Arctic Circle

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File:Arctic circle.svg
The Arctic Circle, at roughly 66.5° north, is a commonly-accepted boundary of the Arctic waters and lands

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.[1] 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.[2][3][4]

The positions of the Arctic and Antarctic Circles vary slightly from year to year. Currently the Arctic Circle is 66°33′51.0″ north of the Equator.[5] 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.[6] 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 Template:Cvt per year.

Etymology

The word arctic comes from the Greek word ἀρκτικός (arktikos: "near the Bear, northern")[7] and that from the word ἄρκτος (arktos: "bear").[8]

Midnight sun and polar night

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File:Axial tilt vs tropical and polar circles.svg
Relationship of Earth's axial tilt (ε) to the tropical and polar circles

The Arctic Circle is the southernmost latitude in the Northern Hemisphere at which the centre of the Sun can remain continuously above or below the horizon for twenty-four hours; as a result, at least once each year at any location within the Arctic Circle the centre of the Sun is visible at local midnight, and at least once the centre is not visible at local noon.[3]

Directly on the Arctic Circle these events occur, in principle, exactly once per year: at the June and December solstices, respectively. However, because of atmospheric refraction and mirages, and also because the sun appears as a disk and not a point, part of the midnight sun is visible, on the night of the northern summer solstice, at a latitude of about 50 minutes of arc (′) (Template:Cvt) south of the Arctic Circle. Similarly, on the day of the northern winter solstice, part of the Sun may be seen up to about 50′ north of the Arctic Circle. That is true at sea level; those limits increase with elevation above sea level, although in mountainous regions there is often no direct view of the true horizon.

Human habitation

File:World map with arctic circle.svg
Plate carrée projection showing the Arctic Circle in red

Script error: No such module "labelled list hatnote". The largest communities north of the Arctic Circle are situated in Russia, Norway, and Sweden: Murmansk (population 295,374) and Norilsk (178,018) in Russia; Tromsø (75,638) in Norway, Vorkuta (58,133) in Russia, Bodø (52,357) and Harstad (24,703) in Norway; and Kiruna, Sweden (22,841). In Finland, the largest settlement in the immediate vicinity of the Arctic Circle is Rovaniemi (62,667), lying Template:Cvt south of the line. Salekhard (51,186) in Russia is the only city in the world located directly on the Arctic Circle.[9]

In contrast, the largest Danish community north of the Arctic Circle, Sisimiut (Greenland), has approximately 5,600 inhabitants. In the United States, Utqiagvik, Alaska (formerly known as Barrow) is the largest settlement north of the Arctic Circle with about 5,000 inhabitants. The largest such community in Canada is Inuvik in the Northwest Territories, with 3,137 inhabitants.

Exclusive economic zones

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The Arctic region, defined as the area north of 66°33′ N latitude, comprises land, internal waters, territorial seas, and exclusive economic zones (EEZs). All land and non-international waters within this circle fall under the jurisdiction of eight states: Canada, the Kingdom of Denmark (via Greenland), Finland, Iceland, Norway, Russia, Sweden, and the United States.

Under international law, including the United Nations Convention on the Law of the Sea (UNCLOS), the North Pole and the surrounding high seas of the Arctic Ocean are not owned by any country. Sovereignty in the region is managed through established maritime zones, though the "Arctic Five" (Canada, Denmark, Norway, Russia, and the U.S.) maintain specific rights over their respective continental shelves and EEZs.

Geography

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File:North polar projection map.svg
North polar projection map showing the Arctic Circle

The Arctic Circle is roughly Template:Cvt in circumference.[10] The area north of the Circle is about Template:Cvt and covers roughly 4% of Earth's surface.[11]

The Arctic Circle passes through the Arctic Ocean, the Scandinavian Peninsula, North Asia, Northern America, and Greenland. The land within the Arctic Circle is divided among eight countries: Norway, Sweden, Finland, Russia, the United States (Alaska), Canada (Yukon, Northwest Territories, and Nunavut), Denmark (Greenland), and Iceland (where it passes through the small offshore island of Grímsey).

