Time domain simulations of preliminary breakdown pulses in natural lightning

TL;DR

This paper presents a simulation of lightning preliminary breakdown pulses using a 3D charge and current flow model, reproducing observed features and highlighting areas for future refinement.

Contribution

It introduces a novel simulation approach for lightning channel electrodynamics, including channel heating and corona sheath effects, to better understand preliminary breakdown processes.

Findings

Simulation reproduces broad features of natural lightning pulses.

Deviations suggest need for more detailed stepping mechanism modeling.

Connects physical channel properties to observed electromagnetic signals.

Abstract

Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism.