The regular pulses bursts in electromagnetic radiation from lightning

A special lightning discharge phenomenon named as Regular Pulses Bursts (RPBs) is analysed. The result shows that the RPBs exist in all 69 lightning discharges within 30 minutes recording. The 190 RPBs in 6 typical lightning discharges are analysed in detail, the result indicates that its typical width of pulses is about 1μs, and inter-pulse interval varies from 4 to 8μs. Four types, namely normal RPBs, back RPBs, symmetry RPBs, and reversal RPBs are classified according to inter-pulse interval and pulse polarity. There is no obvious difference between RPBs in negative cloud to ground (CG) lightning and that in intracloud lightning(IC), but polarity change of most RPBs is frequent in positive CG. The results also show that the RPBs tend to occur in the latter portion of lightning discharges, and many cases are found to be associated with intensive VHF radiation. The waveform of the normal-type RPBs is similar to the dart-stepped leader in negative CG, which is considered caused by the recoil streamers. And the back-type RPBs may be caused by the leaders in cloud.