
Location of the polar regions

Northern Hemisphere permafrost (permanently frozen ground) in purple.
Earth's 'polar regions' are the areas of the globe surrounding the
poles also known as
frigid zones. The
North Pole and
South Pole being the centers, these regions are dominated by the
polar ice caps, resting respectively on the
Arctic Ocean and the continent of
Antarctica. Polar
sea ice is currently diminishing, possibly as a result of
anthropogenic global warming.
Definitions
The
Arctic has numerous definitions, including the region north of the
Arctic Circle (66-33N), or the region north of 60 degrees
north latitude, or the region from the North Pole south to the
timberline.
The
Antarctic is usually defined as south of 60 degrees
south latitude, or the continent of Antarctica. The 1959
Antarctic Treaty uses the former definition.
Climate
Main articles: Polar climate
|Solar radiation in polar regions has a lower intensity because it travels a longer distance through the atmosphere, and is spread across a larger surface area.]]
Polar regions receive less intense
solar radiation because the sun's energy arrives at an oblique angle, spreading over a larger area, and also travels a longer distance through the Earth's atmosphere in which it may be absorbed, scattered or reflected.
The
axial tilt of the Earth has a major
effect on climate of the polar regions. Since the polar regions are the farthest from the
equator, they receive the least amount of sunlight and are therefore frigid. The large amount of ice and snow also reflects a large part of what little sunlight the Polar regions receive, contributing to the cold. Polar regions are characterized by the
polar climate, extremely cold temperatures, heavy
glaciation wherever there is sufficient
precipitation to form permanent ice, and extreme variations in daylight hours, with twenty-four hours of daylight in
summer (the
midnight sun), and darkness at
mid-winter.
Circumpolar Arctic Region
There are many settlements in Earth's north polar region. Countries with claims to arctic regions are: the
United States (
Alaska),
Canada,
Denmark (
Greenland),
Norway, and
Russia. Arctic circumpolar populations often share more in common which each other than with other populations within their national boundaries. As such, the northern polar region is diverse in human settlements and cultures.
Antarctica and the Southern Ocean
The southern polar region has no permanent human habitation.
McMurdo Station is the largest research station in
Antarctica, run by the
United States. Other notable stations include
Palmer Station and
Amundsen-Scott South Pole Station (United States),
Esperanza Base and
Marambio Base (
Argentina),
Scott Base (
New Zealand), and
Vostok Station (Russia).
While there are no indigenous human cultures, there is a complex ecosystem, especially along Antarctica's coastal zones. Coastal
upwelling provides abundant nutrients which feeds
krill, a type of marine crustacea, which in turn feeds a complex of living creatures from penguins to blue whales.
Non-Earth Polar Regions
Other
planets and
natural satellites in the
solar system have interesting quirks about their polar regions. Earth's
Moon is thought to contain substantial deposits of
ice in deep craters in its polar regions, which never see direct
sunlight.
Mars, like Earth, has
polar ice caps. On
Uranus, meanwhile, the extreme tilt of the planet's axis leads to the poles alternately pointing almost directly at the
Sun.
See also
Antarctic
★
Antarctica
★
Ecozone of Antarctica
★
Expeditions of Antarctica
★
Geography of Antarctica
★
★
Antarctic & Sub-Antarctic Islands
Arctic
★
Arctic
★
Arctic Circle
★
Arctic Ocean
★
Canadian Arctic Archipelago
Polar
★
Geographical Pole
★
★
North Pole
★
★
South Pole
★
Geographical Zone
★
Polar Drift
★
Polar Exploration
★
Polar Low
External links
★
★
The Polar Regions
★
International Polar Foundation
★
Arctic Environmental Atlas (UNDP)
★
Earth's Polar Regions on Windows to the Universe
★
Arctic Studies Center, Smithsonian Institution
★
WWF:The Polar Regions
★
World Environment Day 2007 "Melting Ice" image gallery at The Guardian
Gallery