Ozone Hole Over Antarctica Expanded to Size of North America

Professor Nordheim · 11-04-2008, 02:27 AM

NOAA: The ozone hole over Antarctica grew to the size of North America in September, the fifth largest since NOAA satellite records began in 1979.

NOAA scientists, who have monitored the ozone layer since 1962, have determined that this year’s ozone hole has passed its seasonal peak for 2008.

The primary cause of the ozone hole is human-produced compounds called chlorofluorocarbons, or CFCs, which release ozone-destroying chlorine and bromine into the atmosphere. Earth’s protective ozone layer acts like a giant umbrella, blocking the sun’s ultraviolet-B rays. Though banned for the past 21 years to reduce their harmful build up, CFCs still take many decades to dissipate from the atmosphere.

According to NOAA scientists, colder than average temperatures in the stratosphere may have helped play a part in allowing the ozone hole to develop more fully this year.

National Oceanic and Atmospheric Administration

11-04-2008, 02:27 AM	#1
Professor Nordheim Avalon Senior Member Join Date: Sep 2008 Location: Northern Norway Posts: 59	Ozone Hole Over Antarctica Expanded to Size of North America NOAA: The ozone hole over Antarctica grew to the size of North America in September, the fifth largest since NOAA satellite records began in 1979. NOAA scientists, who have monitored the ozone layer since 1962, have determined that this year’s ozone hole has passed its seasonal peak for 2008. The primary cause of the ozone hole is human-produced compounds called chlorofluorocarbons, or CFCs, which release ozone-destroying chlorine and bromine into the atmosphere. Earth’s protective ozone layer acts like a giant umbrella, blocking the sun’s ultraviolet-B rays. Though banned for the past 21 years to reduce their harmful build up, CFCs still take many decades to dissipate from the atmosphere. According to NOAA scientists, colder than average temperatures in the stratosphere may have helped play a part in allowing the ozone hole to develop more fully this year. National Oceanic and Atmospheric Administration