摘要
本文分析了1987年6月28日甘肃中川地区一次雷暴过程中地面4个测站的电场资料,并定量估算了4个地闪的8个回击所中和的电荷量及其高度。负地闪回击所中和的电荷离地高度为4km左右(对应的环境温度为-11.2℃),而正地闪回击所中和的电荷离地高度为2km左右(环境温度+4.9℃)。负地闪大多发生在云闪后的电场恢复阶段,且在开始时往往具有持续几百毫秒的云内放电过程。其激发过程可能是首先在云底部正电荷区产生向上传输的持续正流光,导致云中部负电荷向下移动,并引发向下传输的负先导,最终导致地闪回击的发生。
The simultaneous four-stations electric field and field change data of a thunderstorm occured on June 28, 1987 near Zhongchuan are analysed in this paper, and the location and the amount of charge brought to the ground by each leader-return stroke are calculated for 8 return strokes. The results show that the altitude of the neutralized charge is about 4 km above the ground for negative flashes (the corresponding ambient temperature is -11.2 ℃) and 2 km (+4.9 ℃) for positive flashes.
Negative flashes occur usually during the electric field recovery period following cloud discharges and proceed with intracloud processes lasting several hundreds milliseconds in the begining. Upward going positive streamers from lower positive charge region may play an important role in the initiation of negative groud discharges.
出处
《高原气象》
CSCD
北大核心
1990年第4期405-410,共6页
Plateau Meteorology
基金
国家自然科学基金委的部分资助
关键词
雷暴
地闪
回击
电结构
闪电
Charge structure
Lightning discharge
Return stroke of ground flash
