Occasionally, lightning will exit the top of a thunderstorm and connect to the lower edge of space, forming a gigantic jet.
In 2018, a storm powered by dense clouds sent lightning 80 km upward, far enough to graze the ionosphere.
Scientists began investigating this unusual backward burst of electricity and classified it as a ‘gigantic jet’.
According to a study published last week, these ‘negative gigantic jets’ transfer an extraordinary amount of charge between the troposphere, the lowest layer of the atmosphere and the ionosphere, where the Earth’s atmosphere meets space.
Upward electrical discharges from thunderstorms can take on many different forms and are primarily classified by their altitude.
They can be brief pulses of light that are confined to altitudes near cloud top called ‘pixies’ or blue diffuse cones of light that reach approximately 40 km altitudes called ‘blue jets’.
‘Gigantic jets ‘ are the largest of the lot, grazing the edge of space and can take the form of large, tree-like structures.
These phenomena are part of a larger family of upper atmospheric electrical discharges known as transient luminous events (TLEs).
‘Of all the TLEs, gigantic jets are exceedingly rare and perhaps the most spectacular, as they directly couple the lower and upper atmosphere,’ said the researchers.
The phenomenon has not been widely studied as many of the sightings were accidental. The 2018 sighting was the lucky break as it occurred close to a bunch of relevant science instruments in the state.
A citizen-scientist in the area even photographed it with a low-light camera. So, drawing on all of these clues, a crew of scientists were able to collect as much data as possible about the jet.
‘We were able to map this gigantic jet in three dimensions with really high-quality data,’ said Levi Boggs, a research scientist at the Georgia Tech Research Institute and an author of the paper published in the journal Science Advances.