San Francisco Chronicle

Rapid ice melt alarms scientists

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ANCHORAGE, Alaska — Sea ice along northern Alaska disappeare­d far earlier than normal this spring as a result of exceptiona­lly warm ocean temperatur­es, alarming scientists and coastal residents who rely on wildlife and fish.

Rick Thoman, a climatolog­ist with the Alaska Center for Climate Assessment & Policy at the University of Alaska Fairbanks, posted last week that the northern Bering and southern Chukchi seas are “baking.”

Sea surface temperatur­es last week were as high as 9 degrees above the 19812010 average, reaching into the lower 60s, he said, with effects on the climate system, food web, communitie­s and commerce. Kotzebue and Norton sounds were warmest but the heat extended far into the ocean.

The warmth is weeks ahead of schedule and part of a “positive feedback loop” compounded by climate change. Rising ocean temperatur­es have led to less sea ice, which leads to warmer ocean temperatur­es, Thoman said.

The past five years have produced the warmest seasurface temperatur­es on record in the region, contributi­ng to record low seaice levels.

“The waters are warmer than last year at this time, and that was an extremely warm year,” Thoman said.

Lisa Sheffield Guy of the Arctic Research Consortium of the United States oversees an online platform that allows Alaska Native walrus hunters to share tips on sea ice, weather and hunting. The need for reporting ended May 31 because coastal sea ice had melted.

“When we started in 2010, we would go until the last week of June,” she said.

Warmer ocean temperatur­es come as hunters report large numbers of dead seals off Alaska’s western and northern coasts, Thoman said.

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