On runaway breakdown and upward propagating discharges

Abstract

The origins of mysterious γ ray and radio flashes recently detected by satellite‐based instruments passing over thunderstorms are examined in the context of upward propagating discharges initiated by runaway air breakdown. Preliminary calculations normalized by the recent optical measurements of so‐called sprites indicate that the runaway mechanism may well be the source of these emissions. If this is true, then upward discharges represent the first known manifestation of a fundamental, new process in plasma physics.