Sunday, October 30, 2011

Northern Nights, Northern Lights

This past week we in Helsinki have apparently been treated to a display of Northern Lights, or aurora borealis for the scientifically inclined.  I say “apparently”, since I haven’t been lucky enough to see anything through the cover of low clouds that’s been hanging over Helsinki every time I’ve remembered to look up at the sky. 

As with any event that requires peering up at the night sky, Helsinki has the huge disadvantage of almost never having an actual view of the night sky.  Compared, that is, with other parts of the world.  Check out the night sky in the arid American West sometime and you realize just how much of the heavens (the Milky Way!) folks back in Helsinki have never even seen. 

Aurora over Malmesjaur Lake, Swedish Lapland.  Photo:  Jerry Magnum Porsbjer

But when it comes to the Northern Lights, Helsinki is doubly cursed, because here in Finland the ghostly lights synonymous with the Far North are rarely visible this far south.  While I have seen nice displays of revontulet (the Finnish name, which literally means “foxfires”) a few times in Lapland, I’ve seen them in Helsinki only once or twice in all the time I’ve lived here, and even then they were hardly visible. 

That might be surprising for a city sitting at a latitude of 60 degrees, closer to the North Pole than well over 99.7% of everyone else on Earth.  The thing is, the Northern Lights don’t have anything to do with the pole at the top of the world.  The aurora, which is created when the solar wind streaming from the sun collides with Earth’s atmosphere, is spread out in a ring around the magnetic North Pole, which – not tethered to the actual North Pole – has a tendency to wander around.  For the last century or so, it’s been located somewhere in the Arctic wastes of Canada, moving toward Russia.  That’s why those of us who occasionally carry compasses to different parts of the world have to adjust them from time to time. 

It’s also why the Northern Lights are more visible in North America than in Finland.  They even sometimes make an appearance in my home state of Georgia, like this past week when a powerful solar storm pushed them as far south as both Atlanta and Helsinki.  Only, ironically enough, the folks in Georgia had a better chance of actually seeing them. 

Northern Lights with a rare blue streak.  Photo: Varjisakka

1 comment:

  1. My mom used to tell me of seeing the Aurora when she was a kid in both New Jersey and in Maine. I always dreamed of seeing them and had heard that there were historical accounts of them being seen rarely in the deep South of the USA. And what happens? The one time I've actually had the chance to witness them in my entire life, I'm fast asleep. (When you're a common physical laborer, you tend to fall asleep around nightfall.)

    Oh, well. One of these days I'll venture toward Canada or Alaska and actually see them.