Light Intensity Profiles of Return Strokes at the Bottom of Rocket-triggered and Natural Lightning Channels

Abstract

We report the light intensity profiles of 20 return strokes in rocket-triggered lightning flashes and 4 return strokes in natural lightning flashes recorded by a high speed optical observation device called LAPOS. For all the return strokes, the peak light intensity decreases and the 10% to 90% rise time increases with increasing height. The changes of light intensity and 10% to 90% rise time versus height are much faster in rocket-triggered lightning flashes than those in natural lightning flashes. The peak light intensity and the rise time of rocket triggered strokes at 40 m above the return stroke initiation point are about half and twice, respectively, of those at the initiation point.