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The North American Arctic is composed of the northern polar regions of Alaska (USA), Northern Canada and Greenland. [1] Major bodies of water include the Arctic Ocean, Hudson Bay, the Gulf of Alaska and North Atlantic Ocean. [2] The North American Arctic lies above the Arctic Circle. [3] It is part of the Arctic, which is the northernmost region on Earth. 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. [4]
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. [3] The climate of the region is known to be intensely cold during the year due to its extreme polar location. [5] The area has tundra, Arctic vegetation, [3] glaciers, and, for most of the year, is covered in thick blankets of snow and ice. [5]
It is home to various species of plants, and land, air and marine animals. [6] Due to the severe weather conditions, the region's flora and fauna has had to adapt to survive. [6] In addition to the extreme climate, permafrost and short growing seasons means that trees are unable to grow. [3] The indigenous peoples who migrated from other lands and settled in the North American Arctic also had to adapt to living conditions. [5] Their population has declined since then, however. [5] [ page needed ]
Climate change in the Arctic has caused the region to feel the effects of global warming, with sea levels and temperatures rising, and a changing wildlife population. [4] Marine ecosystems are struggling under increasing pressure from changes in sea ice characteristics. [7] The effects of climate change have also impacted the human population whose way of living and working is facing pressure from the effects as they are finding it challenging to adapt. [4]
The North American Arctic geographical region consists of large land masses. [2] A major portion of the region also consists of large bodies of water. [2] This region is a relatively flat topographic part of the Earth. [2] Since the region is located in an extreme northerly part of the Earth, the sun may only appear above the horizon for a couple of hours during winter while appearing for longer during summer. [5]
The major lands that make up the North American Arctic from west to east are:
Name of land | Country |
---|---|
Alaska | United States |
Yukon, Northwest Territories, Nunavut | Canada |
Greenland | Denmark |
Alaska has endless lowlands and plains. [3] On the northern coast of Alaska, there is a 67-day-long period of darkness which begins in mid-November and ends in February. [5] An 84-day-long period of light begins in early May and finishes in July. [5]
The Arctic portion in Northern Canada covers around a quarter of Canada's landmass at 1.6 million square kilometres (0.62 million square miles). [6] The human population density is one of the lowest on Earth and sits at 1 person per 100 km2. [6] It consists of some of the world's most uninhabitable places yet also is home to extensive herds of caribou. [6] It also contains vast ice fields, mountain glaciers, mountain peaks, shattered rock, ponds, lakes and U-shaped valleys. [6] This region supports approximately 140 species of vascular plants and 600 species of mosses and lichens. [6] There are about 20 species of mammals and 80 bird species. [6]
Greenland is considered an alpine region of the North American Arctic. [3] Vegetation that grows in this area is confined to mostly narrow coastal ice-free fringes which constitutes about 14% of the total area. [3] Poor floras occur in the colder coastal areas in the northern parts of the country while rich floras occur in the southwest parts and inland in the south. [3]
The North American Arctic consists of some of the following major bodies of water:
The North American Arctic's climate is characterized by extremely cold temperatures throughout the year. [5] [ failed verification ] It also experiences high seasonal fluctuations in daylight, and severe winds due to the Earth's tilt and its polar location. [5] During the year, temperatures can span a widespread range with average lows that reach around −38 °C (−36 °F) in winter to average highs that reach approximately 10 °C (50 °F) in summer. [5] [6] The warmest month is July while the coldest month is January. [5] Winters have long dark days without sunlight while summers have days where the sun doesn't set. [5] Parts of the region are covered in ice for most of the year and it can snow during any month of the year and the average annual precipitation is 250 mm (9.8 in). [5] [6]
The region has an abundance of wildlife that has adapted to its intense conditions, ranging from large mammals such as polar bears and muskox, to small birds, and various species of plants. [6] Marine life includes walrus, seals, fish and microscopic ocean organisms such as algae and plankton. [6] The many lakes and rivers are home to fish species such as Arctic char and lake trout.
