Pages

Tuesday, 22 December 2015

Record Hot Arctic

Record Hot Arctic: NOAA’s 2015 Report Card Shows Signs of Failing Climates

21 December, 2015


In NOAA’s most recent annual Arctic Report Card, the records just keep falling as the litany of global warming related events appearing throughout the far north continued to crop up with ever-more dizzying frequency




The 12 month period of October 2014 to September 2015 was the hottest one year time-frame since record keeping began for the Arctic back in 1900. As a result of these record warm temperatures, Arctic sea ice during the Winter hit its lowest maximum extent ever seen. Summer sea ice extent was likewise greatly reduced hitting its 4th lowest extent ever recorded. Old, thick sea ice which represented 20 percent of the ice pack in 1985, has precipitously declined to a mere 3 percent of the ice pack today. Snow cover also took a hit, declining to its second lowest extent on record during 2015 and striking a range of 50 percent below the typical average for the month.
Overall warming of the Arctic is at a much more rapid pace than the rest of the world. This accelerated pace of warming is due, in large part, to loss of snow and sea ice reflectivity during the Spring and Summer months. As a result, more heat is absorbed into dark land and ocean surfaces — a heat that is retained throughout the Arctic over longer and longer periods. And, though NOAA doesn’t report it in the above video, overall higher concentrations of greenhouse gasses like methane and CO2 in or near the Arctic region also contribute to a higher rate of warming (see NOAA’s ESRL figures). In a world that is now rapidly proceeding beyond the 400 ppm CO2 and 485 ppm CO2e threshold, this is exactly the kind of Northern Hemisphere polar amplification we would expect to see.

Warm Winds, Greenland Ice Sheet Melt, and Mass Migrations

NOAA notes a marked change in the distribution of life with mass migrations of all life forms well underway in and around the Arctic. Transitions and disruptions are most highly visible among marine mammals like walruses and polar bears — who are increasingly forced to live on land during the summer months. Meanwhile, an ever-broadening number of non-native fish are invading the Arctic from the south.
south-to-north-weather-pattern-alaska
(South to north weather patterns, like the one featured above, have increasingly drawn warm winds up and over Alaska. An anomalous new weather feature that has merited comment in NOAA’s recent annual Arctic report card. Image from “Arctic Heatwave to Rip Polar Vortex in Half”.)

NOAA also links the warm wind invasion events reported on widely here to the second worst wildfire season ever to strike Alaska in 2015. A dipole feature that displays teleconnections between Arctic snow and ice loss, the hot blob of water in the Northeastern Pacific, and the persistent trough that prevailed over the US East Coast during the Winter of 2014-2015.

Finally, Greenland Ice Sheet surface melt hit a maximum coverage above 50 percent for the first time since the extreme melt that occurred in 2012. NOAA notes that the amount of ice delivered to the ocean by glaciers also increased across Greenland even as recent studies continued to find an increasing prevalence of glacial destabilization and acceleration among Greenland’s ocean-terminating glaciers.
NOAA concludes: “Taken together, 2015 shows a continuing set of major changes in the Arctic.”
Links:
Hat Tip to Alexandr

No comments:

Post a Comment

Note: only a member of this blog may post a comment.