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The Northern Lights exist in the outmost layer of the atmosphere. They are created by electrically charged particles that make the thin air shine, not unlike a fluorescent light. They can be seen in auroral belts that forms 20-25 degrees around the geomagnetic poles, both the north and the south. The Northern Lights, also called Aurora Borealis are one of the most spectacular shows on this earth and can frequently be seen in Iceland from September through April on clear and crisp nights. The Northern Lights occur high above the surface of the earth where the atmosphere has become extremely thin, in an altitude of 100-250km.
What causes this spectacular phenomenon, so characteristic of our northern lights here in Iceland? Well, it's electricity that does it - and of course it all goes back to the sun. Tiny particles, protons and electrons caused by electronic storms on the sun (solar wind) are trapped in the earth's magnetic field and the begin to spiral back and forth along the magnetic lines of force - circle around the magnetic pole, so to speak. While rushing around endlessly in their magnetic trap, some particles escape into the earth's atmosphere. They begin to hit molecules in the atmosphere and these impacts cause the molecules to glow, thus creating the auroras.
White and green are usually the dominant colores but sometimes there are considerable colour variations, as the pressure and composition of the atmosphere varies at different altitudes. At extremely high altitudes where the pressure is low, there tends to be a reddish glow produced by oxygen molecules when they are struck by the tiny particles of the solar wind. At lower altitudes, where there is higher pressure, their impact-irritated oxygen molecules may glow with a greenish tinge and sometimes there is a reddish lower border created by particles colliding with nitrogen molecules in the immediate vicinity.
The phenomenon is easily explained by modern science. What our ancestors may have thought when they gazed into the brightly-lit winter sky is quite another matter. But by all means don't let any scientific explanation spoil your appreciation of the beauty of the Northern Lights. They are a truly impressive spectacle, whatever their cause.
The following link http://www.gsfc.nasa.gov/topstory/20011025aurora.html provides great pictures from space of the poles and the auroras around them.
There are a few Icelandic photographers who have taken great photos of the Northern Lights and you can see some of their work on the following links: http://www.iww.is/art/shs/pages/page1.html
http://www.arctic-images.com/Northern_Lights/Northern_Lights.html
Other interesting Northern Lights links:
http://eiger.physics.uiowa.edu/%7Evis/conjugate_aurora/
http://sec.noaa.gov/pmap/
The content of this page is provided by Nature Explorer
http://www.natureexplorer.is/page.asp?Id=575
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