Nordia 2013 - Northern Lights
The Nordic stamp exhibition NORDIA 2013 will take place in Asgard Sports Center, Gardabaer on 7th-9th June 2013. This is the sixth time that the NORDIA exhibition is held in Iceland. On this occasion Iceland Post will issue a souvenir sheet as it has done in the past with the Northern Lights as its theme.
The sun continually emits a so-called solar wind which is a stream of electrically charged particles. The earth‘s magnetic field repels these particles except around the geomagnetic poles where some of them get through. When they collide with the earth‘s ionosphere in an altitude of about 100-250 km molecules particles in the atmosphere become excited and emit light which we call the northern or the southern lights.
The effects of solar wind are greatest at a collar round the magnetic poles, where the aurora (Northern and Southern Lights) is most prominent. Under normal circumstances Iceland is in the aurora collar during the night. The northern lights can be seen anywhere in Iceland when the so-called aurora collar is over the country on a dark cloudless night. The size and magnitude of the aurora collar is variable depending on solar activity and the solar wind. Small solar activity usually creates a small collar while greater activity results in a large and extensive collar.