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Unusually intense continuing current in lightning produces delayed mesospheric breakdown
Author(s) -
Cummer Steven A.,
Füllekrug Martin
Publication year - 2001
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 - 10.1029/2000gl012214
Subject(s) - lightning (connector) , amplitude , current (fluid) , physics , magnitude (astronomy) , peak current , environmental science , meteorology , atmospheric sciences , optics , astrophysics , power (physics) , electrode , quantum mechanics , electrochemistry , thermodynamics
Ultra low frequency magnetic field measurements made 500–2000 km from positive lightning discharges show a signature that is consistent with unusually high amplitude cloud‐to‐ground continuing lightning current. The magnitude of this nearly constant current moment is as large as 60 kA km and can last at half this amplitude for longer than 150 ms, thereby moving 640 C or more (assuming a 7 km vertical channel length) to the ground after the return stroke. This total charge transfer is more than an order of magnitude greater than most previously reported continuing currents in positive discharges. Three cases analyzed show this strong continuing current flows before, during, and after sprites that initiate more than 40 ms after the return stroke. Accounting for this continuing current, quantitative analysis shows that the total vertical lightning charge moment changes are large enough to produce mesospheric electrical breakdown and long‐delayed sprites.