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Climatic Regions of the United States, Tundra
Subarctic region, compact cover, Tundra climate, musk ox, Arctic Ocean
Tundra climate extends north of the Arctic Circle, from the Subarctic region to the Arctic Ocean. Like the Subarctic region, the Tundra experiences extremely long periods of daylight in the summer and extended periods of darkness during winter months.
Here, only two to six months of the “warm” season are above freezing, and frost may occur on any day of the year. The average temperature for July, the warmest month, never exceeds 10° C (50° F). Temperatures vary according to location, but data recorded at the weather station at Barrow, Alaska, the northernmost community in the United States, show average temperatures of –25° C (–13° F) for January and 4°C° (39° F) for July.
Annual precipitation is less than 360 mm (less than 14 in), and much of the precipitation falls during the warm season in the form of rain or occasional wet snows. The meager winter snowfall is usually dry and powdery so that it forms a very compact cover. Frequently, the small amount of snow that falls is blown by strong winds. Since no forests break the force of the wind or anchor the snow cover, the wind blows the snow into drifts while leaving patches of bare ground.
Tundra soils are largely undeveloped inceptisols. More specifically Tundra soil is of the subdivision cryaquepts, meaning “icy cold,” because permafrost appears close to the surface at a depth of about 40 to 60 cm (16 to 24 in). When not frozen, the top layer of soil is permanently saturated with water, and the prevailing soil conditions are those of a bog. Unlike bogs found in the midlatitudes, the Arctic region’s large areas cannot be drained and are unsuited to agriculture. Better-drained sites of the Arctic fringe regions have soils that are slightly richer in organic material.
There are no trees; natural vegetation consists of mosses, lichens, short bushes, and sedges. These plants provide food for grazing caribou, musk ox, and reindeer. Seals, walruses, and whales are found in adjacent seas. Polar bears roam the shore and nearby ice floes to search for seals and other marine creatures.
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