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Arctic Ocean Deep in the Grips of May Temperature Spike; Beastly Summer Melt Season on the Way?

The Arctic Ocean as it appeared from space on May 6, 2018. Image source: NASA Worldview.

The Arctic sea ice is presently at its second lowest extent ever recorded in most of the major monitors. However, May is shaping up to be far, far warmer than normal for the Arctic Ocean region. If such high temperatures over this typically-frozen part of our world continue for much longer than a couple of weeks at this key time of year, precipitous summer melt is sure to follow.

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During recent years there has been much speculation about when the Arctic Ocean will start to experience ice-free summers as fossil fuel related industries pump higher and higher volumes of greenhouse gasses into the atmosphere. In the early-to-mid 2000s, scientific consensus was that melt would tend to be more gradual and ice-free summers would hold off until the final decades of the 21st Century when the world was around 3-4 C warmer than 19th Century averages.

But the Earth System is far more sensitive to temperature increases than the early forecasts expected. Major Arctic sea ice losses surprised the world during September of 2007 and subsequently in the same month of 2012. Now, it is obvious that a pattern of far more rapid sea ice melt has taken hold. And the scientific consensus appears to have settled on a more likely and much nearer date around the early 2030s — when the world will have warmed by about 1.6 degrees Celsius.

(An oddly warm pattern in which above freezing temperatures have come early to the High Arctic is setting up during May of 2018. Content Source: Climate Reanalyzer. Video source: Scribbler’s Youtube.)

However, when it comes to sea ice, nothing is certain at this time. Any single Arctic year in which temperatures spike — particularly during normal melt season — could result in the losses that we once expected to occur much later in time.

There are many factors that will ultimately determine when a summer ice free state occurs. Warm winters are a major one. And the past two years (2017 and 2018) have seen Arctic winters in which temperatures hit some ridiculous high extremes. But another major factor is the set-up to Arctic summer that takes place during the window months of May and June.

Neven, one of our best Arctic sea ice watchers (you can check his blog out here), notes:

May and June are very important for the rest of the melting season. Not only do we now see these warm air intrusions, but high pressure maintains its presence over parts of the Arctic as well (which means relatively cloudless skies -> insolation -> melt onset and melt pond formation -> preconditioning of the ice pack -> melting momentum that gets expressed during July and August, regardless of the weather)… We have to wait and see what happens, step by step, but this isn’t a good start for the ice.

If May and June are unusually warm, particularly over the Arctic Ocean, then the sea ice — which is already greatly weakened — is bound to face an extended period of above-freezing temperatures. If such a period stretches for 5 months from May through September rather than the typical 4 months (June to September), then we are more likely to see the Arctic Ocean briefly flip into an ice-free or near ice-free state for the first time in human history.

(The coming week is expected to feature between 1 and 10 C above average temperatures for locations across the Arctic Ocean. These are very strong warm departures during May. Last week saw similar extreme warm departures. And we are already starting to see sea ice losses pile up. Image source: Global and Regional Climate Anomalies.)

This year, May is shaping up to be much, much warmer than normal for the High Arctic. Already, a large May temperature spike has occurred (see right image below). A temperature spike which is predicted to continue for at least the next ten days.

Not to put too fine a point on it, but this severe warming trend might end up presenting a bit of a problem. The extended period of melt mentioned above may begin in force — setting off a chain of feedbacks that could tip the Arctic Ocean into a far less frozen or even an ice-free state (under absolute worst case scenarios) this year.

To be clear, this is not a forecast that such a condition is bound to occur during 2018. It is just an analysis of underlying trends and a statement that risks are higher if such trends as we now observe continue. Late May could flip to a cooler than normal regime. June could be cooler and cloudier than normal (as happened during 2016 and 2017). And if that happens again, we may be spared.

(Average Arctic temperatures for 2017 [left] and 2018 [right]. The red line depicts the yearly temperature trend. The green line depicts the Arctic climatological average for 1958-2002 [which was already warmer than normal]. Note the big temperature spike in the right hand graph. That’s where we are now. Image source: DMI. For further reference, see Zack Labe‘s composite temperature analysis for the 80 North region.)

