Arctic
hideThe Arctic (pronounced /ˈɑrktɪk/ or /ˈɑrtɪk/) is the region around the Earth's North Pole, opposite the Antarctic region around the South Pole. The Arctic includes the Arctic Ocean (which overlies the North Pole) and parts of Canada, Greenland (a territory of Denmark), Russia, the United States (Alaska), Iceland, Norway, Sweden and Finland.
The word Arctic comes from the Greek αρκτικός (arktikos), "near the Bear, arctic, northern" and that from the word άρκτος (arktos), which means bear. The name refers either to the constellation Ursa Major, the "Great Bear", which is prominent in the northern portion of the celestial sphere, or to the constellation Ursa Minor, the "Little Bear", which contains Polaris, the Pole Star, also known as the North Star.[citation needed]
The Arctic region can be defined as the area north of the Arctic Circle (66° 33’N), which is the approximate limit of the midnight sun and the polar night. Alternatively, it can be defined as the region where the average temperature for the warmest month (July) is below 10 °C (50 °F); the northernmost tree line roughly follows the isotherm at the boundary of this region. Socially and politically, the Arctic region includes the northern territories of the eight Arctic states, including Sapmi, although by natural science definitions much of this territory is considered subarctic.
The Arctic region consists of a vast, ice-covered ocean (which is sometimes considered to be a northern arm of the Atlantic Ocean) surrounded by treeless permafrost. In recent years the extent of the sea ice has declined. Life in the Arctic includes organisms living in the ice, zooplankton and phytoplankton, fish and marine mammals, birds, land animals, plants, and human societies.
The Arctic region is a unique area among Earth's ecosystems. The cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions.
Due to the poleward migration of the planet's isotherms (about 35 miles per decade during the past 30 years as a consequence of global warming), the Arctic region (as defined by tree line and temperature) is currently shrinking. Perhaps the most spectacular result of Arctic shrinkage is sea ice loss. There is a large variance in predictions of Arctic sea ice loss, with models showing near-complete to complete loss in September from 2040 to some time well beyond 2100. About half of the analyzed models show near-complete to complete sea ice loss in September by the year 2100.
For more information about Arctic, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with arctic
Cave study links climate change to California droughts
Space & Earth / Earth Sciences
Nov 10, 2009 |
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California experienced centuries-long droughts in the past 20,000 years that coincided with the thawing of ice caps in the Arctic, according to a new study by UC Davis doctoral student Jessica Oster and geology professor ...
Tackling new Arctic challenges from space
Nov 05, 2009 |
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International scientists, researchers and decision makers met at the 'Space and the Arctic workshop' to identify the needs and challenges of working and living in the rapidly changing Arctic and to explore how space-based ...
Canada, Greenland accord to protect polar bears
Oct 31, 2009 |
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Canada and Greenland agreed on a series of measures aimed at protecting shared populations of polar bears which roam between the Nunavut territory and the huge arctic island, officials said.
Life's Ancient Island in the Ice
Space & Earth / Earth Sciences
Oct 29, 2009 |
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During the last ice age, massive glaciers covered much of our planet. However, a region of Alaska, Siberia and the Canadian Yukon remained ice-free. This region, known as Beringia, supported unique organisms ...
Feds designate polar bear habitat in Alaska
Oct 22, 2009 |
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(AP) -- The Obama administration said Thursday it is designating more than 200,000 square miles in Alaska and off its coast as "critical habitat" for polar bears, an action that could add restrictions to ...
Arctic lake sediments show warming, unique ecological changes in recent decades
Space & Earth / Earth Sciences
Oct 19, 2009 |
4 / 5 (9) |
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An analysis of sediment cores indicates that biological and chemical changes occurring at a remote Arctic lake are unprecedented over the past 200,000 years and likely are the result of human-caused climate ...
Arctic ice cap 'to disappear in future summers'
Space & Earth / Earth Sciences
Oct 15, 2009 |
2.7 / 5 (31) |
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The Arctic ice cap will disappear completely in summer months within 20 to 30 years, a polar research team said as they presented findings from an expedition led by adventurer Pen Hadow.
Arctic land and seas account for up to 25 percent of world's carbon sink
Space & Earth / Earth Sciences
Oct 14, 2009 |
3.1 / 5 (8) |
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In a new study in the journal Ecological Monographs, ecologists estimate that Arctic lands and oceans are responsible for up to 25 percent of the global net sink of atmospheric carbon dioxide. Under curren ...
Arctic sea ice recovers slightly in 2009, remains on downward trend (w/ Video)
Space & Earth / Earth Sciences
Oct 06, 2009 |
2.4 / 5 (14) |
8
(PhysOrg.com) -- Despite a slight recovery in summer Arctic sea ice in 2009 from record-setting low years in 2007 and 2008, the sea ice extent remains significantly below previous years and remains on a trend ...
Planned emission cuts still mean far hotter Earth
Sep 24, 2009 |
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(AP) -- Earth's temperature is likely to jump nearly 6 degrees between now and the end of the century even if every country cuts greenhouse gas emissions as proposed, according to a United Nations update.
Warming ocean melts Greenland glaciers
Space & Earth / Earth Sciences
Sep 23, 2009 |
2.4 / 5 (9) |
4
(AP) -- With whale fins splashing in the distance, Ruth Curry hauls up her catch from the blustery deck of an icebreaker.
Northern brown bears discovered feeding on whitefish runs
Sep 22, 2009 |
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The discovery of brown (grizzly) bears feeding on migrating broad whitefish in a stream in Mackenzie Delta region of the Northwest Territories has researchers advising increased care in petroleum extraction and infrastructure ...
Arctic ice pack at third lowest extent since 1979: US
Space & Earth / Earth Sciences
Sep 18, 2009 |
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The Arctic sea ice pack thawed to its third smallest size on record during the northern hemisphere summer of 2009, US government scientists said, citing satellite images.
Understand the Arctic before exploiting it
Sep 18, 2009 |
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America's Arctic has long been a place of myth and dream, where the Inupiat Eskimos have thrived, explorers endured and artists found inspiration. While competing visions of the Arctic have clashed in the past, we are now ...
Carcasses of dead walruses spotted on Alaska coast
Sep 17, 2009 |
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(AP) -- Up to 200 dead walruses have been spotted on the shore of Chukchi Sea on Alaska's northwest coast.
