Polar climate

The polar climate regions are characterized by a lack of warm summers. Every month in a polar climate has an average temperature of less than 10 °C (50 °F). Regions with polar climate cover more than 20% of the Earth’s area. Most of these regions are far from the equator, and in this case, winter days are extremely short and summer days are extremely long (or lasting for the entirety of each season or longer). A polar climate consists of cool summers and very cold winters, which results in treeless tundra, glaciers, or a permanent or semi-permanent layer of ice.

Koppen classification worldmap E
Areas of polar climate according to the Köppen classification: tundra (strong turquoise) and ice cap (light turquoise).
Oblique rays 04 Pengo
Solar radiation has a lower intensity in polar regions because the angle at which it hits the earth is not as direct as at the equator. Another effect is that sunlight has to go through more atmosphere to reach the ground.[1]

Subtypes

There are two types of polar climate: ET, or tundra climate; and EF, or ice cap climate. A tundra climate is characterized by having at least one month whose average temperature is above 0 °C (32 °F), while an ice cap climate has no months above 0 °C (32 °F).[2] In a tundra climate, trees cannot grow, but other specialized plants can grow. In an ice cap climate, no plants can grow, and ice gradually accumulates until it flows elsewhere. Many high altitude locations on Earth have a climate where no month has an average temperature of 10 °C (50 °F) or higher, but as this is due to elevation, this climate is referred to as Alpine climate. Alpine climate can mimic either tundra or ice cap climate.

Locations

Ursus maritimus mother with cub
A polar bear with cub

On Earth, the only continent where the ice cap polar climate is predominant is Antarctica. All but a few isolated coastal areas on the island of Greenland also have the ice cap climate. Coastal regions of Greenland that do not have permanent ice sheets have the less extreme tundra climates. The northernmost part of the Eurasian land mass, from the extreme northeastern coast of Scandinavia and eastwards to the Bering Strait, large areas of northern Siberia and northern Iceland have tundra climate as well. Large areas in northern Canada and northern Alaska have tundra climate, changing to ice cap climate in the most northern parts of Canada. Southernmost South America (Tierra del Fuego where it abuts the Drake Passage) and such subantarctic islands such as the South Shetland Islands and the Falkland Islands have tundra climates of slight thermal range in which no month is as warm as 10 °C (50 °F). These subantarctic lowlands are found closer to the equator than the coastal tundras of the Arctic basin.

Arctic

Arctic big
A map of the Arctic. The red line indicates the 10°C isotherm in July and the white area shows the average minimum extent of sea ice in summer as of 1975.[3]

Some parts of the Arctic are covered by ice (sea ice, glacial ice, or snow) year-round, and nearly all parts of the Arctic experience long periods with some form of ice on the surface. Average January temperatures range from about −40 to 0 °C (−40 to 32 °F), and winter temperatures can drop below −50 °C (−58 °F) over large parts of the Arctic. Average July temperatures range from about −10 to 10 °C (14 to 50 °F), with some land areas occasionally exceeding 30 °C (86 °F) in summer.

The Arctic consists of ocean that is almost surrounded by land. As such, the climate of much of the Arctic is moderated by the ocean water, which can never have a temperature below −2 °C (28 °F). In winter, this relatively warm water, even though covered by the polar ice pack, keeps the North Pole from being the coldest place in the Northern Hemisphere, and it is also part of the reason that Antarctica is so much colder than the Arctic. In summer, the presence of the nearby water keeps coastal areas from warming as much as they might otherwise, just as it does in temperate regions with maritime climates.

Antarctica

The climate of Antarctica is the coldest on Earth. Antarctica has the lowest naturally occurring temperature ever recorded: −89.2 °C (−128.6 °F) at Vostok Station.[4] It is also extremely dry (technically a desert), averaging 166 millimetres (6.5 in) of precipitation per year, as weather fronts rarely penetrate far into the continent.

Quantifying polar climate

There have been several attempts at quantifying what constitutes a polar climate.

Climatologist Wladimir Köppen demonstrated a relationship between the Arctic and Antarctic tree lines and the 10 °C (50 °F) summer isotherm; i.e., places where the average temperature in the warmest calendar month of the year is below 10 °C (50 °F) cannot support forests. See Köppen climate classification for more information.

