Analysis on the parameters of the current waveforms of triggered lightning

Abstract

Artificially triggered lightning experiments were carried out at Binzhou, Shandong Province, China during summer form 2005 to 2008. The discharge current at the channel base of triggered lightning were measured. The geometric mean value of the peak current for 21 negative return strokes was 14.6kA, the geometric mean of the 10%—90% risetime was 2.3μs, the geometric mean of the half peak width was 17 μs and the geometric mean of the charge transfer within 1ms of return strokes was 1.2C. There was essentially no correlation between the return stroke peak current and 10％—90% risetime or between return stroke peak and the width of the current waveform at half of its peak value. No dependence of peak current on grounding resistance was found either. There is correlation between return stroke current peak and charge transfer within 1ms after return stroke initiation, and the correlation between return stroke peak and the stepness of the front waveform of return stroke was also found. Compare the parameters of the triggered lightning with natural cloud to ground lightning, it was found that the triggered lightning stroke is similar to subsequent stroke of natural lightning. So the results of triggered lightning can be used to the lighting protection.