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Lightning amplitude spectra in the interval from 100 kHz to 20 MHz
Author(s) -
Weidman C. D.,
Krider E. P.,
Uman M. A.
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/gl008i008p00931
Subject(s) - lightning (connector) , amplitude , spectral line , physics , electric field , range (aeronautics) , computational physics , atomic physics , optics , materials science , power (physics) , quantum mechanics , astronomy , composite material
The electric radiation fields produced by lightning return strokes, stepped leaders, and intracloud discharge processes have been Fourier‐analyzed to determine amplitude spectra for these processes from about 100 kHz to 20 MHz. The fields were recorded under conditions where the lightning locations were known and where the field propagation from the lightning sources to the recording site was entirely over salt water. The spectra for return strokes show an f −1 frequency dependence from 100 kHz to 2 MHz, an f −2 dependence between 2 and 10 MHz, and an f −5 decrease above 10 MHz. In the 1 to 20 MHz range, the spectra of the initial fast transition in return strokes, the initial fast‐rising portion of leader steps and the fast transitions in positive intracloud pulses are surprisingly similar.