368.6 ms, with an average value of 78.7ms. For 14% of the 21 events, the subsequent return strokes have larger optical pulse peak values than the first ones. For the optical pulses of subsequent return stroke in upward lightning, the average/median values of T1, T2 and T3 are 27.5/24.3 μs, 17.0/15.7 μs and 132.2/124.5 μs. Overall, the optical pulse of the first return stroke in downward lightning has the longest rise time, and that of the subsequent return stroke in upward lightning has the shortest. Furthermore, the half-peak width of the optical pulse of subsequent return stroke in upward lightning is lower than that of subsequent return stroke in downward lightning. |
| Key words: optical pulse first return stroke subsequent return stroke downward lightning upward lightning |
