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Photoelectric return-stroke velocity and peak current estimates in natural and triggered lightningTwo-dimensional photoelectric return stroke velocities from 130 strokes are presented, including 86 negative natural, 41 negative triggered, one positive triggered, and two positive natural return strokes. For strokes starting near the ground and exceeding 500 m in length, the average velocity is 1.3 + or - 0.3 X 10 to the 8th m/s for natural return strokes and 1.2 + or - 0.3 X 10 to the 8th m/s for triggered return strokes. For strokes with lengths less than 500 m, the average velocities are slightly higher. Using the transmission line model (TLM), the shortest segment one-dimensional return stroke velocity, and either the maximum or plateau electric field, it is shown that natural strokes have a peak current distribution that is lognormal with a median value of 16 kA (maximum E) or 12 kA (plateau E). Triggered lightning has a medium peak current value of 21 kA (maximum E) or 15 kA (plateau E). Correlations are found between TLM peak currents and velocities for triggered and natural subsequent return strokes, but not between TLM peak currents and natural first return stroke velocities.
Document ID
19900024785
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Mach, Douglas M.
(National Severe Storms Lab. Norman, OK, United States)
Rust, W. David
(NOAA, National Severe Storms Laboratory, Norman OK, United States)
Date Acquired
August 14, 2013
Publication Date
September 30, 1989
Publication Information
Publication: Journal of Geophysical Research
Volume: 94
ISSN: 0148-0227
Subject Category
Meteorology And Climatology
Accession Number
90A11840
Funding Number(s)
CONTRACT_GRANT: NASA ORDER H-39299-B
Distribution Limits
Public
Copyright
Other

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