Accession Number : ADA138136

Title :   Lightning Data Analysis.

Descriptive Note : Final technical rept. Jul 81-Jul 83,


Personal Author(s) : Uman,M A

PDF Url : ADA138136

Report Date : Dec 1983

Pagination or Media Count : 48

Abstract : A detailed lightning channel reconstruction has been performed for a lightning event recorded as a WC-130 aircraft instrumented for electric and magnetic field measurements was flown in South Florida in the vicinity of a network of groundbased stations that provided wideband electric fields at ground level and data that could be used to determine the location of lightning and VHF sources. Maximum rates of change of airborne electric fields from the last few stepped leader pulses and from the fast field transitions of return strokes are shown to be an order of magnitude smaller than those reported for measurements at ground level over salt water. Two sets of calculations are presented for lightning return stroke electric and magnetic fields at flight altitudes, one set assuming an initial peak current which propagates up the channel unattenuated and the second set assuming a current peak which decreases exponentially with height with a decay length of 1.5 km. A recommendation is given for a lightning return stroke test standard for average first and subsequent return strokes and for a comparison of lightning and EMP.

Descriptors :   *Lightning, Electromagnetic wave propagation, Very high frequency, Electric fields, Magnetic fields, Electromagnetic pulses, Nuclear explosions, Comparison, Reprints

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE