We explain what the Northern Lights are, how they are produced and where they can be seen. We also talk about Aurora Borealis in Iceland, Canada, and Norway.
What are the Northern Lights?
The polar aurora (aurora polaris) is an atmospheric phenomenon that appears in certain regions of the planet, on the night sky, during specific periods of the year. They are set appart by their appearance – multicolor lights in elongated shapes over the sky. The name Aurora comes from the Roman goddess of dawn bearing the same name.
They occur near the poles and are called northern lights if they occur in the northern hemisphere. Aurora Polaris occuring in the southern hemisphere are called southern auroras. The phenomenon has intrigued mankind since immemorial times, and was associated with snakes or dragons that crossed the sky, or to particular gods.
The scientific study of Aurora Polaris began in the seventeenth century, and lead to the conclusion that they are particles ejected by the Sun during periodic combustions, crashing against our planet’s magnetosphere. In 1896 the Norwegian physicist Kristian Birkeland managed to reproduce them in the laboratory, greatly facilitating their understanding.
Polar auroras are best seen between September and March (Northern Hemisphere) or between March and September (southern hemisphere). Its shape, colors and duration can vary enormously, oscillating between silhouettes close to the horizon and beams of light that cover the entire sky, tending to disappear as dawn approaches.
How is an aurora borealis produced?
The polar aurora is produced by the collision of the solar wind against Earth’s magnetosphere.Polar auroras occur when the magnetic layer that surrounds our planet, known as magnetosphere, comes into contact with a diverse series of charged solar particles, ejected from the Sun. These ejections are known as solar wind.
These particles travel at speeds of approximately 490 to 1000 kmps, covering the distance between our planet and the center of the Solar System in just two days. However, when they approach our atmosphere, the Earth’s magnetic field repels them, changing their course following the pattern of the magnetosphere, and making them flow around the planet in the same way a river do in front of a stone.
A few particles are trapped in the magnetosphere, charging the atoms in the upper layers of our atmosphere, which release excess energy in the form of visible light. It is a process similar to the one occuring inside neon tubes.
Where are the Northern Lights seen?
As we mentioned previously, polar auroras are usually seen in the vicinity of each Earth’s poles, although they can be observed for short periods in other regions as well. Their strength and duration depend on the intensity of the solar activity. The most common areas for observing the auroras are:
- Northern hemisphere: the coasts of Iceland are a frequent observation point from late August to April, as well as in Alaska, United States, specifically in the vicinity of Denali National Park. The same in the Canadian Northwest Territories, near the town of Yellowknife, or in the greater urban region of northern Norway, very close to the Arctic Circle, in Tromsǿ.
- Southern hemisphere: the auroras in southern Tasmania, Australia and New Zealand are famously beautiful and can be seen throughout the year. However, the best location to watch southern lights is Antarctica itself, the frozen continent, at least on its habitable coasts that face the southern American cone. In this sense, the last cities and regions of Argentina and Chile can also be eventual observation points, such as the island of Ushuaia.
Northern Lights in Iceland
The beauty of the Kirkjufellsfoss waterfall combined with the Northern Lights in Iceland.Iceland’s northern regions, close the Arctic Circle are ideal for observing auroras, especially between September and March, between 6:00 p.m. and 4:00 a.m. The northern coast is a sparsely populated region compared to the warmer south coast, where the capital Reykjavik is located.
Northern Lights in Canada
Northern lights in Yukon, Canada.The northern lights in Canada can are best enjoyed between October and March, in the period of greatest darkness, although they are present throughout the year. The ideal zones to do so are in Yukon, especially in Whitehorse, Yellowknife, Tuktoyaktuk, Nunavut, Manitoba, Kuujjuaq, but also a bit to the south, in British Columbia and Alberta.
Northern Lights in Norway
Aurora Borealis in Tromso, Norway.In Norway, Auroras can be observed from all over the country, although the best regions are nearby the border with the Arctic Circle. The best time for observation spans between September and March. The Lofoten Islands and the north-western coast are good viewing points, as well as Tromsǿ.
Southern aurora or Aurora Australis
The southern auroras can be observed mainly from the bases of Antarctica.The southern lights are just as beautiful as their northern counterparts. There is little to no distinction between the two except for being positioned in opposite hemispheres. However, they are less famous because the access to the South Pole is extremely limited, and Antarctica does not have permanent residents – except for penguins, of course.