Arctic sea ice extent for the month of July was lopsided, scientists said Wednesday. While ice clogged waters in northeast Canada and delayed fuel deliveries there, it broke up and melted north of Alaska where it's usually solid year-round, they said.
A monthly report released by the National Snow and Ice Data Center, titled "Open and Shut," said the flip-flop was unusual but kept overall average ice coverage from hitting a new record low.
The ice extent, or surface area, was measured at 3.38 million square miles in July -- the eighth-lowest for the month of July since satellite records began in 1979. But if the ice hadn't stuck around in eastern Canada's Hudson and Baffin bays, the surface area could have shrunk as low as the record low set in 2012, said Mark Serreze, director of the Boulder, Colorado-based NSIDC.
"Everywhere else is hanging below normal," Serreze said. "It's boosted the Arctic ice total."
It isn't unusual to see such levels of melting in July -- July is usually the month that sees the most ice loss -- but the pace of melting was faster than usual this year, with overall coverage coming within 212,000 square miles of hitting the low levels from 2012, the NSIDC said.
According to the report, sea ice melted faster last month than in July of 2012, but there was just more of it this year. The melt was fast probably because temperatures in the air above the Arctic Ocean were higher than average, but not in regions affecting Hudson Bay and Baffin Bay, where temperatures were lower than average.
Ships can usually navigate those bays in July, but conditions this year made it difficult to send fuel to coastal communities and perform Arctic research, according to the report.
Meanwhile, ice coverage in the Chukchi Sea was below average. Serreze also pointed out that the ice pack in the Beaufort Sea was broken, with holes of water where old and solid ice usually remains into the next season. The "Swiss cheese" will make it easier for the area to absorb heat and potentially melt out the rest of the remaining ice there by the end of summer, he said.
"It's been an interesting month. There's a lot going on," he said.
The extent of Arctic ice affects maritime traffic and the region's ecology.
The U.S. Geological Survey since 2007 has been tracking Pacific walruses that traditionally rely on Chukchi Sea ice to rest. The ice extent in that area has been decreasing, so masses of walruses have been heading to coastlines instead, said Tony Fischbach, a USGS wildlife biologist.
"We realized that there were big changes afoot in the summer and we suspected that it would have some real consequences," Fischbach said.
Serreze predicted that the ice extent in August will be "pretty darn low," but said year-to-year the outcome is highly variable.