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Positive cloud‐to‐ground lightning flashes in severe storms
Author(s) -
Rust W. David,
MacGorman Donald R.,
Arnold Roy T.
Publication year - 1981
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl008i007p00791
Subject(s) - thunderstorm , storm , meteorology , lightning (connector) , environmental science , flash (photography) , thunder , atmospheric sciences , upper atmospheric lightning , tower , geology , physics , lightning strike , geography , power (physics) , quantum mechanics , optics , archaeology
The occurrence of cloud‐to‐ground flashes that effectively lower positive charge to earth (+CG flash) over flat terrain has been documented in the mature stage of severe thunderstorms. Of the 31 documented +CG flashes, most had only one return stroke. Zero‐to‐peak rise times for the strokes averaged 7 µs. The +CG flashes averaged 520 ms in duration, with 25 percent lasting more than 800 ms. Many of these had field changes suggestive of continuing current. Positive flashes have been observed to emanate from several regions of severe storms: high on the back of the main storm tower, through the wall cloud, and from the downshear anvil. Visually most of these positive flashes have emanated from high in the storm, and acoustic mapping of two shows thunder sources to a height of about 15 km.