Electric and Magnetic Fields Predicted by Lightning Return Stroke Electromagnetic Models

We have shown that two types of the lightning return-stroke electromagnetic model can reproduce all of the five features of electric and magnetic field waveforms observed at distances ranging from 1 to 200 km from natural lightning and at distances ranging from tens to hundreds of meters from rocket-triggered lightning. The models include a vertical resistive wire in air loaded by additional distributed series inductance, and a vertical resistive wire embedded in a finite-thickness cylinder having both high relative permittivity and high relative permeability surrounded by air. In both models, the distributed resistance of the vertical wire is nonuniform: relatively high within the bottom 0.5 km and beyond 6 km along the channel.