Huge lake has melted out of Arctic sea ice

By Frank D. Roylance
The Baltimore Sun
(Sep 23, 2006)

Something unusual is going on in the Beaufort Sea, a remote part of the
Arctic Ocean north of Alaska. Over the past six weeks, a huge "lake"
bigger than the state of Indiana has melted out of the sea ice.

Within the past week, this "polynya" -- a Russian word for any open
water surrounded by sea ice -- finally melted through a part of the ice
that separated it from the open ocean, forming a kind of bay in the
planet's northern ice cap.

"The reason we're tracking it is because we had never seen anything
like that before," said Mark C. Serreze, senior research scientist at
the National Snow and Ice Data Center, in Boulder, Colo.

Polynyas occur every year in certain parts of the Arctic where warm
currents and persistent winds clear swaths of sea ice.

But this one, covering 38,000 square miles, is unique in the memory of
scientists who watch the Arctic ice closely because they see it as a
bellwether for the effects of global warming. They've found that the
area of the summer ice cap has been shrinking for at least three
decades, and it's getting thinner, too.

Last year, scientists at NASA and the NSIDC reported the most extensive
summer meltdown of Arctic sea ice on record, and an acceleration in the
rate of its long-term decline.

In a new study reported last week, NASA researcher Josefino Comiso
found that the Arctic's winter ice is also in decline, and at an
accelerating rate.

The ice cap is crucial because it helps regulate the planet's
temperature. Its bright surface reflects 80 percent of the solar energy
that strikes it, sending it back into space.

Climatologists say a smaller ice cap will reflect less solar energy and
expose more open water, which is darker and absorbs 90 percent of the
solar energy that falls on it. It heats up, holds more of that heat
from year to year, and makes it harder for ice to form again in the
fall and winter.

So Arctic temperatures rise. From January through August 2005, they
were 3.6 to 5.4 degrees Fahrenheit warmer than the long-term average
across most of the region.

[ . . . ]

If current rates of summer melting continue, NSIDC researchers have
said, the Arctic Ocean could be completely ice-free in summer before
the end of this century.

[ . . . ]

http://www.hamiltonspectator.com/NAS...=1112101662670