Study on rocket-triggered lightning in Indonesia

本研究的目的是借由日本与印尼在爪哇岛进行的火箭引发闪电合作实验，来研究热带地区闪电的特性。该试验场位于雅加达南部的Puncak Pass附近的茶园内，设有火箭发射器和一个用于控制和观察的小屋。用接地钢丝发射小型火箭作为雷云，从火箭钢丝尖端发射一个向上的先导冲击，触发雷电放电。雷电流和波形由记忆装置测量。从1990年以来，Puncak实验共成功地进行了15次，其中包括1994 ~ 1995年的4次。放电电流的极性除正极性外均为负极性。这与日本的夏季闪电相似。放电中有一半是小于1.5KA的小电流，这是人工触发闪电的一个特征。另一半为大电流，平均9.8kA，最大15 KA，波形与标准雷电冲击波相似，锋1- 10 μ s，半尾50 μ s。在避雷针的触发放电作为雷击损伤的保护现象中，获得了三次令人赞赏的结果。

The object of this research is to study the characteristics of lightning in tropical zone by cooperative experiment of rocket triggered lightning between Japan and Indonesia in Jawa island. Also it is expected that the reserch will promote the protection techniques for lightning damage to electric power and communication systems in Indonesia.The experiment site with rocket launchers and a hut for control and observation was built in tea field near Puncak pass in south of Jakarta. A small rocket was launched with grounded steel wire for thundercloud, then a lightning discharge was triggered after an upward leader stroke was launched from the tip of rocket wire. The lightning current and wave shape were measured by memory devices. The induced voltages at ground and on test power line were obtained with the photograph of discharge.The total of successful triggerings since 1990 in Puncak experiments is 15 including 4 of 1994-1995. The polarity of discharge currents is negative expect one of positive. It is similar to summer lightning in Japan. A half of discharges is small current of less than 1.5KA,which is a feature of artificially triggered lightning. Another half is big current of 9.8kA in average and the maximum of 15KA.The wave shapes are similar to the standard lightning impulse wave with 1-10mus of front and 50 MS of half tail. Another appreciated result was obtained three times in the triggered discharge to a lightning rod as a protection phenomenon for lightning damage.