Reconstruction of lightning channel geometry by localizing thunder sources

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• 作者：J.A.P. Bodhika ; W.G.D. Dharmarathna ; Mahendra Fern ; o ; Vernon Cooray
• 关键词：Thunder ; Localization ; Lightning ; Channel geometry
• 刊名：Journal of Atmospheric and Solar-Terrestrial Physics
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：102
• 期：Complete
• 页码：81-90
• 全文大小：2706 K

文摘

Thunder is generated as a result of a shock wave created by sudden expansion of air in the lightning channel due to high temperature variations. Even though the highest amplitudes of thunder signatures are generated at the return stroke stage, thunder signals generated at other events such as preliminary breakdown pulses also can be of amplitudes which are large enough to record using a sensitive system. In this study, it was attempted to reconstruct the lightning channel geometry of cloud and ground flashes by locating the temporal and spatial variations of thunder sources. Six lightning flashes were reconstructed using the recorded thunder signatures. Possible effects due to atmospheric conditions were neglected. Numerical calculations suggest that the time resolution of the recorded signal and 10 ms^?1error in speed of sound leads to 2 % and 3 % errors, respectively, in the calculated coordinates. Reconstructed channel geometries for cloud and ground flashes agreed with the visual observations. Results suggest that the lightning channel can be successfully reconstructed using this technique.