High current upward lightning flashes in winter
Lightning discharges observed simultaneously with faults of power transmission lines in winter are investigated through simultaneous electromagnetic field observation. Majority of the thus obtained fast-antenna records contained intense bipolar LEMP (lightning electromagnetic impulse), which had been believed that they were generated by energetic cloud discharges. Because investigated faults of power transmission lines would never occur by so-called induced lightning, the recorded field waveforms were related to ground flashes, which transported electric charge from cloud to ground. The evolution of lighting discharges of these types of flashes, observed by a VHF mapping array, showed quite different aspect dependent on the polarity of the initial part of the intense electric field pulses. A possible model of the lightning stroke which generates an energetic bipolar electric field pulse, whose initial polarity is positive polarity and somewhat resembles NNBP, is proposed.
Masaru Ishii Mikihisa Saito Naoki Itamoto
The University of Tokyo, Tokyo 153-8505, Japan Hokuriku Electric Power Co, Toyama 930-0848, Japan
国际会议
第13届国际大气电学会议(The 13th International Conference on Atmospheric Electricity)
北京
英文
2007-08-13（万方平台首次上网日期，不代表论文的发表时间）