Otto Nordenskjöld theorized that winter conditions also play a role: His formula is W = 9 − 0.1 C, where W is the average temperature in the warmest month and C the average of the coldest month, both in degrees Celsius. For example, if a particular location had an average temperature of −20 °C (−4 °F) in its coldest month, the warmest month would need to average 11 °C (52 °F) or higher for trees to be able to survive there as 9 − 0.1(−20) = 11. Nordenskiöld's line tends to run to the north of Köppen's near the west coasts of the Northern Hemisphere continents, south of it in the interior sections, and at about the same latitude along the east coasts of both Asia and North America. In the Southern Hemisphere, all of Tierra del Fuego lies outside the polar region in Nordenskiöld's system, but part of the island (including Ushuaia, Argentina) is reckoned as being within the Antarctic under Köppen's.

In 1947, Holdridge improved on these schemes, by defining biotemperature: the mean annual temperature, where all temperatures below 0 °C or 32 °F (and above 30 °C or 86 °F) are treated as 0 °C (because it makes no difference to plant life, being dormant). If the mean biotemperature is between 1.5 and 3 °C (34.7 and 37.4 °F),[5] Holdridge quantifies the climate as subpolar (or alpine, if the low temperature is caused by altitude).

See also

References

  1. ^ Yung, Chung-hoi. "Why is the equator very hot and the poles very cold?". Hong Kong Observatory. Retrieved 2010-12-02.
  2. ^ McKnight, Tom L; Hess, Darrel (2000). "Climate Zones and Types: The Köppen System". Physical Geography: A Landscape Appreciation. Upper Saddle River, NJ: Prentice Hall. pp. 235–7. ISBN 978-0-13-020263-5.
  3. ^  This article incorporates public domain material from the CIA World Factbook website https://web.archive.org/web/20070613024704/https://www.cia.gov/library/publications/the-world-factbook/reference_maps/pdf/arctic.pdf.
  4. ^ Gavin Hudson (2008-12-14). "The Coldest Inhabited Places on Earth". Eco Worldly. Archived from the original on 2008-12-18. Retrieved 2009-02-08.
  5. ^ Jones, Allan. "Biodiversity lectures and practicals". University of Dundee. Archived from the original on 2007-09-29.

External links

Alpine climate

Alpine climate is the average weather (climate) for the regions above the tree line. This climate is also referred to as a mountain climate or highland climate.

Alpine tundra

Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets lower until it reaches sea level, and alpine tundra merges with polar tundra.

The high elevation causes an adverse climate, which is too cold and windy to support tree growth. Alpine tundra transitions to sub-alpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as Krummholz. With increasing elevation it ends at the snow line where snow and ice persist through summer.

Alpine tundra occurs in mountains worldwide. The flora of the alpine tundra is characterized by dwarf shrubs close to the ground. The cold climate of the alpine tundra is caused by adiabatic cooling of air, and is similar to polar climate.

Arctic Alaska

Arctic Alaska or Far North Alaska is a region of the U.S. state of Alaska generally referring to the northern areas on or close to the Arctic Ocean.

It commonly includes North Slope Borough, Northwest Arctic Borough, Nome Census Area, and is sometimes taken to include parts of the Yukon-Koyukuk Census Area. Some notable towns there include Prudhoe Bay, Barrow, Kotzebue, Nome, and Galena.

Most of these communities have no highways and can only be reached by aircraft or snowmobile in good weather. Originally inhabited by various Alaska Native groups living off hunting, whaling, or salmon fishing, modern settlement in Arctic Alaska was driven first by discoveries of gold and later on by the extraction of petroleum.

The ecosystem consists largely of tundra covering mountain ranges and coastal plains which are home to bears, wolves, sheep, oxen, reindeer, and numerous species of birds, the north coast has been defined as the Arctic coastal tundra ecoregion. Arctic Alaska is also the location of the Arctic National Wildlife Refuge, Gates of the Arctic National Park and Preserve, and the National Petroleum Reserve-Alaska. The Arctic experiences midnight sun in the summer and polar night in the winter.

