@article{oai:nagoya.repo.nii.ac.jp:00019575,
 author = {ISIKAWA, HARUZI and TAKAGI, MASUMI and TAKEUTI, TOSIO},
 journal = {Proceedings of the Research Institute of Atmospherics, Nagoya University},
 month = {Mar},
 note = {The authors have adopted the discontinuous method of recording the atmospheric waveforms, in which each waveform, singly swept on the screen of respective C. R. T., is photographed in the respective frame of 35 mm cine film. These techniques have made it possible to perform an uninterrupted recording of waveforms throughout the period of a thunderstorm often lasting more than several hours, and to deduce statistically more general features common to a certain type of lightning discharges than the continuous method of recording can do. Following these views the authors have made a statistical analysis of waveforms obtained under thunderstom conditions. It has been made clear through the present analysis that: (1) Almost 80% of the recorded stepped leaders preceeding ground discharges has been found to be β type, and this situation has not been changed through two years' observations. (2) Positive space charges presumed to exist at the thundercloud base really activate the formation of β type leaders, neverthless, α type leaders can often be produced even in such cases, where a clear evidence exists that a strong positive space charge centre is present at the cloud base. (3) The nature of the initial portion of a stepped leader is the same for both these two types, and the time interval values between two successive pulses in this portion clearly reduce from larger values, more than 100 μs, to normal values, roughly 50 μs, when the leader steps out of cloud base and develops in the gap between cloud and ground. (4) In some cases a β type leader, followed by a return stroke, produces a train of small pulsations in its final few ms, just before the return stroke appears. The mean time-interval, roughly 20 μs, of these pulsations is clearly smaller than the normal value between step streamers. It is not clear at present whether each of these final pulsations is produced by a step streamer appearing in the last stage of leader development, as the Boys' camera photopraph of a typical a type stepped leader does not represents any reduction of step intervals throughout the final stage of it at all.},
 pages = {1--11},
 title = {ON THE LEADER WAVEFORMS OF ATMOSPHERICS NEAR THE ORIGINS},
 volume = {5},
 year = {1958}
}