Tuesday, 20 December 2016

Warm Arctic Storm to Unfreeze North Pole

Regions Near North Pole to Hit Above Freezing Three Days Before Christmas

19 December, 2016

In our cultural mythology we consider the North Pole to be this permanently frozen wonderland. And, during the 20th Century, the depiction was mostly true. Explorers venturing into the Arctic at that time found towering floes of ice — often measuring 15 to 20 feet high. And, up until the mid 2000s, the Arctic Ocean was permanently frozen from Continent to Pole even during summer. So adventurous skiers could strike out from northern Siberian, and treck to the pole over ice in months like June and July. Now such expeditions require the use of a kayak — if they occur at all.

(A warm storm over Svalbard joins with a chain of systems running from the North Atlantic to the Pole to drive gale force winds and above freezing temperatures into the Arctic in this December 22nd GFS model prediction. Image source: Earth Nullschool.)

Back then, the polar zone in the north appeared to be mostly solid. And if ice moved or melted — it was a slow grind or a rare event. No more. Now, Arctic sea ice extent values have plummeted and the thinner ice that remains is often melting, cracking, and mobile. Now, increasingly, during late fall and early winter temperatures have been rising to near or above freezing. Last year a powerful storm system pulled warming air up out of the North Atlantic — pushing temperatures over the North Pole to above freezing on December 29th. One month later, during late January of 2016, a similar weather system drove temperatures at the North Pole to near freezing.

This year, GFS model runs again show the potential for extreme above average temperatures in the region of the North Pole three days before Christmas. A storm in the Greenland Sea is predicted to strengthen to 940 mb intensity on the 20th and 21st. This system is expected to dredge warm air from the tropical North Atlantic and then fling it all the way to the Pole.
(Temperatures may rise to as high as 55 F [31 C] above average on December 22nd over sections of the Arctic near the North Pole. Note that this dynamic will tend to drive colder air out over the Continents — especially, in this case, toward Siberia. Also note that global temperatures remain well above average even when compared to the warmer than normal 1979 to 2000 time-frame. Image source: Climate Reanalyzer.)

As a result, temperatures in the polar region are expected to rise to near or above freezing. According to GFS model runs, the thermometer at 90 North is expected to hit around -0.3 C (31.5 F) at 0400 UTC on December 22. Meanwhile temperatures on the Siberian side of the Pole at 88 North, 109 East are predicted to hit 0.6 C or 33 F during the same time period. By comparison, temperatures in Southeast Texas at 27.9 N, 97.8 W — not far from from the U.S. Gulf Coast — were about -0.3 C on Monday morning following the passage of a cold front late Sunday.

This level of warmth during December for the Arctic is excessive and the expected readings are in the range of 25 to 31 degrees Celsius above average ( 45 to 55 Fahrenheit warmer than normal). These are near all-time record highs. But it is not just the extreme departures predicted for Wednesday that should be cause for concern, it’s the fact that such a high level of warmth for this region of the Arctic is occurring with a greater and greater frequency. For human-forced climate change — primarily driven by the burning of fossil fuels — is now in the process of radically changing the Arctic environment. And so much warming in the Arctic is a main driver of extreme Northern Hemisphere weather, of glacial melt contributing to sea level rise, and to severe loss of life among key Arctic species.

No comments:

Post a Comment