Return stroke peak current versus charge transfer in rocket‐triggered lightning

Abstract

[1] We examined data on 117 return strokes in 31 rocket-and-wire-triggered lightning flashes acquired during experiments conducted from 1999 through 2004 at the International Center for Lightning Research and Testing at Camp Blanding, Florida, in order to compare the peak currents of the lightning return strokes with the corresponding charges transferred during various time intervals within 1 ms after return stroke initiation. We find that the determination coefficient (R 2 ) for lightning return stroke peak current versus the corresponding charge transfer decreases with increasing the duration of the charge transfer starting from return stroke onset. For example, R 2 = 0.91 for a charge transfer duration of 50 ms after return stroke onset, R 2 = 0.83 for a charge transfer duration of 400 ms, and R 2 = 0.77 for a charge transfer duration of 1 ms. Our results support the view that (1) the charge deposited on the lower portion of the leader channel determines the current peak and that (2) the charge transferred at later times is increasingly unrelated to both the current peak and the charge deposited on the lower channel section. Additionally, we find that the relation between triggered-lightning peak current and charge transfer to 50 ms in Florida is essentially the same as that for subsequent strokes in natural lightning in Switzerland, further confirming the view that triggered-lightning strokes are very similar to subsequent strokes in natural lightning.Citation: Schoene, J., M. A. Uman, and V. A. Rakov (2010), Return stroke peak current versus charge transfer in rockettriggered lightning,

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

“…[] in a study of 143 RSs ( R 2 = 0.76) and by Schoene et al . [] in a study of 117 RSs, ( R 2 = 0.77). However, in their studies of TLFs in Shandong, China, Zhao et al .…”

Lightning current and luminosity at and above channel bottom for return strokes and M‐components

“…We note that triggered lightning return strokes are very similar, if not identical, to natural lightning subsequent strokes, strokes following the first stroke in natural lightning, with regard to measured current amplitudes and wave shapes [e.g., Fischer et al , ; Schoene et al , , ], and hence, the results found in this paper are likely applicable to strokes after the first stroke in natural lightning.…”

Lightning morphology and impulse charge moment change of high peak current negative strokes

“…Rough estimates of peak current, subject to assumptions such as lightning channel geometry and return stroke speed [ Willett et al , 1989; Rachidi et al , 2004], are routinely provided by several nationwide lightning detection systems. Careful studies indicate that these two quantities are highly correlated in rocket‐triggered lightning on time scales of a few hundred microseconds after the return stroke, but this correlation drops with time indicating that the charge transfer at later time is not tightly linked to the return stroke peak current [ Schoene et al , 2010]. A further implication is that the lightning peak current is not necessarily relevant to the total charge transfer shortly after return strokes, which can be evaluated with the impulse charge moment change (iCMC, defined empirically as the product of charge transferred from cloud to ground within 2 ms after the return stroke and its original height above the ground) [ Cummer and Lyons , 2004, 2005].…”