ANTARCTIC WEATHER
"A blinding, shrieking blizzard all day, with the temperature ranging from -60 to -70°F." - Shackleton (1909)

Why is Antarctica so Cold?
Several factors combine to making Antarctica one of the coldest and least hospitable places on the Earth:

• Unlike the Arctic region, Antarctica is a continent surrounded by an ocean which means that interior areas do not benefit from the moderating influence of water.
• With 98% of its area covered with snow and ice, the Antarctic continent reflects most of the sun's light rather than absorbing it.
• The extreme dryness of the air causes any heat that is radiated back into the atmosphere to be lost instead of being absorbed by the water vapor in the atmosphere.
• During the winter, the size of Antarctica doubles as the surrounding sea water freezes, effectively blocking heat transfer from the warmer surrounding ocean.
• Antarctica has a higher average elevation than any other continent on Earth which results in even colder temperatures.

Weather observations in Antarctica have been recorded only for the last 150 years. Detailed climatic monitoring began in the late 1950's. Most Antarctic stations today are equipped with sophisticated weather monitoring technology and are manned by professional meteorologists who perform observations around the clock. Automated stations and remote sensing equipment provide a wealth of previously unattainable data and help to paint a more accurate picture of Antarctic weather continent-wide. Satellite measurements and photographs of the continent continue to reveal valuable information concerning cloud cover, storm movement, ice formation and distribution patterns, and a variety of other environmental characteristics.

- The South Pole -		- The Global Weather System -
Temperatures on the Polar Plateau range from -115°F to +6°F; the mean temperature is -56°F.  Winter wind-chills can plummet to -148°F. Wind speeds average just  12 mph, a mere summer breeze compared to the 198 mph katabatic winds found on the coast of Antarctica. Precipitation averages less than 1" annually. 0.03% average humidity combined with the extreme cold make the South Pole region the world's driest desert. Solar radiation becomes zero as the sun dips below the horizon on March 22 and isn't seen again until September 22.		General: Antarctica and the Southern Ocean are key elements in the global weather system.  This is a system which creates and transfers energy as winds, clouds, rain and all other elements we call "the weather". Circulation: The source of this energy is the sun, and because its heating effect is greater at the equator than at the poles, it creates a circulation in the atmosphere.  Hot moist air rises over the equator and flows at a high level towards the poles, where it cools and sinks.  The equator is therefore a region of low pressure, and the poles are regions of high pressure. Interaction: The atmosphere is not a closed system. It interacts with the land, the ocean, and the ice; and the ice in turn interacts with the ocean.Winds create currents in the ocean. The annual cycle of freezing and melting of the sea ice around Antarctica creates a vertical circulation in the ocean.

Blizzards:
Blizzards are a typical Antarctic phenomenon in which very little, if any, snow actually falls.  Instead the snow is picked up and blown along the surface by the wind, resulting in blinding conditions in which objects less than a meter away may be invisible.

Whiteouts:
Whiteouts are another peculiar Antarctica condition, in which there are no shadows or contrasts between objects.  A uniformly grey or white sky over a snow-covered surface can yield these whiteouts, which cause a loss of depth perception -- for both humans and wildlife.

Solar Energy:
Because of the tilt of the earth's axis relative to its orbit around the sun, the sun does not shine at the South Pole for six months of the year. When the sun does shine, much less solar energy actually reaches the ground at the Pole because the sun's rays pass through a thicker layer of atmosphere than at the Equator. Also, due to the predominance of ice and snow covering Antarctica, most of the sun's rays that do reach the ground are reflected back into space.