Record open water above Alaska

Beaufort and Chukchi Seas have near record open water

Sea Grant News,

28 September, 2017

Temperatures are dropping and the days are getting darker as Alaska moves into autumn. But despite the approaching winter chill, there’s lots of open water north of Alaska—a near record, in fact.

As of this month, the extent of open water from Nome, Alaska, to the sea ice edge in the Arctic is as much as 800 miles—marking an extreme event. That’s according to Walt Meier of the National Snow and Ice Data Center in Boulder, Colorado. Meier gave a status update on sea ice minimum during the September 27 Alaska Marine Policy Forum conference call, hosted by Alaska Sea Grant and the Alaska Ocean Observing System.

Not only do the Beaufort and Chukchi Seas have a lot of open water now, the ice directly to the north continues to melt even though we’ve passed the overall minimum. “It’s still going down, probably because of warm ocean water, as well as wind helping it,” said Meier.

There is going to be a lot of open water well into October, and maybe November off the north coast of Alaska, Meier said. That has potential implications for fall storms and coastal erosion in northwestern Alaska.

“This is of great interest in northwestern Alaska near Nome,” said Gay Sheffield, Alaska Sea Grant’s Marine Advisory agent there. “The return of the ice did not occur at St. Lawrence Island last year until mid January.” There were strong weather events, including a category 2 hurricane during the last week of December, Sheffield said.

Ice in Beaufort Sea north of Point Barrow. Photo by Kelley Elliott, Hidden Ocean 2005 Expedition, NOAA Office of Ocean Exploration.

Meier guessed the ice will be quite late in returning again this year, but NSIDC does not forecast freeze-up dates. “NOAA and the US Navy have a lot of interest in the predictability as well as the Alaska communities. There is a push to predict what’s beyond September but we are not there yet,” he said.

Overall the trend to less arctic ice continues. The amount of multiyear (thicker) ice is much lower than decades ago, and the new ice that forms each year is quite thin.

NSIDC monitors sea ice using passive microwave sensors on a satellite, and has records that go back to 1979. Sea ice reached its minimum on September 13 this year. The overall ice extent for the Arctic is now 1.79 million square miles, making it the eighth lowest record.

In March 2017, the melt season started with the smallest amount of sea ice ever seen in the satellite record, and progressed through May when melting slowed down. The reason it slowed was a persistent low pressure system over most of the Arctic Ocean through the summer. Cloudy skies kept solar energy from coming in and melting the ice.

“But despite the slowed melting overall, in the Alaska region, in the Beaufort and Chukchi Seas, we really saw it melt back quite far north, as folks may be aware,” Meier said. “The ice edge got to almost 80 degrees north. I cannot confirm this but it looks like in some areas that’s as far north as we’ve ever seen it.”

For more information on sea ice see the National Snow and Ice Data Center website.

By Sue Keller