Main stage of the lightning discharge: Mechanism and output characteristics

Physical processes responsible for the lightning discharge are considered. An expression relating the basic physical quantities describing the evolution of the lightning discharge to the magnitude and waveform of the lightning current is found. It is shown that the peak lightning current is proportional to the lightning channel length, the steepness of the current pulse depends on the physical constants of the spark discharge, and the current pulse duration depends on the physical constants of the spark discharge and also on the leader’s space charge density.