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Luminosity progression in dart‐stepped leader step formation
Author(s) -
Wang D.,
Takagi N.,
Uman M. A.,
Jordan D. M.
Publication year - 2016
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2016jd025813
Subject(s) - dart , pulse (music) , rocket (weapon) , luminosity , physics , lightning (connector) , optics , rise time , mechanics , astrophysics , acoustics , computer science , aerospace engineering , power (physics) , engineering , quantum mechanics , detector , galaxy , programming language , voltage
Using a high‐speed optical imaging system, we have observed the step formation bright pulse discharges occurring at the tip of dart‐stepped leaders of rocket triggered lightning with a time resolution of 0.1 µs and a spatial resolution of about 1.4 m. Each of the step formation pulse discharges appeared to initiate at a location immediately below the bottom of its previous pulse discharge and to propagate in bidirectional (upward and downward) waves with a speed on the order of 10 7 m/s. The downward waves of the pulse discharges tended to slow down significantly after they propagated a distance of about 2 m. Based on the results observed in this study and those published in literatures, we propose a conceptual view of leader step formation.