The Arctic's alarming sea change

The Arctic ice cap shrank so much this summer that waves briefly lapped along two long-imagined Arctic shipping routes, the Northwest Passage over Canada and the Northern Sea Route over Russia.

Over all, the floating ice dwindled to an extent unparalleled in a century or more, by several estimates.

Now the six-month dark season has returned to the North Pole. In the deepening chill, new ice is already spreading over vast stretches of the Arctic Ocean. Astonished by the summer's changes, scientists are studying the forces that exposed one million square miles of open water, or 2.6 million square kilometers, beyond the average since satellites started measurements in 1979.

At a recent gathering of sea-ice experts in Fairbanks, Alaska, a geophysicist summarized it this way: "Our stock in trade seems to be going away." Scientists are also unnerved by the summer's implications for the future, and their ability to predict it.

Complicating the picture, the dramatic Arctic change was as much a result of ice moving as melting, many say. A study led by Son Nghiem at NASA, and appearing this week in Geophysical Research Letters, used satellites and buoys to show that winds since 2000 had pushed huge amounts of thick old ice out of the Arctic basin past Greenland. The thin floes that formed on the resulting open water melted quicker or could be shuffled together by winds and similarly expelled, the authors said. Read more @ International Hearald Tribune