Arctic Sea Ice Melt Analysis: The Concerning Development of a Beaufort Warm Pool During Late June

During 2016-2017, the Arctic sea ice, overall, has been hammered by far warmer than normal temperatures. The result has been continued record low Arctic sea ice volume and record low or near record low extent throughout the present period stretching from October of 2016 to late June of 2017. Now, the development of a pool of warm water in the Beaufort Sea even as a strengthening ridge is poised to inject more heat into this key region threatens to increase sea ice melt pressure as we enter mid-summer.

(Far warmer than normal conditions greatly impacted Northern Hemisphere sea ice during 2016 and 2017. Due to this heat spike, the sea ice is presently far more susceptible to summer melt pressure. Image source: NASA GISS.)

Counter-Trend Cooling in May — But Sea Ice Still in Record Low Ranges

Cooler than normal temperatures in the High Arctic during May and near average temperatures over the Arctic Ocean during June resulted in somewhat less less late spring and early summer melt than some had feared.

This counter-trend cooling has set up conditions where sea ice measures in both volume and extent have bounced closer to the 2012 line with PIOMAS departures remaining in record low ranges and JAXA and NSIDC extent measures tracking near second or third lowest on record.

(Region of interest for Beaufort warm pool development and predicted warm air injection over the coming days. The above graphic by Zack Labe compares present Beaufort and CAA conditions with those of last year when melt in the region was rapidly progressing.)

But despite a brief May respite from the most extreme heat of human-forced climate change, the Arctic sea ice remains very fragile and any added warmth at this time from either the ocean, the atmosphere or both can have an out-sized impact on end melt season totals.

Beaufort Warm Pool Development

Moving into Arctic mid-summer, primary factors of concern include both land and ocean surface temperatures as well as the potential development of various weather features harmful to sea ice. Trough development on the Russian side with ridge development over the Beaufort region is generally viewed as harmful — forming warm surface waters that can considerably erode old ice in the Beaufort and near the Canadian Archipelago, while generating a dipole temperature and pressure feature that produces winds which tend to enhance sea ice export through the Fram Strait.

(Warm surface water pool development in the Beaufort and Chukchi seas represents a melt hazard to sea ice if it continues to grow and gather heat. Hot spots currently forming in the Beaufort at 5 C above average in the DMI measure is therefore cause for some concern. The predicted development of a strong high pressure ridge injecting much warmer than usual temperatures into the region will tend to feed energy into these already-warm surface waters. Image source: DMI.)

Throughout June, this form of dipole has tended to emerge — with weak highs forming consistently over the Beaufort and with moderate-to-strong lows gathering on the Russian side centering on the Laptev Sea, but ranging into the Kara, East Siberian Sea, and on into the Central Arctic. This persistent dipole has also aided in the production of warm surface waters in both the Beaufort Sea and in the Chukchi. Sea surface temperatures in this region have already formed into a considerable warm pool with anomalies ranging from 2-5 degrees Celsius above average over an expanding region.

Predicted Injection of Warm Air of the Beaufort

During the coming days, a ridge extending over Northern Canada is predicted to drag a surge of warm air across both the Canadian Archipelago and the Beaufort Sea. Over-ocean temperatures in the Beaufort are expected to considerably vary above the norm — hitting as high as 48.6 degrees Fahrenheit (9.2 C) in some regions. An over-ocean value that is around 7-9 C above average for this time of year.

(Ridge development is expected to inject much warmer than normal temperatures over the already warm Beaufort Sea by July 2nd. This predicted event presents increasing risks of sea ice melt for a key Arctic region. Image source: Earth Nullschool.)

Since oceans tend to moderate both summer heat and winter cold, these are considerable local extremes. And in conjunction with a developing warm pool of ocean surface waters, such above average atmospheric readings represent a melt hazard to sea ice in the critical Beaufort basin and in adjacent regions. Ice in the Canadian Archipelago will also come under melt stress in the event that such a forecast trend develops. Meanwhile, the greatly reduced subset of multi-year ice floating just to the north of the Archipelago will also be subject to the warm air injected by the ridge as well as to the warming of nearby surface waters.

Risks Worth Monitoring

During 2012, the persistent development of a warm water pool in the Beaufort contributed to record low sea ice readings by late summer. This warm pool ate away at the ice edge, wrecking the multi-year ice even as it was eventually thrust into the Central Arctic by a powerful storm emerging over the East Siberian Sea during August. Similar warm pool formation at this time and continuing through July is cause for some concern, which is why a nascent warm pool development during late June is worth continued monitoring.

Links:

NASA GISS

PIOMAS

JAXA

DMI

Earth Nullschool

The Arctic Sea Ice Blog

Hat tip to Zack Labe

Hat tip to Greg

Hat tip to Wili

Arctic Sea Ice Flirts With New Record Lows Dragging Global Coverage Inexorably Down

It’s another winter of far above average temperatures for the Arctic.

Warm air has risen — south to north — over both the North Atlantic and Pacific. It has ridden through the Bering and Barents seas. And it has invaded an Arctic sea ice pack that is far, far more fragile than it has ever been in modern human reckoning.

image

(A parade of warm fronts predicted to run up through the North Atlantic and Barents between Greenland and Northern Europe and on up into the Arctic Ocean on Thursday, March 5. The warm fronts are indicated by regions of perpendicular wind flow across the meridional pattern running northward from the Eastern Seaboard of North America and on into the Arctic. It is a pattern we’ve seen frequently throughout the winter of 2014-2015. One that has resulted both in Arctic warming and extreme polar vortex excursions. Image source: Earth Nullschool. Data Source: Global Forecast Systems Model.)

