When the (solar) winds blow
03. sep 2007 00:00
Mother Nature occasionally puts on spectacular shows on starry winter nights. Like a paintbrush dancing across the heavens, the northern lights display their vivid colours and dynamic shapes. Scientists are now studying the tremendous forces at play from a new angle.
In Latin, the northern lights are called Aurora Borealis and the southern lights are known as Aurora Australis. Aurora was the goddess of the dawn in ancient Greece. Boreal means northern, while austral means southern. PHOTO: BJØRN JØRGENSEN/NN/SAMFOTO/INTERNATIONAL POLAR YEAR
The location of Norway far to the north on planet Earth gives Norwegians a front row seat for studying the northern lights. This natural phenomenon appears on cold, clear winter nights, painting the heavens with strokes of yellowish-green, blood red and scarlet.
The northern lights are ignited by a stream of electrically charged particles that the sun hurls out at speeds of more than one million kilometres an hour! This stream of gas is also known as the solar wind. The solar wind tends to concentrate on the areas around the north and south poles. Just 100 km above the Earth's surface, the solar wind runs into the atmosphere, the layer of air that envelops the planet. The solar wind creates the splendid colours of the auroras when it ignites gases in the atmosphere.
The EISCAT radar system was built to study the northern lights. EISCAT has its main station in Tromsø, but it also has installations in Kiruna in northern Sweden, Sodankylä in northern Finland and on Svalbard (Spitsbergen). PHOTO: TORFINN KJÆRNET/ INTERNATIONAL POLARYEAR
Research on the northern lights gives us important information about what is taking place in the Earth's atmosphere. The electrical charges emitted by the sun can wreak havoc on power grids and computers. What is more, they can affect navigation systems on aircraft and ships. Northern lights researchers are trying to figure out why this happens.
Thus far, scientists have concentrated on the northern lights, and they have not yet investigated whether the same mechanisms are in play when the southern lights illuminate the Antarctic skies. During International Polar Year, many researchers are trying to determine whether the solar wind has the same impact on both poles. Norwegian scientists will be retrieving data from the EISCAT radar system on Svalbard and in northern Norway. They will also be studying satellite images.
Legends about the northern lights
There are many myths and legends about the northern lights. Some people believed that dead people's souls lived on in the northern lights. The Inuit, the indigenous peoples of Greenland and Canada, believed the phenomenon was created by spirits playing football in heaven! In Finland, the northern lights were believed by some to be 'fox fires', created by sparks from the tails of foxes as they scampered across the mountains.
Translated by Linda Sivesind
*Published in 'Polar Research', supplement to 'Nysgjerrigper' no. 3-07*
Last modified: 03.09.2007