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曹冬杰, 郄秀书, 杨静, 等. 闪电初始放电阶段亚微秒电场变化波形特征[J]. 大气科学, 2011, 35(4): 645-656. DOI: 10.3878/j.issn.1006-9895.2011.04.05
引用本文: 曹冬杰, 郄秀书, 杨静, 等. 闪电初始放电阶段亚微秒电场变化波形特征[J]. 大气科学, 2011, 35(4): 645-656. DOI: 10.3878/j.issn.1006-9895.2011.04.05
CAO Dongjie, QIE Xiushu, YANG Jing, et al. Analysis on Characteristics of Sub-microsecond Electric Field Change Waveform during the Initial Stage of Lightning Discharge[J]. Chinese Journal of Atmospheric Sciences, 2011, 35(4): 645-656. DOI: 10.3878/j.issn.1006-9895.2011.04.05
Citation: CAO Dongjie, QIE Xiushu, YANG Jing, et al. Analysis on Characteristics of Sub-microsecond Electric Field Change Waveform during the Initial Stage of Lightning Discharge[J]. Chinese Journal of Atmospheric Sciences, 2011, 35(4): 645-656. DOI: 10.3878/j.issn.1006-9895.2011.04.05

闪电初始放电阶段亚微秒电场变化波形特征

Analysis on Characteristics of Sub-microsecond Electric Field Change Waveform during the Initial Stage of Lightning Discharge

  • 摘要: 本文选取2008年西藏羊八井地区与2009年东北大兴安岭地区快、 慢天线闪电电场变化仪观测资料, 对云闪起始阶段和地闪预击穿阶段亚微秒电场变化波形特征进行了统计分析, 发现, 无论是云闪还是地闪, 初始阶段快电场变化波形均表现为一系列脉冲形式, 且以归一化幅值小于0.5、 脉冲宽度小于等于10 μs的窄脉冲为主; 同低海拔地区相比, 高原地区地闪预击穿阶段脉冲总数相对较高, 窄脉冲所占比例相对较低, 幅值可与首次回击峰值相比拟的双极性大脉冲的发生比例较低。在统计的基础上, 对产生双极性脉冲的物理机制进行了分析, 发现较大的电流传输速度和电流衰减长度, 是导致双极性大脉冲波形幅值远大于其它脉冲的主要原因。

     

    Abstract: The characteristics of sub-microsecond electric field change waveforms during the initial stage of intracloud (IC) flashes and preliminary breakdown process of cloud-to-ground (CG) flashes have been studied based on the observation data. The data include fast electric field change and slow electric field change of IC flashes and CG flashes measured in Yangbajing of the Tibetan Plateau in 2008, and in Da Hinggan Ling in 2009. It is found that the electric field change waveforms during the initial stage of IC flashes and preliminary breakdown process of CG flashes appear as a series of pulses. The majority of pulses are narrow with pulse width less than or equal to 10 μs. The majority of pulses are weak with the normalized amplitude value less than 0.5. Compared with the lower altitude area, the number of pulses during the preliminary breakdown process of negative CG flashes measured in the Tibetan Plateau is larger and the proportion of narrow pulses is smaller. The proportion of large bipolar pulses with large peak-to-peak amplitude that is equal to or larger than the peak amplitude of electric field change of the first return stroke is small. Based on the statistics, the mechanism of discharge processes that produce bipolar pulses has been discussed theoretically. It is found that if the propagation speed of current pulse and the damp length of current pulse are large, the peak-to-peak amplitude of bipolar pulse will be large.

     

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