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Warm, Southerly Winds Gust to Hurricane Force Over Greenland in Staggering Early Season Heatwave — Temperatures Now Hitting up to 41 Degrees (F) Above Average at Summit

The wavy, crazy Jet Stream.

Over the past few years, it’s become more and more clear that a human-forced heating of the Arctic has basically driven the Jet Stream mad. Big loops, omega blocks, and huge ridges and troughs have all become a feature of the new climate we’re experiencing. Related to these features have been a number of superstorms, severe droughts, ocean hot and cold pools, and extreme rainfall events.

Trough US East Coast Ridge Greenland

(The Jet Stream once again mangled. A strong trough shoved cool air over the US East Coast this weekend as a facing ridge prepared to hurl a bulge of extreme warmth up and over Greenland on Monday. Image source: Earth Nullschool.)

As we have  seen with Sandy, the Pacific Hot Blob, the UK floods, The California Drought, the record Alaska and Canadian Wildfire Seasons of 2015, the Russian Heatwave and Fires of 2011, the Pakistan Floods of 2011, and so, so many more extreme weather events, these new climate features present a risk of generating extraordinary or never before seen weather. Intense storms, extreme winds, and extreme cold flashes and heatwaves can all be generated as the result of such mangled weather patterns. And for much of the North Atlantic this past weekend, such abnormal conditions dominated. The US East Coast experienced a freak cold flash, the UK was pummeled by yet one more unseasonable gale, but perhaps worst of all — a head of extraordinarily warm air roared northward, riding upon gale to hurricane force winds, setting sights on Greenland.

Cool Flash for Eastern US, Extreme Heat for Greenland

This past weekend, the US weather news was all awash with comments on Winter-like conditions in April for the Northeast and Mid-Atlantic US as a deep trough tore down from the Canadian Archipelago and Hudson Bay. The trough brought with it snow flurries, freeze warnings, and rather cold conditions for April to this region of the US. Temperatures ranged from 10-20 degrees (F) below average for this area. But compared to what was setting up to happen in the ridge zone over the Atlantic, the East Coast cool spell was quite mild considering the relative extreme heat readying for a Greenland invasion.

The warm wind pulse began in the North Atlantic in a tropical region near 26 North, 55 West. This warm air flooded in train over thousands of miles of open ocean. Running northward, it roared along the back of a high pressure system centered over the Mid Atlantic Ridge and in front of two strong lows — one centered near Newfoundland and a second over southwestern Baffin Bay.

In places, the pressure gradient between the lows and highs was so tightly packed that the northward flowing airs hit hurricane force. Off the southwest tip of Greenland, winds consistently achieved hurricane force gusts. And these winds flowed on northward, bringing with them a surge of above freezing temperatures to much of Baffin Bay and a large section of Western Greenland.

By 10:00 UTC, Monday, April 11th — Thule, on the Northwest Coast of Greenland near the Nares Strait was experiencing sustained southerly winds along the northern edge of this warm air pulse at 45 mph with gusts hitting a hurricane force 75 mph. Temperatures for Thule by that time had hit 34 degrees (F) or about 32 degrees (F ) above average.

Extreme Greenland Heatwave

(Extreme Arctic heat strikes Greenland on April 11, 2016. There readings for a large area hit a range 36 degrees Fahrenheit or more above average for a large region over Baffin Bay and Greenland. This extreme pulse of unseasonable warm air contributed to overall temperature departures of +4.75 C (8.55 F) above average for the Arctic. A very high departure for this region of the world at this time of year and an extension to a period of record Arctic warmth in 2016. Image source: Climate Reanalyzer.)

Further south, Nuuk was experiencing 45 F readings (or about 20 F above average) coordinate with heavy rain and strong southerly winds. Yet further south, in Kangerlussuaq near the southwest coast of Greenland, temperatures spiked to 61 F — or 36 F above the average April 11 reading of 25 F.

