On the Lightning M-Component Electric Fields at Close Distances With Special Attention to Lightning Channel Inclinations

In this article, the authors analyze the electric fields of the lightning M-component at close distances, taking into account the characteristics of the lightning channel, particularly focusing on the inclination of the channel. The study considers both fast and slow M-component waveforms. The lightning channel characteristics examined include the inclination of the channel, variations in channel length, wave speed, and current attenuation. The authors compare three typical lightning channel geometries: a vertical channel, a fully inclined channel, and an inclined channel with a vertical channel at the bottom. The results demonstrate that the presence of a grounded and vertical channel significantly influences the waveform of the M-component electric fields at close distances. The late-time response of the M-component electric fields is notably affected by the inclination angle, azimuth angle, and current decay. The simulation results are compared to previous studies that investigated different lightning channel geometries. The authors suggest considering both the channel geometry and current exponential decay along the grounded channel to accurately reproduce the M-component electric fields.