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Initial‐stage pulses in upward lightning: Leader/return stroke versus M‐component mode of charge transfer to ground
Author(s) -
Flache D.,
Rakov V. A.,
Heidler F.,
Zischank W.,
Thottappillil R.
Publication year - 2008
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 - 10.1029/2008gl034148
Subject(s) - lightning (connector) , current (fluid) , physics , peak current , meteorology , optics , power (physics) , electrode , electrochemistry , quantum mechanics , thermodynamics
We analyzed high‐speed video images and corresponding current records for eight upward lightning flashes initiated by the Peissenberg tower (160 m) in Germany. These flashes contained a total of 33 measurable initial stage (IS) current pulses, which are superimposed on steady IS currents. Seven IS pulses had relatively short (<8 μ s) 10‐to‐90% risetimes and 26 IS pulses had relatively long (>8 μ s) risetimes. Six (86%) of seven IS current pulses with shorter risetimes each developed in a newly‐illuminated branch, and 25 (96%) of 26 IS pulses with longer risetimes occurred in already luminous (current‐carrying) channels. These results support the hypothesis that longer risetimes are indicative of the M‐component mode of charge transfer to ground, while shorter risetimes are associated with the leader/return stroke mode. Similar results were obtained for M‐component pulses that are superimposed on continuing currents following return‐stroke pulses.