Funding helps students explore ongoing mysteries of STEVE

A project at the University of Calgary is preparing for a space mission to try to learn more about a long, glowing ribbon of purple light that sometimes arches across the night sky.

The light, known as STEVE — or Strong Thermal Emission Velocity Enhancement — had been observed and photographed by aurora borealis chasers for decades before being studied by scientists. Researchers have determined it’s not an aurora, but there are still questions about the phenomenon.

• Photo above: From left, Kasey Walters and Ebube Anachebe stand with Johnathan Burchill and Kaleigh Beer. Walters and Anachebe are two of the students who will be working on the IMAGER project this summer.

“There are some mysteries about STEVE, like why it gets so hot,” says Dr. Johnathan Burchill, PhD, an adjunct associate professor and manager of research projects with the Department of Physics and Astronomy in the Faculty of Science.

“It’s thousands of degrees above the background atmospheric temperature and it’s so structured. It’s very narrow as you move northward past it but, if you were to look east and west, it extends for possibly hundreds of kilometres.”

The project, known as Innovative Measurements of Auroral Geophysics for Education and Research (IMAGER), is going ahead with support from the Canadian Space Agency. It’s also backed by Alberta’s major innovation fund’s SDTech AB Space and Defense Technology project.

Burchill plans to fly improved University of Calgary mini plasma imagers on two space missions while training science students.

The missions include the CalgaryToSpace FrontierSat cubesat and the Swedish SYSTER rocket campaign.

“They’re both related to the physics of the upper atmosphere and the ionized component of it,” Burchill said. “There’s lots of electric charge in the upper atmosphere in what we call the ionosphere.

“Understanding how the ionosphere interacts with the rest of the upper atmosphere is an exciting area — at least for me — of basic physics research.”

The plasma imager, which was first developed in 2018, is to be used to measure ion drift around the aurora.

Kaleigh Beer, president of CalgaryToSpace, says the organization has worked with Burchill to support the project with its satellite.

“It’s a nano satellite, it’s only about the size of a loaf of bread, but there’s been a lot that’s gone into it,” she says. “It’s really expensive hardware that’s specialized for space.

“In order to support Dr. Burchill’s science mission with the plasma imager, there’s a bunch of requirements that need to be met and so we’ve needed to purchase specialty hardware for that as well. We’re just about to finalize that part of it — the most expensive phase of the project.”

Beer says the satellite will serve as an orbital platform for the mini plasma imager.

“The entire mission was developed around this instrument,” she says. “We have worked with Dr. Burchill over the years, and he has adapted the instrument specifically to be flown on a mini satellite.”

Burchill says the imager, which he describes as a high-tech windsock, would allow scientists to measure the wind direction and wind speed of the ionized component of STEVE.

“There are forces in the upper atmosphere that can cause the ionosphere to move really fast — like thousands of meters a second…” he explains. “And so it’s a bit of a mystery … what forces are setting up those forces, what’s causing that to happen.

“We hope to get enough measurements of the wind speed and direction and more details about the ionosphere inside the structure to help us piece together what may be causing the large flows and then when you have large flows, what’s kind of cool about this is, there’s a really close association between motion and temperature.”

It’s similar, he says, to rubbing your hands together quickly to warm them up.

“The ionosphere is starting to have a really strong drift through the background atmosphere and there’s a drag between the two and that heats up the background atmosphere to these thousands of Kelvin. It’s really curious what’s happening and we’re trying to figure that out.”

He says there’s a lot of interest in learning more about STEVE.

“It’s a cool atmospheric phenomenon that’s begging to be explained.”