The Arctic Circle is one of the two polar circles, and the northernmost of the five major circles of latitude as shown on maps of Earth at about 66° 34' N. Its southern counterpart is the Antarctic Circle.
The Arctic Circle marks the southernmost latitude at which, on the winter solstice in the Northern Hemisphere, the Sun does not rise all day, and on the Northern Hemisphere's summer solstice, the Sun does not set. These phenomena are referred to as polar night and midnight sun respectively, and the further north one progresses, the more obvious this becomes. 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 position of the Arctic Circle is not fixed and currently runs 66°33′50.3″ 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, the Arctic Circle is currently drifting northwards at a speed of about 14.5 m (48 ft) per year.
Etymology
The word arctic comes from the Greek word ἀρκτικός (arktikos: "near the Bear, northern") and that from the word ἄρκτος (arktos: "bear").
Midnight sun and polar night
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.
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 (′) (90 km (56 mi)) 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
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). Rovaniemi (62,667) in Finland is the largest settlement in the immediate vicinity of the Arctic Circle, lying 6 km (4 mi) south of the line. Salekhard (51,186) in Russia is the only city in the world located directly on the Arctic Circle.
In contrast, the largest North American 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.
Geography
The Arctic Circle is roughly 16,000 km (9,900 mi) in circumference. The area north of the Circle is about 20,000,000 km2 (7,700,000 sq mi) and covers roughly 4% of Earth's surface.
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
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
Starting at the prime meridian and heading eastwards, the Arctic Circle passes through:
Gallery
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Northern Polar Circle Globe on Vikingen island marking the Arctic Circle in Norway -
Arctic Circle sign by the Inland Line railway, Sweden -
The white borderline of the Arctic Circle at the Santa Claus Village in Rovaniemi, Finland -
Arctic Circle sign in the Republic of Karelia, Russia -
Arctic Circle sign by the Yamalo-Nenets Autonomous Okrug, Russia -
A sign in the Sakha Republic (Yakutia), Russia -
Arctic Circle marker on island of Grímsey in Iceland -
A sign along the Dalton Highway marking the location of the Arctic Circle in Alaska, United States -
Polcirkeln portal in Gällivare, Sweden -
Arctic Circle line in Rovaniemi, Finland c. 1865
See also
- 60th parallel north
- Arctic cooperation and politics
- Arctic haze
- Circumpolar star
- Scott Polar Research Institute
- Territorial claims in the Arctic
- Tropic of Cancer
- Tropic of Capricorn
References
- "Arctic FAQ - Frequently Asked Questions about the Arctic".
- "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.
- N.B.: 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 & Astrophysics. 51 (1): 127–135. Bibcode:1976A&A....51..127B.
- Liddell, Henry; Scott, Robert. "Arktikos". A Greek–English Lexicon. Perseus Digital Library.
- Liddell, Henry; Scott, Robert. "Arktos". A Greek–English Lexicon. Perseus Digital Library.
- Burn, Chris. The Polar Night (PDF). The Aurora Research Institute. Retrieved 28 September 2015.
- Всеволод Липатов (26 April 2011). "Город на Полярном круге". ToGeo.ru (in Russian). Archived from the original on 8 August 2014. Retrieved 23 July 2021.
- Nuttall, Mark (2004). Encyclopedia of the Arctic Volumes 1, 2 and 3. Routledge. p. 115. ISBN 978-1579584368.
- 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.
External links
- Terra Incognita: Exploration of the Canadian Arctic—Historical essay about early expeditions to the Canadian Arctic, illustrated with maps, photographs and drawings
- Temporal Epoch Calculations ©2006 by James Q. Jacobs Download: Epoch v2009.xls (modify D4)
- Useful constants" See: Obliquity of the ecliptic
