闪电先导传输过程中通道温度的变化

Variation of the channel temperature in the transmission of lightning leader

依据无狭缝高速摄谱仪获得的闪电梯级先导和直窜先导发展阶段的光谱,分析了先导传输过程中通道温度随时间的演化和沿通道高度的变化特征.结果表明:先导头端温度略高于后端温度,主要与头端集聚的电荷量相对较多有关;另外,梯级先导通道出现节点的位置上温度有明显升高,亮度也增强;直窜先导通道温度比梯级先导通道的温度高,但低于回击通道的温度,且沿着直窜先导通道的发展方向,通道温度略呈升高趋势.

According to the time-resolved spectra of lightning stepped leader and dart leader processes, thechannel temperature as well as its evolution characteristics with time and along the channel in thetransmission process of leader have been analyzed. The results show that the temperature of the leader tipis slightly higher than that of the trailing end, which should due to a large amount of electric charge on theleader tip. In addition, both the temperature and the brightness are enhanced on the position of thechannel node. The channel temperature of dart leader is higher than that of the stepped leader but lowerthan that of the return stroke. Meanwhile, the channel temperature of the dart leader slightly increaseswhen the dart leader propagates to the ground.