Premium
Properties of unipolar magnetic field pulse trains generated by lightning discharges
Author(s) -
Kolmašová Ivana,
Santolík Ondřej
Publication year - 2013
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 - 10.1002/grl.50366
Subject(s) - amplitude , microsecond , lightning (connector) , waveform , pulse (music) , physics , magnetic field , pulse amplitude modulation , spectrum analyzer , pulse wave , train , computational physics , optics , acoustics , voltage , power (physics) , laser , cartography , quantum mechanics , detector , geography
We analyze and describe trains of regular unipolar microsecond‐scale magnetic field pulses produced by intracloud lightning discharges. Waveforms of the magnetic field are measured using a newly developed broadband analyzer with a sampling interval of 12.5 ns. The observed trains contained several tens of pulses, and the time interval between neighboring pulses typically varied between 1 and 10 µs. The amplitude of the pulses also varied by 1 order of magnitude. A systematic analysis of these variations is done for the first time. The interpulse interval is usually increasing (on average by 4.1 µs during a train), and the pulse amplitude is decreasing (on average by 15% of the maximum value within a given train). We propose a possible generation mechanism based on a hypothesis that periodical charge structures are present in the thundercloud. This mechanism can explain the observed evolution of peak amplitudes and interpulse intervals.