摘要
１９９６年夏季在江西南昌附近进行的人工触发闪电野外实验中，用新开发的不接地的火箭－导线技术成功地在雷暴云下的负环境电场中触发了云对地闪电。我们用一套成像率为１０００幅／秒的高速数字化摄像系统对下行负先导进行了观测。资料分析揭示了下行负先导始发、发展和接地的特点。负先导开始时速度缓慢，它在向地面行进中曲折、分枝并最后终止于４ｍ高接地良好的引流杆顶端。下行先导接地瞬间产生的电流脉冲其电流密度的空间分布是不均匀的。通过个例分析提出了空中触发闪电初始先导发生和发展的物理图像。
In the field experiment of artificially triggering lightning conducted near Nanchang, Jiangxi in the summer of 1996, 3 lightning flashes were successfully triggered by use of newly-developed technique with ungrounded rocket-wire system in negative ambient electric field of thunderclouds. A high-speed digital camera with 1 000F/s framing rate was used for the observation. Data analysis revealed the characteristics of the initiation, propagation and connection to the ground of the downward-moving negative leader, which progressed at a lower speed and showed zigzag, branching on its way to the ground, and finally terminated on the tip of a 4m high, well grounded lightning rod. The current density along the channel was not uniform on the moment when the downward leader touched the ground. A physical model of leader inception and propagation in altitude triggered lightning was presented through case analyses.
出处
《高原气象》
CSCD
北大核心
1998年第1期24-33,共10页
Plateau Meteorology
基金
国家自然科学基金
关键词
空中触发闪电
双向先导
下行先导
接地行为
闪电
Altitude triggered lightning Bi-directional leader Downward-moving negative leader Attachment process
