1. The Timing of Cloud-to-Ground Lightning Relative to Total Lightning Activity.
- Author
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MacGorman, Donald R., Apostolakopoulos, Ivy R., Lund, Nicole R., Demetriades, Nicholas W. S., Murphy, Martin J., and Krehbiel, Paul R.
- Subjects
LIGHTNING ,STORMS ,ATMOSPHERIC electricity ,METEOROLOGICAL precipitation - Abstract
The first flash produced by a storm usually does not strike ground, but little has been published concerning the time after the first flash before a cloud-to-ground flash occurs, particularly for a variety of climatological regions. To begin addressing this issue, this study analyzed data from very-high-frequency (VHF) lightning mapping systems, which detect flashes of all types, and from the U.S. National Lightning Detection Network (NLDN), which identifies flash type and detects roughly 90%% of cloud-to-ground flashes overall. VHF mapping data were analyzed from three regions: north Texas, Oklahoma, and the high plains of Colorado, Kansas, and Nebraska. The percentage of storms in which a cloud-to-ground flash was detected in the first minute of lightning activity varied from 0%% in the high plains to 10%%-20%% in Oklahoma and north Texas. The distribution of delays to the first cloud-to-ground flash varied similarly. In Oklahoma and north Texas, 50%% of storms produced a cloud-to-ground flash within 5-10 min, and roughly 10%% failed to produce a cloud-to-ground flash within 1 h. In the high plains, however, it required 30 min for 50%% of storms to have produced a cloud-to-ground flash, and 20%% produced no ground flash within 1 h. The authors suggest that the reason high plains storms take longer to produce cloud-to-ground lightning is because the formation of the lower charge needed to produce most cloud-to-ground flashes is inhibited either by delaying the formation of precipitation in the mid- and lower levels of storms or by many of the storms having an inverted-polarity electrical structure. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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