Wednesday, October 27, 2010

Tundra Climate Facts

The arctic fox makes its home in the tundra.


The tundra is a unique climate region (or biome) on Earth, characterized by its cold, dessicated climate and harshness to living things. Alpine and Antarctic tundra are rarer, and the arctic tundra is considered its own separate biome.


Location


The tundra is found along the nearly unbroken upper margins of Eurasia and North America. This includes parts of Scandinavia, a vast stretch of Siberia, western Alaska, the Northwest Territory, the Canadian territory Nunavut, upper Quebec, and the coastlines of Greenland. Tundra in Antarctica and at high, alpine elevations are often considered their own separate biomes.


Environment


Although the tundra is associated with polar climates, it should not be confused with polar ice regions or the cold coniferous forests of the taiga areas. It is more like a transitional climate between the subarctic regions and the ice caps. The tundra is not quite cold enough to be arctic, but it is also an area mostly devoid of trees, unlike other subarctic regions. Most of the vegetation consists of grass, moss, lichens, and small shrubs.


Temperature


Temperatures in the tundra never rise above 10 degrees Celsius, or 50 degrees Fahrenheit, even during the warmest periods. For nine months of the year, the temperature is below freezing. Permanently frozen ground called permafrost is a prominent feature of the tundra and the reason why trees don't grow there. Layers near the surface may thaw during the warmest months and then freeze the rest of the year.


Seasons


The ocean currents near the coastal areas of tundra create seasonal lag due to the fact that water is denser than air and takes longer to heat up or cool down. The wind that blows in from the ocean will thus have a moderating effect on land temperatures. In eastern North America and western Eurasia, the warmest month is August instead of July. In western Siberia, the coldest month is delayed until March. The summer season is considered unusual because it is the only time of the year when the temperature may climb above freezing. During the rest of the year, it is below freezing. Winter months can reach negative 25 degrees Celsius.


Precipitation


The tundra is so dry that it has a lower absolute humidity than the tropical desert. Most of the tundra will experience less than 250 mm of precipitation a year, but coastal regions may experience slightly more. The height of precipitation usually comes in the warmest months around July or August. Some areas may be susceptible to fog because of maritime air that drifts ashore and is chilled to its dew point.


Wildlife


According to the Alaskan Department of Fish and Game, many animals, such as hares, caribou, foxes, squirrels, lemmings, and shrews make their home on the tundra but require specific adaptations such as heavy coats of fur, short-limbs, heat-efficient bodies, longer reproduction cycles (trout, for instance, take ten years instead of six to reach maturity), camouflage, and the ability to hibernate. Plants in the tundra tend to be perennial. They have also adapted specific features such as hair for warmth and the retention of old leaves for nutrient conservation.







Tags: below freezing, degrees Celsius, during warmest, home tundra, North America