Major types of vegetation of the North American Arctic include tundra, polar desert and polar semi-deserts with minor ones being coastal salt marshes and grasslands. [3] Flora must try to grow in a harsh environment that experiences continuous sunlight during the summer, and low temperatures, dry winds, heavy snow and frozen ground and soil throughout the year. [5] Freezing and thawing of soil affects vegetation patterns as it results in formations of patterned ground such as circles, nets and stone stripes. [3] Both plant diversity and species are relatively low in numbers due to lack of nutrient availability. [3] [6] There is evidence that shows that diversity of species in the region is strongly correlated to warmer temperatures. [3]
Due to permafrost, a short growing season, and dark and long winters of strong winds and extreme cold, the region experiences being almost treeless with only vegetation such as moss and lichen being able to live. [3] Although not many species of plants succeed in surviving in this environment, the ones that do tend to be small and have a short seasonal life cycle, with the exception of algae which has been observed to have the ability to survive all year round. [5] Even though annual precipitation is extremely low, there are numerous lakes, ponds and wetlands that are able to support relatively lush vegetation. [6] The cycle often begins in spring, with major growth during July before the end of August when winter is about to arrive and ends the cycle. [3]
Plants that have adapted to the climate in the region have the ability to grow rapidly in the small timeframe of prime growing conditions in summer due to their ability to conserve water. [5] Plants avoid the harsh wind and chill by growing close to the ground and cluster densely. [6] Other ways that plants have adapted include having a smaller surface area to lessen water evaporation, vertical leaves to aid in receiving more sunlight, waxy leaves to assist in moisture retention, and antifreeze to enable them to continue photosynthesis under freezing conditions. [5]
Compared to warmer regions of the Earth, fauna species in the North American Arctic are small but populations are large. [6] The animal population can either hibernate if conditions allow it or has to remain active as it is unable to hibernate due to absence of ice-free shelter in the region. [6] This is also the reason why there aren't any reptiles and only a small number of amphibians. [6] Though numbers are depleting, the region is home to other marine life such as different species of whales and seals. [6] The region supports an enormous population of migratory birds that migrate to the region in the summer for breeding and many large fisheries. [6] Due to ice melting and turning into ponds during summer, the ecosystem also sees insects including moths and mosquitoes. [6]
Some animals have adapted to the conditions in the region by conserving heat, with many species covered in heavy fur coats and having thick layers of fat beneath the skin while others have developed compact body shapes. [5] They are characterized as having shorter legs and tails, and smaller ears compared to their relatives. [6] Many species of animals have stiff fur on their feet to create a barrier between their pads and toes, and the snow which allows them to walk more easily. [6] Despite almost being frozen, some insects can survive by going into a dormant state and allowing their naturally occurring antifreeze-like compounds to take effect. [5] The most common coping strategy, however, is to migrate seasonally and find a more suitable habitat for the winter, which can commonly be seen in birds. [5]
Animals have a small window of opportunity to successfully reproduce and birth of their young has to coincide with the abundance of prey otherwise the food chain will be disrupted. [6] Species that have adapted well tend to dominate the food chain. [6]
The population of the region is sparse, and its people are thought to be descendants of people who migrated northward from central Asia after the Ice Age. [5] They include the Inuit, Yupik, Aleut, Athabascans and Iñupiat. [5] [6] After living in the North American Arctic for over thousands of years, they have developed unique traditions in order to adapt to the extreme climate conditions such as hunting animals and fishing during specific times of the year and gathering and preserving plants over the summer in preparation for winter. [5] They constructed tents, clothes, tools and weapons out of animal skin, antlers, teeth, horns and bones. [5]
