Another month has passed, and scientists are announcing another monthly record low for Arctic sea ice.
The extent of sea ice in May was the lowest measured for that month since satellite recording began in 1979, the National Snow and Ice Data Center reported Tuesday. The record-low in May follows record lows posted for January, February and April and a record-low winter maximum reached in March.
The low-extent pattern is spread across the Arctic, said Mark Serreze, director of the Colorado-based NSIDC. "It's pretty much low everywhere, on the Pacific side and the Atlantic side," he said.
Ice extent is defined as the area where at least 15 percent of sea surface is frozen.
The melt is now two to four weeks ahead of the pace set in 2012, the year when the record-low minimum was set, the NSIDC said, and much of that has been evident in the southern Beaufort Sea off northern Alaska and northwestern Canada.
Ice in the Beaufort is already broken up, and holes have become large and are expected to contribute to future melt, Serreze said.
"You've got the big open water areas already opening up between the floes," Serreze said. "They're just going to absorb a lot of heat this summer and accelerate the melt."
Just how far the ice pack will melt and whether a new record-low minimum will be reached depends on summer weather, he said.
Sparser snowpack on land may also be a contributor to summer melt.
Spring snow cover in the Northern Hemisphere, recorded from March to May, was the lowest in the 50-year record kept by Rutgers University's Global Snow Lab. That fits a long-term trend of reduced snowpack in spring, with this year's new spring record low putting an "exclamation point" on the trend after months of record-warm Arctic weather, Serreze said.
"We've had a crazy winter and spring, and now we seem to be paying for it," he said.