Arctic Circle

The Arctic Circle is one of the two polar circles, and the northernmost of the five major circles of latitude. It is shown on maps of Earth at about 66° 34' N. Its southern counterpart is the Antarctic Circle.

The Arctic Circle marks the southernmost latitude for which at the December solstice (winter) the Sun does not rise and at the June solstice (summer) the Sun does not set. These phenomena are referred to as polar night and midnight sun, respectively, and the closer to the pole one goes, the longer that situation persists. For example, in the Russian port city of Murmansk (three degrees north of the Arctic Circle) the Sun stays below the horizon for 20 days before and after the winter solstice, and above the horizon for 20 days before and after the summer solstice.

The positions of the Arctic and Antarctic Circles vary slightly from year to year. Currently the Arctic Circle is 66°33′50.9″ north of the Equator. Its latitude depends on Earth's axial tilt, which fluctuates by a margin of some 2° over a 41,000-year period due to tidal forces resulting from the orbit of the Moon. Consequently, in the current epoch the Arctic Circle is drifting toward the North Pole, while the Antarctic Circle drifts towards the South Pole, each at a speed of about 14.5 m (48 ft) per year.

Etymology

The word arctic comes from an ancient Greek word meaning "near the Bear, northern." This ancient word itself comes from another word meaning "bear."

Midnight sun and polar night

Further information: Midnight sun and Polar night

The Arctic Circle is the southernmost latitude in the Northern Hemisphere where the Sun can stay above or below the horizon all day long. Because of this, at least once each year in any place inside the Arctic Circle, the Sun can be seen at midnight, and there are also times when it is not seen at noon.

Exactly on the Arctic Circle, these special events happen once a year during the June and December solstices. However, because of how the Earth's air bends light and how we see the Sun as a round shape and not a single point, parts of the midnight sun can be seen a little bit south of the Arctic Circle. Similarly, during the winter solstice, a bit of the Sun can be seen a little bit north of the Arctic Circle. This is true at sea level, but the effect can change a little if you are higher up.

Human habitation

The largest communities north of the Arctic Circle are found in Russia, Norway, and Sweden. Cities such as Murmansk, Norilsk, and Tromsø have thousands of people living there. Other notable places include Vorkuta, Bodø, Harstad, and Kiruna.

In other countries, Sisimiut in Greenland and Utqiagvik, Alaska each have around 5,000 residents. Inuvik in the Northwest Territories is the largest settlement in Canada north of the Arctic Circle.

Exclusive economic zones

Main article: Territorial claims in the Arctic

The Arctic region includes land and waters north of 66°33′ N latitude. Eight countries have control over parts of this area: Canada, the Kingdom of Denmark (through Greenland), Finland, Iceland, Norway, Russia, Sweden, and the United States. According to international law, including the United Nations Convention on the Law of the Sea, the North Pole and the surrounding waters are not owned by any single country. Rights in the region are handled through maritime zones, with specific countries having control over their own areas.

Geography

The Arctic Circle is a special line around the Earth at about 66° 34' North. It is about 16,000 kilometers long, and the area north of it covers about 20 million square kilometers, which is about 4% of the Earth's surface.

The Arctic Circle goes through the Arctic Ocean, the Scandinavian Peninsula, North Asia, Northern America, and Greenland. Eight countries share land inside the Arctic Circle: Norway, Sweden, Finland, Russia, the United States (Alaska), Canada (Yukon, Northwest Territories, and Nunavut), Denmark (Greenland), and Iceland.

The climate in the Arctic Circle is usually very cold. However, the coastal areas of Norway stay milder because of the Gulf Stream, keeping ports free of ice all year. In some places, like Norilsk in Russia, summers can get warm, up to around 30°C, while winters can be extremely cold, often below −50°C.

Starting from the prime meridian and moving east, the Arctic Circle passes through many places.