Due to Western culture, native peoples now make up approximately 16% of the population of Alaska and they now live in wooden homes, and purchase clothing and food. [5] Climate change has also affected the traditional way of life, which doesn't exist for most anymore, as melting ice has impacted hunting and fishing. [4] Some communities are under threat from coastal erosion and it has already driven other communities to relocate. [4]
Climate change, which is a phenomenon also known as the greenhouse effect, is the warming that occurs when certain gases in the atmosphere prevent heat from escaping. [8] The North American Arctic is particularly susceptible to the effects of climate change compared to other regions. [4] Climate change has caused the temperature in the region to rise, extreme weather events, changing wildlife populations and habitats, and sea ice to melt resulting in rising sea levels. [8] [9] In November 2016, the daily average temperature was 2.22 °C (36.00 °F) lower than usual and sea ice cover was less than the previous recorded low in November 2012. [4]
Ice sheets have been observed to form later, separate earlier, and rapidly decline in age, thickness distribution and regional coverage. [7] The ice in the southern Beaufort Sea separates 7 weeks earlier than it used to during 1964 to 1974. [7] An instance of climate change contributing to ice loss was the 13th most extreme Arctic storm recorded that impacted sea ice in the Beaufort and Chukchi seas. [7] In 2012, a cyclone had formed over Siberia and ended in the Canadian Arctic Archipelago during a period where large wave generation, oceanic upwelling, and mechanical forcing affected the ocean and its covering ice sheets. [7]
There is also potential for carbon dioxide and methane levels to rise in the atmosphere as a result of increased production by micro-organisms in thawing permafrost. [7] Climate change will significantly impact the plant species by causing an increase of shrubs, which will disrupt the regional vegetation, and a decrease in certain species of flora. [9] It has also caused a decline in survival rates of fauna which will cause a heavy strain on the ecosystem. [6]
Climate change in the region has attracted worldwide attention and interest in reduction of effects. [4] This is because effects to the North American Arctic has direct consequences on the rest of the world including sea levels rising worldwide. [4] The rising of sea levels is a critical issue as the region plays a role in the ventilation of the Atlantic and Pacific, and due to the impact that melting sea ice has on the acceleration of global warming and increased fluxes of green house gases into the atmosphere. [7]
In physical geography, tundra is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra.
Taiga or tayga, also known as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga or boreal forest is the world's largest land biome. In North America, it covers most of inland Canada, Alaska, and parts of the northern contiguous United States. In Eurasia, it covers most of Sweden, Finland, much of Russia from Karelia in the west to the Pacific Ocean, much of Norway and Estonia, some of the Scottish Highlands, some lowland/coastal areas of Iceland, and areas of northern Kazakhstan, northern Mongolia, and northern Japan.
The Arctic is a polar region located at the northernmost part of Earth. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway, northernmost Sweden, northern Finland, Russia, the United States (Alaska), Canada, Danish Realm (Greenland), and northern Iceland, along with the Arctic Ocean and adjacent seas. Land within the Arctic region has seasonally varying snow and ice cover, with predominantly treeless permafrost under the tundra. Arctic seas contain seasonal sea ice in many places.
The polar climate regions are characterized by a lack of warm summers but with varying winters. Every month a polar climate has an average temperature of less than 10 °C (50 °F). Regions with a polar climate cover more than 20% of the Earth's area. Most of these regions are far from the equator and near the poles, and in this case, winter days are extremely short and summer days are extremely long. A polar climate consists of cool summers and very cold winters, which results in treeless tundras, glaciers, or a permanent or semi-permanent layer of ice. It is identified with the letter E in the Köppen climate classification.
Norway is a country located in Northern Europe in the northern and western parts of the Scandinavian Peninsula. The majority of the country borders water, including the Skagerrak inlet to the south, the North Sea to the southwest, the North Atlantic Ocean to the west, and the Barents Sea to the north. It has a land border with Sweden to the east; to the northeast it has a shorter border with Finland and an even shorter border with Russia.
