Electrical discharge propagation in and around space charge clouds

Abstract

The electron trapping characteristic of a solid dielectric material (polymethylmethacrylate) is exploited to study electrical discharge propagation in laboratory‐scale space charge clouds. Similarities with the static and dynamic behaviors of thundercloud electricity are identified, and a combination of theoretical and empirical scaling relationships enables a rough translation of parameters from laboratory scale to thundercloud scale. Applications of the laboratory technique to specific thunderstorm situations reinforce the value of discharge structure studies in exposing the very important space charge configuration that gives rise to lightning.

Criteria for sprites and elves based on Schumann resonance observations

“…In contrast, the return stroke extension may pervade the lower layer (Figure 16b) more easily to produce long continuing current than it does in the upper sheet, owing to the larger potential drop in the longer vertical channel in the latter case. The discharge structure in Figure 16b is akin to the forms observed in laboratory experiments in which the space charge was also sheet-like [Williams et al, 1985]. Elve events are notably less common than sprite events.…”

A Thermodynamic, kinematic and microphysical analysis of a jet and gigantic jet‐producing Florida thunderstorm

“…For example, the distance between charge centers may play a role. Williams et al [1985] and MacGorman et al [1989] note that the main charge regions tend to drift vertically apart over the lifetime of a storm. This would increase the amount of charge needed to reach the breakdown threshold and increase the electric potential.…”

“…The detections are grouped into flashes using a maximum 1 s time difference which is sufficient given the relatively low CG and IC rates. In particular, previous studies have shown that in regions of large charge density, a lightning flash branches more densely and can travel greater distances [Mansell et al, 2002;Williams et al, 1985]. The 4DLSS system relies on frequency to identify a lightning event as a stepped leader and other in-cloud lightning mechanisms generate radio pulses.…”

CELLS v1.0: updated and parallelized version of an electrical scheme to simulate multiple electrified clouds and flashes over large domains

“…Then Barthe and Pinty (2007b) developed a probabilistic branching algorithm adapted from the dielectric breakdown concept to mimic the horizontal extension of the flash toward regions of high charge density. The present scheme keeps the idea of charge density criterion to build a 3-D branched discharge (Williams et al, 1985) and to monitor the fractal nature of the flash (Niemeyer et al, 1984) as previously highlighted.…”

“…1d). Williams et al (1985) initiated discharges through plastic slabs with regions of stronger and weaker negative charge density. They observed that the discharges tend to propagate toward regions of high charge density, which underlined the importance of the charge density in discharge propagation.…”