一次多回击自然闪电的高速摄像观测

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李俊, 张义军, 吕伟涛, 董万胜, 陈绍东, 李斌. 一次多回击自然闪电的高速摄像观测[J]. 应用气象学报, 2008, 19(4): 401-411. 复制到剪切板

Li Jun, Zhang Yijun, Lǜ Weitao, Dong Wansheng, Chen Shaodong, Li Bin. Observation of a Natural Cloud-to-ground Lightning with Multiple Return Strokes[J]. Journal of Applied Meteorological Science, 2008, 19(4): 401-411 复制到剪切板

一次多回击自然闪电的高速摄像观测

李俊¹, 张义军^1,2, 吕伟涛¹, 董万胜¹, 陈绍东^1,3, 李斌⁴

1. 中国气象科学研究院雷电物理和防护工程实验室, 北京 100081;
2. 中国气象科学研究院灾害天气国家重点实验室, 北京 100081;
3. 广东省气象局, 广州 510080;
4. 广州市气象局, 广州 510080

2007-07-23 收到, 2008-04-03 收到修改稿.

资助项目: 国家科技部基础平台项目 (2004DEA71070) 和公益性行业科研专项 (GYHY2007622) 共同资助

摘要: 2006年8月1日在广东省从化市利用成像率为5000幅/s的高速摄像系统观测得到了一次包含有13个回击过程的自然负地闪, 其梯级先导的传播速度为10⁶ m/s的量级; 一次企图先导的传播速度随高度的降低而减小; 一次直窜先导的传播速度随高度的降低而增加。有3次继后回击相对积分亮度的峰值大于首次回击相对积分亮度的峰值。研究发现:此次自然闪电的继后回击及紧跟其后的连续电流过程的发光总量与该次继后回击之前闪电通道的截止时间有关, 较大的发光总量对应于较长的截止时间, 较小的发光总量对应于较短的截止时间, 但两者没有固定的比例关系。

关键词: 地闪多回击高速摄像

Observation of a Natural Cloud-to-ground Lightning with Multiple Return Strokes

Li Jun¹, Zhang Yijun^1,2, Lǜ Weitao¹, Dong Wansheng¹, Chen Shaodong^1,3, Li Bin⁴

1. Laboratory of Lightning Physics and Protection Engineering, Chinese Academy of Meteorological Sciences, Beijing 100081;
2. State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081;
3. Guangdong Provincial Meteorological Bureau, Guangzhou 510080;
4. Guangzhou Meteorological Bureau, Guangzhou 510080

Abstract: A field experiment on artificially rocket-triggered lightning and natural lightning observation is conducted in summer of 2006 in Conghua, Guangdong. The luminosity characteristics of lighting discharges are observed simultaneously by using a video camera and a Redlake MotionPro HS-4 high-speed camera which consists of a 512×512 pin photodiode array module. A cloud-to-ground (CG) lightning with 13 return strokes (RS) is observed by using the high-speed camera with a frame rate of 5000 frames per second at 16:52:51 Aug 1, 2006. The distance from the high-speed camera to the flash is about 2.1 km. The record of the electric field on the surface of the earth shows that this CG lightning discharge transports the negative charge in cloud to the ground. All of the 13 strokes propagate along the same main channel and have one ground termination.The duration of this flash is 822.4 ms. The peak luminance of the 2nd, 3rd, and 8th return strokes are brighter than that of the first one, being 25% of all 12 subsequent return strokes. Of the 13 strokes, 6 (46 %) present some luminosity persistence after the return stroke frame. The durations of 2 persistence luminosity are in excess of 40 ms (CC (continuing current) following 9th stroke:157.6 ms; CC follow ing 10th stroke:221 ms).There are 17 Mcomponents occurring during the 6 continuing current occurrences. The luminosity characteristics of 3 leaders are examined. The average speed of the stepped leader is 2.23×106 m/s. It is a β-type leader according to the previous results which the stepped leader emerges from the cloud base and develops with a high average speed of the order of 10⁶ m/s. The speed of the attempted leader before the 4th return stroke exhibits the decrease as it develops down toward the ground.The speed of the dart-stepped leader before the 13th return stroke appears to increase as it approaches the ground. Cut-off time is the time when the lightning channel shows no luminosity between two adjacent return strokes. In other words, it is the sum of the time from the frame that the previous return stroke and the CC followed disappears to the frame that the next return stroke is observed. Total luminosity is the sum of luminance of the frames including the return stroke and the CC followed. It is found that the cut-off time before a subsequent return stroke exhibits a consistent trend with the total luminosity of this subsequent return stroke and the CC followed (although there is no fixed proportionality between them), especially there is a proportionality relationship between them after the 9th return stroke. The geometric average of 17 Mcomponents' lasting time is 1.28 ms, and that of 11 intervals between the consecutive M-components is 1.69 ms.

