|
Antarctica has the strongest winds in the world and these are called katabatic winds. Their name comes from the Greek, `kata’ meaning downwards. These Antarctic winds have been measured at 320 km/h and are some of the strongest winds measured on our planet at ground level, outside those in some tornadoes.
BAS Equipment in the wind/snow
Katabatic winds are created by the cooling of air close to the surface of the ice sheet on the higher parts of the continent. As this cold heavy air sinks, it presses down hard, pushing away all the air that was underneath. This process creates a downhill wind which, by the time it reaches the coast, is blowing at great force.
For early explorers to Antarctica, katabatic winds were as big a problem as the cold as the winds were so fierce; often explorers would have to crawl along on their hands and knees to carry out daily tasks. Douglas Mawson later called Antarctica `the home of the blizzard’ as during his 1912-13 expedition at Cape Denison, on the Adélie Land coast, he experienced gale-force winds on all but one of 203 consecutive winter days.
`It demanded physical steel, iron nerve, to step out from shelter into a ninety-mile (eighty-knot) gale, blowing cold at around twenty degrees below freezing. Sometimes men stood at forty-five degrees, leaning into the steady gale, to cut the ice for melting…Throughout May the wind normally blew around ninety-five miles per hour and men attending the wind recorders suffered frostbite’…On May 25 Mawson examined the instruments and recorded that there had been blasts above two hundred miles an hour.
Satellite composite image of Antarctica - NASA
So what do Antarctic winds have to do with climate change? Although you can't see a boundary, the Southern Ocean is made up of the most southerly reaches of the Atlantic, Pacific and Indian oceans, as well as the water that surrounds Antarctica. Winds from Antarctica push the cold surface waters from around Antarctic north, where they meet the south flowing warmer waters of the Atlantic, Pacific and Indian oceans. The boundary where they meet is known as the Antarctic Convergence, and it lies approximately 2,000 km off the coast of Antarctica.
Where the ocean currents meet, the warmer water turns east, driven by westerly winds. The cold water sinks below the warm water and some of it carries on moving north at the bottom of the ocean. This process represents part of a global system of winds and ocean currents that help to transfer heat around the globe and regulate temperatures. Without these movements, the polar regions would be colder and the equator would be hotter.
Every year scientists from over 27 different countries conduct experiments in Antarctica not reproducible in any other place in the world and use their findings to forecast future changes to our planet. Britain has been involved in Antarctic research and exploration for more than 200 years. For over 50 years the British Antarctic Survey (BAS), an institute of the Natural Environment Research Council, has been undertaking the majority of the United Kingdom's research on and around the continent.
It was scientists working at a British Antarctic research station who first identified a hole in the Earth’s ozone layer in 1985. The ozone layer protects the Earth from many of the harmful effects of the Sun’s rays.
|
Amazing Antarctica