Lightning from thunderstorms doesn’t just strike the ground. Sometimes it goes up, forming a rarely seen type of electrical discharge known as a "gigantic jet" that connects the top of the clouds to the lower edge of space. Observations of a single one of these gigantic jets has challenged some expectations about this phenomenon but has also provided a better understanding of how these Transient Luminous Events (TLEs) form.
As reported in Science Advances, the team was able to study one of these jets in three dimensions based on a combination of satellite data, radio waves, and radar. But the starting point of the investigation was a photograph taken by a citizen scientist of a jet in Oklahoma.
“Kevin Palivec [the photographer] has a low-light camera in Central Texas that he sometimes randomly operates, and he had captured this a couple of years ago,” lead author Levi Boggs, from the Georgia Tech Research Institute, told The Washinton Post. The picture “was kind of sitting around. I was told about it and I decided to investigate a little bit.”
The jet started from an area on the cloud top that measured around 50 by 50 kilometers (31 by 31 miles) at about 15 to 20 kilometers (9 to 12 miles) altitude. It then sparked upwards, reaching the ionosphere, the portion of our planet’s atmosphere that extends from about 48 kilometers (30 miles) above the surface to the edge of space at about 965 km (600 mi).
The event transferred an enormous amount of charge between the cloud and the ionosphere. Regular lightning has a very broad range, but the gigantic jet in Oklahoma delivers three times the maximum you get from lightning.
This gigantic jet was also peculiar because it happened in a thunderstorm over land instead over the sea, where they are much more common. But this may hint at why they form.
The storm seemed to be lacking in lightning striking downwards, similar to storms over the ocean. This could have led to an accumulation of charges in the clouds that created the conditions for gigantic jets.
There is still so much that we don’t know about this and many other lightning phenomena in the upper atmosphere.
[H/T: The Washinton Post]