However, we are already on a much higher ramp for spring temperatures in the northern polar region than during 2017. And though 2016 saw a slightly warmer than normal spring near the pole, the May 2018 spike already far exceeds anything we saw at that time. So much, in fact, that present temperatures for May 6 are comparable to those typically seen during early June from the 80 degree N Latitude line to the Pole.

This higher ramp and related record warmth is already accelerating melt. Sea ice losses over recent days have greatly picked up and we are getting closer to record low daily ranges. If melt accelerates to a point, the greatly expanded darker ocean surfaces will draw in more heat from the sun’s rays during June — potentially overcoming the impact of the increased early summer cloudiness we have seen during recent years. Such a scenario, if it continues to develop, would be a nightmare from the climate change perspective.

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Big Warm-up Predicted for Northwest Territory as Pacific Side of Arctic Melts Out Early

The long-term trend for Arctic sea ice is inexorably down. Year-after-year, decade-after-decade, the human-driven accumulation of heat in the Arctic has taken a terrible toll. Recently, mid March through mid April showed record low sea ice extents for any period since record keeping began in 1979.

Over the past two weeks, extent levels bounced back to around 4th to 6th lowest on record as winds shifted to north-to-south through the broad region between Greenland and the Kara Sea. For this region, melt pressure had been quite strong throughout Winter as a powerful warm flow of air flooded up from the North Atlantic.

Sea ice concentration

(Ice in the Bering and the Sea of Okhotsk is rapidly melting. Warming and sea ice melt ramp-up may also be on tap for both the Hudson Bay and the Beaufort as south-to-north air flows associated with the Ridiculously Resilient Ridge intensify. Image source: NSIDC.)

The shift, which has occurred coincident with upper-level winds running up from the Ridiculously Resilient Ridge in the Eastern Pacific, over Alaska and the Northwest Territories of Canada, into the Beaufort and on past the pole, has been pushing sea ice southward toward the Barents and into the Fram Strait. The result has been minor sea ice expansion in the near Greenland region at the cost of much more rapid melt in the Bering Sea, the Sea of Okhotsk and a very earl season break up of ice in the Beaufort.

Pacific Side Warming and Beaufort Break-up

Overall, this Pacific-side warming of the Arctic has driven extent levels back down into the range of 3rd to 4th lowest on record for this time of year. And rapid melt in the Bering, the Sea of Okhost, together with warming in the Beaufort and Hudson Bay may result in new challenges to record lows over the coming days.

By late April, break-up of Beaufort Sea ice is particularly dramatic with very large polynyas forming in a broad region into and north of the Canadian Archipelago and extending on into the off-shore region of the Mackenzie Delta:

Beaufort Sea Ice April 26 2015

(The Beaufort Sea shows extensive break-up and lackadaisical re-freeze on April 26th 2015. Note the extensive dark cracks and polynyas [holes] in the MODIS satellite image above. Such late-spring proliferation of polynyas and cracks can critically reduce albedo as melt season progresses. The Beaufort’s location also makes it vulnerable to continued warm air influx over a very warm Northeastern Pacific Ocean. Image source: LANCE MODIS.)

Temperatures within the Beaufort Sea and near the Canadian Archipelago are still cold enough to support some re-freeze in the Polynya regions. However, closer to the Mackenzie Delta, temps have trended more and more toward near freezing or above freezing levels (sea water freezes at around 28 degrees Fahrenheit). The result is a rather large region with no new ice formation.

More Warm air on the Way

As of 5 PM Eastern Standard time, temperatures in the Mackenzie Delta on the shores of the Beaufort Sea were pushing 32 degrees Fahrenheit. Meanwhile, 50 degree temperatures dominated the region of Great Slave Lake further upstream and southward. These readings are in the range of 8-15 degrees above normal for this time of year, resulting in an early melt pressure for the Mackenzie River and for coastal regions near the post-thaw river outflow zones.

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(Big warm-up near the Mackenzie River and through the Northwest Territory in April  28th’s GFS model prediction. Temperatures in the low 70s gather around Great Slave Lake as above freezing temperatures drift down the Mackenzie River reaching all the way to Arctic Ocean Shores. Note near and above sea water freezing temperatures [28 F] throughout the Bering, Beaufort, northwest sections of the Canadian Archipelago and Hudson Bay in the above image. Image source: Earth Nullschool.)