Climate of the United States

The climate of the United States varies due to differences in latitude, and a range of geographic features, including mountains and deserts. Generally, on the mainland, the climate of the U.S. becomes warmer the further south one travels, and drier the further west, until one reaches the West Coast.

West of the 100th meridian, much of the U.S. has a cool to cold semi-arid climate in the interior upper western states, to warm to hot desert and semi-arid climates in the rest of the western and southwestern U.S. East of the 100th meridian, the climate is humid continental in northern areas (locations roughly above 40 north latitude), transitioning into a humid temperate climate from the southern plains, and lower Midwest east to the Middle Atlantic states. A humid subtropical climate is found approximately from southern Oklahoma, eastward to extreme southeast Virginia southward, including the Gulf states and South Atlantic states, extending into south-central Florida. A Mediterranean climate prevails along most of the California coast, while southern Florida has a tropical climate, the warmest region on the US mainland.Higher-elevation areas of the Rocky Mountains, the Wasatch Range, Sierra Nevada, and Cascade Range are alpine. Coastal areas of Oregon and Washington have an oceanic climate. The state of Alaska, on the northwestern corner of the North American continent, is largely dominated by a subarctic climate, but with a subpolar oceanic climate in the southeast (Alaska Panhandle), southwestern peninsula and Aleutian Islands, and a polar climate in the north.

The primary drivers of weather in the contiguous United States are the seasonal change in the solar angle, the migration north/south of the subtropical highs, and the seasonal change in the position of the polar jet stream.

In the Northern Hemisphere summer, the subtropical high pressure systems move northward and closer to the United States mainland. In the Atlantic Ocean, the Bermuda High creates a south-southwest flow of warm, humid air over the southern, eastern and central United States - resulting in warm to hot temperatures, high humidity and occasional to frequent showers and/or thunderstorms. In the Northern Hemisphere summer, high pressure in the Pacific Ocean builds toward the California coast, resulting in a northwesterly airflow, creating the cool, dry, and stable weather conditions prevalent along the West Coast in summer.

In the Northern Hemisphere winter, the subtropical highs retreat southward. The polar jet stream (and associated conflict zone between cold, dry air masses from Canada and warm, moist air masses from the Gulf of Mexico) drops further southward into the United States - bringing major rain, ice and snow events, and much more variable temperatures, with rapid temperature rises and falls not uncommon. Areas in the southern U.S. (Florida, the Gulf Coast, the Desert Southwest, and southern California) however, often have more stable weather, as the polar jet stream's impact does not usually reach that far south.

Weather systems, be they high-pressure systems (anticyclones), low-pressure systems (cyclones) or fronts (boundaries between air masses of differing temperature, humidity and most commonly, both) are faster-moving and more intense in the winter/colder months than in the summer/warmer months, when the belt of lows and storms generally moves into southern Canada.

The Gulf of Alaska is the origination area of many storms that enter the United States. Such "North Pacific lows" enter the U.S. through the Pacific Northwest, then move eastward across the northern Rocky Mountains, northern Great Plains, upper Midwest, Great Lakes and New England states.

Across the central states from late fall to spring, "Panhandle hook" storms move from the central Rockies into the Oklahoma/Texas panhandle areas, then northeast toward the Great Lakes. They generate unusually large temperature contrasts, and often bring copious Gulf moisture northward, resulting sometimes in cold conditions and possibly-heavy snow or ice north and west of the storm track, and warm conditions, heavy rains and potentially-severe thunderstorms south and east of the storm track - often simultaneously. Across the northern states in winter usually from Montana eastward, "Alberta clipper" storms track east and bring light to moderate snowfalls from Montana and the Dakotas across the upper Midwest and Great Lakes states to New England, and often, windy and severe Arctic outbreaks behind them. When winter-season Canadian cold air masses drop unusually far southward, "Gulf lows" can develop in or near the Gulf of Mexico, then track eastward or northeastward across the Southern states, or nearby Gulf or South Atlantic waters. They sometimes bring rain, but can bring snow or ice across the South, mostly in interior or northern areas.

