The aurora borealis is an spectacular natural phenomena that, in Earth, occurs mainly in the polar areas, both north and south. In the north hemisphere they’re commonly known as northern lights, and they’re one of the main reasons why people goes to places like Kiruna . Well, at least that’s the main reason why I went there.
The aurorae originate due to the solar wind flowing past the Earth. When it’s oriented favorably (mostly southwards), the solar wind connects with the Earth magnetic field, accelerating its particles towards the planet and provoking its collision with the atmosphere. The particles of the atmosphere are then excited, and they loose that energy both because of other collisions, or emitting light, what creates the northern lights.
The color of the lights depend upon the particles that emit the light. The most common colors are green and red, emitted by atomic oxygen. On the other hand, molecular nitrogen and nitrogen ions produce a little bit of red and very intense violet aurorae.
To see the northern lights, the environmental conditions have to be special: the sky has to be as clear as possible, you have to be away from luminous noise sources (that is, you have to be away from any city). Also, the sky has to be as dark as possible, so as we are in the arctic circle, and from approximately april to september there are places in which we have the midnight sun, usually the best dates are between mid september to the end of march.
For more detailed (and technical) information in how and when to see the aurorae, as well as forecasts, take a look at the related links in the end of the post. There you can also find details in how to take great pictures of the northern lights.
In our case, we were moderately lucky with the aurorae. We saw 2 from the plane, while we were about to land in the airport, but unfortunately, we couldn’t take any decent picture. They looked very similar to the one in the picture below. The rest of the time we spent in Kiruna, the weather was completely cloudy, and the most we could see was one behind the clouds. At least we have the ones we saw from the plane, but I wish we had been able to enjoy them more.
As a suggestion, if you go there, book in advance a seat at the Aurora Sky Station of Abisko, because as it’s over the clouds, if there’s an aurora, you’ll be able to see it without any trouble. If I go back to Kiruna, for sure that will be my choice.
The impressive pictures of this post were taken in Nordkapp (Norway) by the lucky Pablo Municio, a friend from my home university who is also doing the Erasmus in Sweden, but in his case, in Västerås. If you can read in Spanish, take a look at his blog: k|nt
Official site: Abisko.
Virtual Finland: Aurora Borealis - The Northern Lights.
Dick Hutchinson: Shooting the Aurora Borealis.
Space Weather Prediction Center: Tips on Viewing the Aurora.
Space Weather Prediction Center: Auroral Activity.
Official site: Advanced Composition Explorer.