Comment on "Return stroke transmission line model for stroke speed near and equal that of light" by R. Thottappillil, J. Schoene, and M. A. Uman

Abstract

Electric fields on the ground 500 m, 5 km, and 50 km from the lightning channel base computed using the transmission line (TL) and antenna theory (AT) return-stroke models for a typical subsequent stroke current at the channel base and a return-stroke speed equal to the speed of light (v = c) are compared. The AT model gives a total electric field peak that is about 10% lower than the field peak predicted by the TL model. Optical measurements of the return-stroke speed within the bottom 100 m of the lightning channel are reviewed and found to be not supporting the assumption of v = c.