[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/arctic-circle-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/en\/wiki24\/arctic-circle-wikipedia\/","headline":"Arctic Circle – Wikipedia","name":"Arctic Circle – Wikipedia","description":"Boundary of the Arctic Map of the Arctic, with the Arctic Circle in blue and the 10\u00b0C July mean isotherm","datePublished":"2022-04-21","dateModified":"2022-04-21","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/en\/wiki24\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/3\/31\/Arctic_circle.svg\/300px-Arctic_circle.svg.png","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/3\/31\/Arctic_circle.svg\/300px-Arctic_circle.svg.png","height":"376","width":"300"},"url":"https:\/\/wiki.edu.vn\/en\/wiki24\/arctic-circle-wikipedia\/","wordCount":3086,"articleBody":"Boundary of the Arctic  Map of the Arctic, with the Arctic Circle in blue and the 10\u00b0C July mean isotherm in redThe Arctic Circle is one of the two polar circles, and the most northerly of the five major circles of latitude as shown on maps of Earth. Its southern equivalent is the Antarctic Circle.The Arctic Circle marks the southernmost latitude at which, on the Winter solstice, the shortest day of the year in the northern hemisphere, the Sun will not rise all day, and on the Summer solstice, the longest day of the year in the northern hemisphere, the Sun will not set. These phenomena are referred to as polar night and midnight sun respectively, and the further north one progresses, the more pronounced these effects become. For example, in the Russian port city of Murmansk, three degrees above the Arctic Circle, the Sun does not rise above the horizon for 40 successive days in midwinter.[1][2][3]The position of the Arctic Circle is not fixed and currently runs 66\u00b033\u203249.4\u2033 north of the Equator.[4] Its latitude depends on the Earth’s axial tilt, which fluctuates within a margin of more than 2\u00b0 over a 41,000-year period, owing to tidal forces resulting from the orbit of the Moon.[5] Consequently, the Arctic Circle is currently drifting northwards at a speed of about 14.5\u00a0m (48\u00a0ft) per year.Table of ContentsEtymology[edit]Midnight sun and polar night[edit]Human habitation[edit]Geography[edit]Climate[edit]Sites along the Arctic Circle[edit]See also[edit]References[edit]External links[edit]Etymology[edit]The word arctic comes from the Greek word \u1f00\u03c1\u03ba\u03c4\u03b9\u03ba\u03cc\u03c2 (arktikos: “near the Bear, northern”)[6] and that from the word \u1f04\u03c1\u03ba\u03c4\u03bf\u03c2 (arktos: “bear”).[7]Midnight sun and polar night[edit]  Relationship of Earth’s axial tilt (\u03b5) to the tropical and polar circlesThe Arctic Circle is the southernmost latitude in the Northern Hemisphere at which the center 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 center of the Sun is visible at local midnight, and at least once the center is not visible at local noon.[8]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 may be seen on the night of the northern summer solstice up to about 50 minutes (\u2032) (90\u00a0km (56\u00a0mi)) 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\u2032 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.  At night, bright aurora borealis are a fairly common sight in the Arctic Circle. The picture of the northern lights in Rovaniemi.Human habitation[edit]  Cylindrical projection showing the Arctic Circle in redThe largest communities north of the Arctic Circle are situated in Russia, Norway, and Sweden: Murmansk (population 295,374) and Norilsk (178,018) in Russia; Troms\u00f8  (75,638) in Norway, Vorkuta (58,133) in Russia, Bod\u00f8 (52,357), and Harstad (24,703) in Norway; and Kiruna, Sweden (22,841). Rovaniemi (62,667) in Finland is the largest settlement in the immediate vicinity of the Arctic Circle, lying 6\u00a0km (4\u00a0mi) 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 North American community north of the Arctic Circle, Sisimiut (Greenland), has approximately 5,600 inhabitants. In the United States, Utqia\u0121vik, Alaska (Formerly 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 people living there.Geography[edit]The Arctic Circle is roughly 16,000\u00a0km (9,900\u00a0mi) in circumference.[10] The area north of the Circle is about 20,000,000\u00a0km2 (7,700,000\u00a0sq\u00a0mi) 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 Gr\u00edmsey).Climate[edit]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\u00a0\u00b0C (86\u00a0\u00b0F), while the winter temperatures frequently fall below \u221250\u00a0\u00b0C (\u221258\u00a0\u00b0F).Sites along the Arctic Circle[edit]Starting at the prime meridian and heading eastwards, the Arctic Circle passes through:See also[edit]References[edit]^ “40 days without the sun. How? Polar Night begins in Murmansk”. Auroravillage.info. 3 December 2018. Retrieved 24 March 2022.^ Burn, Chris. The Polar Night (PDF). The Aurora Research Institute. Retrieved 28 September 2015.^ NB: This refers to the true geometric center which actually appears higher in the sky because of refraction by the atmosphere.^ “Obliquity of the Ecliptic (Eps Mean)”. Neoprogrammics.com. Retrieved 13 May 2014.^ Berger, A. L. (1976). “Obliquity and Precession for the Last 5000000 Years”. Astronomy and Astrophysics. 51 (1): 127\u2013135. Bibcode:1976A&A….51..127B.^ Liddell, Henry; Scott, Robert. “Arktikos”. A Greek\u2013English Lexicon. Perseus Digital Library.^ Liddell, Henry; Scott, Robert. “Arktos”. A Greek\u2013English Lexicon. Perseus Digital Library.^ Burn, Chris. The Polar Night (PDF). The Aurora Research Institute. Retrieved 28 September 2015.^ \u0412\u0441\u0435\u0432\u043e\u043b\u043e\u0434 \u041b\u0438\u043f\u0430\u0442\u043e\u0432 (26 April 2011). “\u0413\u043e\u0440\u043e\u0434 \u043d\u0430 \u041f\u043e\u043b\u044f\u0440\u043d\u043e\u043c \u043a\u0440\u0443\u0433\u0435”. ToGeo.ru (in Russian).^ Nuttall, Mark (2004). Encyclopedia of the Arctic Volumes 1, 2 and 3. Routledge. p.\u00a0115. ISBN\u00a0978-1579584368.^ Marsh, William M.; Kaufman, Martin M. (2012). Physical Geography: Great Systems and Global Environments. Cambridge University Press. p.\u00a024. ISBN\u00a0978-0-521-76428-5.External links[edit]"},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/arctic-circle-wikipedia\/#breadcrumbitem","name":"Arctic Circle – Wikipedia"}}]}]