The winds have been fed by the warmest ocean surface temperatures ever seen in the aftermath of the hottest year on record (2014). They have pushed against ice packs off Irkutsk in Russia. They have driven ice northward and melted it throughout the Bering. And they have pushed 10-20 foot waves against the ice along the coasts of Greenland, in the Strait near Svalbard, and in the Barents west of Novaya Zemlya.

Near Record Low Arctic Sea Ice

This warm air influx has had a strong effect on the sea ice. Even in the far north near the pole, sea ice has been occasionally observed to thin this winter, reaching 80-90 percent concentration in a broad patch just south of the pole. Marked thinning for an area from which thicker, multi-year ice has undergone an extended retreat and 2 meter thick ice is now the mainstay. A mere shadow of ice for a region that once featured great hills and mounds of stable ice bounded by bridges between the North American and Asian Continents.

Now, over the greatly thinned and reduced ice, periods when temperatures have neared or even exceeded the point at which sea ice melts (28 F) have become more and more common in a broad wedge covering the Arctic Ocean between Novaya and the pole itself. When combined with the warm waters continuing to invade the Arctic Ocean from the flanks and from below, it’s enough to have again pushed sea ice to near record low extents for this time of year:

chart

(Arctic sea ice extent for March 1 of 2015 shown by the purple line sandwiched between the orange line [2011] and the pink line [2006]. Yesterday’s sea ice extent was second lowest in the record with 2006 being the lowest and 2011 running in as third lowest for the date. 2012 [dotted green], 2007 [light blue] and 1979 [dark blue] were added for reference. Image source: NSIDC.)

At the current measure of 14,450,000 square kilometers, that’s well less than what we’ve seen during previous decades. More than 2,000,000 square kilometers, or about an area the size of Greenland, less than 1979’s extent for March 1, for example.

And the total could well go lower — testing new record ranges for early March. For the Arctic is about to see another major influx of warm air.

Starting tomorrow and through Saturday, warm southerly winds will ride up into both the Bering and through the Barents side of the Arctic Ocean east of Novaya Zemlya. The warm air influx will be strongest through the Barents region, pushing temperatures as warm as 30 F to withing 200 miles of the North Pole:

image image

(Forecast for Wednesday finds 30 F temperatures riding up through the Barents and deep into the Arctic Ocean to within 200 miles of the North Pole. Note that similar temperatures appear in Ohio on the same day in the second frame. Image source: Earth Nullschool. Data source: Global Forecast Systems Model.)

For comparison Ohio, many hundreds of miles to the south and well outside the Arctic, will see the same reading at the same time. It’s another major warm air influx that will again drive against the ice pack. A continuation of a decades long assault that will bring with it further threat of record lows in Arctic sea ice. One that could set the 2015 melt season up for a rather low launching pad if the major gains seen during this time of year in 2012, 2013, and 2014 don’t manage to materialize.

NASA Study Finds 35,000 Square Kilometers of Sea Ice Lost Each Year Globally

As Arctic sea ice faces the potential for new all-time lows, a recently released NASA study puts these losses in a global context.

This important broader assessment shows that both Arctic sea ice loss and global sea ice loss since 1979 has followed an unequivocal trend of thinning and recession. This ongoing loss is despite the fact that Antarctica has seen some minor gains in sea ice extent during that same period.

Claire Parkinson, author of the study, noted:

“Even though Antarctic sea ice reached a new record maximum this past September, global sea ice is still decreasing. That’s because the decreases in Arctic sea ice far exceed the increases in Antarctic sea ice.”

A graphic illustration of sea ice trends shows how rates of global and Arctic decline compare when adding in the slight and far more gradual sea ice gains occurring near Antarctica:

polar_trend_graphs_1979-2013

(NASA Polar Trend Graph shows Arctic, Antarctic, and combined global sea ice trends. Note the slight gain for Antarctica as compared to a precipitous fall for the Arctic even as the global trend shows a marked downswing. Image source: NASA.)

Massive losses in the Arctic are likely due to the fact that the sea ice there sits upon a warming ocean surrounded by warming continents. By contrast, Antarctic sea ice sits in the Southern Ocean whose surface waters are often cooled both by winds and by an increasing outflow of cold, fresh water from the melting Antarctic glaciers. Factors that serve as a minor surface counter-trend to the larger warming signal. A signal, that for Antarctica, is driving an assault of warm water at the ice sheets from the depth of hundreds of feet below the ocean surface.

Overall, the Arctic has lost of an average of 2 million square kilometers since 1979. Antarctic gains of about 700,000 square kilometers are enough to result in a global loss of around 1.3 million square kilometers over the period. That’s equal to about 35,000 square kilometers lost each year or an area the size of the State of Maryland.

Finally, it’s important to note that recent studies have shown (as hinted at above) that sea ice gain around Antarctica is being driven by cold water and ice berg outflows ramping up as the great glaciers of Antarctica increase their melt rates. The melt, which is driven by a pool of warm water expanding hundreds of feet beneath the ocean surface and at the base of ice sheets and ice shelves is creating a kind of heat conveyor which spreads cool water along the surface even as it pulls more warm water in from underneath.

So it appears even the slight ice gain for Antarctica has a connection to human caused warming. One that is even more ominously linked to an exponentially ramping rate of land ice loss from Antarctica itself.

Links:

NSIDC

NASA: Global Sea Ice Diminishing, Despite Antarctic Gains

Earth Nullschool

Global Forecast Systems Model

Expanding Arctic Sea Ice is Flooding Warning Bell

Cryosat Shows Rate of Antarctic Land Ice Loss Doubled During Last Decade

Hat Tips:

The Arctic Sea Ice Blog

Anna

Dnem

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