In the cold season (generally November to March), most precipitation occurs in conjunction with organized low-pressure systems and associated fronts. In the summer, storms are much more localized, with short-duration thunderstorms common in many areas east of the 100th meridian and south of 40 latitude. In the warm season, storm systems affecting a large area are less frequent, and weather conditions are more solar {sun} controlled, with the greatest chance for thunderstorm and severe weather activity during peak heating hours, mostly between 3 PM and 9 PM local time. From May to August especially, often-overnight mesoscale-convective-system (MCS) thunderstorm complexes, usually associated with frontal activity, can deliver significant to flooding rainfall amounts from the Dakotas/Nebraska eastward across Iowa/Minnesota to the Great Lakes states. From late summer into fall (mostly August to October), tropical cyclones (hurricanes, tropical storms and tropical depressions) sometimes approach or cross the Gulf and Atlantic states, bringing high winds, heavy rainfall, and storm surges (often topped with battering waves) to coastal areas.

Community Climate System Model

The Community Climate System Model (CCSM) is a coupled global climate model (GCM) developed by the University Corporation for Atmospheric Research (UCAR) with funding from the National Science Foundation (NSF), the Department of Energy (DoE), and the National Aeronautics and Space Administration (NASA). The coupled components include an atmospheric model (Community Atmosphere Model), a land-surface model (Community Land Model), an ocean model (Parallel Ocean Program), and a sea ice model (Community Sea Ice Model). CCSM is maintained by the National Center for Atmospheric Research (NCAR).

Its software design assumes a physical/dynamical component of the climate system and, as a freely available community model, is designed to work on a variety of machine architectures powerful enough to run the model. The CESM codebase is mostly public domain with some segregable components issued under open source and other licenses. The offline chemical transport model has been described as "very efficient".The model includes four submodels (land, sea-ice, ocean and atmosphere) connected by a coupler that exchanges information with the submodels. NCAR suggested that because of this, CCSM cannot be considered a single climate model, but rather a framework for building and testing various climate models.

Elisabeth Isaksson

Elisabeth Isaksson is a Swedish glaciologist and geologist who has researched polar climate history on the basis of ice cores. She has also studied snow and ice pollution on the Norwegian island of Svalbard and has participated in award-winning European projects on Antarctic climate change.

Far North (Russia)

The Extreme North or Far North (Russian: Крайний Север, Дальний Север) is a large part of Russia located mainly north of the Arctic Circle and boasting enormous mineral and natural resources. Its total area is about 5,500,000 square kilometres (2,100,000 sq mi), comprising about one-third of Russia's total area. Formally, the regions of the Extreme North comprise the whole of Yakutia, Magadan Oblast, Chukotka Autonomous Okrug, Kamchatka Krai and Murmansk Oblast, as well as certain parts and cities of Arkhangelsk Oblast, Komi Republic, Tyumen Oblast, Krasnoyarsk Krai, Irkutsk Oblast, Sakhalin Oblast, Khabarovsk Krai, as well as all islands of the Arctic Ocean, its seas, the Bering Sea, and the Sea of Okhotsk.

Due to the harsh conditions of the area, people who work there have traditionally been entitled by the Russian government to higher wages than workers of other regions. As a result of the climate and environment, the indigenous peoples of the area have developed certain genetic differences that allow them to better cope with the region's environment, as do their cultures.

Hovgaard Island (Greenland)

Hovgaard Island (Danish: Hovgaard Ø) is a large uninhabited island of the Greenland Sea, Greenland. The island was named after Andreas Hovgaard, a Polar explorer and officer of the Danish Navy who led an expedition to the Kara Sea on steamship Dijmphna in 1882-83.Polar climate prevails in Hovgaard Island. The average annual temperature in the area is -17 °C. The warmest month is July when the average temperature reaches -2 °C and the coldest is February when the temperature sinks to -29 °C.