This warm pool is predicted to intensify through tomorrow with temperatures reaching the low 70s Fahrenheit (22 C) near Great Slave Lake and temperatures along Mackenzie Delta shores continuing to edge up over freezing. The warm pool will then linger for another few days before shifting east over Hudson Bay through early next week, pushing temperatures between 10 to 25 degrees Fahrenheit above normal there.

By late next week, long range forecasts show another warm ridge extension through the Mackenzie Delta and melt pressure on the near-shore Beaufort re-intensifying.

Overall, with Arctic Oscillation predicted to remain neutral, melt pressure in the Arctic would tend to reduce somewhat. However, with both Bering and Okhotsk rapidly melting out and with warmth predicted to persist and intensify for those seas as well as for the Beaufort and for Hudson Bay, it appears there’s an even shot that early melt season will proceed at a more brisk than typical pace — again challenging new record lows into early May.

Links:

National Snow and Ice Data Center

NASA’s LANCE-MODIS

Earth Nullschool

The Euro Model

The Arctic Sea Ice Blog

 

 

Pulse of Warm Air Brings Above-Freezing Temps to North Pole; Cyclone, Central Ice Thinning Projected to Continue

It’s happened. An early-season Scandinavian heatwave has pushed above freezing temperatures all the way into the central Arctic.

A powerful atmospheric blocking pattern that spawned record 80+ degree temperatures in Scandinavia this weekend has elongated, stretching all the way into the central Arctic. As the bulge increased in amplitude, it brought warmer air with it. Temperatures at the North Pole over the past week ranged from 5-10 degrees Fahrenheit. Now, we are seeing temps around 33 degrees, a range of ‘warmth’ usually reserved for mid summer.

You can see the culprit of this warm air injection on the map below. Note the large bulge in the Jet Stream appearing over Scandinavia and reaching all the way to the North Pole:

jetstream_norhem_00June3

(Image source: California Regional Weather Service)

This pulse of warmer air is now riding over regions where sea ice was thinned by a persistent, moderate-strength Arctic cyclone that lasted for about a week. The cyclone churned and dispersed the ice, causing large cracks to form even in a region very close to the North Pole. The freezing point of sea water is about 29 degrees Fahrenheit, so we’ll have to see if this warmer air combined with near constant sunlight has any further melting effect (see The Big Thin Begins to learn more about this event).

You can see these above -freezing temperatures running up over Svalbard and on to the North Pole on the map below. Note that temperatures displayed here are in Celsius, not Fahrenheit:

Northpoleabovefreeze

(Image source: Uni-Koeln)

Particularly interesting is that 40 degree F reading on the northeastern tip of Greenland. But the high 30s and low 40s blanket Svalbard as well.

Weather forecast model maps show this pulse of warm air persisting through tomorrow. Then colder air returns along with stormier weather.

A related feature is the persistent cyclone that chewed away at the central ice for much of last week. It has now transitioned to the Beaufort Sea where it appears to be strengthening. Intensification is expected to continue through tomorrow. Then, the cyclone is projected to swing back to the Central Arctic by late Tuesday, apparently feeding on warmer, moister air as it intensifies to a 980-985 mb low by early Wednesday.

CentralArcticLow

(Image source: ECMWF)

Longer range forecasts show the cyclone persisting as it continues its strange dance around the Central Arctic.

We’ll have to watch the ice pack for further breakage and fracture from these two events. A continued thinning of the central ice so early in the year would be unprecedented. Yet it seems possible enough to continue monitoring.

It’s worth noting that CICE model forecasts show the thickest sea ice just north of the Canadian Arctic Archipelago suffering a sustained thinning. This event, should it arise, would likely be the result of this persistent cyclone combined with intensifying warm air pulses:

arcticictn_nowcast_anim30d

(Image source: US Navy CICE)

Links:

California Regional Weather Service

Uni-Koeln

ECMWF

Ice Melt Season Begins In Arctic

IJISextentNeven

(Image Source: Arctic Ice Blog)

Neven, over at the Arctic Ice Blog, has tentatively called a beginning to the Arctic sea ice melt season. Neven notes that sea ice area according to Cryosphere Today reached maximum on February 27th and sea ice extent, according to IJIS reached maximum on March 15th.

