Characteristics of Electromagnetic Fields due to Winter Lightning Stroke Current to a High Stack

Abstract

For lightning strikes to a tall structure peculiar to a winter season, in order to study propagation and distribution of lightning stroke currents along the lightning path and the tall structure, we try to simultaneously observe the lightning current and the electromagnetic field waveforms caused by the winter lightning to a high stack. This paper describes the simultaneously observed results and the analysis of the electromagnetic field based on the observed lightning currents. We observed the lightning current waveforms with a very fast wave-front. On the wave-front of these lightning currents, there appear the reflection currents between the stack and the lightning channel. Taking account of the propagation and the distribution of the lightning current along the stack for the electromagnetic field calculation, the observed electromagnetic fields agree with the calculated ones at the wave-front. (author abst.)