Modeling the lightning earth flash return stroke for studying its effects on engineering systems

A self-consistent mathematical model for predicting the lightning return stroke current and the potential profiles along the lightning channel is presented. The currents calculated from the model may be used to determine the effects of direct hits on systems. Procedures are also given for computing lightning radiated electromagnetic pulses. Knowing these radiated fields from computation, their interaction with engineering systems may also be studied. The computer simulator of the lightning flash reported is a reliable tool to characterize the critical electromagnetic environment which lightning generates. An analytical solution for a diffusion model of the return stroke is also examined. It is shown that such a model will give a grossly erroneous current at the earth end and that, contrary to observations, the current and velocity of the return stroke rapidly decay. The model adequately accounts for the plasma and electromagnetic phenomena associated with the return stroke