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An evaluation of lightning flash characteristics using LDAR and NLDN networks with warm season southeast Texas thunderstorms

A comparison of flash parameters from the National Lightning Detection
Network (NLDN) is made with data obtained from the Houston Lightning Detection and
Ranging II (LDAR) network. This research focuses on relating the peak current and
number of strokes in a negative flash (multiplicity) of lightning with the spatial extent
and mean altitude of three-dimensional lightning in 1407 flashes as mapped by the
LDAR network. It is shown that increasing negative multiplicities over the range two
through ten exhibit, on average, a higher flash extent with higher multiplicities. Singlestroke
flashes have mean heights of nearly 2 km greater. Higher order multiplicities (2
to 10+) were correlated with mean source heights near 8 km. Increasing multiplicity
tends to be associated with greater flash extents increasing more horizontally than
vertically with a 50% to 70% increase in flash extent. No obvious relationship between
peak current and flash extent was observed. Examining peak current and mean height
shows that low current flashes (<10kA) exhibit higher mean heights. However, this may
be due to intra-cloud only flashes being reported as cloud to ground events by the
NLDN. Bipolar flashes do not show much variation with height and flash extent with the exception of negative-first bipolar flashes, which exhibited mean flash extents twice
that of other types. Finally, the flash detection efficiency is 99.7% within 60 km of the
network center.

Identiferoai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/85994
Date10 October 2008
CreatorsJurecka, Joseph William
ContributorsOrville, Richard E.
PublisherTexas A&M University
Source SetsTexas A and M University
Languageen_US
Detected LanguageEnglish
TypeBook, Thesis, Electronic Thesis, text
Formatelectronic, born digital

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