Record low sea ice, warmer sea surface temperatures, repeat: why the Arctic keeps melting
Northwest Alaska is in a feedback loop that is making the low Arctic ice situation worse.
“It’s both cause and effect,” says Rick Thoman with the Alaska Center for Climate Assessment and Policy. “Particularly off the Beaufort Coast right now. There’s large areas of open water that would historically have been still ice-covered at this point.”
Open water absorbs more solar radiation than snow and ice, which typically reflects more energy than it absorbs. As the open water absorbs the radiation, it warms, which it turn leads to more ice melting which means more open water.
“It’s June. Lots of 24-hour sunshine, at least when it’s clear, and that sun is going to heat water, instead of melting snow and ice,” says Thoman.
Both the Chukchi and Beaufort Seas have the lowest sea ice for this time of year since they began measuring by satellite in 1979. According to Thoman, the ice extent now is what would be typical for the first week of August.
“We’ve got another solid two more months--two to three months of melt to go in the Chukchi and Beaufort Seas, so at this point really we’ve got nowhere to go but down,” says Thoman. “It’s surely going to be the case that by the time we get to late September, there’s going to be no sea ice within hundreds of miles of Alaska.”
In some areas around Kotzebue and Eastern Norton Sound, sea surface temperatures are up to 10 degrees Fahrenheit above normal. Is there a connection with the warm ocean temperatures and the recent reports of dead whales and high seal mortality? Thoman says we’ll have to wait and see.
“We’ll have to wait for the biologists to tell us what’s going on, but clearly there’s something unusual going on and impacts to the food that whales and seals eat is a potential problem. We know the Bering Sea ecosystem has changed with the lack of winter ice the last couple of years,” Thoman says. “That affects the entire food web.”