In the northern hemisphere passes the Arctic Circle and in the South, respectively - line South of the Arctic zone.The first is considered the boundary zone of temperate climate and the Arctic.Antarctic Circle is considered to be the boundary of the Antarctic climate.21-22 June (summer solstice) the sun never sets, and the winter solstice (December 21-22) - does not rise.
Due to changes in the tilt of the earth axis, there is a daily shift of the line of the Arctic Circle (Arctic circle) to three meters a day, and up to one hundred meters per year.Experts have made calculations up to 2015 year.It was found that the first Arctic Circle will shift to the north.In the following nine years after 2015, the year - four hundred meters to the south.
boundary of the polar night is determined by the polar circle, if the sun is a bright spot, while the earth has no atmosphere.In fact, the day begins with the appearance of the top of the solar disk.Moreover, the apparent position of the light above the real due to the refraction (bending of rays in the atmosphere).In this regard, the Arctic Circle lies at fifty minutes south of the border of the polar night.
The concept Arctic circle was introduced Eudoxus of Cnidus (disciple of Plato).He understood the connection between the tilt axis and the planet's brightness in different areas of the Earth's climate and bound latitude.Eudoxus introduced the definition of "Climate".Location of the Arctic Circle, in his opinion, it was 54 degrees.All places him they were considered unfit for human life.
Around the year 327 BCthe first sailor, who was able to cross the Arctic Circle, was the geographer Pytheas.Arctic day, he watched in the Norwegian Sea.
first sailor, sail across the Southern Circle, was Cook.It happened during his world tour.
Arctic Circle in Europe passes through the territory of Norway, Finland, Russia and Sweden.Line intersects in Russian Republic of Karelia, Murmansk region Kandalaksha Bay and Mezenskaya Bay in the White Sea, Nenets, Komi and other regions.Part of the mainland, which is located to the north of the circle is called the Arctic.
For Bering Strait line continues in America.In this area, the Arctic Circle runs through Alaska, three regions of Canada.Then the line goes on Baffin Island, Fox Bay, Greenland, and the Davis Strait.
Circle North in the North Atlantic runs through the Danish Straits, the island of Grimsey, Iceland-owned, as well as the Norwegian and Greenland Seas.
Southern circle crosses several areas of Antarctica and the Southern Ocean.The line passes through the Antarctic Peninsula, the Lazarev Sea, Weddell, Cosmonauts, Amundsen Gulf and the Sea Reeser Lans.From the shores of the Gulf of Amundsen's polar circle crosses the line of the Commonwealth Sea, Enderby Land and Princess Elizabeth, the coast of Truth, Davis Sea, the Bay of Vincennes in Mawson Sea and Beach Knox.Then the line goes alternately on the ocean and on various shores in the Wilkes Land.Not far from the "Dumont d'Urville" (French stations) out in the Pacific sector of the Southern Ocean from the Antarctic continent.
