|Ozone hole bigger and bigger
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|Author:||Catherine [ Sun Oct 22, 2006 11:22 am ]|
|Post subject:||Ozone hole bigger and bigger|
Ozone hole bigger and bigger
By Devika Bhat and agencies
This image, provided by Nasa, captures this year’s ozone hole over Antarctica, which has been
declared by scientists in the US
as the biggest and deepest on record.
"From September 21 to 30, the average area of the ozone hole was the largest ever observed, at 10.6 million square miles (27.4 square kilometres)," said Paul Newman, of Nasa’s Goddard Space Flight Centre outside Washington.
The ozone layer, a form of oxygen in the upper atmosphere which shields Earth from the sun’s harmful ultraviolet rays, thins out over the South Pole each year. This is largely due to human-made compounds releaing chlorine and bromine gases into the stratosphere, eating into the barrier and causing the hole.
If the stratospheric weather conditions had been normal, the ozone hole would be expected to reach a size of about 8.9 million to 9.3 million square miles (23 million to 24 million square kilometres), about the surface area of North America, Nasa said in a statement.
The size of the ozone hole varies year to year depending on temperature variations in the Antarctic stratosphere. Colder temperatures result in larger and deeper ozone holes, while warmer temperatures lead to smaller ones. This year, the lower stratosphere was about 5 degrees Celsius (9 degrees Fahrenheit) cooler than average.
|Author:||mga [ Wed Oct 25, 2006 11:42 am ]|
i wish they'd make up their minds on what that thing is doing....one time it's growing, the next it's shrinking....
Gone by 2050 ... the ozone hole over Antarctica.Photo: NASA
The incredible shrinking ozone hole
The level of chlorine from chlorofluorocarbons in the atmosphere is falling, and the hole in the ozone layer over Antarctica should close by 2050, Australian scientists have revealed.
http://www.smh.com.au/articles/2002/09/ ... 63580.html
|Author:||Catherine [ Wed Oct 25, 2006 6:28 pm ]|
...hmmm...are those Aussie scientists for us or against us?
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