The growth of Arctic sea ice this winter hit the lowest level on record because of unusually warm temperatures, U.S. scientists said on March 28.
On March 24, sea ice reached this year's maximum of 14.52 million square kilometers of the Arctic Ocean, the National Snow and Ice Data Center said. That's 12,950 square kilometers less than the old record low set last winter, and 1.1 million square kilometers less than the 30-year average.
It was so warm that the Barents Sea between Russia and the U.S. state of Alaska was close to ice-free most of the winter, which is very unusual.
Records go back to 1979, when satellites started measuring sea ice.
Scientists say air temperatures over the Arctic Ocean for the months of December, January and February were 2 to 6 degrees Celsius above average throughout the Arctic's regions.
This year's ice cover didn't break the record low by much, but it's "an exclamation point" on a longer-term trend related to global warming, said NASA scientist Walt Meier.