Climate

Script error: No such module "labelled list hatnote". The climate north of the Arctic Circle is generally cold, but the coastal areas of Norway have a generally mild climate as a result of the Gulf Stream, which makes the ports of northern Norway and northwest Russia ice-free all year long. In the interior, summers can be quite warm, while winters are extremely cold. For example, summer temperatures in Norilsk, Russia will sometimes reach as high as 30 °C (86 °F), while the winter temperatures frequently fall below −50 °C (−58 °F).

Sites along the Arctic Circle

File:Santa Land Rovaniemi Arctic Circle2.jpg
Arctic Circle near to Santa Claus Village in Rovaniemi, Finland
File:Polar circle monument (08).jpg
Arctic Circle monument in Salekhard, Russia
File:Arctic Circle Sign - Auyuittuq National Park, Baffin Island, Nunavut, Canada.jpg
Parks Canada Arctic Circle sign in Auyuittuq National Park, Baffin Island, Nunavut, with Mount Thor in the background
File:Northern lights at the Arctic Circle.jpg
Aurora Borealis above Arctic Circle sign along the Dempster Highway in Yukon at Lua error: callParserFunction: function "#coordinates" was not found.
File:Rovaniemi - Aurora Borealis.jpg
At night, bright aurora borealis are a fairly common sight in the Arctic Circle. The picture of the northern lights in Rovaniemi.

Starting at the prime meridian and heading eastwards, the Arctic Circle passes through:

Coordinates
(approximate)
Country, territory, or ocean Notes
Lua error: callParserFunction: function "#coordinates" was not found.  Atlantic Ocean Norwegian Sea
Lua error: callParserFunction: function "#coordinates" was not found. Norway Islands and skerries of Træna Municipality, Nordland County
Lua error: callParserFunction: function "#coordinates" was not found. Atlantic Ocean Trænfjorden [no], Norwegian Sea
Lua error: callParserFunction: function "#coordinates" was not found. Norway Islands and skerries of Nesøya, Nordland County
Lua error: callParserFunction: function "#coordinates" was not found. Atlantic Ocean Nesøyfjorden [no], Norwegian Sea
Lua error: callParserFunction: function "#coordinates" was not found. Norway Islands and skerries of Storselsøya, Nordland County
Lua error: callParserFunction: function "#coordinates" was not found. Atlantic Ocean Kvarøyfjorden [no], Norwegian Sea
Lua error: callParserFunction: function "#coordinates" was not found. Norway Islands and skerries of Rangsundøya, Nordland County, including Vikingen island
Lua error: callParserFunction: function "#coordinates" was not found. Atlantic Ocean Værangfjorden [no], Norwegian Sea
Lua error: callParserFunction: function "#coordinates" was not found. Norway Nordland County
Lua error: callParserFunction: function "#coordinates" was not found. Sweden Norrbotten County (Provinces of Lapland and Norrbotten)
Lua error: callParserFunction: function "#coordinates" was not found. Finland Lapland Region, crosses Rovaniemi Airport
Lua error: callParserFunction: function "#coordinates" was not found. Russia Republic of Karelia
Lua error: callParserFunction: function "#coordinates" was not found. Murmansk Oblast
Lua error: callParserFunction: function "#coordinates" was not found. Republic of Karelia
Lua error: callParserFunction: function "#coordinates" was not found. Grand Island, Murmansk Oblast
Lua error: callParserFunction: function "#coordinates" was not found. Arctic Ocean Kandalaksha Gulf, White Sea, Barents Sea
Lua error: callParserFunction: function "#coordinates" was not found. Russia Kola Peninsula, Murmansk Oblast — for about 7 km (4.3 mi)
Lua error: callParserFunction: function "#coordinates" was not found. Arctic Ocean Kandalaksha Gulf, White Sea, Barents Sea
Lua error: callParserFunction: function "#coordinates" was not found. Russia Kola Peninsula, Murmansk Oblast
Lua error: callParserFunction: function "#coordinates" was not found. Arctic Ocean White Sea, Barents Sea
Lua error: callParserFunction: function "#coordinates" was not found. Russia Nenets Autonomous Okrug
Lua error: callParserFunction: function "#coordinates" was not found. Komi Republic
Lua error: callParserFunction: function "#coordinates" was not found. Yamalo-Nenets Autonomous Okrug
Lua error: callParserFunction: function "#coordinates" was not found. Arctic Ocean Gulf of Ob, Kara Sea
Lua error: callParserFunction: function "#coordinates" was not found. Russia Yamalo-Nenets Autonomous Okrug
Lua error: callParserFunction: function "#coordinates" was not found. Krasnoyarsk Krai
Lua error: callParserFunction: function "#coordinates" was not found. Yukaghir Highlands, Sakha Republic
Lua error: callParserFunction: function "#coordinates" was not found. Anadyr Highlands and Chukotka Mountains, Chukotka Autonomous Okrug
Lua error: callParserFunction: function "#coordinates" was not found. Arctic Ocean Chukchi Sea
Lua error: callParserFunction: function "#coordinates" was not found. United States Seward Peninsula, Alaska
Lua error: callParserFunction: function "#coordinates" was not found. Arctic Ocean Kotzebue Sound, Chukchi Sea
Lua error: callParserFunction: function "#coordinates" was not found. United States Alaska—passing through Selawik Lake
Lua error: callParserFunction: function "#coordinates" was not found. Canada Yukon
Lua error: callParserFunction: function "#coordinates" was not found. Northwest Territories, passing through Great Bear Lake
Lua error: callParserFunction: function "#coordinates" was not found. Nunavut
Lua error: callParserFunction: function "#coordinates" was not found. Arctic Ocean Foxe Basin
Lua error: callParserFunction: function "#coordinates" was not found. Canada Nunavut (Baffin Island), passing through Nettilling Lake and Auyuittuq National Park (sign location)
Lua error: callParserFunction: function "#coordinates" was not found. Atlantic Ocean Davis Strait
Lua error: callParserFunction: function "#coordinates" was not found. Greenland passing through Kangerlussuaq Fjord and Schweizerland
Lua error: callParserFunction: function "#coordinates" was not found. Atlantic Ocean Denmark Strait
Lua error: callParserFunction: function "#coordinates" was not found. Greenland Sea
Lua error: callParserFunction: function "#coordinates" was not found. Iceland Island of Grímsey
Lua error: callParserFunction: function "#coordinates" was not found. Atlantic Ocean Greenland Sea
Lua error: callParserFunction: function "#coordinates" was not found. Norwegian Sea

