Effects of soil uniformity on radial electric field of lightning electromagnetic pulse

Abstract

Soil homogeneity has a significant influence on the propagation of lightning radial electric fields (Er) aboveground and subsurface, which might have a substantial impact on several systems near the lightning strike area. This study aims to adequately understand the influence of soil homogeneity on Er propagation across various soil water percentages. The return stroke (RS) channel was modeled using the MTLE model. COMSOL was employed to model the RS channel, the lightning electromagnetic field (LEMF), and the frequency-dependent soil (FDS). Er were measured at different observing distances from the lightning strike. The influence of waveforms, polarities, and peak magnitudes of the aboveground and subsurface Er over various soil profiles and at different distances from the lightning source were studied. The findings reveal that soil homogeneity has a substantial impact on the above and below-ground fields and their behaviors with varying water percentages. The vertically stratified soil has an effect on the magnitude of the measured Er (both above and below ground), where higher peaks are observed in the non-uniform soil. In contrast, the horizontally stratified does affect the subsurface Er, which has a lower peak value and faster tail in the uniform soil fields.