Giant jets are the largest known electric shocks, powerful rays that can rise up to 90 km high. During a storm in Colombia and with the help of high-speed cameras, researchers from the Polytechnic University of Catalonia have managed to capture for the first time since its inception one of these rare phenomena.
They photograph for the first time the birth of a giant jet Sequence of a giant jet captured by researchers in Colombia. As the sensitive cameras used are monochromatic, the software colors the images only by their intensity, appearing bluish and green tones (although above 35-40 km these jets are reddish in reality). / UPC Lightning Research Group.
In the tropical regions, above the great storms, sometimes the greatest electric shocks exist: the giant jets. They start in the cloud like a powerful upward beam, creating a very characteristic shape, with a filamentous and bluish-colored lower part produced below 30 km and a very branched reddish upper that can reach 90 km altitude .
With high-speed cameras and in Colombia, images of the precise moment in which one of these gigantic jets is formed have been captured for the first time
The formation of these rare phenomena that, curiously, takes place exclusively in areas close to the tropics, is still a mystery to the scientific community. It can only be observed at night, like other related events, such as blue jets or so-called sprites or sprites (carrot or column-shaped) and elves or elves (ring-shaped).
Now, researchers from the Ray Research Group of the Polytechnic University of Catalonia (UPC), together with a colleague from Duke University (USA), have first captured images of the precise moment in which one of these gigantic jets is formed and then they have followed their evolution step by step.
The discovery of the jet and the capture of the images has been made on the north coast of Colombia. In summer 2017 the researchers used a portable fast camera system near the Colombian city of Santa Marta, which operated at 900 images per second.
Then, in 2018, a second campaign was carried out in Barranquilla and Cartagena to detect this phenomenon, in which we worked with a very high speed system, which operated at 5,000 images per second.
A historical recording
With these cameras, the researcher Oscar Van der Velde of the Lightning Research Group of the UPC closely monitored developing storms, hoping that the phenomenon would appear.
The follow-up paid off: during the two campaigns, 12 giant jets were produced on six different nights, five of which were successfully registered by the high-speed camera.
This breakthrough is important to unravel the mysteries surrounding electrical phenomena in the atmosphere and the coupling between atmospheric layers.
The image of the formation of the giant jet captured has been taken with a temporal resolution of 200 microseconds and shows, for the first time, the first flash from which it is triggered. The results are published in open in the journal Nature Communcations.
The sequence of the images demonstrates, in addition, that the formation of a giant jet develops step by step, experienced from 40 km high a continuous jump until reaching the ionosphere (90 km).
According to the authors, this historical fact is important to unravel the mysteries surrounding electrical phenomena in the atmosphere and the coupling between atmospheric layers, a scientific field still very incipient.
This is how Van der Velde acknowledges: “With our work we have been able to provide very valuable information to understand how and why they form, but what happens inside the clouds remains a mystery. Nor do we know why giant jets only form in the tropics area. The current models to describe them are still very basic, so the images we capture with our teams are very important for the scientific community. “