The Arctic National Wildlife Refuge or Arctic Refuge is a national wildlife refuge in northeastern Alaska, United States, on traditional Iñupiaq and Gwich'in lands. The refuge is 19,286,722 acres (78,050.59 km2) of the Alaska North Slope region, with a northern coastline and vast inland forest, taiga, and tundra regions. ANWR is the largest national wildlife refuge in the country, slightly larger than the Yukon Delta National Wildlife Refuge. The refuge is administered from offices in Fairbanks. ANWR is home to a diverse range of endemic mammal species; notably, it is one of the few North American locations with all three endemic American bears—the polar bear, grizzly bear, and American black bear, each of which resides predominantly in its own ecological niche. Besides the bears, other mammal species include the moose, caribou, wolves, red and Arctic fox, Canada lynx, wolverine, pine marten, American beaver, and North American river otter. Further inland, mountain goats may be seen near the slope. Hundreds of species of migratory birds visit the refuge yearly, and it is a vital, protected breeding location for them. Snow geese, eiders and snowy owls may be observed as well.
The ringed seal is an earless seal inhabiting the Arctic and sub-Arctic regions. The ringed seal is a relatively small seal, rarely greater than 1.5 metres (5 ft) in length, with a distinctive patterning of dark spots surrounded by light gray rings, hence its common name. It is the most abundant and wide-ranging ice seal in the Northern Hemisphere, ranging throughout the Arctic Ocean, into the Bering Sea and Okhotsk Sea as far south as the northern coast of Japan in the Pacific and throughout the North Atlantic coasts of Greenland and Scandinavia as far south as Newfoundland, and including two freshwater subspecies in northern Europe. Ringed seals are one of the primary prey of polar bears and killer whales, and have long been a component of the diet of indigenous people of the Arctic.
Yukon is in the northwestern corner of Canada and is bordered by Alaska, British Columbia and the Northwest Territories. The sparsely populated territory abounds with natural scenery, snowmelt lakes and perennial white-capped mountains, including many of Canada's highest mountains. The territory's climate is Arctic in territory north of Old Crow, subarctic in the region, between Whitehorse and Old Crow, and humid continental climate south of Whitehorse and in areas close to the British Columbia border. Most of the territory is boreal forest with tundra being the main vegetation zone only in the extreme north and at high elevations.
Polar ecology is the relationship between plants and animals in a polar environment. Polar environments are in the Arctic and Antarctic regions. Arctic regions are in the Northern Hemisphere, and it contains land and the islands that surrounds it. Antarctica is in the Southern Hemisphere and it also contains the land mass, surrounding islands and the ocean. Polar regions also contain the subantarctic and subarctic zone which separate the polar regions from the temperate regions. Antarctica and the Arctic lie in the polar circles. The polar circles are imaginary lines shown on maps to be the areas that receives less sunlight due to less radiation. These areas either receive sunlight or shade 24 hours a day because of the earth's tilt. Plants and animals in the polar regions are able to withstand living in harsh weather conditions but are facing environmental threats that limit their survival.
The Arctic Cordillera is a terrestrial ecozone in northern Canada characterized by a vast, deeply dissected chain of mountain ranges extending along the northeastern flank of the Canadian Arctic Archipelago from Ellesmere Island to the northeasternmost part of the Labrador Peninsula in northern Labrador and northern Quebec, Canada. It spans most of the eastern coast of Nunavut with high glaciated peaks rising through ice fields and some of Canada's largest ice caps, including the Penny Ice Cap on Baffin Island. It is bounded to the east by Baffin Bay, Davis Strait and the Labrador Sea while its northern portion is bounded by the Arctic Ocean.
Arctic ecology is the scientific study of the relationships between biotic and abiotic factors in the arctic, the region north of the Arctic Circle. This region is characterized by two biomes: taiga and tundra. While the taiga has a more moderate climate and permits a diversity of both non-vascular and vascular plants, the tundra has a limited growing season and stressful growing conditions due to intense cold, low precipitation, and a lack of sunlight throughout the winter. Sensitive ecosystems exist throughout the Arctic region, which are being impacted dramatically by global warming.
