Summer Ice Clogs Northwest Passage

A rare cloud-free day on August 27, 2009, provided a clear view of part of the Canadian Arctic Archipelago.

Lingering summertime ice across the Canadian Arctic has made trans-polar navigation more difficult over the past month despite the two previous consecutive hot summers that provided virtually clear sailing.

The Canadian Ice Service says pockets of more extensive freezing last winter and drifting concentrations of thick, older ice caused “choke points” across the Northwest Passage.

Despite this summer’s apparent pause in a dramatic trend of Arctic melting, the U.S. Snow and Ice Data Center has predicted another near-record meltdown by mid-September, when Arctic ice normally reaches its minimum coverage.

In a related finding, U.S. scientists using a combination of satellite images and military submarine records from the cold war era say the Arctic ice has declined by 53 percent since 1980.

The study results were published in the journal Geophysical Research Letters.

NASA's cryosphere program manager Tom Wagner told reporters: "A fantastic change is happening on Earth -- it's truly one of the biggest changes in environmental conditions on Earth since the end of the ice age.”

Image: NASA Earth Observatory