Observations of streamer formation in sprites
Observations of streamer formation in sprites
复制标题
精灵中流光形成的观察
DOI：
10.1029/2006gl027854
复制
发表时间：
2007
影响因子：
5.2
通讯作者：
T. Kammae
中科院分区：
文献类型：
--
作者：
M. McHarg;H. Stenbaek;T. Kammae
在50 μs图像曝光时间下，以10,000 fps记录了精灵。在这个时间分辨率，它是有可能解决流光尖端的时间发展。记录显示，精灵开始与一个飘带头形成在近80公里的高度。在增亮过程中，流光头快速向下移动，流光通过后约300 μs会产生更持久的辐射。这本质上就是C - sprite。在一些事件中，也观察到向上移动的飘带头，在这种情况下，我们有一个胡萝卜精灵。流线速度在106到107米/秒之间变化。观测到105 - 1010m /s2量级的正加速度和负加速度。向上的流光，当出现时，总是比向下的流光更晚，从更低的高度开始，它们从精灵中的现有结构开始。
Sprites have been recorded at 10,000 fps with 50 μs image exposure time. At this time resolution it is possible to resolve the temporal development of streamer tips. The recordings show that sprites start with a streamer head forming at an altitude near 80 km. The streamer head moves rapidly downwards while brightening, and ∼300 μs after streamer passage longer lasting emissions ensues. This is essentially the C‐sprite. In some events upward moving streamer heads are also observed, in which case we have a carrot‐sprite. The streamer speeds vary between 106 and 107 m/s. Both positive and negative accelerations, of magnitude 105 – 1010 m/s2, were observed. Upward streamers, when present, always start later and from a lower altitude than downward streamers, and they start from existing structure in the sprite.