Doyle Rice, USA TODAY
Published 4:20 p.m. ET Jan. 31, 2020
There’s a new type of aurora in town called “the dunes.” Scientists think it’s a visible display of atmospheric waves.
Amateur photographers in Finland have discovered a new form of aurora, scientists announced in a new study published this week.
Nicknamed “the dunes,” the aurora is helping scientists better understand a mysterious layer of Earth’s atmosphere.
“For the first time we can actually observe atmospheric waves through the aurora – this is something that hasn’t been done before,” said Minna Palmroth, a space physicist at the University of Helsinki and lead author of the new study.
The aurora – nighttime light displays in the atmosphere near Earth’s poles – take on various shapes and forms, the American Geophysical Union said. They often appear as rippling curtains of green, red, or purple light.
But in October 2018, amateur auroral photographers in Finland discovered a new auroral form that resemble a striped veil of clouds or dunes on a sandy beach.
The dunes appear as thin ribbons of green light in the sky, extending toward the equator for hundreds of miles. Most auroral light displays are oriented vertically, like curtains hanging down from the sky, but the dunes are arranged horizontally, like fingers reaching toward the horizon.
According to the study, the researchers suspect the dunes are visible manifestations of air undulations called atmospheric waves. If their theory proves correct, the dunes could provide a way to understand a part of Earth’s upper atmosphere that is notoriously difficult to study.
At about 60 miles in altitude, this region of the atmosphere is too high for balloons and planes to reach, but too low for satellites and spacecraft to directly observe, the American Geophysical Union said.
“Collaborations with citizen scientists are getting increasingly important because they can become ‘mobile sensors’ that chase interesting aurora easily and catch new features that scientists didn’t notice before,” Toshi Nishimura, a research associate professor of electrical and computer engineering at Boston University’s Center for Space Physics, who was not part of the study, told Space.com.
For centuries, the aurora borealis, aka the northern lights, have fascinated skywatchers. It forms when particles flowing from the sun get caught up in the Earth’s magnetic field. The particles then interact with molecules of atmospheric gases to cause the famed glowing red and green colors of the aurora.
The lights are visible in both the far northern and southern parts of the world. The southern lights are known as aurora australis.
The new study was published in the journal AGU Advances.
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