New Type of Aurora Called 'The Dunes' Documented

davidwr writes: Remember the aurora-that-wasn't called STEVE from last April? Well, amateur stargazers in Finland are at it again. This time it's for a new kind of aurora dubbed "the dunes." These new aurora are thought to be an example of a "mesosphereic bore" in which oxygen is exited by the solar wind or possibly gravity waves. The original paper can be found at here. News of it can be found at ScienceAlert, Live Science, and probably elsewhere. The researchers say the dunes emerge at an altitude of about 62 miles in the upper reaches of the mesosphere, and are visible simultaneously from different locations in Finland and Sweden.

The University of Helsinki has posted a video of the new type of Aurora Borealis on their YouTube channel.

This is pretty cool

[93 Escort Wagon]

But - independent of the science - I have to say that watching that video made me long to see an honest-to-goodness aurora again. Many years ago, we had the good fortune of viewing them during several evenings while making a trek up the Al-Can highway.

You can - on rare occasions - see aurora here in western Washington state... but it's rather mediocre compared to the aurora visible from northern BC or the Yukon - and that's assuming you're lucky enough to get a cloudless night when the aurora is out.

Re:

[nitehawk214]

I have seen a STEVE and it is very underwhelming. I need to just take some time someplace north and see some real aurora.

Had me worried for a moment...

[asackett]

I read "...in which oxygen is exited by the solar wind..." and thought uh oh, Venus here we come. TFA cleared that up for me.

Re:

[rossdee]

Well Exit is this month's theme, what with the Sussex Royals, and Brexit is tomorrow... the UK is probably north enough to see aurora

Can someone explain to me...

[Rei]

... what the defining characteristics of "The Dunes" are? Because that looks like a pretty normal aurora to me. "Steve" was rather weird, but I'm used to this sort of "rippling green bands" stuff. On a good night you'll get multiple bands, each stretching all the way east-to-west

Re:

[Zocalo]

Judging by the image, I'd say it's the combination of the rippling vertical "curtain" combined with the horizontal trailing edge leading away from it. While the photographic example and video in the linked Science Alert article show this structure pretty clearly, the illustration showing the structure of the aurora in the mesosphere is probably better at explaining why this is a specific type of auroral structure in its own right.

Not a new type

[WillAffleckUW]

I used to see those all the time during military missions in Northern BC.

Problem is there aren't a lot of people there.