Ice cap climate

An ice cap climate is a polar climate where no mean monthly temperature exceeds 0 °C (32 °F). The climate covers areas in or near the polar regions, such as Antarctica and Greenland, as well as many high mountaintops. Such areas are covered by a permanent layer of ice and have no vegetation, but they may have animal life, that usually feeds from the oceans. Ice cap climates are inhospitable to human life. Antarctica, the coldest continent on Earth, sustains no permanent human residents, but has some civil inhabitants in proximity to research stations in coastal settlements that are maritime polar and there are some communities that are situated in a transitional zone between the two climates, but barely qualify as a tundra. Some places like Antarctica had a different climate before having an ice cap climate.

Iqaluit

Iqaluit ( ee-KAL-oo-it; French: [ikalɥi(t)]; Inuktitut: ᐃᖃᓗᐃᑦ [iqaːluit]), meaning "place of fish", is the capital of the Canadian territory of Nunavut, its largest community, and its only city. It was known as Frobisher Bay from 1942 to 1987, after the large bay on the coast of which the city is situated, when the traditional Inuktitut name was restored.

In 1999, Iqaluit was designated the capital of Nunavut after the division of the Northwest Territories into two separate territories. Before this event, Iqaluit was a small city and not well known outside the Canadian Arctic or Canada, with population and economic growth highly limited. This is due to the city's isolation and heavy dependence on expensively imported supplies, as the city, like the rest of Nunavut, has no road, rail, or even ship connections for part of the year to the rest of Canada. The city has a polar climate, influenced by the cold deep waters of the Labrador Current just off Baffin Island; this makes the city of Iqaluit cold, although the city is well south of the Arctic Circle.

As of the 2016 census, the population was 7,740 (Population Centre: 7,082), an increase of 15.5 percent from the 2011 census. Iqaluit has the lowest population of any capital city in Canada. Inhabitants of Iqaluit are called Iqalummiut (singular: Iqalummiuq).

Kenneth M. Golden

Kenneth "Ken" Morgan Golden is an American applied mathematician and Distinguished Professor at the University of Utah. He is recognized as the "Indiana Jones of Mathematics" for his work in polar climate modeling and has traveled to the polar regions eighteen times, in total, to study sea ice.

Microthermal

In climatology, the term microthermal is used to denote the continental climates of Eurasia and North America.

The word microthermal is derived from two Greek words meaning "small" and "heat". This is misleading, however, since the term is intended to describe only the temperature conditions that prevail during the winter months, rather than those of the entire year.

The characteristic feature of the microthermal climate is cold winters — specifically, winters that are cold enough to ensure that snow will remain on the ground continuously for a fixed period of time every year. Conceptually, an average temperature of 0°C or colder is assumed to be necessary to bring this about; thus the climate of a location where at least one full month is this cold is classified as microthermal (however, at least one month in the summer must average 10°C or higher; otherwise the climate would be reckoned as polar). This definition places all of the world's microthermal climates in the Northern Hemisphere, as the absence of broad land masses at upper-middle latitudes in the Southern Hemisphere precludes the existence of such temperature conditions there.

Microthermal climates are typically subdivided into three categories based on the temperature characteristics of the summer season. The southernmost of the three is frequently referred to as the temperate continental climate, and has hot summers — that is to say, at least one month has an average temperature of 22°C (71.6°F) or above. The middle zone is often labelled hemiboreal, and no summer month there has an average temperature as warm as 22°C, but at least four months will average 10°C (50°F) or higher. The northernmost of the three microthermal zones is the subarctic, or boreal zone; there only one to three months will have average temperatures of at least 10°C.

In North America, microthermal climates commence north of Boston along the Atlantic seaboard, this line drifting gradually southward further inland, reaching approximately 38° at the eastern edge of the Rocky Mountains, then curving dramatically northward near the Pacific coast, reaching the Pacific Ocean just south of Juneau, Alaska. In Asia, the latitude at which these climates begin is several degrees lower due to the pervasive influence of the vast Siberian anticyclone, or high-pressure system, and in continental Europe the line actually runs longitudinally rather than latitudinally, cutting through central Poland after beginning north of the Arctic Circle along the Norwegian coast, thereafter moving diagonally across Scandinavia.

