Scientists film huge beam of energy shooting into space

Scientists confirm the most powerful reverse lightning ever recorded.

The “giant jet” over Oklahoma (video screenshot. Please turn your phone 90 degrees to the left to view). Chris Holmes

Lightning is the lateral discharge of clouds to the ground, or inside clouds. But in 2018, a science enthusiast filmed a giant lightning strike back into space from the top of the clouds over Oklahoma, North America.

The professional name of this kind of reverse lightning is “gigantic jets”, and it occurs only 1,000 times a year on average worldwide, but it can release more than 50 times the power of ordinary lightning. Researchers have just confirmed that the science enthusiast had the privilege of capturing the most powerful single “giant jet” ever recorded.

By analyzing satellite and radar data, the researchers studied the radio waves generated by the jets and found that the jets transported a total of about 300 coulombs of electricity from the tops of the clouds to the bottom of the ionosphere. Smaller, ordinary lightning bolts typically only have 5 coulombs of charge.

The ionosphere is located at the top of the earth’s atmosphere more than 60 kilometers above the ground. It is the transition layer between the atmosphere and space and is mainly composed of charged particles. The end of this jet has been extended up to about 96 kilometers above the ground.

Studying reverse lightning is very difficult because no one knows when and where it will appear. But this time it was very lucky, because it happened within the observation range of multiple weather radars and weather satellites, and it happened to be located near the center of an antenna array dedicated to studying lightning.

Scientists seized this rare opportunity to study the jet. The researchers found that tiny streams of electrons at the end of the jet generated most of the high-frequency radio waves. It is these electron flows that create the direct connection between the top of the cloud and the bottom of the ionosphere.

The researchers also found that reverse lightning and ordinary lightning are similar in some ways. For example, they found that the part of the jet immediately following the tiny electron stream at the end of the jet had the strongest current and the highest temperature. The temperature there is as high as 4426 degrees Celsius; the electron flow itself is only about 204 degrees Celsius. This difference also exists in ordinary lightning.

But scientists still don’t know much about what causes reverse lightning. Most of the “giant jets” occur in the tropics. Theoretically, there may be some obstacle at the bottom of the cloud layer, which makes it difficult to discharge to the ground, so that more and more charges are accumulated in the cloud layer, and finally a breakthrough is found in the opposite direction. Observational records also show that the amount of ground-to-ground lightning produced by clouds where reverse lightning occurs is generally low.

refer to

3D Study of “Gigantic Jet” Provides New Insights into Upward Lightning Bursts