Arctic warming

Extremely cold Arctic air and severe winter weather swept southward into much of the U.S. in mid-January 2024, breaking daily low temperature records from Montana to Texas. Tens of millions of people were affected by dangerously cold temperatures, and heavy lake-effect snow and snow squalls have had severe effects across the Great Lakes and Northeast regions. These severe cold events occur when the polar jet stream – the familiar jet stream of winter that runs along the boundary between Arctic and more temperate air – dips deeply southward, bringing the cold Arctic air to regions that don’t often experience it. Surface temperatures at 7 a.m. EST on Jan. 16, 2024. Temperatures below freezing are in blue; those above freezing are in red. The jet stream is indicated by the light blue line with arrows. Mathew Barlow/UMass Lowell, CC BY An interesting aspect of these events is that they...

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...

In the Arctic, the freedom to travel, hunt and make day-to-day decisions is profoundly tied to cold and frozen conditions for much of the year. These conditions are rapidly changing as the Arctic warms. The Arctic is now seeing more rainfall when historically it would be snowing. Sea ice that once protected coastlines from erosion during fall storms is forming later. And thinner river and lake ice is making travel by snowmobile increasingly life-threatening. Ship traffic in the Arctic is also increasing, bringing new risks to fragile ecosystems, and the Greenland ice sheet is continuing to send freshwater and ice into the ocean, raising global sea level In the annual Arctic Report Card, released Dec. 13, 2022, we brought together 144 other Arctic scientists from 11 countries to examine the current state of the Arctic system. Some of the Arctic headlines of 2022 discussed in the Arctic Report Card. NOAA Climate.gov...