Characteristics of the initial stage and return stroke currents of rocket‐triggered lightning flashes in southern China

Abstract

This study investigates the initial stage (IS) and return stroke (RS) currents of 50 triggered lightning flashes (TLFs) that were conducted in southern China. The IS of the negative TLFs has a longer duration and larger average current, charge transfer, and action integral than those reported elsewhere, with geometric means (GMs) of 347.9 ms, 132.5 A, 45.1 C, and 10.0 × 103 A2 s, respectively. Two positive TLFs containing no RS have much greater average currents, charge transfers, and action integrals in the IS when compared with the negative TLFs. The RS has a greater peak current (17.2 kA; GM, same to below), charge transfer within 1 ms (1.3 C), and action integral within 1 ms (5.8 × 103 A2 s), and shorter 10% to 90% rise time (0.4 μs) than elsewhere. The peak current is prominently correlated with the rate of rise, charge transfer within 1 ms, and action integral within 1 ms. Furthermore, when the total duration of the RS and any following continuing currents is longer than 40 ms, the peak current, charge transfer within 1 ms, and action integral within 1 ms of the RS are seldom greater than 25 kA, 2.6 C, and 15 × 103 A2 s, respectively. It is indicated that TLFs containing RSs tend to have a longer duration but a smaller charge transfer during the IS than those without RS. The peak current of the RS is weakly correlated with its preceding silence period when there was no channel base current.

Optical and Current Measurements of Lightning Attachment to the 356-m-High Shenzhen Meteorological Gradient Tower in Southern Coastal Area of China

“…The leader had an average speed ranging from 0.4 to 1.1 × 10 5 m/s with a mean value of 0.8 × 10 5 m/s and a step length ranging from 0.8 to 2.2 m for the 5 steps during the first 200 µs of the leader initiation. Similar results for UPL in rocket-triggered lightning were also observed [19,20,22,23].…”

“…4 (a), for the initial UPL and continuous current process for Case 2. ICCP is one typical characteristic of the initial stage of upward discharges from towers or rocket-triggered lightning discharges [14], [18], [19]. As can be seen from Fig.…”

Initial Leader Properties During the Preliminary Breakdown Processes of Lightning Flashes and Their Associations With Initiation Positions

“…In 2015, the LFEDA was comprised of nine sensors in Guangzhou, China, with the distance between any two sensors being approximately between 6 and 60 km, as shown in Figures , , and . In the detection for the artificially triggered lightning flashes conducted at the Guangzhou Field Experiment Site for Triggered Lightning (Zheng et al, ) located in the northern part of the LFEDA network in 2015, the LFEDA located all the triggered lightning flashes, with an average location error of 102 m for the return strokes (Shi et al, ). In an investigation of a bolt from the blue causing human death, the LFEDA gave the positions of all seven return strokes with error ranging from 3 to 57 m and a mean value of 27 m (Fan et al, ).…”

Characteristics of Electromagnetic Signals During the Initial Stage of Negative Rocket‐Triggered Lightning

“…The flashes analyzed in this study were acquired during the SHATLE and GCOELD campaigns in 2015. The SHATLE campaign has been conducted in Binzhou, SHandong Province since 2005, and the experiment has been described in details by Qie et al () and Yang et al (); the GCOELD campaign has been performed in Conghua, Guangdong Province since 2006, and the layout of the experimental site was described by Zhang et al () and Zheng et al ().…”