A new aurora? Researchers say 'the dunes' aren't like the usual lights in the sky

Via:  perrie-halpern  •  2 months ago  •  18 comments

By:   Denise Chow

A new aurora? Researchers say 'the dunes' aren't like the usual lights in the sky
In October 2018, several aurora enthusiasts who regularly photograph the shimmering lights noticed something unusual.

S E E D E D   C O N T E N T


Auroral dunes photographed on Oct 7, 2018 near Laitila, Finland. Pirjo Koski

Skywatchers in Finland are no stranger to auroras.

These dramatic nighttime light shows typically grace the Finnish skies roughly 200 nights out of the year. But in October 2018, several aurora enthusiasts who regularly photograph the shimmering lights noticed something unusual.

Where the lights of regular auroras are typically arranged vertically to create a rippling, curtain-like effect, the skywatchers instead saw luminous green arcs structured horizontally and extending hundreds of miles toward the horizon.

Now, new research has found that these unusual displays are a new type of aurora, nicknamed “the dunes” because their appearance in the night sky resembles wind-sculpted ridges. Scientists say studying how these auroras form could help them better understand the process by which charged particles from space interact with Earth’s upper atmosphere.

200129-aurora-dunes-ew-1255p_ca28734f2d3 A new type of aurora called "the dunes" discovered by aurora chasers in Finland is helping scientists better understand a mysterious layer of Earth's atmosphere. AGU

“There are all kinds of things that happen in an aurora that are signs of what is happening in outer space,” said Minna Palmroth, a space physicist at the University of Helsinki and lead author of a study published Tuesday in the   journal AGU Advances   that details the dunes. “The auroras are like fingerprints.”

Auroras occur when electrons ejected from the sun bombard Earth’s magnetic field and interact with gases in the planet’s atmosphere to create the stunning green, purple, red and blue lights of the northern and southern lights.

Palmroth and her colleagues studied the dunes and noticed that in addition to their horizontal alignment, the lights appeared to undulate like a wave in the night sky.

The researchers think the dunes may get their appearance from so-called atmospheric waves in a layer of the Earth’s upper atmosphere, 50 to 75 miles above the surface. It’s a region of the atmosphere that is not well studied, but Palmroth said the dunes could offer some unique insights.

“When electrons from space collide with atmospheric oxygen in denser parts of the wave, they emit more light,” she said. “In the wave’s truss, you don’t see as much light.”

Palmroth thinks this slice of the atmosphere, which encompasses the boundary between the planet’s atmosphere and the cosmos beyond, is hypersensitive to changes in solar activity. Energy transferred in this part of the atmosphere when charged particles collide with atmospheric oxygen could explain why the dunes behave differently from other auroras.

More research is needed to confirm how the dunes form, and Palmroth and her colleagues hope their follow-up studies could include observations from a spacecraft.

Palmroth, who published a guidebook in October 2018 for aurora enthusiasts, said she was first alerted to the existence of the dunes by amateur skywatchers across Finland. Though she has not witnessed the dunes herself, she worked closely with seasoned aurora photographers to study the light displays.

Since Palmroth and her colleagues published their findings, they have been contacted by skywatchers in the U.S. and Canada who have reported other instances of the dunes, which could prove useful as the scientists look to expand their research.

For now, though, Palmroth is hopeful that her research will allow her to witness the stunning lights in person.

“Perhaps I’ll get to go on an aurora tour and see them soon,” she said.


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Perrie Halpern R.A.
1  seeder  Perrie Halpern R.A.    2 months ago

Pretty cool, right?

Buzz of the Orient
1.1  Buzz of the Orient  replied to  Perrie Halpern R.A. @1    2 months ago

Maybe, but maybe it's a "sign" from God to say the end of the world is coming, in the event that one of two things happen - the Palestinians agree to the "Deal of the Century" or Trump is re-elected. 

1.2  igknorantzrulz  replied to  Perrie Halpern R.A. @1    2 months ago

don't you have to head South to see Northern Lights ?

Trout Giggles
1.2.1  Trout Giggles  replied to  igknorantzrulz @1.2    2 months ago


Larry Hampton
2  Larry Hampton    2 months ago

We get lottsa Northern Lights. I saw some like these in Minot, ND  in ‘84. I was a sophomore in college and most of the quad was outside half the night oohing and ahhing. Very cool.

2.1  bccrane  replied to  Larry Hampton @2    2 months ago
 in ‘84.

I believe that was the same year our Ausie broke his leg and I would take him out at night for a walk, the one night, it was a moonless winter night, the snow was a pinkish orange and you could see for miles, it was so bright the whole sky was lit and we are below the 45th in Michigan.

Perrie Halpern R.A.
2.2  seeder  Perrie Halpern R.A.  replied to  Larry Hampton @2    2 months ago

You are so lucky. I have always wanted to see them but never have. Sometimes we get them in Maine, but there was a time a few years ago, that for some reason the Carolinas got them, which was really weird. 

3  Kavika     2 months ago

Very cool indeed. As Larry stated when you live as far north as we did/do you get to see the Northern lights. It is a amazing experience.

Perrie Halpern R.A.
3.1  seeder  Perrie Halpern R.A.  replied to  Kavika @3    2 months ago

There has to be a benefit to freezing your butts off, LOL!

Trout Giggles
4  Trout Giggles    2 months ago

We used to see them quite often in Alaska during the winter. One really cold night (it was about -35 F), somebody came into the dorm and started hollering that we all needed to get outside and see the show. That night the Lights put on a spectacular show for the 45 seconds I could stand it.

Perrie Halpern R.A.
4.1  seeder  Perrie Halpern R.A.  replied to  Trout Giggles @4    2 months ago


-35 F does make it a challenge to see anything, but the inside of a building. 

Trout Giggles
4.1.1  Trout Giggles  replied to  Perrie Halpern R.A. @4.1    2 months ago

that was the usual temperature in January

Buzz of the Orient
5  Buzz of the Orient    2 months ago

I was able to see the Northern lights from my lakeside cottage, perhaps because there was almost no city lights interference. 

Perrie Halpern R.A.
5.1  seeder  Perrie Halpern R.A.  replied to  Buzz of the Orient @5    2 months ago


You were pretty up north, so I can see why you could see them. I would like to see them in my lifetime.

5.1.1  bccrane  replied to  Perrie Halpern R.A. @5.1    2 months ago

Then I would suggest getting up and going out at night, preferably a moonless night and away from city lights.  The northern lights can be just a few pillars of light from the north and not very impressive, but they are the northern lights just the same. 

Buzz of the Orient
5.1.2  Buzz of the Orient  replied to  Perrie Halpern R.A. @5.1    2 months ago

To get the full picture, one would have to take a video of them, to see them shimmer and change.  Photos are okay, but then you see only part of the show. 

6  sandy-2021492    2 months ago

Seeing the northern lights is on my bucket list.

6.1  KDMichigan  replied to  sandy-2021492 @6    2 months ago

Plan a vacation to Sleeping bear sand dunes, 


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