How and Why Do Cold Environments Vary Spatially and Temporally?
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- Date Submitted: 09/15/2010 04:47 PM
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How and why do cold environments vary spatially and temporally?
Introduction:
Cold Environments are icy landscapes that occur in polar areas and high mountainous regions of the world where the temperature is constantly below 0oC. They are characterised by very cold temperatures together with lots of snow and ice, and few plants and animals. They have also experienced relatively little commercial exploitation and have low human population densities. However, not all ‘cold’ environments are the same as they can be subdivided into glacial and periglacial areas. A glacial area is defined as an area that has a large body of ice, consisting of largely recrystallized snow that shows evidence of downslope or outward movement due to the pull of gravity. A periglacial environment however, is an area ‘near to or at the fringes of an ice sheet,’ (Waugh, D 2000, Geography; An Integrated Approach, Nelson Thornes, United Kingdom) where frost and snow have had a major impact upon the landscape.
1.1 What causes a cold environment?
There are many climatic processes which help cold environments to form; this includes latitude, altitude, albedo, anticyclones and ocean currents.
1.2 Latitude, altitude and anti-cyclones
High latitude areas (60o-90o north and south of the equator) are cold because they receive low levels of solar radiation per unit area due to the curvature of the earth’s surface. In addition, the tilt of earth’s axis of rotation means polar areas are in permanent darkness for several months each winter. Dense, cold air sinks at the poles creating anticyclones, with relatively clear skies. This promotes heat loss from the ground lowering temperatures further. Near the poles, low summer temperatures help to retain winter snowfall, even near sea level. At about 30ºN and S latitude, subtropical high pressure yields low precipitation, thus glaciers occur only on the highest (coldest) mountains. Glaciers at or near the equator are typically affected by tropical...
Introduction:
Cold Environments are icy landscapes that occur in polar areas and high mountainous regions of the world where the temperature is constantly below 0oC. They are characterised by very cold temperatures together with lots of snow and ice, and few plants and animals. They have also experienced relatively little commercial exploitation and have low human population densities. However, not all ‘cold’ environments are the same as they can be subdivided into glacial and periglacial areas. A glacial area is defined as an area that has a large body of ice, consisting of largely recrystallized snow that shows evidence of downslope or outward movement due to the pull of gravity. A periglacial environment however, is an area ‘near to or at the fringes of an ice sheet,’ (Waugh, D 2000, Geography; An Integrated Approach, Nelson Thornes, United Kingdom) where frost and snow have had a major impact upon the landscape.
1.1 What causes a cold environment?
There are many climatic processes which help cold environments to form; this includes latitude, altitude, albedo, anticyclones and ocean currents.
1.2 Latitude, altitude and anti-cyclones
High latitude areas (60o-90o north and south of the equator) are cold because they receive low levels of solar radiation per unit area due to the curvature of the earth’s surface. In addition, the tilt of earth’s axis of rotation means polar areas are in permanent darkness for several months each winter. Dense, cold air sinks at the poles creating anticyclones, with relatively clear skies. This promotes heat loss from the ground lowering temperatures further. Near the poles, low summer temperatures help to retain winter snowfall, even near sea level. At about 30ºN and S latitude, subtropical high pressure yields low precipitation, thus glaciers occur only on the highest (coldest) mountains. Glaciers at or near the equator are typically affected by tropical...