Arctic

The Arctic (pron.: / ˈ ɑr k t ɪ k / or / ˈ ɑr t ɪ k /) is a polar region located at the northernmost part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Denmark (Greenland), Norway, the United States ( Alaska), Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost. The area can be defined as north of the Arctic Circle (66° 33'N), 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, although by natural science definitions much of this territory is considered subarctic. 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. 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.

Etymology

The word Arctic comes from the Greek ἀρκτικός (arktikos), "near the Bear, arctic, northern" and that from the word ἄρκτος (arktos), meaning 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.

Climate

The Arctic's climate is characterized by cold winters and cool summers. Precipitation mostly comes in the form of snow. The Arctic's annual precipitation is low, with most of the area receiving less than 50 cm (20 in). High winds often stir up snow, creating the illusion of continuous snowfall. Average winter temperatures can be as low as −40 °C (−40 °F), and the coldest recorded temperature is approximately −68 °C (−90 °F). Coastal Arctic climates are moderated by oceanic influences, having generally warmer temperatures and heavier snowfalls than the colder and drier interior areas. The Arctic is affected by current global warming, leading to Arctic sea ice shrinkage and Arctic methane release.

Due to the poleward migration of the planet's isotherms (about 35 mi (56 km) 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.

Biota

Plants

Arctic vegetation is composed of plants such as dwarf shrubs, graminoids, herbs, lichens and mosses, which all grow relatively close to the ground, forming tundra. As one moves northward, the amount of warmth available for plant growth decreases considerably. In the northernmost areas, plants are at their metabolic limits, and small differences in the total amount of summer warmth make large differences in the amount of energy available for maintenance, growth and reproduction. Colder summer temperatures cause the size, abundance, productivity and variety of plants to decrease. Trees cannot grow in the Arctic, but in its warmest parts, shrubs are common and can reach 2 m (6 ft 7 in) in height; sedges, mosses and lichens can form thick layers. In the coldest parts of the Arctic, much of the ground is bare; non-vascular plants such as lichens and mosses predominate, along with a few scattered grasses and forbs (like the arctic poppy).

Animals

Herbivores on the tundra include the Arctic hare, lemming, muskox, and caribou. They are preyed on by the Arctic fox and wolf. The polar bear is also a predator, though it prefers to hunt for marine life from the ice. There are also many birds and marine species endemic to the colder regions. Other land animals include wolverines, ermines, and Arctic ground squirrels. Marine mammals include seals, walrus, and several species of cetacean— baleen whales and also narwhals, killer whales and belugas.

Paleo-history

During the Cretaceous, the Arctic still had seasonal snows, though only a light dusting and not enough to permanently hinder plant growth. Animals such as Chasmosaurus, Hypacrosaurus, Troodon, and Edmontosaurus may have all migrated north to take advantage of the summer growing season, and migrated south to warmer climes when the winter came. A similar situation may also have been found amongst dinosaurs that lived in Antarctic regions, such as Muttaburrasaurus of Australia.

Indigenous population

The earliest inhabitants of North America's central and eastern Arctic are referred to as the Arctic small tool tradition (AST) and existed c. 2500 BC. AST consisted of several Paleo-Eskimo cultures, including the Independence cultures and Pre-Dorset culture. The Dorset culture ( Inuktitut: Tuniit or Tunit) refers to the next inhabitants of central and eastern Arctic. The Dorset culture evolved because of technological and economic changes during the period of 1050–550 BC. With the exception of the Quebec/ Labrador peninsula, the Dorset culture vanished around 1500 AD. Supported by genetic testing, evidence shows that Dorset culture, known as the Sadlermiut, survived in Aivilik, Southampton and Coats Islands, until the beginning of the 20th century.

Dorset/ Thule culture transition dates around the 9th–10th centuries. Scientists theorize that there may have been cross-contact of the two cultures with sharing of technology, such as fashioning harpoon heads, or the Thule may have found Dorset remnants and adapted their ways with the predecessor culture. Others believe the Thule displaced the Dorset. By 1300, the Inuit, present-day Arctic inhabitants and descendants of Thule culture, had settled in west Greenland, and moved into east Greenland over the following century. Over time, the Inuit have migrated throughout the Arctic regions of Canada, Greenland, Russia and the United States.

