Electrical Field Parameters of Natural Return Strokes at Different Distances

This article presents the electric field waveforms of natural return strokes recorded by Foshan Total Lightning Location System. The distance ranges from 10 to 300 km. The evolution of parameters for positive first and negative first and subsequent return stroke electric field waveforms along with distance change is analyzed. The results show that the risetime, fall time, half-peak width, and zero-crossing time become longer with longer distance, and these four parameters of the negative return strokes show more clear linear relation with distance than the positive return strokes. For the overshoot duration, the values for both positive and negative return strokes increase with distance at 10-200 km, but when the distance is larger, the distance dependence becomes less obvious. The values of the initial peak normalized to 100 km and 20 kA remain the same in general for all the return strokes. For the overshoot amplitude and the ratio of overshoot to initial peak, the values for both positive and negative return strokes increase with distance. The return stroke electric field waveforms at far distances are more likely to show clear opposite polarity overshoot.

Automated summary

This article presents the electric field waveforms of natural return strokes recorded by Foshan Total Lightning Location System. The evolution of parameters for both positive and negative return strokes is analyzed with respect to distance. The results show that the risetime, fall time, half-peak width, and zero-crossing time become longer with longer distance. The negative return strokes exhibit a more clear linear relation with distance compared to the positive return strokes. The values of overshoot duration increase with distance at 10-200 km, but become less obvious at larger distances. The values of initial peak remain the same for all return strokes. The overshoot amplitude and the ratio of overshoot to initial peak increase with distance for both positive and negative return strokes. The return stroke waveforms at far distances are more likely to exhibit clear opposite polarity overshoot.