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Global distribution and properties of continuing current in lightning
Author(s) -
Bitzer Phillip M.
Publication year - 2017
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2016jd025532
Subject(s) - lightning (connector) , lightning detection , current (fluid) , peak current , meteorology , upper atmospheric lightning , environmental science , lightning strike , thunderstorm , remote sensing , geology , physics , oceanography , power (physics) , electrode , quantum mechanics , electrochemistry
Continuing current is a process in lightning in which the current in a conducting channel can flow for much longer than in a typical lightning discharge. The phenomenon can be characterized by the continuous optical emission that accompanies the current flow. Using the Lightning Imaging Sensor (LIS), lightning with continuing current is identified on a global scale. Lightning that contains optical emission over at least five consecutive LIS frames, roughly 7–9 ms, are classified as continuing current flashes. This differs from typical lightning discharges that produce optical emission for one or two consecutive frames. Of the flashes detected by LIS, 11.2% contain continuing current. These flashes optically radiate over a larger footprint and have a longer duration than ones that do not. The spatial distribution of these flashes indicates that regions of high lightning activity may not be correlated with a high likelihood of continuing current flashes. Further, oceanic and winter lightning are shown to have a higher proportion of continuing current flashes. Finally, 25–40% of flashes identified by LIS to have continuing current have only an intracloud pulse detected by the National Lightning Detection Network (NLDN), with no cloud‐to‐ground strokes detected.