An Analysis of Discharge Process of One Cloud‐to‐Ground Lightning Flash on the Qinghai‐Xizang Plateau

Abstract

The processes of return-stroke and intracloud discharge just before the first return stroke have been studied by using the data from a high-speed digital camera (1000 frames/s), slow antenna, fast antenna and VHF wide-band interferometer in Nagqu, the Qinghai-Xizang Plateau. The results suggest that the intracloud process occurred between the lower positive charge region and the middle negative charge region below the cloud. The negative charge region was located at about 2.8∼4.5km above the ground. The region of discharge initiation in the cloud was about 1.0∼1.7km above the ground. The initial streamer of discharge showed several horizontal branches when it progressed out of the cloud body. The velocity of stepped leader was estimated to be about 1×10 5 m/s. During its propagation to the ground, the leader channel showed a bigger curl. The first return stroke of the lightning had no difference with that in the lower altitude regions, and its current peak value was about 24.1 kA. But the subsequent strokes were quite weak on the Plateau.