See also

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References

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  1. ^ Page Module:Citation/CS1/styles.css has no content."Arctic FAQ - Frequently Asked Questions about the Arctic".
  2. ^ Page Module:Citation/CS1/styles.css has no content."40 days without the sun. How? Polar Night begins in Murmansk". Auroravillage.info. 3 December 2018. Retrieved 24 March 2022.
  3. ^ a b Page Module:Citation/CS1/styles.css has no content.Burn, Chris. The Polar Night (PDF). The Aurora Research Institute. Retrieved 28 September 2015.
  4. ^ N.B.: This refers to the true geometric center which actually appears higher in the sky because of refraction by the atmosphere.
  5. ^ Page Module:Citation/CS1/styles.css has no content."Obliquity of the Ecliptic (Eps Mean)". Neoprogrammics.com. Retrieved 13 May 2014.
  6. ^ Page Module:Citation/CS1/styles.css has no content.Berger, A. L. (1976). "Obliquity and Precession for the Last 5000000 Years". Astronomy & Astrophysics. 51 (1): 127–135. Bibcode:1976A&A....51..127B.
  7. ^ Page Module:Citation/CS1/styles.css has no content.Liddell, Henry; Scott, Robert. "Arktikos". A Greek–English Lexicon. Perseus Digital Library.
  8. ^ Page Module:Citation/CS1/styles.css has no content.Liddell, Henry; Scott, Robert. "Arktos". A Greek–English Lexicon. Perseus Digital Library.
  9. ^ Page Module:Citation/CS1/styles.css has no content.Всеволод Липатов (26 April 2011). "Город на Полярном круге". ToGeo.ru (in русский). Archived from the original on 8 August 2014. Retrieved 23 July 2021.
  10. ^ Page Module:Citation/CS1/styles.css has no content.Nuttall, Mark (2004). Encyclopedia of the Arctic Volumes 1, 2 and 3. Routledge. p. 115. ISBN 978-1579584368.
  11. ^ Page Module:Citation/CS1/styles.css has no content.Marsh, William M.; Kaufman, Martin M. (2012). Physical Geography: Great Systems and Global Environments. Cambridge University Press. p. 24. ISBN 978-0-521-76428-5.

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