Publicações

The advent of high-speed motion CCD video cameras allowed the use of temporal highresolution video images of lightning flashes. High-speed cameras are now an essential tool in lightning research. Being able to see and analyze sequential, time resolved images of lightning processes is greatly improving our understanding of this complex phenomenon. Flash characteristics like stroke multiplicity, interstroke time interval, flash duration, number of ground contacts are easily determined. With these cameras, the missing of strokes that occur at relatively short time intervals is practically excluded. The presence of continuing current events, the waveshape of their intensity and the occurrence of M components can be observed. Also, the elapsed time since the return stroke and time interval between successive M components can be measured. In addition, recoil leaders that retrace fine branch structures during the propagation of positive leaders to ground were observed for the first time with these cameras. This review paper will describe some recent findings obtained with high-speed videos.