Perhaps more remarkable and disturbing were the predicted extreme readings at Summit Greenland — expected to hit 21 degrees Fahrenheit on Monday or about 41 degrees (F) above a typical daily high of -20 (F) for this time of year. It’s worth noting that in July average high temperatures for Summit Greenland usually range near 12 degrees (F). So current expected highs for April 11, 2016 are nearly 10 degrees warmer than a normal July day. By comparison, if such an extreme high temperature departure were to have occurred in my hometown of Gaithersburg, MD on the same date (April 11th), readings would have exceeded a remarkable 106 Degrees Fahrenheit.

Year of Record Arctic Warmth Continues

The recent warm, wet wind outbreak over Greenland is but one more odd event in a year of extreme warmth for the Arctic. Warm wind invasions over the North Atlantic, Barents, Baffin Bay, Greenland Sea, Western Europe, Alaska, Western Canada, the Barents, and sections of Central Asia have been a persistent feature throughout both Winter and Spring. Meanwhile, consistent temperature spikes to near freezing or above freezing over the Arctic Ocean and related waters have contributed to Arctic sea ice hitting new seasonal lows.

Freezing Degree Days NOAA

(Arctic heat has been literally off-the charts for the region above 80 degrees North during 2016. This area has now experienced nearly 1,000 fewer freezing degree days than during a typical year of the already warmer than normal 1980-2010 period. Extreme Arctic warmth of this kind has negative impacts both to the health of Arctic sea ice and to that of the various glacier systems in Greenland, Svalbard and Northern Canada. Image source: NOAA/CFSv2/CFSR.)

Overall, the Arctic has experienced unprecedented warmth for 2016. In reference to this fact, NOAA measures recording freezing degree days indicate that both the Arctic and the High Arctic above 80 degrees North Latitude are experiencing their warmest year ever recorded. These new extreme high temperatures are achieving an extraordinary departure above previous temperature measures and are a feature of the highest anomalies occurring over any portion of a record warm world. In other words, if you were to look for the region of the world that’s being hit hardest by a human-forced warming spurred on by rampant fossil fuel burning, the Arctic would light up like a fireworks display on the 4th of July.

Tropical heat, in the form of a record El Nino generated warmth, has tended to transfer pole-ward in the Northern Hemisphere during 2016 due to various weaknesses in the Jet Stream. A primary region for this transfer has occurred over the North Atlantic and Europe with secondary transfer zones over the Eastern Pacific, Western North America, and over a shifting zone throughout Northern Asia.

An extraordinary polar amplification of this kind — one that includes Equator-to-Pole heat transfers — risks hitting or increasing the intensity of a number of harmful climate tipping points. These include the amplifying feedbacks of increasing rates of sea ice melt and Arctic carbon store response. In addition, extreme warmth over Greenland risks further glacial destabilization, increasing rates of sea level rise, and increasing weather instability in the North Atlantic.

Links:

Earth Nullschool

Climate Reanalyzer

Thule Air Base Weather Statistics

Thule Air Base Current Weather Conditions

Nuuk Greenland Weather

Nuuk Climatology

Kangerlussuaq Average Temperatures

Kangerlussuaq Weather

Summit Greenland Weather

Summit Greenland Climatology

NOAA/CFSv2/CFSR

Hat Tip to Kevin Jones

Scientific Hat Tip to Dr. James Hansen

Scientific Hat Tip to Dr. Jennifer Francis

Scientific Hat Tip to Dr. Jeff Masters

 

 

 

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The Arctic Heatwave: Greenland, Alaska, Scandinavia, Heat Domes and a Mangled Jet Stream

Over the past year, we’ve now experienced three major heatwaves north of the Arctic Circle. Greenland melted under a freakish blanket of heat-trapping clouds, Scandinavia saw an early June heatwave that sent temperatures into the 80s, 30 to 40 degrees hotter than normal, and just this week Alaska experienced record heat that sent temperatures there into the upper 90s, probably the hottest temperatures ever recorded there.

Now, a combination of new research reveals changes to the Jet Stream that enable warm air to enter the Arctic even as a thickening atmosphere sets in place conditions where powerful ‘heat domes’ are more likely to form.

Unprecedented Heat, Melt In Greenland

Our story begins in Greenland during July of 2012. At that time, a powerful blocking pattern enabled a strong high pressure system to form over that frozen land. An upward swing in the jet stream pumped ever-warmer air over its vast ice sheets. Finally, record temperatures were reached both along the coast-line and even at the center of its three kilometer high glaciers. Temperatures in the Greenland interior rocketed to 60 degrees.

