CHARACTERISTICS OF THE LEADING PROCESSES TO THE ARTIFICAL INDUCED LIGHTNING IN THE AIR
ZHANG YIJUNDONG WANSHENGZHANG GUANGSHUQIE XIUSHUCold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences, Lanzhou 730000, China
We have studied the physical processes leading to one triggered lightning flash using the altitude-triggering technique. The main characteristics of the triggered lightning are inferred from data of simultaneous electric field change measurements at two stations and highly time-resolved optical signals. The results reveal the characteristics of leading propagation to the triggered lightning. When the rocket attached with a thin steel wire is ascending to the height of several hundred meters, a typical bi-directional leader is initiated at the top and bottom end of the wire. When the negative leader propagating downward approaches to the ground, a positive connecting leader is excited from the ground and propagates upwards. The average speed of the negative and connecting positive leaders is around 0.86×105m/s. A mini-return stroke is produced with the connection to the ground of downward negative leader. The upward positive leader initiated from the top end of wire propagates at a speed of about 1.1×105m/s.