It may be a bit early to say with complete assurance that the melt season has begun. But indicators do appear to be in line with Neven’s estimate.

All measures for extent and area are now showing the sea ice to be in slow decline. Further, powerful blocking patterns over Greenland and Eastern Siberia continue pumping warm air into the Arctic even as they assault the central and northern US with continued wintery weather. As we can see in the image below, temperatures are well above normal in the Arctic for this time of year.

WorldtempmapMar20

(Image source: NOAA)

Hotter than usual temperatures have settled over all of the Arctic with a particularly warm area hovering over Baffin Bay. These high temperatures combine with a powerful Arctic high pressure system and strong negative Arctic Oscillation to aid in sea ice erosion at the edges while stressing the central ice even as the sun begins to lift above the Arctic Circle.

Greenland is again gathering more heat energy than is usual for this time of year, with the current blocking pattern established directly over its western half. NSIDC has already noted a number of melt days for the south-east coast of Greenland and was forced to recalibrate their melt model early due to the winter emergence of heat baked into the ice sheet from last summer. This event resulted in both residual melt and higher ice-sheet temperatures.

Last of all, a large cracking event which began in February continues to expand over the Arctic. The most recent image from the Canadian Weather Office provides a very vivid picture of what’s happening:

Canadian weather office

The high pressure system currently dominating the Arctic provides very clear skies  over much of the region. So we can see directly down to the ice pack. There, the Beaufort Sea displays extraordinarily extensive cracking. To the north and east,  a thin line of cloud pushed up by warmer air to the south obscures a small section of the ice. But beyond that we see a region around the North Pole also displaying large and expanding cracks.

All of this — the cracking, the abnormal heat, the early Greenland melt and left over heat from last summer, would seem to mark a rather ominous start to the 2013 melt season.

Links:

http://nsidc.org/greenland-today/

Arctic Sea Ice Area Below 2.4 Million Square Kilometers

Today Arctic sea ice measurements showed a new low for area at 2.37 million square kilometers, 533,000 square kilometers below the record low set last year.

Sea ice extent remained stable, holding near its new record low of 3.68 million square kilometers for JAXA and 3.54 million square kilometers for NSIDC.

Based on satellite observation, it appears that ice has spread slightly even as it thinned and new holes opened up, suggesting weather conditions consolidating the ice sheet have relaxed somewhat.

Melt rates have leveled off a bit over the past few days. If this slowing continues, we may finally see the natural abatement that leads up to the end of a typical melt season. Currently, such a call is too early to make, but it does appear possible.

Current ice loss totals below previous record lows are as follows (parenthesis show previous record year):

JAXA Extent: -572,000 square kilometers (2007)

Cryosphere Today Area: -533,000 square kilometers (2011)

PIOMAS Volume: -400 cubic kilometers (2011)

NSIDC Extent: -630,000 square kilometers (2007)

By all measures this is a crash year likely second only to 2007. It is part of a much larger trend of sea ice decline that started at the beginning of the 20th century and has accelerated since the 1970s, reaching a particularly rapid pace over the past 10 years.

There has been lots of chatter over the cryo blogosphere today about potentials for future melt and the reasons this melt season happened. In short, it’s the record melt that shouldn’t have been. All other things being normal, we would have seen the recovery climate change deniers kept pointing toward. But all other things are clearly not normal and a number of people are doing their best to expose the underlying trends.

One of the underlying trends involves the large loss of sea ice volume seen in 2007 and 2010. In his excellent analysis of sea ice volume loss for 2010, Chris Reynolds recently noted:

“To dismiss 2007 and 2010 as mere weather driven events is to ignore the crucial fact that the forcings driving sea ice loss are unremitting and are not giving the ice time to recover. As the ice gets thinner open water formation efficiency goes up and weather driven loss events become more likely.”

You can read Chris’s full blog on the subject here.

It is these underlying volume losses that set the stage for this year’s large sea ice area and extent losses. It is also valid proof that global warming forcings have reached a point that is not allowing the Arctic sea ice to recover.

Links:

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi

http://arctic.atmos.uiuc.edu/cryosphere/

http://nsidc.org/

http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

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