Key words: CG lightning multi-return stroke high-speed camera

[1]	张义军, 孟青, 马明, 等. 闪电探测技术发展和资料应用. 应用气象学报, 2006, 17, (5): 611–620.
[2]	陈渭民. 雷电学原理. 北京: 气象出版社, 2003: 290-291.
[3]	Martin A Uman, The Lightning Discharge. Florida: Academic Press Inc, 1987: 353-354.
[4]	Wang D, Takagi N, Watanabe T, Recent progress in the study of lightning propagation characteristics by using ALPS. Journal of Atmospheric Electricity, 2005, 25, (2): 69–77.
[5]	Morean J P, Alliot J C, Mazur V, Aircraft lightning initiation and interception from in situ electric measurements and fast video observations. J Geophys Res, 1992, 97: 15903–15912. DOI:10.1029/92JD01077
[6]	王才伟, 刘欣生, 董万胜, 等. 人工触发闪电通道的发光特征. 高原气象, 1998, 17, (1): 10–23.
[7]	王才伟, 刘欣生, 董万胜, 等. 正环境电场中闪电先导的始发和传播. 高原气象, 1998, 17, (1): 65–74.
[8]	张义军, 周秀骥. 雷电研究的回顾和进展. 应用气象学报, 2006, 17, (6): 829–834.
[9]	王道洪, 郄秀书, 郭昌明. 雷电与人工引雷. 上海: 上海交通大学出版社, 2000.
[10]	Qie X, Yu Y, Guo C, et al. Some features of stepped and dartstepped leaders near the ground in natural negative clound-to-ground lightning discharges. Annales Geophysicae, 2002, 20, (6): 863–870. DOI:10.5194/angeo-20-863-2002
[11]	Rakov Vladimir A, Martin A Uman, Lightning Physics and Effects. Cambridge: Cambridge University Press, 2003: 122-123.
[12]	Campos Leandro Z S, Marcelo M F Saba, Osmar Pinto Jr, et al. Waveshapes of continuing currents and properties of M-components in natural negative cloud-to-ground lightning from highspeed video observation. Atmospheric Research, 2006. DOI:10.1016/j.atmosres.2006.09.002
[13]	Ballarotti M G, Saba M M F, Pinto O Jr, High-speed camera observations of negative ground flashes on a millisecond-scale. Geophys Res Lett, 2005, 32: L23802. DOI:10.1029/GL2005GL023889
[14]	Rakov V A, Uman M A, Thottappillil R, Review of lightning properties from electric field and TV observation. J Geophys Res, 1994, 99: 10745–10750. DOI:10.1029/93JD01205
[15]	Fisher R J, Schnetzer G H, Thottappillil R, et al. Parameters of triggered-lightning flashes in Florida and Alabama. J Geophys Res, 1993, 67: 637–647.
[16]	Thottappillil R, Rakov V A, Uman M A, K and M changes in close lightning ground lashes in Florida. J Geophys Res, 1990, 95: 18631–18640. DOI:10.1029/JD095iD11p18631
[17]	Rakov V A, hottappillil R T, Uman M A, Electric field pulses in K and M changes of lightning ground flashes. J Geophys Res, 1992, 97: 9953–9950.
[18]	Krehbiel P R, Brook M, McCrory R A, An analysis of the charge structure of lightning discharges to ground. J Geogphys Res, 1979, 84: 2432–2456. DOI:10.1029/JC084iC05p02432
[19]	张翠华, 张义军, 张广庶, 等. 地闪连续电流特征的统计分析. 高原气象, 2000, 19, (3): 371–378.


图 1. 闪电通道相对积分亮度随时间变化 Fig 1. Relative integrated luminosity of the CG lightning channel versus time


图 2. -1.0~0.0 ms的高速摄像照片 (a)-1.0 ms, (b)-0.8 ms, (c)-0.6 ms, (d)-0.4 ms, (e)-0.2 ms, (f)0.0 ms Fig 2. Frame sequence of first leader/return stroke from-1.0 ms to 0.0 ms (a)-1.0 ms, (b)-0.8 ms, (c)-0.6 ms, (d)-0.4 ms, (e)-0.2 ms, (f)0.0 ms


图 3. 经处理的184.6~186.2 ms高速摄像照片 (a)184.6 ms, (b)184.8 ms, (c)185.0 ms, (d)185.2 ms, (e)185.4 ms, (f)185.6 ms, (g)185.8 ms, (h)186.0 ms, (i)186.2 ms Fig 3. Frame sequence processed from 184.6 ms to 186.2 ms (a)184.6 ms, (b)184.8 ms, (c)185.0 ms, (d)185.2 ms, (e)185.4 ms, (f)185.6 ms, (g)185.8 ms, (h)186.0 ms, (i)186.2 ms


图 4. 第4次回击前企图先导速度随高度变化 Fig 4. Variation of speed of the attempted leader before the 4th RS with height


图 6. 第13次回击前先导速度随高度变化 Fig 6. Variation of speed of the dart-stepped leader before the 13th RS with height


图 7. 回击前截止时间和回击及其后连续电流过程发光总量变化 Fig 7. Variations of cut-off time and total luminosity with the order of return stroke


图 8. 第9次 (a) 和第10次 (b) 回击后长连续电流过程的亮度变化波形 Fig 8. Waveshapes of long continuing current with M-components following the 9th (a) and the 10th (b) return stroke


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