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|Wednesday, 26 October 2011 08:01|
The Northern Lights zone is a circle around the Magnetic North Pole. The section of Northern Norway north of Vesterålen is situated in this zone and, as a result, this is where you have the best chance of seeing the Northern Lights. Tromsø is situated right in the centre of the Northern Lights zone.
There are other places in the Northern Hemisphere located in this zone. However, except Iceland, the majority of these areas are sparsely populated or uninhabited and for most people are difficult to access or virtually inaccessible. The Northern Lights are visible on occasions in central and southern areas of Scandinavia, and also in parts of Southern Canada and the US Midwest, but not nearly as often as we experience here. Aurorae are produced by the collision of charged particles from Earth's magnetosphere, mostly electrons but also protons and heavier particles, with atoms and molecules of Earth's upper atmosphere (at altitudes above 80 km (50 miles)). The particles have energies of 1 to 100 keV. They originate from the Sun and arrive at the vicinity of Earth in the relatively low-energy solar wind. When the trapped magnetic field of the solar wind is favorably oriented (principally southwards) it connects with Earth's magnetic field, and solar particles enter the magnetosphere and are swept to the magnetotail. Further magnetic reconnection accelerates the particles towards Earth.
When the storms on the sun are at their most intense, the Northern Lights are visible over central and southern Europe and in parts of the USA. However, this is so rare that very few people living in these regions have ever seen the Northern Lights. In earlier times, outbreaks of the Northern Lights were seen as warnings of disasters or other calamities.
An old Scandinavian name for northern lights translates as "herring flash". It was believed that northern lights were the reflections cast by large swarms of herring onto the sky.
Another Scandinavian source refers to "the fires that surround the North and South edges of the world". This has been suggested as evidence that the Norse ventured as far as Antarctica, although this is insufficient to form a conclusion.
The Finnish name for northern lights is revontulet, fox fires. According to legend, foxes made of fire lived in Lapland, and revontulet were the sparks they whisked up into the atmosphere with their tails.
In Estonian they are called virmalised, spirit beings of higher realms. In some legends they are given negative characters, in some positive ones.
The Sami people believed that one should be particularly careful and quiet when observed by the northern lights (called guovssahasat in Northern Sami). Mocking the northern lights or singing about them was believed to be particularly dangerous and could cause the lights to descend on the mocker and kill him/her.
The Algonquin believed the lights to be their ancestors dancing around a ceremonial fire.
In Latvian folklore northern lights, especially if red and observed in winter, are believed to be fighting souls of dead warriors, an omen foretelling disaster (especially war or famine).
In Russian folklore aurora borealis was associated with the fire dragon ("Ognenniy Zmey"), who came to women and seduced them in the absence of their husbands.
In Scotland, the northern lights were known as "the mirrie dancers" or na fir-chlis. There are many old sayings about them, including the Scottish Gaelic proverb "When the mirrie dancers play, they are like to slay." The playfulness of the mirrie dancers was supposed to end occasionally in quite a serious fight, and next morning when children saw patches of red lichen on the stones, they say among themselves that "the mirrie dancers bled each other last night". The appearance of these lights in the sky was considered a sign of the approach of unsettled weather.
Many prospectors during the Klondike Gold Rush believed that the Northern Lights were the reflection of the mother lode of all gold.
The Inuit people of Alaska tell the traditional tale of their ancient ancestors who are seen in the rippling movements of the northern lights. They say that the "shadows" within the display are relatives and friends who have gone to the sky and march along or dance to remind the living people of their presence. When the dogs bark and howl at the sounds of the aurora borealis, it's said that the dogs recognize their one-time companions in the colorful display.
What exactly are Northern Lights
The Northern Lights stem from when large numbers of electrically charged particles (electrons) at high speed stream in towards the Earth along its magnetic field and collide with the highest air particles. The air then lights up rather like what happens in a fluorescent light tube. The resulting colors reflect which gases we find up there, the most usual yellow-green color coming from oxygen. Red coloring is also due to oxygen with a contribution from nitrogen. The violet we often see at the lower edge of the aurora is due to nitrogen, as is most blue coloring. The charged particles originate from the sun, and it is the “weather” conditions on the sun that decide whether or not we will see the aurora. Particles can stream out from the sun and some are captured by the Earth’s magnetic field and find their way into the polar regions. On the way, they travel out into the night side of the Earth and gain extra energy - we still lack understanding of exactly what happens out there!
Where can i see the Northern Lights
Contrary to intuition, seeing the Northern Lights isn't just a matter of heading "north." The Lights usually circle the globe in a circular or elliptical band centered on the earth's North Magnetic Pole, which is not at the same location as the North Geographic Pole, but rather is offset in the direction of northern Canada. Furthermore, auroral displays aren't strongest at the North Magnetic Pole; the band of greatest auroral activity is usually offset from the Magnetic Pole by 20 degrees or so.
This quirk is actually fairly convenient for would-be aurora watchers. It means that locations in the north-central United States, for example Minnesota and North Dakota, and also southern Canada see Northern Lights much more frequently than they would if the Lights were centered on the North Geographic Pole. Alaska and Lapland (the northern part of Finland, Norway and Sweden) also fall in the region of greatest probability, while the far-north territory of Siberia that misses out on some of the Lights (because the Magnetic Pole is displaced away from that region) tends to be more inaccessible to the traveler.
A curiosity is that the exact location of the North Magnetic Pole varies from year to year, sometimes by tens of miles. The Pole has been moving north for a few years now as of 2006; it's now near Ellesmere Island in the nearly uninhabited far north of Canada. As a consequence, the advantages of being on the "right side" of the earth are not as pronounced as they were some years ago. Still, there's a slight North American bias even today in your chance of seeing the Lights.
This said, the actual latitudes of the Lights vary considerably. In times of high solar activity (more on that later), the Lights may be seen in North America at latitudes as low as 35 degrees north, meaning that all but the southernmost parts of the United States may get a display. The offset of the Pole keeps solar storms from benefiting Europe quite as strongly, but most of the countries of northern Europe will get displays during periods of solar storms.
How often can you see the Northern Lights?
In Troms and Finnmark, we can see the Northern Lights every other clear night, if not even more frequently. From southern Norway, sightings would be only a few times a month while in central Europe hardly more than a few times a year and they have even been seen from the Mediterranean but only a few times each century. To the north of the auroral zone, on Spitzbergen, the Northern Lights are a common sight, although they don’t appear as often as in northern Norway.
Can i see the Northern Lights in Oslo?
The answer is definitely - Yes! Once every hundred years you can see northern lights as far south as equator. Of course in Oslo it happen much more often - at least few times in a winter season. If your main goal is just to see Northern Lights its advised to travel more north and maximize your chances.
|Last Updated on Wednesday, 30 November 2011 05:34|