Initial Breakdown Pulse Parameters in Intracloud and Cloud‐to‐Ground Lightning Flashes
Initial Breakdown Pulse Parameters in Intracloud and Cloud‐to‐Ground Lightning Flashes
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云内和云地闪电中的初始击穿脉冲参数
DOI：
10.1002/2017jd027729
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
M. Stolzenburg
中科院分区：
文献类型：
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作者：
E. M. Smith;T. Marshall;S. Karunarathne;R. Siedlecki;M. Stolzenburg
本研究分析了最大的初始击穿（IB）脉冲在闪光从四个风暴在佛罗里达，从三个传感器阵列的数据。沿着确定最大IB脉冲的范围归一化、零至峰值幅度及其每次闪光的高度、持续时间和定时。40次云内（IC）和32次云对地（CG）闪光的适当数据可用。按闪光类型划分的最大IB脉冲幅度直方图相似，IC闪光的平均值（中位数）为1.49（1.05）V/m，CG闪光的平均值（中位数）为−1.35（−0.87）V/m。在30个IC闪光中，最大的IB脉冲的振幅与高度呈弱的负相关。25个CG闪光的最大IB脉冲的幅度显示没有高度相关性。IC中最大IB脉冲的持续时间平均为CG中的两倍（96 μs对46 μs），并且所有CG持续时间均<100 μs。在IC中，最大IB脉冲持续时间与幅度之间存在正相关关系;排除离群值后，线性相关系数为0.385。IC闪光中的最大IB脉冲通常在第一IB脉冲（平均4.1ms）之后比CG闪光中的情况（平均0.6ms）更长的时间发生。在这两种闪光类型中，约30%的情况下，最大的IB脉冲是第一个IB脉冲。在一次风暴中，所有42个具有触发数据的IC闪光都有IB脉冲。
This study analyzes the largest initial breakdown (IB) pulse in flashes from four storms in Florida; data from three sensor arrays are used. The range‐normalized, zero‐to‐peak amplitude of the largest IB pulse was determined along with its altitude, duration, and timing within each flash. Appropriate data were available for 40 intracloud (IC) and 32 cloud‐to‐ground (CG) flashes. Histograms of amplitude of the largest IB pulse by flash type were similar, with mean (median) values of 1.49 (1.05) V/m for IC flashes and −1.35 (−0.87) V/m for CG flashes. The largest IB pulse in 30 IC flashes showed a weak inverse relation between pulse amplitude and altitude. Amplitude of the largest IB pulse for 25 CG flashes showed no altitude correlation. Duration of the largest IB pulse in ICs averaged twice as long as in CGs (96 μs versus 46 μs), and all of the CG durations were <100 μs. Among the ICs, there is a positive relation between largest IB pulse duration and amplitude; the linear correlation coefficient is 0.385 with outliers excluded. The largest IB pulse in IC flashes typically occurred at a longer time after the first IB pulse (average 4.1 ms) than was the case in CG flashes (average 0.6 ms). In both flash types, the largest IB pulse was the first IB pulse in about 30% of the cases. In one storm all 42 IC flashes with triggered data had IB pulses.