My meteor video system captured sprites early on the morning of 8 November 2014.
Sprites are one form of transient luminous event or upper atmospheric lightning. In the upper atmosphere, very high above active thunderstorms, there are various forms of electrical discharge (sprites, elves, blue jets and even gnomes and pixies!) that are poorly understood and which were not even recognised until the last 20 years or so. In the last few years, it has been realised that video systems designed to capture meteors may also capture these fleeting phenomena which seem to occur at similar heights to meteors. Early this morning, my meteor camera caught two (and possibly three) sprites associated with thunderstorms that were over Northern France and the English Channel (120 – 150km away from here) at the time. I am thrilled to have video of one of the atmosphere’s most elusive sights.
At 03:20 the system captured a “columnar sprite” or possibly a “blue jet” (Clearly visible in the lower centre of the image captured from the video). As I look at the video in detail (frame by frame) I can see a very faint general flash along the lower right of the screen one frame (1⁄25 second) before the sprite appears. I think this was the very distant lightning reflected in clouds that were just below the horizon here and possibly from some clouds that are just visible in the image, between here and the storm. (The video camera is extremely sensitive, so this seems possible. Lightning is easily bright enough to be seen from 150km away at night if you are high enough. I was once thrilled to watch from the window of an airliner at night as lightning coursed backwards and forwards through a line of towering African thunderstorms. The captain reassured us that we were over 100miles away from them). The sprite lasts three video frames or 3/25th second, with only one frame being bright as shown in the image. A blue jet is emitted from the top of the thunderstorm cloud, so this is more likely to be a column sprite – an emission high in the upper atmosphere (perhaps up to 100km) above the storm.
The video shows a very much fainter sprite happening about 1⁄5 second before this one, to its left and lower down.
At 03:37 (see main image) the system captured a classic “carrot” sprite – very clear and bright. Again, it is possible to see a brightening along the horizon, which I assume to be from lightning, about 1⁄25 second before the sprite appears. This sprite appears on four video frames (4⁄25 second in total). The central column appears first then the “carrot”. Like lightning, sprites are a very short lived phenomenon.
Such sensitive video systems are very noisy – the backgrounds look like snowstorms, and trying to convert the video to web format makes it even worse. I will try to process a viewable video and share it. On my computer, it is possible to work through frame by frame to see the details. The sprites are fairly bright. If you had been looking in exactly the right place (and had you eyes open and focused at the split second the sprites occurred) you could have seen them with the naked eye.
I have reported the sprites to researchers at Bath University, as well as to the UK meteor network.