Friday, October 20, 2006

The Sky is falling

Breakout the sunscreen:

WASHINGTON - This year's ozone hole over Antarctica is bigger and deeper than any other on record, US scientists reported on Thursday.

The ozone layer shields Earth from the sun's harmful ultraviolet rays, and the layer thins out over the South Pole each year, primarily because human-made compounds release ozone-eating chlorine and bromine gases into the stratosphere.
"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 Center outside Washington.

That's just a bit bigger than my back garden. For comparison, Europe is 4,010,000 square miles.

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.

Scientists measure the total amount of ozone from the ground to the upper atmosphere in Dobson Units, and a NASA satellite detected a low level of 85 Dobson Units on Oct. 8 of the East Antarctic ice sheet.

Less ice for cocktails.

WASHINGTON - The vast sheet of ice that covers Greenland is shrinking fast, but still not as fast as previous research indicated, NASA scientists said on Thursday.

Greenland's low coastal regions lost 155 gigatons (41 cubic miles) of ice each year between 2003 and 2005 from excess melting and icebergs, the scientists said in a statement.

The high-elevation interior gained 54 gigatons (14 cubic miles) annually from excess snowfall, they said.

This is a change from the 1990s, when ice gains approximately equaled losses, said Scott Luthcke of NASA's Planetary Geodynamics Laboratory outside Washington.

"That situation has now changed significantly, with an annual net loss of ice equal to nearly six years of average water flow from the Colorado River," Luthcke said.


The ice mass loss in this study is less than half that reported in other recent research, NASA said in a statement, but it still shows that Greenland is losing 20 percent more mass than it gets in new snowfall each year.

"This is a very large change in a very short time," said Jay Zwally, a co-author of the study. "In the 1990s, the ice sheet was growing inland and shrinking significantly at the edges, which is what climate models predicted as a result of global warming.

Glad to be moving to a point on high ground nowhere near a glacier, flood plain or ozone hole.

:: Posted by pete @ 21:36