Monday 7 June 2010

UNSPEAKABLY NORSK THING - AURORA BOREALIS

Have you ever seen the Northern Lights?

I’ve seen them several times from Scotland, but not from Norway, as yet. I have a few days left and it’s June and I’m in the south of Norway, so my chances are virtually nil right now. But I have my spies, so I’m sure I’ll see them a few more times before the century is over. The best time to catch them is meant to be between October and March, and the further north you go, the better your chances.

But nothing is certain with ‘the Tricky Lady’ as she is called. We humans have no definite way of forecasting when this extraordinary phenomenon is likely to appear.

Now, here’s the scientific bit.....just so you know. The Aurora Borealis is caused by streams of charged particles from the sun, the solar winds, flowing past and elongating the earth’s magnetic field in the polar regions (if you happen to be in the southern hemisphere, you’ll obviously be looking out for the ‘Aurora Australis’ instead). Since the field curves in a sort of halo surrounding the magnetic poles, the charged particles are drawn down towards the earth. As they react with electrons in the upper atmosphere, around 160K above the earth, energy is released which creates a visible ‘aurora’. It’s estimated that during a time of high activity, one single ‘aurorial storm’ can produce a trillion watts of electricity.

If anyone can think of a more extraordinary natural sight, I should like to know what it could be...perhaps it is the fact that you are not guaranteed to see it that makes the Aurora Borealis so thrilling. If you are lucky enough to witness it, you might see great streaks of vibrating light, pillars, wisps, and haloes of pale green, light yellow or rose. In times of extreme activity, the colours can be deeper green, a brighter yellow and crimson. Great sheets of pure colour waft about in the sky, and if you didn’t know it was a naturally occurring phenomenon, you might well be terrified out of your wits. Even the most sceptical of humans cannot help thinking that seeing such a sight feels like a genuine gift from some sort of higher power. Over the centuries, all sorts of beliefs, myths and legends have grown up around the aurora, and however the science might enlighten us, I cannot think that people will ever cease to wonder at it.

Er, did I have a camera with me each time I saw the Northern Lights? Nope. You’ll just have to believe me. But I refer you to a fellow blogger, Kjetil Skogli, a photographer and tour guide based in Tromso, and an expert on the Aurora Borealis. I could never compete with his photographs which will take your breath away. Find them at http://foto.kskogli.no

1 comment:

  1. I've seen the aurora once in Scotland, a truly spectacular show one Easter near solar maximum, once at night from an aircraft over N. Canada and once from Central London where I live.

    I think there are some other natural sights that might rank with the aurora. Lightning for one, certainly a total solar eclipse and a really impressive set of sun halos would run it close. I've often seen ordinary 22 and more rarely the 46 degree halos, sun dogs and the circum-zenith arc, but rarely, if ever anything as good as these. Look out for the wonderful "green flash" pictures too.

    http://www.zmescience.com/other/science-abc/8-examples-of-photometeors-w-pics/

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