My astronomy professor alerted me to this website today: http://spaceweather.com/archive.php?view=1&day=01&month=10&year=2010
Recently, Joel Gonzalez recorded a rare phenomenon known as a gigantic jet near Kennedy Space Center. For those of you who watched the video in the link, you might be thinking “well, that’s cool, but it lasted only a second or so.” True, it’s hard to appreciate the magnitude of the gigantic jet based on the video, but don’t be fooled–this is some awesome science at work!
When we think of thunderstorms, we think of two things–the first is thunder (obviously) and second is the brilliant event that can spark thunder in the first place–lightning. Lightning is a large discharge of electrical energy in the atmosphere during a thunderstorm, or sometimes during volcanic eruptions or dust storms, which can also build up static electricity. During a thunderstorm, lightning bolts can erupt out of the bottom of the cloud and even hit the ground at supersonic (faster than sound) speed, which is why you hear thunder afterwards (the sound is too slow to keep up, and so there is a delay). But what about at the top of a storm?
This picture, a representation of upper atmospheric electrical effects (from wikipedia, I know, but it’s still good) shows just how awesomely large these effects are. And the names of these events are pretty funny–I’d love to know who named these events “elves” and “sprites.”
A sprite (as seen in the picture) is triggered by “a discharge of positive lightning between the thundercloud and the ground.” These sprites happen in clusters, and can not only be that brilliant reddish orange color, but also greenish blue. Less common are the blue jets (also shown in picture), which are conical projections coming up from the top of the cloud, making it appear similar to lightning in the opposite direction, but thicker, longer, and brighter. Even rarer (so we believe) are gigantic jets, which Gonzalez captured on video; these jets are similar to blue jets, except they reach twice as long (up to 50+ miles high into the atmosphere–for perspective, the Empire State Building is about 1/4 of a mile high), and have only been recorded a handful of times, especially in storms over water. Blue jets in general aren’t like sprites in that they are associated with lightning strikes. Instead, they may be associated with strong hail! They are also much brighter than sprites, and last roughly one second. They weren’t discovered until 2001, and since they are usually seen over ocean storms, it’s amazing that Joel Gonzalez was able to capture this gigantic jet at all!
These gigantic jets are believe to contribute somehow to a flow of electricity around the entire planet, but details are fuzzy. According to the San Francisco Chronicle, it’s like a river of electricity around the globe, and sometimes, “like a bursting dam,” the energy can explode out in the form of lightning, sprites, elves, or jets (or a combination, of course!). I highly recommend looking into the study of electricity in the atmosphere, it’s fascinating stuff! I know the study of lightning is called “fulminology”, but I’m not sure if these events are lumped together into that field. Hopefully now, you’ll have new sense of excitement when watching that video, and any other video showing (or seeing from your window) an active thunderstorm! What you see is, in truth, awe inspiring.