On the dynamics of hot air plasmas related to lightning discharges: 2. Electrodynamics

In this paper, we develop a model of electrical discharge in air for the simulation of some of the electrical processes involved in lightning discharges, as in lightning return strokes and dart leaders. The discharge is initiated by a vertical electrical field and modeled using a nonlinear R-L-C circuit model, with which we attempt to simulate initiation, growth, radial expansion, and decay of electrical discharges related to lightning. This gas dynamic type model includes also both detailed air chemistry and accurate air radiation transport, as described in the first part of this article. For certain parameter configurations, our first lightning-related discharge simulations compare well with lightning observations and actual knowledge in terms of chronology, charge and energy depleted, current created, electron concentration, temperature, pressure, and optical signature. We also discuss the difficulties to obtain fully consistent results due to the wide parameter variability, their uncertainty, and the complexity of the physics involved.