A spectacular sight

The dancing northern lights
The dancing northern lights in the night sky are a sight for the gods which winter holidaymakers in Greenland will in all likelihood come to experience. From the early autumn the night sky is regularly illuminated by the northern lights’ green glow. It is a natural phenomenon that always causes excitement and wonder among those who have never seen it before.

The Inuit people have also allowed themselves to wonder at the sight down through the ages, and the northern lights have often challenged the imagination. A well-known legend relates that when the northern lights dance in the night sky, it means that the dead are playing football with a walrus skull. Today certain tribes think that children will be particularly intelligent if they are born in the magical glow of the northern lights.

Aurora Borealis in Greenland
The northern lights – or Aurora Borealis as it is officially known – actually occur all year round, but cannot be seen during the summer months in Greenland due to the midnight sun. The phenomenon is often seen around midnight and is best experienced on a dark, clear night in the period from September to April. If you are travelling during this period, you can see the northern lights from anywhere in the country, whilst in South Greenland the northern lights can be seen from as early as the end of August.

Flickering molecules and particles

The northern lights are a fascinating phenomenon caused by collisions between the sun’s electrically charged particles and molecules and atoms in the Earth’s atmosphere. The spectacular light show takes place in the upper atmosphere at a height of approximately 100 kilometres (62 miles) and can best be compared to candles flickering in the wind or fluttering curtains in shades of green and yellow. Greenland is one of the best places in the world to observe the northern lights.

On www.swpc.noaa.gov they write the following about a sattelite surveillance project: 
"Instruments on board the NOAA Polar-orbiting Operational Environmental Satellite (POES) continually monitor the power flux carried by the protons and electrons that produce aurora in the atmosphere. SEC has developed a technique that uses the power flux observations obtained during a single pass of the satellite over a polar region (which takes about 25 minutes) to estimate the total power deposited in an entire polar region by these auroral particles. The power input estimate is converted to an auroral activity index that ranges from 1 to 10.

If you want to see a visualization of the auroral activity, as a "layer" in Google Earth, press here to download the layer file (you need to have Google Earth installed on your computer to run the file!)