Effects of return stroke parameters and soil water content on EMF characteristics

Abstract

Electromagnetic pulses produced by lightning return strokes travel long distances both aboveground and underground. This study investigated the effects of return stroke parameters on electromagnetic propagation over lossy ground. The lightning return stroke channel was modeled using the Modified Transmission Line with Exponential Decay (MTLE) model. Electromagnetics was modeled using a frequency domain solver in the form of finite element analysis via COMSOL software. The studied stroke current parameters were peak, rise time, and decay time. In addition, the effects of soil water content was studied. Aboveground and underground electric and magnetic fields followed and were directly affected by the lightning current waveshape. The underground fields were affected by soil water content. In contrast, the aboveground fields are not affected by water content except for the radial electric field.