2009年4月6日星期一

Research: Arctic ice smaller, thinner, younger

BEIJING, April 7 (Xinhuanet) -- The Arctic is stepping on smaller and thinner
ice than ever before,with strong old ice increasingly being replaced by
quick-to-melt young ice, said researchers with NASA and the National Snow and
Ice Data Center in Colorado.








The Arctic is stepping on smaller and thinner ice than ever before,with strong old ice increasingly being replaced by quick-to-melt young ice
The Arctic is stepping on smaller and thinner ice than ever
before,with strong old ice increasingly being replaced by
quick-to-melt young ice.(File
photo)


According to the researchers, this winter's maximum Arctic sea ice extent was
5.85 million square miles (15million and 150,000 square kilometers) -- about
278,000 square miles (720,000 square kilometers) less than the Arctic average
between 1979 and 2000.


In normal winters, ice is often about 10 feet(3 meters )thick or more, but
this year, the thick ice cap barely penetrates the bull's-eye of the Arctic
Circle.


"We're not set up well for summertime," ice data center scientist Walt Meier
said, "We're in a very precarious situation."


The amount of thick sea ice hit a record wintertime low of just 378,000
square miles this year, down 43 percent from last year, Meier said.


Usually, younger, thin ice accounts for about 70 percent of the ice cover.
This year it reaches 90 percent, Meier added.


Sea ice is important because it reflects sunlight away from Earth. The more
it melts, the more heat is absorbed by the ocean, heating up the planet even
more, said NASA polar regions program manager Tom Wagner. That warming also can
change weather patterns worldwide and it alters the ecosystems for animals such
as polar bears.

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