Recoil Leader and Associated Discharge Features Observed During the Progression of a Multi-Branched Upward Lightning Flash

摘要

Using a high-speed video camera and a high-speed optical imaging system, we observed a multi-branched upward lightning flash that exhibited several special discharge features. One special feature is that a series of recoil leaders and the subsequent discharges caused by the connection of some recoil leaders to a conducting channel could extend a discharge channel like a leader. Another special feature is that the subsequent discharge could be similar to either a return stroke (RS) or an M-component or something between. It seems that when a recoil leader initiated in a more conductive channel with a closer distance to a conducting channel, its subsequent discharge is similar to an M-component. In cases with opposite conditions, the subsequent discharge will become similar to a RS. In conditions between the above two cases, a discharge that is intermediate between the RS and M-component will occur.