Arctic lake melts out of sea ice into ocean

By Frank D. Roylance
The Baltimore Sun

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.

As of Tuesday, NSIDC reported that the summer sea ice this year had shrunk to the fourth-smallest September minimum on record.