Aurora Viewing At It's Best

You need three ingredients to see the Aurora Borealis, or Northern Lights, as they are sometimes called.  You need a solar flare sending charged particles out into space, colliding with gasses in the atmosphere of Earth.  You also need dark skies, without the light pollution that plagues much of the U.S. these days.  And lastly, you need a cloudless, clear night.  The Log Cabin Wilderness Lodge just outside of Tok, Alaska, has some of the darkest skies you'll find anywhere in the world.  Our sunny interior climate consistently brings some of the clearest skies in all of Alaska. Coastal cities tend to be warmer due to the effect of oceanic warming, but this also brings more moisture into the atmosphere, clouding over the aurora. 

Aurora chasers come to Tok just to see the Aurora Borealis.  How do they predict the best nights to go chasing, and decide where to go?  They look at something called the Kp index.  The Kp index, measured from 0-9, is derived from global observatories all over the world, and measures the geomagnetic disturbance of particles in the Earth's atmosphere. A Kp of 5 or greater indicates a significant solar storm, and a good chance of seeing the Aurora. 

Most commonly we see green lights, although recently we saw a great rare storm of red lights!  The color of the lights are caused by charged particles from the sun colliding with different gasses in the Earth's atmosphere at different altitudes.  Oxygen at lower altitudes (20-150 miles above sea level) produces green lights. At higher altitudes, oxygen colliding with solar particles produces red lights.  The red storm we just had a few weeks ago was seen all the way in Florida, because of the high altitude at which the lights appeared.

Blue and purple aurora are produced by nitrogen at lower altitudes, and it is fairly common to see edges of pinkish purple on dancing green lights, produced by a mix of oxygen and nitrogen.

No matter the color, the aurora is an awe-inspiring experience, never to be forgotten.  At the Lodge you can view the aurora out our many pictures windows on every side of the lodge, or bundle up and watch them outside.  When you get chilly, sit a spell in the steam sauna to warm up.  It is sure to be a magical night you'll remember forever.