两次仅有连续电流的负极性人工引发雷电特征分析

对2006年8月28日在广州从化人工引发的两次雷电(F184626和F185503)的特征进行了分析。这两次触发闪电都是经典负极性慢型放电过程，整个放电过程仅有连续电流没有回击，但连续电流过程中包含有多个M分量。两次过程触发时地面电场分别为-6.1 kV/m和-8.2 kV/m，触发高度分别约336 m和244 m。资料分析表明，两次人工引发雷电形成稳定上行正先导之前，出现多次明显的双极性脉冲，脉冲间隔平均值分别为18.12 ms和16.64 ms；在上行正先导产生初始阶段出现明显的阶梯特性，梯级先导脉冲的平均间隔分别为20 ms和24 ms，总持续时间都约为250 ms，脉冲的宽度约1 ms。8月28日的两次触发闪电与以往北方正极性的慢型放电过程相比有连续电流持续时间较长等特征。

Characteristics Analysis of Two Negative Artificially Triggered Lightning Discharges With Only Continuous Current

In this paper the characteristics of two lightning discharges (named F184626 and F185503) artificially triggered in Conghua, Guangzhou on Aug. 28 in 2006 were analyzed. Both of them are classical negative artificial lightning without return stroke besides continuous discharging and M component. Just before the triggering, the ground electric field is -6.1 kV/m and -8.2 kV/m respectively, and the triggered altitude of the two discharges are about 336 m and 244 m respectively. The results show that obvious double-polarity pulse occurs before the triggering of steady upper-ward positive leader, the average value of pulse interval is 18.12 ms and 16.64 ms respectively; obvious stepped leaders occur at the early stage of occurrence of stable streamer, and the average interval of stepped leader pulse is about 20 ms and 24 ms respectively; the total lasting time is about 250 ms, and the width difference of pulses is basically 1 ms. The discharges on Aug. 28 in the summer of 2006 had much longer durations of continuous discharging than that in the north.