Physical Processes Related to Discharges in Planetary Atmospheres

Abstract

This paper focuses on the rudimentary principles of discharge physics. The kinetic theory of electron transport in gases relevant to planetary atmospheres is examined and results of detailed Boltzmann kinetic calculations are presented for a range of applied electric fields. Comparisons against experimental swarm data are made. Both conventional breakdown and runaway breakdown are covered in detail. The phenomena of transient luminous events (TLEs), particularly sprites, and terrestrial gamma-ray flashes (TGFs) are discussed briefly as examples of discharges that occur in the terrestrial environment. The observations of terrestrial lightning that exist across the electromagnetic spectrum and presented throughout this volume fit well with the broader understanding of discharge physics that we present in this paper. We hope that this material provides the foundation on which explorations in search of discharge processes on other planets can be based and previous evidence confirmed or refuted.R. Roussel-Dupré ( ) · J.J. Colman · E. Symbalisty

High-Energy Atmospheric Physics: Terrestrial Gamma-Ray Flashes and Related Phenomena

“…In Fig. 2, we show Monte Carlo calculations by Lehtinen et al (1999) with an empirical fit by Inan and Lehtinen (2005); Monte Carlo calculations presented by Babich et al (2004aBabich et al ( , 2005 with an empirical fit to the same Monte Carlo results by Babich et al (2004a); Monte Carlo calculations by Dwyer (2003) and with an empirical fit given by ; Boltzmann equation calculations by Roussel-Dupré et al (2008) with an empirical fit by Milikh and Roussel-Dupré (2010); and Monte Carlo calculations by Celestin and Pasko (2010) for the Møller scattering cross-section and an alternative electron impact ionization model for the secondary electron production. Because some work found the avalanche lengths (λ) directly and some work found the avalanche times (τ ), we convert all data to avalanche lengths using the work of as follows λ = τ v, where v = 0.89c is the average avalanche propagation speed, which is in good agreement with the speed found by Babich and Bochkov (2011).…”

“…For positrons, it includes elastic scattering by nuclei, scattering by free electrons, bremsstrahlung and two body annihilation. Roussel-Dupré et al (2008) compiled accurate energy loss rates and interaction crosssections and further developed the Fokker-Planck form of the relativistic Boltzmann equation for RREAs. They then solved the equations numerically using a finite volume, cell centered, time explicit, spatially second order accurate algorithm.…”

Underlying mechanisms of transient luminous events: a review

“…In a more accurate theory, the runaway electrons are described by the Boltzmann transport equation for fast electron distribution function f (r, p, t) over the coordinates r and momenta p (e.g. see recent reviews by Roussel-Dupré et al, 2008, and by Milikh and Roussel-Dupré, 2010):…”

“…Nagano and Watson, 2000). The models of runaway breakdown in the atmosphere are based on the assumption that cosmic rays are capable of producing the shower of secondary particles called an extensive air shower (EAS) (Gurevich et al, 1999b;Lehtinen et al, 1999;Zybin, 2001, 2004;Inan and Lehtinen, 2005;Roussel-Dupré et al, 2008;Milikh and Roussel-Dupré, 2010). The incident cosmic ray particle energy to initiate runaway breakdown was estimated to be greater than or of the order of 10 15 eV (Gurevich et al, 1999b).…”

“…D Appl. Phys., 41, 2008; recent reviews by Ebert and Sentman, 2008;Roussel-Dupré et al, 2008;Ebert et al, 2010;Inan et al, 2010;Milikh and Roussel-Dupré, 2010, and references therein).…”