University of Alberta physicists upend what is known about northern lights

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What scientists thought caused certain classes of northern lights is not what causes certain classes of northern lights.

In a landmark study that has toppled what scientists know about the night sky, UAlberta physicists Robert Rankin and Dmytro Sydorenko found that the ionospheric feedback instability (IFI)—the mechanism thought to be the cause of certain types of northern lights—not only doesn’t cause northern lights, it may not even exist at all.

What scientists thought caused certain classes of northern lights is not what causes certain classes of northern lights.

In a landmark study that has toppled what scientists know about the night sky, UAlberta physicists Robert Rankin and Dmytro Sydorenko found that the ionospheric feedback instability (IFI)—the mechanism thought to be the cause of certain types of northern lights—not only doesn’t cause northern lights, it may not even exist at all.

“These findings fly in the face of what is now commonly accepted in the world of space science,” said Rankin. “Our research shows that conditions necessary for the ionospheric feedback instability to occur are very unlikely, meaning it cannot be the cause of something as regular as the Aurora Borealis.”

The Sydorenko and Rankin model maps the activity of Alfvén waves generated in Earth’s ionosphere—a region between 100 to 1,000 kilometres into the magnetosphere containing plasma and Earth’s geomagnetic field. Here, ultralow frequency plasma waves are thought to become trapped and amplified through the IFI. However, the researchers’ new model shows that the waves do not interact with the ionosphere in a uniform way—something researchers have long considered to have a causal link to the Aurora Borealis.

 

Continue reading at University of Alberta.

Photo via University of Alberta.