Apparent Lightning Return Stroke Speed and the Correction

[摘要] A varying return-stroke speed during the propagation process along the lightning channel is extensively reported. In this paper, we found, due to the propagation time difference of the emitted light by lightning in the propagation path from the lightning channel to the optical observation point, even in the case of an assumed constant return-stroke speed, the observed speed, termed as the apparent return-stroke speed, is not constant. For conventional return-stroke engineering models that the return stroke is assumed to propagate from the ground, we investigated the influence of the observation distance, the observation altitude, and the assumed value of the return-stroke speed on the variation trend of the apparent speed. In addition, the deviation of the apparent speed from its actual value is compared for the concerned influencing factors. The need of propagation time correction in obtaining the characteristics of return stroke propagation from the time-resolved optical records is emphasized here.

[发布机构] China Ship Development and Design Center, Wuhan; 430064, China^1

[学科分类] 环境科学（综合）

[关键词] Engineering models;Initiation process;Lightning channel;Lightning return stroke;Optical observations;Propagation paths;Propagation process;Return stroke