Polar sea ice

The year 2023 shattered the record for the warmest summer in the Arctic, and people and ecosystems across the region felt the impact. Wildfires forced evacuations across Canada. Greenland was so warm that a research station at the ice sheet summit recorded melting in late June, only its fifth melting event on record. Sea surface temperatures in the Barents, Kara, Laptev and Beaufort seas were 9 to 12 degrees Fahrenheit (5 to 7 degrees Celsius) above normal in August. While reliable instrument measurements go back only to around 1900, it’s almost certain this was the Arctic’s hottest summer in centuries. Summer heat extremes in 2023 and over time. NOAA, Arctic Report Card 2023 The year started out unusually wet, and snow accumulation during the winter of 2022-23 was above average across much the Arctic. But by May, high spring temperatures had left the North American snowpack at a recor...

Ocean temperatures have been off the charts since mid-March 2023, with the highest average levels in 40 years of satellite monitoring, and the impact is breaking through in disruptive ways around the world. The sea of Japan is more than 7 degrees Fahrenheit (4 degrees Celsius) warmer than average. The Indian monsoon, closely tied to conditions in the warm Indian Ocean, has been well below its expected strength. Spain, France, England and the whole Scandinavian Peninsula are also seeing rainfall far below normal, likely connected to an extraordinary marine heat wave in the eastern North Atlantic. Sea surface temperatures there have been 1.8 to 5 F (1 to 3 C) above average from the coast of Africa all the way to Iceland. So, what’s going on? Sea surface temperatures are running well above the average since satellite monitoring began. The thick black line is 2023. The orange line is 2022. The 1982-2011 average is the middle dashed li...

As winds and waves from Typhoon Merbok devastated communities along the coast of Western Alaska in 2022, Reppi Swan Sr.’s phone began to ring at Kivalina, a barrier island 80 miles above the Arctic Circle. A neighboring family had lost 3 feet of land to the rumbling lagoon, and their home was now sitting just 6 feet from the angry water’s edge. Reppi called his brother Joe Swan Jr. and quickly slid into his insulated rain gear. As a volunteer first responder, Reppi plans for emergencies like this. He and his wife, Dolly, had been patrolling the island for dangerous erosion every few hours during the storm. To prepare, he had already inspected the city’s heavy equipment and located a pile of boulders left over from a recent construction project. Working through the rain, Reppi delivered boulders to the threatened home. With their cousin Carl Swan serving as a spotter, Joe carefully arranged the boulders with a backhoe to stabilize the bank. It would hold at lea...

Atmospheric rivers – those long, narrow bands of water vapor in the sky that bring heavy rain and storms to the U.S. West Coast and many other regions – are shifting toward higher latitudes, and that’s changing weather patterns around the world. The shift is worsening droughts in some regions, intensifying flooding in others, and putting water resources that many communities rely on at risk. When atmospheric rivers reach far northward into the Arctic, they can also melt sea ice, affecting the global climate. In a new study published in Science Advances, University of California, Santa Barbara, climate scientist Qinghua Ding and I show that atmospheric rivers have shifted about 6 to 10 degrees toward the two poles over the past four decades. Atmospheric rivers on the move Atmospheric rivers aren’t just a U.S West Coast thing. They form in many parts of the world and provide over half of the mean annual runoff in these regions, including the U.S. Southeas...