Non-stationary corona around multi-point system in atmospheric electric field: I. Onset electric field and discharge current

• Published in: Journal of atmospheric and solar-terrestrial physics 2014-03, Vol.109, p.80-90
• Main Authors: Bazelyan, E.M., Raizer, Yu.P., Aleksandrov, N.L.
• Format: Article
• Language: English
• Subjects: Corona current evolution; Corona space charge layer; Multi-point corona discharge; Thundercloud electric field
• ISSN: 1364-6826; 1879-1824
• DOI: 10.1016/j.jastp.2013.03.029

The properties of a non-stationary glow corona maintained near the tips of a multi-point ground system in a time-varying thundercloud electric field have been studied numerically and analytically. Computer and analytical models were developed to simulate the corona discharge initiated from a system of identical vertical conductive electrodes distributed uniformly over a grounded plane surface. The simulation was based on a solution of the electrostatic equation for electric field and continuity equations for light and aerosol ions. The development of individual corona space charge layers from different points and the formation of a united plane layer were considered. The effect of system dimensions and that of the distance between electrodes on the external electric field corresponding to corona onset near the rod tips was investigated. The evolution in time of the corona current was calculated for systems with various numbers of coronating rods in time-varying atmospheric electric field. In the limit of infinite number of coronating rods, reasonable agreement was obtained between numerical calculations and analytical theory considering the effect of surrounding rods on the corona discharge from a given rod in a simplified integral way. Conditions were determined under which the corona properties of a multi-point system are similar to the properties of a plane surface emitting ions into the atmosphere. In this case, the corona current density is governed by the time derivative of the thundercloud electric field and is independent of the ion mobility and of the coronating system dimensions. The total corona space charge injected into the atmosphere per unit area by a given instant is controlled by the thundercloud electric field at this instant and depends on the geometrical parameters of the system only indirectly, through the corona onset atmospheric electric field. This simple model could be used to simulate a corona discharge during thunderstorms at the earth’s surface covered with dense vegetation. In particular, according to the model of an emitting plane, the current densities in the range 1–10nA/m2 are expected when the thundercloud electric field increases by ∼50kV/m over time interval in the range 30–300s, in qualitative agreement with the analysis of available field observations. •We study a corona near a multi-point ground system in a thundercloud field.•Computer codes are developed to study the properties of corona.•Onset external electric fiel