Scotland and the Antarctic

Section 7: The legacy of Bruce ... The Earth's magnetism

Aurora and the solar wind

The journals of many Antarctic voyages mention the aurora australis, which is similar to the aurora borealis of the Arctic. The explorers realised that the aurora had a link with latitude, and further realised that this latitude was based on the magnetic poles. A link must exist between magnetism and the aurora.

The aurora is now known to be caused by the effect of gases coming from the sun (plasma) as they are diverted around the Earth's magnetosphere. Some of these gases leak through the magnetosphere at its weakest points - the poles - and collide with oxygen and nitrogen particles to form the aurora.

The solar wind has the greatest effect on the Earth during sun spot activities every 11 years. These flares can cause magnetic storms which have shut down power stations, disrupted radio transmissions and even knocked out some satellites. This could be very serious as global positioning satellites (GPS) are now used by all aircraft and ships for navigation.