In addition to having one of the coldest climates on Earth, Antarctica also experiences fierce winds and extreme dryness.
Antarctica is the fifth-largest of the seven continents and it doubles in size during the winter due to the sea ice that forms along its coastline. The continent is generally circular in shape and covers the entire South Pole. One large point of land, called the Antarctic Peninsula, juts out into the Southern Ocean and points towards South America.
There are two main areas in Antarctica. West Antarctica, also known as Lesser Antarctica, is smaller and includes the Antarctic Peninsula. It is an extension of the Andes Mountains, which are located in South America. The other area is known as Greater Antarctica or East Antarctica. The two areas are separated by the Transantarctic Mountains.
General Climate of Antarctica
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Antarctica is cold all year round because it is the furthest away from the sun’s rays. In the polar region, the sun disappears for six months during the Southern Hemisphere’s fall and winter, which is March 22nd to November 22nd.
During the spring and summer, the ice reflects the sun’s rays back into the atmosphere and this prevents the warming of the land. Only a small amount of heat is radiated back into the air and because it is very dry, it is not absorbed in the atmosphere.
Compared to other continents, the altitude of Antarctica is higher than average. The air is always colder at higher elevations so this also contributes to an overall frigid climate.
There are three climatic regions, which are the Antarctic Peninsula, the coastal areas, and the interior. Each area has unique qualities in addition to the general climate conditions in Antarctica.
Climate of the Antarctic Peninsula
Due to extending further north than the rest of Antarctica, the Peninsula has a warmer and wetter climate. The influence of the ocean also moderates the climate. In the summer, the temperatures rise above freezing and rain will fall instead of snow. The peninsula is also susceptible to strong winds and bad storms because of the strong prevailing westerly wind and gales that form on the ocean.
Climate in the Antarctic Coastal Areas
The coastal areas are affected by the moderating influence of the adjacent water. In the winter, major cyclonic storms form in the ocean and pick up moisture. In turn, this brings heavy snowfall to Antarctica. In the summer, the coastal areas are not as warm as the Peninsula but they do not have rain.
Climate in the Antarctic Interior
The interior is the coldest part of the continent because it receives indirect rays from the sun in the summer and no sun in the winter. It is far away from the ocean and is not under the moderating influence of the water. The highest land elevation in Antarctica is in the interior and this makes it the coldest area on the continent.
At the South Pole, there is a constant high-pressure system in existence and it is fed by a cold air mass. The polar area is considered a desert area having less than two inches per year of precipitation.
The snowfall is light in the interior of Antarctica but it is susceptible to blizzards due to the strong winds blowing the snow on the ground. On the polar plateau, the temperatures drop rapidly in the winter but then remain steady all season. The summer lasts for one month, starting in the middle of December.
In the summer, there is more solar radiation because the surface of the ice is darker than it is in winter. A temperature inversion is common in the interior. This is when cold air is trapped under a layer of warmer air. The temperature difference between the two air masses can be as much as 50°F.
Winds from the interior of Antarctica, blow toward the coast. This is caused by gravity pushing the heavier and colder air away from the polar region. These winds are called katabatic winds and when they reach the coast, it creates a westbound ocean current known as the East Wind Drift due to the rotation of the Earth.
Average Temperatures in the Antarctic
According to Adventure-Life, the average seasonal temperatures are as follows:
Summer
- Peninsula +0.8° C
- Coastal -0.2° C
- Interior -32.1° C
Fall
- Peninsula -4.5° C
- Coastal -17.4° C
- Interior – 64.7° C
Winter
- Peninsula -11.6° C
- Coastal -21.7° C
- Interior -66.9° C
Spring
- Peninsula -6.1° C
- Coastal -15.5° C
- Interior -57.1° C
Antarctica does not have a native population and the only people who live there are scientists who work at stations scattered throughout the continent. There is no government located in Antarctica but there is an administrative body consisting of 43 countries that signed the Antarctic Treaty of 1959.
Sources
- About the Continent. United States Antarctic Program. National Science Foundation Office of Polar Programs. Accessed January 6, 2011.
- Antarctic Weather. The Antarctic Connection. Accessed January 6, 2011.
- Antarctica Weather. Adventure Life. Accessed January 6, 2011.
- Ward, Paul. Tourism in Antarctica. Cool Antarctica. 2001. Accessed January 6, 2011.