论文标题
负面闪电领导者的无线电发射揭示了内部仪表结构
Radio emission from negative lightning leader steps reveals inner meter-scale structure
论文作者
论文摘要
我们使用低频阵列(Lofar)来探测雷电放电中负电荷等离子体通道(负领导者)的踏脚过程的动力学。我们观察到,在领导者的每个步骤中,VHF的多个脉冲(30〜-〜80 MHz)辐射以短次脉冲爆发($ <10 \μ$ s)排放。这是在每个领导者步骤中发生的电晕闪光灯期间的流媒体形成的证据,这是在自然闪电中没有观察到的,它可以帮助解释闪电领导者的X射线发射,因为实验室领导者的X射线往往与Corona Flash相关。出乎意料的是,我们发现垫脚长度与地面附近观察到的长度非常相似,但是阶梯时间大得多,但尚不清楚。这些结果将有助于改善闪电传播模型,并最终改善闪电保护模型。
We use the Low Frequency ARray (LOFAR) to probe the dynamics of the stepping process of negatively-charged plasma channels (negative leaders) in a lightning discharge. We observe that at each step of a leader, multiple pulses of VHF (30~--~80 MHz) radiation are emitted in short-duration bursts ($<10\ μ$s). This is evidence for streamer formation during corona flashes that occur with each leader step, which has not been observed before in natural lightning and it could help explain X-ray emission from lightning leaders, as X-rays from laboratory leaders tend to be associated with corona flashes. Surprisingly we find that the stepping length is very similar to what was observed near the ground, however with a stepping time that is considerably larger, which as yet is not understood. These results will help to improve lightning propagation models, and eventually lightning protection models.