Homogeneized Models for Large-scale Streamer Corona Discharges

Streamer coronas are a fundamental component of several types of atmospheric discharges. As first stage in the ionization of virgin air, they surround lightning leaders and drive the electric current that maintains the temperature required for the leader's high conductivity. Giant jets and sprites are esentially extensive coronas. Possibly, Compact Intracloud Discharges (CIDs) -alternatively called Narrow Bipolar Events (NBEs) on account of their radio signature- are a manifestation of streamer coronas within thunderclouds [1].

A corona is composed of hundreds or thousands of streamer discharges, a number so large that it is currently out of reach even for circuit-based streamer models [2]. Here we propose to use multiscale modeling techniques to derive a homogeneized description of a corona discharge with dynamics described by a series of partial differential equations for coarse-grained variables.

In this presentation we first derive rigurously equations for the idealized case of a planar corona. Then, using heuristic arguments, we build a general model for arbitrary geometries. Finally, we discuss implications for the study of lightning leaders and CIDs.

[1] Rison, W., Krehbiel, P. R., Stock, M. G., Edens, H. E., Shao, X.-M., Thomas, R. J., Zhang, Y. (2016). Observations of narrow bipolar events reveal how lightning is initiated in thunderstorms. Nat. Comm., 7, 10721. https://doi.org/10.1038/ncomms10721

[2] Luque, A., and U. Ebert (2014), Growing discharge trees with self-consistent charge transport: The collective dynamics of streamers, New J. Phys., 16(1), 013039, doi:10.1088/1367-2630/16/1/013039.