Lightning Observation in Inland Plateau Area of China

1997年夏在中国高原内陆地区进行了一次综合野外试验，获得了自然闪电和人工触发闪电的一些资料。以下是数据分析的一些初步结果。对于自然放电，通过宽带干涉仪对两个放电源的数据和电容天线的电场变化分析表明，云内放电通常是从较低的负电荷中心开始的负先导，然后向云的上部传播。放电噪声源与雷达回波的对比也表明，噪声源主要集中在云层的上、下两层，在人工触发闪电方面，我们在中国内陆高原地区首次成功地进行了高空触发正放电闪电的双向超前过程。根据基极电流、电场变化和光学图像的同步观测结果，提出了该触发正极放电的双向先导发展的跟踪模型。在火箭到达几百米的高度后，一个向下的正向导轨首先从与火箭相连的钢丝的下端发起。几微秒后，一条负引线在同一根导线的上端启动，并向上传播。当向下的正向导联下降并与导线接地时，发生脉动放电。此外，还成功地进行了一次典型的正触发闪电实验，并直接观测到了该放电中与正向负先导相关的电流。

A few data on natural and artificially triggered lightning have been obtained during a comprehensive field experiment carried out in the summer of 1997, in inland plateau area of China. Following are some of the preliminary results of data analysis.For natural discharges, analyzes on the data of both discharge sources by wide-band interferometer and electric field change by capacitive antennas indicate that a intra-cloud discharge usually begins with a negative leader initiating from the lower negative charge center and then propagating towards the upper part of the cloud. The comparison of discharge noise sources with radar echoes also show that the noise sources mainly concentrated within a up and a low two layrs in the cloud.For artificially triggering lightning, we have succeeded firstly on altitude triggered positive discharge lightning with a bi-directional leader process in inland plateau area of China. According to the simultaneous observation results of base current, electric field change and optical image, following model of bi-directional leader development for this triggered positive discharge has been figured out. After the rocket reaches a height of a few hundred meters, a downward positive leader firstly initiated from the lower end of the wire attached to the rocket. A few microseconds later, a negative leader intiated at the up end of the same wire and propagating upward. When the downward positive leader going down and connecting with a wire grounded, a pulsating discharge occurred. In addition, a classical positive triggered lightning was also succeeded and the current associating with the upward negative leader in this discharge was observed directly.