Temperatures over the Arctic ocean are as much as 50 degrees F (30 Celsius) above normal. It's above freezing in places that are normally 20 below zero in degrees F. Arctic sea ice collapse on the Atlantic side has allowed warm storms to penetrate the central Arctic. This extreme heat is destabilizing the northern hemisphere's atmospheric circulation all the way up to the top of the stratosphere. (Full-size image here.)by Gaius PubliusNo, this is not a Season of Merry and Bright post, despite the phrase "North Pole" in the headline. It's a climate post, to keep you up on the news.Nick Visser writing at the Huffington Post:
North Pole Forecast To Be 50 Degrees Warmer Than Normal This WeekFor the second year in a row, the Arctic is way hotter than it's supposed to be. Temperatures in the Arctic are predicted to soar nearly 50 degrees above normal on Thursday [December 22] in a pre-Christmas heat wave that will bring the frozen tundra scarily close to the melting point.It’s the second year in a row the North Pole ― now in perpetual darkness after saying goodbye to the sun in late October ― has seen abnormally high temperatures around the Christmas holiday. It’s also the second time this year. In November, temperatures in the region skyrocketed 36 degrees above normal.The weather forecast adds to a string of climate change-related indicators setting off serious warning bells in 2016. Polar sea ice is at record lows, and during last month’s heat wave, the region lost 19,000 square miles of it in just five days. The National Snow and Ice Data Center called the melt an “almost unprecedented occurrence.”
And it's not just the North Pole: "The World Meteorological Organization has said it expects 2016 likely will surpass last year as the hottest year in recorded history."Changes in the Jet StreamIf you're thinking, "Well, we don't live in the Arctic, so it doesn't affect us ... yet," you'd be wrong. All of these changes to atmospheric temperature in the Arctic are affecting global air circulation, including the jet stream.From a highly technical post at Daily Kos by "FishOutOfWater," a geochemist by profession (emphasis mine):
The lack of sea ice has dramatically affected the northern hemisphere’s atmospheric circulation for months. The heat this fall has formed a warm dome over the Arctic ocean and provided moisture for deep, early Siberian snow. A record deep Siberian snow pack for October pushed south of normal developing a deep pool of cold air over central Siberia.The much larger than normal temperature contrasts (gradients) across Central Eurasia have intensified the polar jet stream across Asia and the north Pacific Ocean. This is a predicted consequence of intense early snowfall in Siberia associated with warm water entering the Arctic seas. This fall has had all time record minimum sea ice extent in the seas north of Eurasia and this unprecedented weather pattern is the atmospheric response to these warm waters so deep into the Arctic.Intense atmospheric waves, associated with intense storms have whipped across both the Pacific and Atlantic. When intense storms approached the Arctic from both the Pacific and Atlantic in late October the stratospheric polar vortex was pinched from both sides, a 2 wave pattern, and split in two.This stratospheric polar vortex split is unprecedented for so early in the Arctic winter season as far as I know. The stratospheric polar vortex is now unstable and may undergo a major midwinter warming in the next ten days [posted in mid-November]. It may be the earliest major midwinter warming ever seen.
More about the "polar vortex" and the jet stream:
When the vortex of the arctic is strong it is well defined, there is a single vortex and the arctic air is well contained; when weaker, which it generally is, it will break into two or more vortices; when very weak, the flow of arctic air becomes more disorganized and masses of cold arctic air can push equatorward, bringing with it a rapid and sharp temperature drop....When the polar vortex is weak, high pressure zones of the mid latitudes may push poleward, moving the polar vortex, jet stream, and polar front equatorward. The jet stream is seen to "buckle" and deviate south. This rapidly brings cold dry air into contact with the warm, moist air of the mid latitudes, resulting in a rapid and dramatic change of weather known as a "cold snap".[3]
This is what happens when the jet stream is destabilized and wanders ("meanders") due to a weak Arctic polar vortex.Meanders of the northern hemisphere's jet stream developing (a, b) and finally detaching a "drop" of cold air (c); orange: warmer masses of air; pink: jet stream (click to enlarge; source)It's beyond doubt that changes in the jet stream are changing our weather. And a "meandering jet stream" is more and more in our future, perhaps a permanent addition. Welcome to the anteroom of the Palace of Climate Chaos.Is it an emergency yet? (Click the link for something you can do about it.)GP
