Arctic ice-up has begun

October 28, 2007

Courtesy of Far North Science
By Doug O'Harra

Arctic ice of the Far North ocean has begun its inexorable wintery expansion as darkness spreads and temperatures fall.

Source: NSIDC

The latest report from the National Snow and Ice Data Center offers details, but it's not very reassuring.

The extent of Arctic ice surpassed the previous all-time minimum record of 2005 only on Oct. 24. A gander at the fall and rise of 2007 ice cover reminds us of a startling fact: Vast expanses of the Arctic Ocean were ice free for the first time in history more than two months.

Amid all this slushy angst, the Pacific walrus had decamped to the northwestern Alaskan coast in such numbers that Native elders were stunned and marine mammal scientists were rattled, as FNS reported earlier this month.

Barrow blogger Anne Brygger reports seeing a lone walrus swept along in broken floes off the coast, apparently caught up in shattered pans that just won't freeze hard.

"For the last few days ice has been showing up from somewhere to the north & east," she writes in the latest post from Tundra Garden. "It's small chunks, but they have 6 inches or more thickness, so they're not brand new.

"This is really late."

In their latest dispatch, posted on line Oct. 16, the ice gurus at NSIDC report sea ice extent has expanded to about 2.18 million square miles - a 37 percent increase since the Arctic cap set its all-time minimum record of 1.59 million square miles on Sept. 16.

The Northwest Passage has also refrozen, after opening for the first time in modern history.

"Though some portions of the channels appear to still be fairly free of ice, all possible routes would now require ice-hardened vessels or icebreakers to transit," the NSIDC says.

But all this new ice is thin, first year stuff, easily melted in the spring. And the coverage remains way below what normally appears during the fall freeze up.

The differences from climate norms for the previous century continue to increase, even though the 2007 melt season has ended and the ice has begun its seasonal recovery. As of October 16, the extent was 3.20 million square kilometers (1.23 million square miles) below the long-term average.

Check out the NSIDC dispatch for three different animations that show the disturbing ameoba-like gyrations of the 2007 ice draw down.

Anne Brygger, in Tundra Garden, describes a forlorn site that captures the climate uncertainty of these times.

Yesterday, a walrus came riding by on the ice (it's the dark spot on the ice). For the last several weeks, huge herds of walruses have been beaching themselves along the Chukchi Sea coast at various spots.

The females and calves normally stay with the ice in this area, but it pulled back so far this summer that it wasn't over waters where they could find food. They need to be able to dive and find clams & such, but the ice was over much deeper waters, so they had to swim for it.

Most of Far North Science is written and edited by Doug O'Harra, a writer and journalist based in Anchorage, Alaska.