The boundary between the microthermal and polar climate zones is farthest north in western Europe (actually within the Arctic Circle there), and farthest south along the east coast of North America (at about 56° North latitude on the central coast of Labrador); it then trends northward across Canada before dropping south again as it courses through Alaska. Throughout most of Siberia, the boundary tends to follow the Arctic Circle fairly closely.

In addition to having various summer temperature regimes, microthermal climates also differ from one another in how much precipitation they receive — such climates may be humid, semiarid or arid. Most of the Turkestan-Gobi desert system has an arid microthermal climate, while the best-known example of the semiarid microthermal climate can be found in the "steppes of Central Asia" immortalized by Russian classical music composer Alexander Borodin.

North American Arctic

The North American Arctic comprises the northern portions of Alaska (USA), Northern Canada and Greenland. Major bodies of water include the Arctic Ocean, Hudson Bay, the Gulf of Alaska and North Atlantic Ocean. The western limit is the Seward Peninsula and the Bering Strait. The southern limit is the Arctic Circle latitude of 66° 33’N, which is the approximate limit of the midnight sun and the polar night.

The Arctic region is defined by environmental limits 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. The area has tundra and polar vegetation.

Payer Peak

Payer Peak, (Danish: Payer Tinde or Payers Fjeld) is a mountain in King Christian X Land, Northeast Greenland. Administratively it is part of the Northeast Greenland National Park zone.

The region around Payer Peak is uninhabited. This mountain is located in the high Arctic zone, where Polar climate prevails. The average annual temperature in the area is −17 °C. The warmest month is June when the average temperature rises to −2 °C and the coldest is November with −23 °C.

Petermann Peak

Petermann Peak, (Danish: Petermann Bjerg), also known as Petermann Fjeld, Petermanns Topp and Petermann Point is a mountain in King Christian X Land, Northeast Greenland. Administratively it is part of the Northeast Greenland National Park zone.

The area around Petermann Peak is uninhabited. This mountain is located in the high Arctic zone, where Polar climate prevails. The average annual temperature in the area is −16 °C. The warmest month is June, when the average temperature rises to −2 °C, and the coldest is January, with −22 °C.

Polar regions of Earth

The polar regions, also called the frigid zones, of Earth are the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitudes are dominated by Earth's polar ice caps: the northern resting on the Arctic Ocean and the southern on the continent of Antarctica.

Tundra

In physical geography, tundra () is a type of biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра (tûndra) from the Kildin Sami word тӯндар (tūndâr) meaning "uplands", "treeless mountain tract". Tundra vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline.

There are three regions and associated types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra.

William Richard Peltier

William Richard Peltier, Ph.D., D.Sc. (hc) [1] (born 1943), is University Professor of Physics at the University of Toronto. He is director of the Centre for Global Change Science [2], past principal investigator of the Polar Climate Stability Network [3], and the Scientific Director of Canada's largest supercomputer centre, SciNet [4]. He is a fellow of the Royal Society of Canada, of the American Geophysical Union, of the American Meteorological Society, and of the Norwegian Academy of Science and Letters..

His research interests include: atmospheric and oceanic waves and turbulence, geophysical fluid dynamics, physics of the planetary interior, and planetary climate.

He is notable for his seminal contributions to the understanding of the dynamics of the deep Earth, both concerning the nature of the mantle convection process and the circulation of the visco-elastic interior caused by the loading of the surface by continental scale ice sheet loads. His gravitationally self-consistent global theory of Ice-Earth-Ocean interactions has become widely employed internationally in the explanation of the changes of sea level that accompany both the growth and decay of grounded ice on the continents, both during the Late Quaternary era of Earth history and under modern global warming conditions. His models of the space-time variations of continental ice cover since the last maximum of glaciation are employed universally to provide the boundary conditions needed to enable modern coupled climate models to be employed to reconstruct past climate conditions. A most notable contribution to work of this kind has been his theory of the so-called Dansgaard-Oeschger millenial timescale oscillation of glacial climate. He has been the primary contributor to the global reconstructions ICE-3G, ICE-4G, ICE-5G (VM2), and the most recent ICE-6G (VM5)model. These models are important for the quantification of post-glacial rebound and late Pleistocene to Holocene variations in sea level.

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