Evaluation of a first return stroke model considering the lightning channel tortuosity

•We model the linear charge density for tortuous lightning channels.•The model predicts greater accumulations of charge near to the tip of the leader.•We evaluate a first return stroke model including the channel's tortuosity.•Including the tortuosity, the peak currents are attenuated.•Including the tortuosity, a time delay in the currents can be observed.

In this paper, the influence of the lightning channel tortuosity on the spatial and temporal return stroke current distribution, is evaluated. A return stroke model, developed with the current generation concept, has been used. The random tortuosity of the lightning channel is represented by a numerical model which also enables the linear charge density modeling. It is shown, that when the tortuosity of the lightning channel is taken into account, the return stroke current profile exhibits an amplitude attenuation and a time delay with respect to the current profile of the associated straight and vertical channel. It is worth pointing that the results presented in this paper are theoretical and obtained by means of numerical simulation, with exception of the linear charge density model, which was obtained using both, numerical simulation as well as experimental data obtained previously by other authors, as described in the paper.