正极性人工触发闪电的向上负先驱脉冲放电过程研究  

Discharge Characteristics of Upward Negative Precursors in Positive Triggered Lightning

作　　者：吕冠霖 蒋如斌[2] 李宗祥 袁善锋 张鸿波[2] 李晓[5] 刘昆[1] 陈睿凌 刘明远[2,4] LÜGuanlin;JIANG Rubin;LI Zongxiang;YUAN Shanfeng;ZHANG Hongbo;LI Xiao;LIU Kun;CHEN Ruiling;LIU Mingyuan(Chengdu University of Information Technology,Colloge of Electronic Engineering,Chengdu 610225;Key Laboratory of Middle Atmosphere and Global Environment Observation(LAGEO),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;State Key Laboratory of Nuclear Biological and Chemical Protection for Civilian,Beijing 102205;University of Chinese Academy of Sciences,Beijing 100049;University of Science and Technology of China,Hefei 230026)

机构地区：[1]成都信息工程大学电子工程学院,成都610225 [2]中国科学院大气物理研究所中层大气和全球环境探测重点实验室,北京100029 [3]国民核生化灾害防护国家重点实验室,北京102205 [4]中国科学院大学,北京100049 [5]中国科学技术大学,合肥230026

出　　处：《大气科学》2024年第2期497-506,共10页Chinese Journal of Atmospheric Sciences

基　　金：国家重点研发计划项目2017YFC1501502;国家自然科学基金项目41775012;四川省重点研发计划项目2019YFG0104。

摘　　要：利用人工触发正极性闪电的综合同步探测资料,对引雷火箭上升过程中发生于金属导线顶端的向上负先驱脉冲放电过程进行了研究。除常规认识的峰值电流为十几到几十安培的先驱脉冲放电以外,高垂直分辨率电流探测系统记录到丰富的弱脉冲放电过程。所有孤立发生的脉冲放电,均为弱脉冲,且在所有常规强度的先驱脉冲(簇)放电之前约20μs,均识别到这种弱脉冲。对测量到的弱脉冲、脉冲型脉冲和波纹型脉冲进行统计,得到了各自的峰值电流(3.6 A、32.2 A、11.1 A)、上升时间(0.39μs、0.9μs、3.2μs)、持续时间(2.8μs、5.1μs、12.7μs)和转移电荷量(4.7μC、50.8μC、83.2μC)。常规强度的先驱脉冲形成了可探测的发光通道,簇状先驱脉冲的放电通道具有与自持先导初始阶段相一致的梯级发展传输特征,二维平均速度在105 m s^(−1)量级。分析相邻先驱脉冲发光通道的时空关系,发现后一次先驱脉冲放电通道的起始高度一般位于前一次先驱脉冲放电通道的顶端,通道梯级延伸时电荷分布的调整降低了通道区域的电场强度。先驱脉冲放电是金属导线顶端形成了先导但又由于条件不足而熄灭的过程。In this work,upward negative precursors at the triggering wire tip during the ascent of the rocket were explored using comprehensive data from the rocket-triggered lightning experiment.Except for those typical precursors with a peak current of tens of amperes,abundant weak current pulses were identified,which is attributed to the high vertical resolution current detection.All isolated current pulses were weak,and those typical-intensity precursors(or clustered precursors)were preceded by weak current pulses at an interval of approximately 20μs.For the weak,impulsive,and ripple pulses,their geometric mean values for peak current were 3.6,32.2,and 11.1 A;moreover,rise times for these pulses to increase their current from 10% to 90% peak were 0.39,0.9,and 3.2μs,durations were 2.8,5.1,and 12.7μs,and charge transfer values were 4.7,50.8,and 83.2μC,respectively.The typical-intensity precursors formed visible discharge channels that can be detected using optical means,and the channel development of those clustered precursors involved stepwise features,consistent with the initial sustained upward leaders,with an average 2D speed in the order of 105 m/s.The temporal and spatial relationships of adjacent precursor-producing channels were also examined.The new precursor channel was found to start at the height of the previous channel tip.The important adjustment of charge distribution due to the stepped channel extension reduced the electric field intensity in the channel region.The precursors were actually un-sustained leader development,producing an initial leader channel segment at the triggering wire tip,but they eventually extinguished due to insufficient conditions.

关 键 词：人工触发闪电 负极性先驱脉冲 击穿 先导 

分 类 号：P427[天文地球—大气科学及气象学]