(Anomalous late season melt for Greenland along the coastal regions both north and south. Image source: NSIDC.)
It’s Fall in the Arctic. Temperatures are dropping. Sea ice is expanding. Snow and frigid weather slowly advance through these extreme northern lands.
But the pace of cooling this year — as in recent years — is far slower than what we would have typically seen just a few decades ago.
For in a crescent encircling the North Pole from the Laptev Sea through the Beaufort through the Canadian Archipelago and on into Greenland, temperatures are ranging between 5 and 12 degrees Celsius above average (9-20 degrees F). This extra atmospheric heat has tipped the entire Arctic into a +2.3 positive temperature anomaly — a rather high range for so early in the season. A strong polar amplification evident well in advance of a winter which is likely to see total positive anomalies reach between 3-6 C for the entire Arctic.
(GFS temperature anomaly map for October 9 of 2014 shows the world at a very hot +0.69 positive anomaly above the already hotter than typical 1979-2000 average. Arctic anomalies now average +2.3 C with spikes in the range of +12 C for some locations. Note the +3-11 C hot spot over Greenland. Image source: University of Maine.)
The oceans are bleeding record or near record heat into the Arctic atmosphere. The thinned sea ice, in the range of 6th lowest on record, allows more of that heat to hit the air. High amplitude waves in the Jet Stream deliver more heat than ever before from the lower latitudes. An a heavy overburden of greenhouse gasses — at even higher concentrations than in the rest of the world — traps more and more long wave radiation trying to escape into space as the sun’s angle lowers and the long winter night approaches.
For many regions of the Arctic, what this means is more Summer-like conditions continuing on into Fall. For Greenland, this has meant levels of melt that are more than two standard deviations outside the norm for the month of October.
Greenland Still Melting in October
Over Southern Greenland, we’ve seen temperatures in the range of 10 to -14 C from the coastline to the top of the ice sheet. And over Northeastern Greenland, we still see temperatures approaching freezing — an up shot of the warm air and water pool in the ocean zone between Greenland and Svalbard.
As a result of this lingering warmth, NSIDC measures are showing melt through substantial zones — one around the western coastal region near the Jackobshavn Glacier and another in Northeast Greenland in the Zachariae Glacier outflow region. Pushing melt totals more into the range of what is typical for either late May or early September.
(Greenland melt plot for 2014 showing 3-4 percent of the ice sheet melting during early October. A rate of melt outside the 2 standard deviation range and one that is highly atypical for this time of year. Image source: NSIDC.)
Throughout the next couple of days, unseasonal warmth is expected to build back into Southern Greenland and to possibly take root in the northwestern coastal region. With 5-18 C above average temps expected for many areas, it is likely that the abnormal Greenland melt will continue for at least the next couple of days.
As noted above, conditions remain in place for the Arctic to continue to experience highly abnormal warmth as Fall continues its advance into winter — with warmer than normal temperature departures likely to peak coincident with the deepest periods of Arctic darkness.
Hat Tip to Andy