The Arctic Circle is one of the two polar circles and the northernmost of the five major circles of latitude as shown on maps of Earth at about 66 34 N Its southern counterpart is the Antarctic Circle The Arctic Circle at roughly 66 5 north is the boundary of the Arctic waters and lands The Arctic Circle marks the southernmost latitude at which on the winter solstice in the Northern Hemisphere the Sun does not rise all day and on the Northern Hemisphere s summer solstice the Sun does not set These phenomena are referred to as polar night and midnight sun respectively and the further north one progresses the more obvious this becomes 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 position of the Arctic Circle is not fixed and currently runs 66 33 50 3 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 the Arctic Circle is currently drifting northwards at a speed of about 14 5 m 48 ft per year EtymologyThe word arctic comes from the Greek word ἀrktikos arktikos near the Bear northern and that from the word ἄrktos arktos bear Midnight sun and polar nightRelationship of Earth s axial tilt e 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 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 90 km 56 mi 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 habitationPlate carree projection showing the Arctic Circle in red 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 Tromso 75 638 in Norway Vorkuta 58 133 in Russia Bodo 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 km 4 mi south of the line Salekhard 51 186 in Russia is the only city in the world located directly on the Arctic Circle In contrast the largest North American 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 GeographyMap all coordinates using OpenStreetMap Download coordinates as KML GPX all coordinates GPX primary coordinates GPX secondary coordinates The Arctic Circle is roughly 16 000 km 9 900 mi in circumference The area north of the Circle is about 20 000 000 km2 7 700 000 sq mi and covers roughly 4 of Earth s surface 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 Grimsey Climate 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 Arctic Circle near to Santa Claus Village in Rovaniemi FinlandArctic Circle monument in Salekhard RussiaParks Canada Arctic Circle sign in Auyuittuq National Park Baffin Island Nunavut with Mount Thor in the backgroundAurora Borealis above Arctic Circle sign along the Dempster Highway in Yukon at 66 33 55 N 136 18 26 W 66 56528 N 136 30722 W 66 56528 136 30722 Arctic Circle sign 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 Notes66 34 N 0 0 E 66 567 N 0 000 E 66 567 0 000 Prime Meridian Atlantic Ocean Norwegian Sea66 34 N 12 3 E 66 567 N 12 050 E 66 567 12 050 Nordland County Norway Norway Islands and skerries of Traena Municipality Nordland County66 34 N 12 18 E 66 567 N 12 300 E 66 567 12 300 Norwegian Sea Atlantic Ocean no Norwegian Sea66 34 N 12 29 E 66 567 N 12 483 E 66 567 12 483 Nordland County Norway Norway Islands and skerries of Nesoya Nordland County66 34 N 12 41 E 66 567 N 12 683 E 66 567 12 683 Norwegian Sea Atlantic Ocean no Norwegian Sea66 34 N 12 49 E 66 567 N 12 817 E 66 567 12 817 Nordland County Norway Norway Islands and skerries of Storselsoya Nordland County66 34 N 12 52 E 66 567 N 12 867 E 66 567 12 867 Norwegian Sea Atlantic Ocean no Norwegian Sea66 34 N 12 57 E 66 567 N 12 950 E 66 567 12 950 Nordland County Norway Norway Islands and skerries of Rangsundoya Nordland County including Vikingen island66 34 N 13 3 E 66 567 N 13 050 E 66 567 13 050 Norwegian Sea Atlantic Ocean no Norwegian Sea66 34 N 13 12 E 66 567 N 13 200 E 66 567 13 200 Nordland County Norway Norway Nordland County66 34 N 15 33 E 66 567 N 15 550 E 66 567 15 550 Norrbotten County Sweden Sweden Norrbotten County Provinces of Lapland and Norrbotten 66 34 N 25 50 E 66 567 N 25 833 E 66 567 25 833 Lapland Province Finland Finland Lapland Region crosses Rovaniemi Airport66 34 N 29 28 E 66 567 N 29 467 E 66 567 29 467 Karelia Russia Russia Republic of Karelia66 34 N 31 36 E 66 567 N 31 600 E 66 567 31 600 Murmansk Russia Murmansk Oblast66 34 N 32 37 E 66 567 N 32 617 E 66 567 32 617 Karelia Russia Republic of Karelia66 34 N 33 10 E 66 567 N 33 167 E 66 567 33 167 Murmansk Russia Grand Island Murmansk Oblast66 34 N 33 25 E 66 567 N 33 417 E 66 567 33 417 Kandalaksha Gulf White Sea Arctic Ocean Kandalaksha Gulf White Sea Barents Sea66 34 N 34 28 E 66 567 N 34 467 E 66 567 34 467 Murmansk Oblast Russia Russia Kola Peninsula Murmansk Oblast for about 7 km 4 3 mi 66 34 N 34 38 E 66 567 N 34 633 E 66 567 34 633 Kandalaksha Gulf White Sea Arctic Ocean Kandalaksha Gulf White Sea Barents Sea66 34 N 35 0 E 66 567 N 35 000 E 66 567 35 000 Murmansk Oblast Kola Peninsula Russia Russia Kola Peninsula Murmansk Oblast66 34 N 40 42 E 66 567 N 40 700 E 66 567 40 700 White Sea Arctic Ocean White Sea Barents Sea66 34 N 44 23 E 66 567 N 44 383 E 66 567 44 383 Nenets