Characteristics of a multi-stroke “bolt from the blue” lightning-type that caused a fatal disaster

Abstract

Observational data from the low-frequency electric-field detection array (LFEDA) and radar were used to study the precise location of a fatal accident caused by a lightning in Conghua, Guangzhou, China, 2017. Based on a comprehensive analysis, the lightning was concluded to be a negative “bolt from the blue” ground flash with seven return strokes. The first return stroke was on June 3 at 16:36:49.219 with a peak current intensity of −30.9 kA. The LFEDA system mapped the development of the lightning channel. The horizontal distance from the edge of the cloud anvil area (0 dBz) to the return stroke point was about 0.3 km, the horizontal distance from the edge of the precipitation area (18 dBz) to the return stroke point was about 1.8 km, and the return stroke channel extended as far as 3 km out of the cloud. There was no cloud cover above the head of the victim. The electric field waveform of the return strokes detected by the LFEDA system showed multi-peak characteristics, and all seven return strokes were multiple-termination strokes. The most probable mechanism for the lightning injuries was the side flash.