A massive electrical discharge known as a “gigantic jet” – the strongest one seen so far – that shot 50 miles up into space has provided scientists with new information about the spectacular atmospheric phenomenon.

Stages of how the gigantic formed over Oklahoma in May 2018. Credit: Chris Holmes

A research team led by Levi Boggs, a researcher at the Georgia Tech Research Institute, has just published a detailed 3D description of a 2018 lightning: it was an upper-atmospheric lightning that occurred in Oklahoma airspace four years ago and was the most powerful gigantic jet studied so far, carrying 100 times as much electrical charge as the typical lightning bolt we see during thunderstorms. The new findings were published in Science Advances.

Unlike conventional lightning, upper-atmospheric lightning happens in the ionosphere, that is, well above the level of storm clouds – and downward lightning. These upside down lightning strikes are simply beams of light that come into existence alongside ‘normal’ lightning, but point in the opposite direction. They are much more powerful than their down-facing counterparts, sometimes even threatening technologies that orbit Earth.

The gigantic jet that appeared over Oklahoma in 2018 is believed to be the most intense and strongest of its kind so far – at least of those we have witnessed. It is estimated to have carried an electric charge of 300 coulombs, about a hundred times more than conventional lightning and twice the charge of the largest ionospheric lightning previously observed.

Boggs learned about the Oklahoma event from a colleague, who told him about a gigantic jet that had been photographed by a citizen-scientist who had a low-light camera in operation on May 14, 2018. The footage revealed never-before-seen details about these mysterious upward strikes that have “broad implications to lightning physics beyond that of gigantic jets,” according to Boggs.

“I was really intrigued because observations of gigantic jets are really rare—only a few per year if that,” Boggs explained in an email. “So I seize any chance to study them, because trying to capture them with dedicated field campaigns is very difficult. This was a random chance that I was told about this video, and luckily the event in the video was also observed by a ground-based radio mapping network and optical instruments in geostationary orbit.”

The upward discharge included relatively cool (approximately 400 degrees Fahrenheit) streamers of plasma, as well as structures called leaders that are very hot – more than 8,000 degrees Fahrenheit.

“We were able to map this gigantic jet in three dimensions with really high-quality data,” Boggs wrote. “We were able to see very high frequency (VHF) sources above the cloud top, which had not been seen before with this level of detail.”

Another gigantic jet photographed from an airplane flying over India. Image Credit & Copyright: Hung-Hsi Chang/NASA

Using satellite and radar data, the researchers were able to establish where above the cloud the very hot leader portion of the discharge was located. And this is groundbreaking news for science. According to Steve Cummer, professor of electrical and computer engineering at Duke, who uses the electromagnetic waves that lightning emits to study the powerful phenomenon:

“The VHF and optical signals definitively confirmed what researchers had suspected but not yet proven: that the VHF radio from lightning is emitted by small structures called streamers that are at the very tip of the developing lightning, while the strongest electric current flows significantly behind this tip in an electrically conducting channel called a leader.”

What this means is that the 3D locations for the lightning’s optical emissions were well above the cloud tops! Wow.