Lightning Discharge as a Self-Organizing Transport Network. Part 1. The Concept of an Asymmetric Discharge Tree

Abstract

Lightning is a self-developing transport system of plasma channels demonstrating the ability to self-regulation due to self-consistent maintenance of zero total charge of the entire branched discharge network. The lightning structural evolution is accompanied by significant morphological changes: new plasma channels appear, and some of old ones disappear. The accomplished work was in general aimed at studying intracloud lightning and cloud-to-ground discharges up to the moment the latter come in contact with the ground. It has been shown, as part of the study, that the ability of lightning, as an open system, to maintain its structural “homeostasis” is closely linked with macroscale asymmetry: the lightning morphological and transport properties are caused by loss of electric discharge tree structural symmetry when the discharge polarity changes for the opposite. Indeed, the asymmetry of electric field threshold strength levels needed to support the growth of positive and negative streamers leads to pronounced macroscale effects in the physics of lightning. Ground discharges of negative polarity consist most often of a series of strokes passing through the same channel, while positive flashes are as a rule limited to a single stroke. Negative and positive lightning leaders have significant morphological differences: the growth of positive leaders is accompanied by development of negative recoil leaders, whereas no one has observed positive recoil leaders, if they exist at all. The results of the study are presented in two parts. This article contains an introductory part that sets out the narration general context, and, by analogy with the hierarchical Horton-Strahler scheme used for river systems, analyzes the asymmetry of the spatial distribution of capacitance in different parts of the lightning discharge tree. The concept of a point of zero induced charge or a reversing point is discussed.