Other Circumpolar North indigenous peoples include the Buryat, Chukchi, Evenks, Inupiat, Khanty, Koryaks, Nenets, Sami, Yukaghir, and Yupik, who still refer to themselves as Eskimo which means "snowshoe netters", not "raw meat eaters" as it is sometimes mistakenly translated.

International cooperation and politics

The eight Arctic nations (Canada, Denmark (Greenland & The Faroe Islands), Finland, Iceland, Norway, Sweden, Russia, and USA) are all members of the Arctic Council, as are organizations representing six indigenous populations. The Council operates on consensus basis, mostly dealing with environmental treaties and not addressing boundary or resource disputes.

Though Arctic policy priorities differ, every Arctic nation is concerned about sovereignty/defense, resource development, shipping routes, and environmental protection. Much work remains on regulatory agreements regarding shipping, tourism, and resource development in Arctic waters.

Research in the Arctic has long been a collaborative international effort, evidenced perhaps most notably by the International Polar Year. The International Arctic Science Committee, hundreds of scientists and specialists of the Arctic Council, and the Barents Euro-Arctic Council are more examples of collaborative international Arctic research.

Territorial claims

No country owns the geographic North Pole or the region of the Arctic Ocean surrounding it. The surrounding Arctic states that border the Arctic Ocean — Canada, Denmark (via Greenland), Iceland, Norway, Russia, and the United States —are limited to a 200 nautical miles (370 km; 230 mi) economic zone around their coasts.

Upon ratification of the United Nations Convention on the Law of the Sea, a country has ten years to make claims to an extended continental shelf beyond its 200 nautical mile zone. Due to this, Norway (which ratified the convention in 1996), Russia (ratified in 1997), Canada (ratified in 2003) and Denmark (ratified in 2004) launched projects to establish claims that certain Arctic sectors should belong to their territories.

On August 2, 2007, two Russian bathyscaphes, MIR-1 and MIR-2, for the first time in history descended to the Arctic seabed beneath the North Pole and placed there a Russian flag made of rust-proof titanium alloy. The mission was a scientific expedition, but the flag-placing during Arktika 2007, raised concerns of a race for control of the Arctic's vast petroleum resources.

Foreign ministers and other officials representing Canada, Denmark, Norway, Russia, and the United States met in Ilulissat, Greenland on May 28, 2008 at the Arctic Ocean Conference and announced the Ilulissat Declaration, blocking any "new comprehensive international legal regime to govern the Arctic Ocean," and pledging "the orderly settlement of any possible overlapping claims."

As of 2012, Denmark is claiming the continental shelf between Greenland and the North Pole.

Exploration

Since 1937, the whole Arctic region has been extensively explored by Soviet and Russian manned drifting ice stations. Between 1937 and 1991, 88 international polar crews established and occupied scientific settlements on the drift ice and were carried thousands of kilometers by the ice flow.

Pollution

The Arctic is comparatively clean, although there are certain ecologically difficult localized pollution problems that present a serious threat to people’s health living around these pollution sources. Due to the prevailing worldwide sea and air currents, the Arctic area is the fallout region for long-range transport pollutants, and in some places the concentrations exceed the levels of densely populated urban areas. An example of this is the phenomenon of Arctic haze, which is commonly blamed on long-range pollutants. Another example is with the bioaccumulation of PCB's ( polychlorinated biphenyls) in Arctic wildlife and people.

Preservation

There have been many proposals to preserve the Arctic over the years. Most recently a group of stars at the Rio Earth Summit, on June 21, 2012, proposed protecting the Arctic, similar to the Antarctic protection. The initial focus of the campaign will be a UN resolution creating a global sanctuary around the pole, and a ban on oil drilling and unsustainable fishing in the Arctic.