Greenland Melt 2012

(Image source: Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory)

Within only a few days, almost the entire ice sheet was experiencing some kind of melt. A record 90% of the ice sheet succumbed, far out-pacing the previous record of 52 percent set just two years before in 2010.

Draped over top of this melt was a freakish layer of low clouds. Clouds are, generally, thought to block heat from the sun. But, in this case, it appeared the clouds had locked heat in, recirculating it and keeping it close to the ice, forming a heat-trapping blanket over Greenland.

Far above this low cloud layer, the atmosphere was growing ever thicker. A towering high pressure system known as a heat dome was sucking in the warmer air from around and beneath it, trapping it in a denser and denser layer. From the south, a long-period, very persistent blocking pattern fed warmer, moister air into this heat dome. Meanwhile, the sea ice, which had tended to insulate Greenland from direct assaults of heat in the past, had retreated far behind its usual summer lines of defense.

As a result, Greenland baked.

In the media, contrarians did their best to down-play what was clearly a catastrophic event. They retreated to their usual ‘natural variability’ claims. But the closest event bearing any similarity to the 2012 event happened in the 19th Century and it didn’t occur at the end of a long string of worsening melt. Context formed a mire which contrarians were having ever-greater difficulties extracting themselves from.

The Scandinavian Heat Wave

But context was coming back to haunt us yet again as June 2013 rolled around. This time, another blocking pattern had emerged — creating a strange whirl in the Jet Stream. The path of atmospheric current followed a course much like a river bends through a marsh. It coiled, snake-like, bending back on itself, forming cut off circles.

This punch of colder air extended from Greenland all the way into central Europe. This extrusion of Arctic atmosphere resulted in one of the most extreme winter/spring periods Europe has ever experienced. Record snows were followed by record floods. By June, some water gauges on Europe’s largest rivers recorded the highest levels since the 1500s. It was the third 1,000 year flood to occur within the last 13 years.

But the colder, stormier air didn’t penetrate any deeper than Eastern Europe. There, it doubled back on itself, heading up and back into the North Atlantic. In front of this coil of air, this blocking pattern that had persisted over Europe since winter, rose a burst of heat. This pulse flowed into Scandinavia where it stagnated. Heat pooled in this region and, in a few days, records were being shattered across such improbable Arctic regions as Finland. 80 degree temperatures reigned in a region that usually experienced 40 degree weather this time of year.

In about a week, the Scandinavian Heat Wave had backed off, but temperatures remained well above average into mid-June.

The Alaskan Heat Wave

But heat was, again, about to re-emerge just two weeks later in another improbable region of the Arctic.

This time, a blocking high pressure system that had created a high amplitude wave in the Jet Stream over the Pacific Ocean just south of Alaska and west of British Columbia was about to preform an exotic trick. Alaska, resting just north of this blocking ridge had lain beneath a front of cold air for much of May. So while areas of California, Nevada, Arizona, Washington, Oregon, and British Columbia were experiencing abnormally warm conditions, Alaska experienced temperatures that had plunged into record low territory for many cities.

Contrarians proclaimed the end of global warming for Alaska. But the heat was coming and they only had to wait one month. By June, the blocking pattern which had kept cold air to the north and warmer air to the south began to edge into Alaska. Temperatures flipped from the 20s to the 70s for many regions. Barrow, which had experienced a warmer than average winter and spring, saw temperatures rise into what, for it, was the balmy 40s.

But this pulse of warmer than average air wasn’t finished. The current of Jet Stream cut off, giving this warm high pressure system an encapsulating band of winds. Conditions were now right for the formation of another heat dome. And form it did. By Monday of this week, temperatures had rocketed to 98 degrees in some places of the Alaska interior, possibly breaking the all-time record high for the hottest temperature ever recorded, at any time, in Alaska.

Today, temperatures for Barrow, one of the coldest cities on Earth, are projected to hit 70 degrees, about 31 degrees above the average high for this time of year.

