It was getting dark, the rain was pouring down, and a flash of lightning flashed through the air. But instead of hitting the ground or gliding between the clouds, the lightning bolt did something unexpected: It exploded straight up from the tops of the clouds, shooting 50 miles (80 kilometers) into the sky, skimming through space the lower edge of .
Bolts like these are called jumbo jets. They’re the rarest and most powerful type of lightning, occurring just 1,000 times a year and emitting more than 50 times the energy of a typical lightning bolt — and now, scientists have just discovered the most powerful giant jet to date.
In a study published Aug. 3 in the journal scientific progress (opens in new tab), researchers analyzed a giant jet shot out of the clouds over Oklahoma in 2018.By studying the jet’s radio waves Using satellite and radar data launches, the team learned that the bolt moves about 300 coulombs of energy from the top of the cloud to the lower ionosphere — Separate layers of charged particles EarthFrom the upper atmosphere of the vacuum of space – about 60 times the 5 coulomb output of a typical lightning bolt.
“The charge transfer is almost twice the largest of the previous giant jets and rivals the largest cloud-to-ground stroke ever recorded,” the researchers wrote in the study.
related: What is the longest lightning bolt ever recorded?
Capturing such detailed data on large-scale lightning requires equally great luck. On May 14, 2018, a citizen scientist in Hawley, Texas, filmed the jet with a low-light camera and observed a huge electrical discharge shoot out of the cloud tops and then travel about 60 miles (96 kilometers) away from the jet. The charged particles in the ionosphere are connected to the ground.
Scientists analyzing the footage found that, fortunately, the jet occurred near the center of a Large Lightning Mapping Array (LMA) — a network of ground-based radio antennas used to map the location and timing of lightning strikes. The jet is also within range of several weather radar systems as well as a network of weather observation satellites.
Combining these sources allowed the researchers to study the size, shape and energy output of the giant jet in unprecedented detail. The researchers found that the jet’s highest-frequency radio wave emissions (the kind the LMA uses to detect) come from small structures called streamers that form at the very tip of lightning and create “direct electrical currents” between clouds. connect”. top and lower ionosphere,” said lead study author Levi Boggs, a Georgia Institute of Technology research scientist, said in a statement (opens in new tab).
At the same time, the strongest current flows in a section called the leader behind the streamer.The data also shows that while the anchors are relatively cool, temperature Around 400 degrees Fahrenheit (204 degrees Celsius), the leader was scorching hot, with temperatures over 8,000 degrees Fahrenheit (4,426 degrees Celsius). The difference applies to all lightning strikes, not just giant jets, the researchers wrote.
So why does lightning sometimes explode upwards instead of downwards? Scientists still don’t fully understand this, but it likely involves some sort of blockage that prevents lightning from escaping from the cloud base; the team added that giant jets are typically observed in storms that don’t produce many cloud-to-ground lightning strikes.
“For whatever reason, cloud-to-ground emissions are generally suppressed,” Boggs said. “In the absence of the lightning discharges we typically see, the giant jets may have mitigated the build-up of excess negative charge in the cloud.”
Jumbo jets are also most commonly reported in the tropics, the team noted. That makes the record-breaking jet over Oklahoma all the more remarkable. The jet was not part of a tropical storm system. More research — and more luck — is needed to understand these epic, upside-down lightning strikes.
Originally published on Live Science.