Climate change

The Arctic is especially vulnerable to the effects of global warming, as has become apparent in the melting sea ice in recent years. Climate models predict much greater warming in the Arctic than the global average, resulting in significant international attention to the region. In particular, there are concerns that Arctic shrinkage, a consequence of melting glaciers and other ice in Greenland, could soon contribute to a substantial rise in sea levels worldwide. The climate models on which the IPCC report Nr.4 is based, give a range of predictions of Arctic sea ice loss, showing near-complete to complete loss in September anywhere 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. More recently, the Catlin Arctic Survey concluded that summer ice loss would occur around 2029. It has been apparent though since 2007, that those models grossly underestimate sea ice loss.

A good source for the measurement of arctic sea ice can be found here:.

As can be seen in the two plot at the right, since about 1995 to 2000, all three size numbers of the arctic sea ice shield (extent, area and volume) are decreasing in an accelerated way (extent can be seen here: ). This downward movement is modulated by statistical variations, which lead to considerable media attention, when a new record has been reached.

Concerning melting records, 2012 was a productive year, thus corroborating the tendency of the past decade. This may have been furthered by a strong summer storm cyclone, a rare event in the arctic, which spread the already very thin ice and caused mixing of the cold surface waters with deeper warmer water layers. According to the University of Bremen, in September 2011 the Arctic ice cap was smaller than ever before recorded since the satellite measurements started in the 1970s. Arctic ice is declining in area and thinning. Arctic temperatures have risen more than twice as fast as the global average over the past half century. The speed of change has shocked scientists. If current trends continue, a largely ice-free Arctic in the summer is likely within 30 years – up to 40 years earlier than was anticipated by the IPCC Fourth Assessment Report.

As the volume of sea ice until recently could not be measured by remote sensing as easy as its extent, numerical models have been made to estimate the ice thickness field between known points, which then is summed up to yield ice volume. The resulting volume over time – plot reveals a much stronger loss of ice than ice extent studies suggest.

The current Arctic shrinkage is leading to fears of Arctic methane release. Release of methane stored in permafrost could cause abrupt and severe global warming, as methane is a potent greenhouse gas. On millennial time-scales, decomposition of methane hydrates in the Arctic seabed could also amplify global warming. Previous methane release events have been linked to the great dying, a mass extinction event at the boundary of the Permian and Triassic, and the Paleocene–Eocene Thermal Maximum, in which temperatures abruptly increased.

Apart from concerns regarding the detrimental effects of warming in the Arctic, some potential opportunities have gained attention as well. The melting of the ice is making the Northwest Passage, the shipping routes through the northernmost latitudes, more navigable, raising the possibility that the Arctic region will become a prime trade route. In addition, it is believed that the Arctic seabed may contain substantial oil fields which may become accessible if the ice covering them melts. These factors have led to recent international debates as to which nations can claim sovereignty or ownership over the waters of the Arctic.

The National Oceanic and Atmospheric Administration's Arctic Report Card presents annually updated, peer-reviewed information on recent observations of environmental conditions in the Arctic relative to historical records.

Arctic waters

Arctic lands

Geographic Designation	National Affiliation	Designation
Alaska	United States	State
Aleutian Islands	United States	Alaskan Archipelago
Arkhangelsk Oblast	Russia	Federal subject
Canadian Arctic Archipelago	Canada	Canadian Archipelago
Diomede Island (Big)	Russia	Island
Diomede Island (Little)	United States	Island
Finnmark	Norway	County
Franz Josef Land	Russia	Federal subject archipelago
Greenland	Denmark	Autonomous country
Grímsey	Iceland	Island
Jan Mayen	Norway	Island
Lapland	Finland	Region
Lapland	Sweden	Province
New Siberian Islands	Russia	Archipelago
Nordland	Norway	County
Norrbotten	Sweden	Province
Northwest Territories	Canada	Territory
Novaya Zemlya	Russia	Federal subject archipelago
Nunavik	Canada	Northern part of Quebec
Nunavut	Canada	Territory
Russian Arctic islands	Russia	Islands
Sápmi	Norway, Sweden, Finland, Russia	Fennoscandia region
Severnaya Zemlya	Russia	Federal subject archipelago
Siberia	Russia	Region
Svalbard	Norway	Governor of Svalbard archipelago
Troms	Norway	County
Yukon	Canada	Territory
Wrangel Island	Russia	Zapovednik (nature reserve)