Scientists who study glaciers and polar ice are called glaciologists. There are permanent research stations based in Polar Regions, manned by glaciologists who can discover a great deal about the Earth. Working in laboratories dug out of the ice, they investigate layers of ice that contain gases and substances from climatic conditions of the past. Ice cores are also drilled from the ice and taken back to laboratories for detailed testing.
Earth has two polar regions – the Arctic and the Antarctic – and each is considerably larger than the lower 48 United States. The most distinctive features of both polar regions are cold climate and abundant snow and ice, caused by the extreme annual variation of sunlight. At the North and South Poles, the sun is below the horizon for six consecutive months, then above the horizon for the next six months. Poleward of the Arctic and Antarctic Circles (currently approximately 66º 34’ North and South) there is at least one 24-hour period each year when the sun is continuously above the horizon, and one when it is continuously below it. These circles are sometimes used to define the boundaries of the polar regions. Other definitions are poleward of treeline and poleward of the line where the average surface air temperature exceeds 10º C in the warmest month of the year.
The central Arctic is an ocean with depths exceeding 4000 meters, topped by sea-ice (frozen seawater) of average thickness 3 meters. The sea-ice moves continually in response to winds and ocean currents, with typical speeds of 5-10 km per day. Tundra, a treeless land of low growing vegetation, covers the northern fringes of the surrounding continents.
The central Antarctic is a continent, covered by a massive sheet of glacial ice (formed by accumulation of snowfall) of average thickness 2000 meters. The glacial ice moves slowly downhill in response to gravity, with horizontal speed on the order of 10m per year. The vast Southern Ocean surrounds the continent, and supports a canopy of sea-ice thinner on average than its Arctic counterpart.
People settled in the Arctic thousands of years ago, and when explorers from lower latitude reached the Arctic, they found established cultures based on subsistence hunting. In the Antarctic the human presence is limited primarily to tourists and scientists who stay for a season or a year.
The polar regions are home to a surprising variety of animals and plants. Each species has adapted to the prolonged periods of sunlight and darkness, the low temperature, and the snow and ice. In the central Arctic, polar bears and Arctic foxes roam the surface of the pack ice. In Antarctica penguins inhabit the perimeter of the continent, feeding in the coastal waters and rearing their young on the ice surface. Marine mammals such as whales and seals abound in the Arctic and the Antarctic, though there are differences of species, for example the walrus lives only in the Arctic, while the leopard seal is an Antarctic resident. Caribou, musk ox, grizzly bears and lemmings range over the Arctic tundra.
Polar science is a broad term encompassing the scientific study of any aspect of the polar regions. Science treats phenomena as consequences of general laws, which may be refuted or not refuted by following the scientific method of observation, hypothesis, experiment and measurement. Polar science has its disciplines, sub-disciplines and inter-disciplines, e.g. physics, chemistry, biology, anthropology, sociology, oceanography, meteorology, biogeochemistry, botany, zoology, and ecology. A large fraction of polar science fits well under the heading “environmental science”, which sometimes is taken to mean the study of everything non-human that interacts with humans. Thus defined, polar science encompasses much. It applies equally to the zoologist fastening a tracking device to a polar bear on the Arctic pack ice, as to the theoretical physicist working on mathematical expressions of thermodynamic principles to predict how a gas migrates through the glacial ice sheet on Antarctica. The last 30 years or so have seen a notable increase in research concerned with long term, progressive changes in the polar regions. This increase has been spurred by theories of climate change as a response to increased concentrations of greenhouse gases in the atmosphere, and by observations of large scale environmental change, especially in the Arctic.
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