Polar ice caps form because high-latitude regions receive less energy in the form of solar radiation from the sun than equatorial regions. This results in lower surface temperatures. Seasonal variations of the ice caps will take place due to varied solar energy absorption as the planet or moon revolves around the sun. Additionally, in geologic time scale, the ice caps may grow or shrink due to climate variation.
A polar ice cap or polar ice sheet is a high-latitude region of a planet or moon that is covered in ice. This term is somewhat of a misnomer since an ice cap is less than 50,000 km² and is always over land: a larger area of ice is called an ice sheet. Polar ice caps do not have size, composition or geologic requirements of being over land, but they must be centered in the polar region.
The Antarctic polar ice cap is a truly unique biome.The climate is very harsh, both on the land and in the water.The soil is dry and rocky, with little vegetation.With a short growing season, cold temperatures, few plants exist.Thus, there is little decomposition and little organic matter in the soil which might help plant growth.This is the antithesis of the Temperate Deciduous Biome forests that have a lot of plant growth, lots of decomposition, and thus very rich soils that encourage further plant growth.
The sun is very intense when there is no cloud cover because there is nothing to create shade. Ozone depletion has been a problem in the Antarctic, and there is some thought that penguins and aquatic organisms near the surface of the water (ie. coral near Australia) may be affected by the increased level of UV light.
The cold temperatures, combined with the high winds, leads to a significant windchill. Even in peak summer the temperatures reached only + 5C. In the winter it is so cold that it is almost impossible to travel here. In 1999 a female doctor at a research base took care of her on starting cancer problems because planes could not fly in during the winter season.
The land mass of the Earth's south pole, in Antarctica, is covered by the Antarctic ice sheet. It covers an area of almost 14 million km² and contains 30 million km³ of ice. Around 90% of the fresh water on the Earth's surface is held in this ice sheet. In addition, the West Antarctic Ice Sheet covers 3.2 million km² and the Ross Ice Shelf covers 0.5 million km².
Earth's north pole is covered by floating pack ice (sea ice) over the Arctic Ocean. Portions of the ice that don't melt seasonally can get very thick, up to 3–4 meters thick over large areas, with ridges up to 20 meters thick. One-year ice is usually about a meter thick. The area covered by sea ice ranges between 9 and 12 million km².
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