Greenland, Scandinavia, Alaska, three record heat waves above the Arctic Circle all in the last year. What in the world had happened to the weather?

Enter the Experts…

A number of climate scientists and meteorologists have begun to grapple with the new, unstable regime of weather gripping the Arctic. These include Dr. Jennifer Francis of Rutgers University, Stu Ostro of The Weather Channel, and Dr. Edward Hanna of the University of Sheffield.

Dr. Francis, last year, provided compelling scientific evidence that the erosion of Arctic sea ice and the rapid melt of Northern Hemisphere snow cover during the summer time resulted in changes to the Jet Stream. This erosion of sea ice and land snow resulted in less of the Arctic’s cold air being trapped within the Arctic. It also resulted in more floods of warmer air coming up from the south. This north-south motion of air masses had the net effect of reducing the temperature difference between the Arctic and the mid-lattitudes. As a result, the river of air surrounding the pole known as the Jet Stream began to slow down, forming large dips and bulges.

As these dips formed and the air slowed, the Jet Stream had more of a tendency to become stuck. This sticking in place created ‘blocking patterns’ in which a given set of weather was more likely to persist over long periods of time. Recent examples of these blocking patterns and their related weather include Europe’s extreme winter and spring of 2012-2013 and the 2012 US Heatwave and related 2012-2013 drought. Further, without the collision of Arctic and Tropical air masses enabled by a massive dip and up-swing in the polar Jet Stream near the US East Coast, it is doubtful that the Hybrid Superstom Sandy would have ever formed.

Dr. Francis notes an increased frequency of such extreme, blocking pattern spawned, events and the picture she paints provides us with a much better understanding of how climate change is impacting our weather.

Recently, Dr. Francis spoke on the subject of climate change in an event entitled “The Alarming Science Behind Climate Change’s Increasingly Wild Weather”  with the weather Channel’s Stu Ostro. Stu brings a different yet complimentary set of knowledge to the new observations presented by Dr. Francis. Over the past couple of decades, Stu has noted what appears to be a ‘thickening’ of the atmosphere. He equates it to a cake batter which, when heated, tends to rise. This rising atmosphere, according to Stu, has led to the formation of powerful, persistent high pressure systems. As Stu noted in a recent article in Mother Jones:

“The frequency of these really strong ridges of high pressure aloft, these anomalous high pressures aloft are increasing.”

And the result is some rather alarming consequences.

A recent paper headed by Dr. Edward Hanna at the University of Sheffield implicates both the mangled Jet Stream and a powerfully thickened high pressure system in the record 2012 melt in Greenland. According to the paper:

Our analysis allows us to assess the relative contributions of these two key influences to both the extreme melt event and ongoing climate change. In 2012, as in recent warm summers since 2007, a blocking high pressure feature, associated with negative NAO conditions, was present in the mid-troposphere over Greenland for much of the summer. This circulation pattern advected relatively warm southerly winds over the western flank of the ice sheet, forming a ‘heat dome’ over Greenland that led to the widespread surface melting.

Dr. Hanna’s paper pointed out the movement of warmer air over Greenland via a strong blocking pattern in the Jet Stream and the building up of a powerful ‘heat dome’ and blocking high pressure system over the ice sheets. Hanna also added the contribution that lower level clouds enhanced, rather than inhibited, melt.

Together, this research points toward how receding sea ice and a warming climate are setting in place conditions that are causing these Arctic heat waves. And the recent heatwaves in Greenland, Scandinavia, and Alaska provide excellent illustrations of the kind of events we can expect with greater frequency in the future.

Links:

Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory

Dr. Jennifer Francis: Understanding the Jet Stream

One Meteorologist’s Come to Jesus Moment on Climate Change

‘Heat Dome’ Melted Ice Sheet in 2012

Atmospheric and Oceanic Climate Forcing of the Exceptional Greenland Ice Sheet Surface Melt in Summer 2012

Heatwave Sends Temperatures in Alaska to 94 Degrees

Human Climate Change is Wrecking the Jet Stream: UK Met Office Calls Emergency Meeting

Arctic Sea Ice Melt, Methane Release Shows Amplifying Feedbacks From Human-Caused Climate Change

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