Arctic sea ice hits second-lowest level ever says NASA
“The sea ice is not only declining, the pace of the decline is becoming more drastic,” NASA scientist Joey Comiso said. “The older, thicker ice is declining faster than the rest, making for a more vulnerable perennial ice cover.”
MONTREAL — Sea ice in the Arctic declined last month to the second-lowest level ever recorded, the U.S. National Aeronautics and Space Administration said Tuesday.Satellite data showed the summertime sea ice coverage in the north narrowly missed the all-time record low, which was attained in 2007, NASA said in a statement.
The Arctic sea ice recedes every summer as the sun’s rays reach higher into the northern hemisphere and sea ice reaches its annual minimum each year in September.
Joey Comiso, a scientist at NASA’s Goddard Space Flight Center, said the sustained low minimum sea ice levels are part of a large-scale decline over the past three decades.
“The sea ice is not only declining, the pace of the decline is becoming more drastic,” Mr. Comiso said. “The older, thicker ice is declining faster than the rest, making for a more vulnerable perennial ice cover.”
The spread of Arctic sea ice on Sept. 9, the lowest point this year, was 4.33 million square kilometres, NASA said. Averaged over the month of September, ice extent was 4.61 million square kilometres. This places 2011’s Arctic ice area as the second-lowest both for the daily minimum extent and the monthly average. Ice extent was 2.43 million square kilometres below the 1979 to 2000 average.
The sea ice announcement came two days after another announcement, this time about a gaping hole in the ozone layer above the Arctic.
The hole covered two million square kilometres — about twice the size of Ontario — and allowed high levels of harmful ultraviolet radiation to hit large swaths of northern Canada, Europe and Russia this spring, a team of 29 international research scientists said.
The measurements helped confirm that chlorine-based pollutants in the stratosphere, 18 to 20 kilometres above the ground, triggered a process that chewed up molecules in the ozone layer that protect Earth from the sun’s intense ultraviolet light.
Kilde: Montreal Gazette, 5.10.2011
Les artikkelen her http://news.nationalpost.com/2011/10/04/arctic-sea-ice-hits-second-lowest-level-ever-nasa/
