ASK THE METEOROLOGIST
“What causes the Northern Lights?”
Walker, Mae Richardson Elementary
The sun is the basic cause of the Aurora. They occur at each of the Earth’s poles, and the one that we are talking about involves the North Pole, called the Aurora Borealis. The South Pole aurora is known as the Aurora Australis.
The surface of the sun is constantly boiling and changing because it is so hot, so we see things like sunspots and solar flares, which release particles out into space. The sun also creates what’s called a “solar wind,” which helps transport the particles discharged from the sun. Because of the magnetic charge of the Earth’s poles, they attract the particles. As they enter the Earth’s magnetic field, the particles interact with the molecules of oxygen and nitrogen, which then causes the show in the sky.
Whether the particles from solar flares interact with oxygen or nitrogen molecules affect the color of the aurora. Collisions with oxygen molecules create green and yellow lights across the sky, while nitrogen creates red or violet. The altitude can also determine what color the aurora glows, that is, whether it’s more red or green.
The best time to see the Aurora Borealis is during the winter months when there are cold, clear nights and low pollution. The best place? Alaska or northern Canada, but sometimes enhanced solar activity allows the lights to be visible from lower latitudes. Also, in the southern hemisphere, the Aurora Australis is best visible in Antarctica.
Chief Meteorologist Kate McKenna