Autonomous Okrug Russia Russia Nenets Autonomous Okrug66 34 N 50 51 E 66 567 N 50 850 E 66 567 50 850 Komi Republic Russia Komi Republic66 34 N 63 48 E 66 567 N 63 800 E 66 567 63 800 Yamalo Nenets Autonomous Okrug Russia Yamalo Nenets Autonomous Okrug66 34 N 71 5 E 66 567 N 71 083 E 66 567 71 083 Gulf of Ob Arctic Ocean Gulf of Ob Kara Sea66 34 N 72 27 E 66 567 N 72 450 E 66 567 72 450 Yamalo Nenets Autonomous Okrug Russia Russia Yamalo Nenets Autonomous Okrug66 34 N 83 3 E 66 567 N 83 050 E 66 567 83 050 Krasnoyarsk Krai Russia Krasnoyarsk Krai66 34 N 106 18 E 66 567 N 106 300 E 66 567 106 300 Sakha Republic Russia Yukaghir Highlands Sakha Republic66 34 N 158 38 E 66 567 N 158 633 E 66 567 158 633 Chukotka Autonomous Okrug Russia Anadyr Highlands and Chukotka Mountains Chukotka Autonomous Okrug66 34 N 171 1 W 66 567 N 171 017 W 66 567 171 017 Chukchi Sea Arctic Ocean Arctic Ocean Chukchi Sea66 34 N 164 38 W 66 567 N 164 633 W 66 567 164 633 Seward Peninsula Alaska United States United States Seward Peninsula Alaska66 34 N 163 44 W 66 567 N 163 733 W 66 567 163 733 Kotzebue Sound Arctic Ocean Arctic Ocean Kotzebue Sound Chukchi Sea66 34 N 161 56 W 66 567 N 161 933 W 66 567 161 933 Alaska United States United States Alaska passing through Selawik Lake66 34 N 141 0 W 66 567 N 141 000 W 66 567 141 000 Yukon Canada Canada Yukon66 34 N 133 36 W 66 567 N 133 600 W 66 567 133 600 Northwest Territories Canada Northwest Territories passing through Great Bear Lake66 34 N 115 56 W 66 567 N 115 933 W 66 567 115 933 Nunavut Canada Nunavut66 34 N 82 59 W 66 567 N 82 983 W 66 567 82 983 Foxe Basin Hudson Bay Arctic Ocean Foxe Basin66 34 N 73 25 W 66 567 N 73 417 W 66 567 73 417 Baffin Island Nunavut Canada Canada Nunavut Baffin Island passing through Nettilling Lake and Auyuittuq National Park sign location 66 34 N 61 24 W 66 567 N 61 400 W 66 567 61 400 Davis Strait Atlantic Ocean Atlantic Ocean Davis Strait66 34 N 53 16 W 66 567 N 53 267 W 66 567 53 267 Greenland Greenland passing through Kangerlussuaq Fjord and Schweizerland66 34 N 34 9 W 66 567 N 34 150 W 66 567 34 150 Denmark Strait Atlantic Ocean Atlantic Ocean Denmark Strait66 34 N 26 18 W 66 567 N 26 300 W 66 567 26 300 Greenland Sea Greenland Sea66 34 N 18 1 W 66 567 N 18 017 W 66 567 18 017 Grimsey Iceland Iceland Island of Grimsey66 34 N 17 59 W 66 567 N 17 983 W 66 567 17 983 Greenland Sea Atlantic Ocean Atlantic Ocean Greenland Sea66 34 N 12 32 W 66 567 N 12 533 W 66 567 12 533 Norwegian Sea Norwegian SeaGalleryNorthern Polar Circle Globe on Vikingen island marking the Arctic Circle in Norway Arctic Circle sign by the Inland Line railway Sweden The white borderline of the Arctic Circle at the Santa Claus Village in Rovaniemi Finland Arctic Circle sign in the Republic of Karelia Russia Arctic Circle sign by the Yamalo Nenets Autonomous Okrug Russia A sign in the Sakha Republic Yakutia Russia Arctic Circle marker on island of Grimsey in Iceland A sign along the Dalton Highway marking the location of the Arctic Circle in Alaska United States Polcirkeln portal in Gallivare Sweden Arctic Circle line in Rovaniemi Finland c 1865See also60th parallel north Arctic cooperation and politics Arctic haze Circumpolar star Scott Polar Research Institute Territorial claims in the Arctic Tropic of Cancer Tropic of CapricornReferences Arctic FAQ Frequently Asked Questions about the Arctic 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 N B 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 amp Astrophysics 51 1 127 135 Bibcode 1976A amp A 51 127B Liddell Henry Scott Robert Arktikos A Greek English Lexicon Perseus Digital Library Liddell Henry Scott Robert Arktos A Greek English Lexicon Perseus Digital Library Burn Chris The Polar Night PDF The Aurora Research Institute Retrieved 28 September 2015 Vsevolod Lipatov 26 April 2011 Gorod na Polyarnom kruge ToGeo ru in Russian Archived from the original on 8 August 2014 Retrieved 23 July 2021 Nuttall Mark 2004 Encyclopedia of the Arctic Volumes 1 2 and 3 Routledge p 115 ISBN 978 1579584368 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 External linksWikimedia Commons has media related to Arctic Circle Look up arctic circle in Wiktionary the free dictionary Terra Incognita Exploration of the Canadian Arctic Historical essay about early expeditions to the Canadian Arctic illustrated with maps photographs and drawings Temporal Epoch Calculations c 2006 by James Q Jacobs Download Epoch v2009 xls modify D4 Useful constants See Obliquity of the ecliptic
