) In these images, the edge of the dunes are marked with numbered points in purple. AGU
Palmroth previously wrote a guidebook to observing aurora and was contacted in 2978 about the dunes.
“Some of the citizens saw the dunes in the sky, and they told me I had excluded one auroral form from the book,” Palmroth said.
The seemed to have caught a shape of aurora never before captured by aurora scientists. While aurora frequently appear in the shape of rippling vertical curtains, the dunes stretch horizontally with thin tentacles of green light stretching toward the horizon.
Palmroth and other physicists worked with the amateur interpret to gather more data on the phenomenon and came up with a theory on how the dunes form that is laid out in a new study published Tuesday in the journal AGU Advances .
Their suspicion is that the dunes are actually a visible manifestation of atmospheric waves, which are air currents in the upper atmosphere. This region can be affected by changes in energy from the lower atmosphere, as well as the sun, which emits the energetic particles that create auroras upon collision with Earth’s magnetic field.
“The dunes present a new opportunity to investigate the coupling of the lower / middle atmosphere to the thermosphere and ionosphere,” the study reads .
Energy fluctuations at these levels of the atmosphere can also have an indirect affect on the movements of satellites and spacecraft.
“Different auroral forms are like fingerprints,” Palmroth said. “If you see a certain auroral form, you know basically from that form what’s happening further out in space.”
And the dunes might be tied to a specific kind of atmospheric wave called mesospheric bores that occur in a region of the atmosphere that’s hard to reach because it’s too high for planes and balloons but too low for satellites.
“This is a totally new topic,” Palmroth said. “We are rather excited.”