Diagnostics and propagation of radiation from lightning discharges

Abstract

The role of stepped leader channel ionization on return current flow has been studied. It is shown that for <i>T</i>_e> <i>T</i>_i, the downward traversing electron beam in the stepped leader ionized channel gives rise to plasma oscillations with a finite decay rate. The electron beam propagating downward and ion beam propagating upward give rise to resulting return current. The return current in the lightning channel may become oscillatory as a result of plasma wave interaction. The electromagnetic radiation from an oscillatory return current source becomes variable. Such variations in recorded whistler intensity are often observed in whistler sonograms.