About 1,702 species of plants live on the Arctic tundra, including flowering plants, short shrubs, herbs, grasses, and mosses. These plants are adapted to short, cold growing seasons. They have the ability to withstand extremely cold temperatures in the winter, and grow and reproduce in summer conditions that are quite limiting.
Due to climate change in the Arctic, this polar region is expected to become "profoundly different" by 2050. The speed of change is "among the highest in the world", with the rate of warming being 3-4 times faster than the global average. This warming has already resulted in the profound Arctic sea ice decline, the accelerating melting of the Greenland ice sheet and the thawing of the permafrost landscape. These ongoing transformations are expected to be irreversible for centuries or even millennia.
The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately 14,060,000 km2 (5,430,000 sq mi) and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, although some oceanographers call it the Arctic Mediterranean Sea. It has also been described as an estuary of the Atlantic Ocean. It is also seen as the northernmost part of the all-encompassing world ocean.
Svalbard is a Norwegian archipelago in the Arctic Ocean. The climate of Svalbard is principally a result of its latitude, which is between 74° and 81° north. Climate is defined by the World Meteorological Organization as the average weather over a 30-year period. The North Atlantic Current moderates Svalbard's temperatures, particularly during winter, giving it up to 20 °C (36 °F) higher winter temperature than similar latitudes in continental Russia and Canada. This keeps the surrounding waters open and navigable most of the year. The interior fjord areas and valleys, sheltered by the mountains, have fewer temperature differences than the coast, with about 2 °C lower summer temperatures and 3 °C higher winter temperatures. On the south of the largest island, Spitsbergen, the temperature is slightly higher than further north and west. During winter, the temperature difference between south and north is typically 5 °C, and about 3 °C in summer. Bear Island (Bjørnøya) has average temperatures even higher than the rest of the archipelago.
Polar seas is a collective term for the Arctic Ocean and the southern part of the Southern Ocean. In the coldest years, sea ice can cover around 13 percent of the Earth's total surface at its maximum, but out of phase in the two hemispheres. The polar seas contain a huge biome with many organisms.
An ice cap climate is a polar climate where no mean monthly temperature exceeds 0 °C (32 °F). The climate generally covers areas at high altitudes and polar regions, such as Antarctica and some of the northernmost islands of Canada and Russia. Most of Greenland is under the influence of an ice cap climate, although the coasts are prone to more influence from the sea, providing more tundra climates. Some regions on the islands of Norway's Svalbard Archipelago facilitate an ice cap climate. Areas with ice cap climates are normally covered by a permanent layer of ice and have no vegetation. There is limited animal life in most ice cap climates, which are usually found near the oceanic margins. Although ice cap climates are inhospitable to human life and no civilian communities lie in such climates, there are some research stations scattered in Antarctica and interior Greenland.
The Hudson Plains Ecoregion is a vast, flat, and waterlogged landscape. This ecoregion covers a 369,000 square kilometer area along the south shoreline of the Hudson Bay, which includes the Canadian provinces of Eastern Quebec, Northern Ontario and Western Manitoba. Because of the location of the ecoregion, winter prevails for many months of the year and rising temperatures, along with melting ice, makes fog common. The short summers provide a home for thousands of migrating birds. The region is used by humans for its mineral resources and hydroelectric power as a result of the abundance of water and emergent societal needs. Though relatively uninhabited and undisturbed, the natural resources of the Hudson Plains are still subject to anthropogenic activities. Its climatic, geographic, and evolutionary patterns categorize it as one of many ecoregions in North America.
The Canadian Arctic tundra is a biogeographic designation for Northern Canada's terrain generally lying north of the tree line or boreal forest, that corresponds with the Scandinavian Alpine tundra to the east and the Siberian Arctic tundra to the west inside the circumpolar tundra belt of the Northern Hemisphere.
The Tundra of North America is a Level I ecoregion of North America designated by the Commission for Environmental Cooperation (CEC) in its North American Environmental Atlas.