人工触发闪电放电电流的间接测量及其特征分析

INDIRECT MEASUREMENT OF ARTIFICIALLY TRIGGERED LIGHTNING DISCHARGE CURRENT AND ITS CHARACTERISTIC ANALYSIS

Magnetostatic field at the close range of artificially triggered lightning was measured by a magnetic field antenna system. The characteristic of triggered lightning current deduced from the magnetic field antenna system is consistent with that of direct current measurement by coaxial shunt system, electric field charge measurement by slow antenna and relative luminosity measurement by photocell system. Triggered lightning for storms in Yongdeng, Gansu is initiated with the upward going negative leader, under the influence of the dominant lower positive charge of storm, which propagates upwards followed by continuous current process. The speed of leader propagation was calculated from synchronous measurements of close magnetic and electric field and also from synchronous measurements of electric field change at two stations, results being the order of 105m/s. The triggered lightning lasts a few tens of milliseconds with the neutralized change of a few coulombs.