Ozone Hole Above Antarctic Grows
GENEVA (AP) _ The ozone hole over Antarctica grew to its largest size ever in September, covering an area 2 1/2 times the size of Europe, the World Meteorological Organization said Thursday.
Scientists expect the hole in the ozone _ the protective layer that shields the earth from damaging ultraviolet rays _ to grow each September because of temperature fluctuations.
But last month, it grew by more than 15 percent, exposing not only Antarctica but a huge swath of the Pacific and Atlantic oceans, including the southern tip of South America, to harmful ultraviolet rays, WMO official Rumen Bojkov told a news conference Thursday.
Ozone, a gas in the stratosphere, protects Earth from harmful UV radiation. Its depletion, thought to be caused by manmade chemicals used in aerosols and refrigeration, is believed to expose humans and animals to increased risks of skin cancer and cataracts.
Because of temperature changes, ozone levels are expected to improve between now and the end of the year or early next year, Bojkov said.
Still, he said, the ozone layer depletion in September ``was very, very serious.″
He said a World Meteorological Organization base station in Tierra del Fuego, in southern Argentina, reported a ``very unusually″ low level of ozone in the atmosphere for the month.
He said the ozone reduction was more severe than in previous years because a whirlpool-like atmospheric phenomenon that develops each year above the South Pole _ the polar vortex _ was larger than usual.
The polar vortex is a moving cyclone with a low-pressure, cold center in which ozone is less likely to be present.
An additional cause of ozone depletion is the chlorine and bromine released by manmade chemical compounds such as chlorofluorocarbons that are contained in some aerosol sprays.