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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

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Summer 2014 Melt Season to Ramp up in Early May Heat Wave: Fixed Jet Stream, Dual Ridges Form Sea Ice Achilles Heel

For many months the weather pattern has been essentially fixed. A ridge over China and Eastern Russia combined with warm air flows over Central Asia to amplify heat from Siberia and on into the Arctic Ocean. On the other side of the Pacific, a harmonic pattern involving warm southerly air flows over Alaska and Western Canada has also transported an inordinate amount of highly anomalous heat into the Arctic.

These warm ridges have been consistently reinforced by high amplitude Jet Stream waves. During the Winter of 2013-2014, these same atmospheric heat transport engines collapsed the polar vortex, causing melt, avalanches, and 60 degree F temperatures for Alaska in January all while pulling Arctic air down over the Eastern United States throughout the winter months.

For Alaska, Western Canada and the Eastern US, it is a general pattern that has now lasted nearly 14 months. A blocking pattern that weather historians everywhere should take note of as a general evidence of atmospheric changes resulting from human-caused warming and a validation in observation to the findings of Dr. Jennifer Francis.

Early Season Melt in the Bering Sea

This warm air flow also severely retarded sea ice formation in the Bering Sea between Alaska and far Eastern Russia throughout winter. Now, this poorly formed ice is rapidly melting out as a barrage of storms and continued warm, southerly air flows result in ongoing degradation. Recent observations show a rather extreme loss of sea ice in this region over the past 18 days:

Bering and Chukchi Seas April 10Bering and Chukchi Seas April 27

(LANCE-MODIS comparison of Bering and Chukchi Sea Ice on April 10 [left image] and April 27 [right image]. Image source: LANCE MODIS. Hat Tip to Arctic Sea Ice Forums Poster Frivolousz21.)

As we can clearly see in the two images above, both snow cover and sea ice have experienced severe losses in this region from April 10 to April 27. Warm southerly winds have continued to push ice northward enhancing melt as temperatures typically remained near or above -2 C (the temperature at which sea ice begins to melt) in most regions. Snow losses amplified warmer than freezing water flows into adjacent ocean basins, also enhancing sea ice losses as land masses continued to warm.

Heat Pulse for Bering, Chukchi, East Siberian and Beaufort Seas

Over the next six days, this general warming trend is expected to spike, bringing with it a front of much hotter than usual temperatures extending along a broad zone of the Arctic Ocean north of Canada, Alaska and East Siberia and nearly reaching the North Pole at maximum extent.

The pulse is expected to bring 18-32 F above average temperatures for this region, pushing daily highs into the mid 30s to mid 40s over the Arctic Ocean and to nearly 50 F over waters directly adjacent to the Alaskan coast. GFS model runs for May 2, 2014 show this powerful warm air invasion, indicated by the wave of green on the map below, extending well into the Arctic Ocean with extraordinarily warm temperatures in the mid-to-upper 60s over a broad swath of Central Alaska:

Arctic Heatwave Friday May 2

(GFS temperature model for May 2, 2014. Image source: University of Maine.)

Such an intense warm pulse will greatly involve the Bering, the Chukchi, the East Siberian and Beaufort Seas. It will likely most significantly impact sea ice in regions of the Bering Sea and near-shore zones of the Chukchi and Beaufort. The early season heat wave may also enhance the ice weakening process throughout the affected zone by softening the sea ice and by creating the potential for melt pond formation.

The Major Impact of Early Season Melt Pond Formation

During May and June, early melt pond formation can have a dramatic impact on sea ice melt much later in the season as the darker pools reduce ice sheet albedo serving as a kind of heat lens that bores down through the ice surface. Eventually, the melt ponds connect, forming larger and larger volumes over the ice face until the sea ice is almost completely overwhelmed. In the last phase, melt breaks down through the ice surface to contact the ocean. At this point, the sea ice is typically splintered into much smaller and disassociated fragments.

A recent paper in the journal Nature has found that a multiplication of such early season melt ponds may well be a predictive indicator of end season sea ice extent, area and volume values come September.

The paper notes:

Our simulations show that melt ponds start to form in May, a maximum extent of 18% is reached in the climatological mean at mid-July, and there are hardly any exposed ponds left by mid-August. The strong interannual variability and the positive trend are striking. Whereas in 1996, the year with the highest September ice extent since 1979, the maximum pond fraction reaches only 11%, in 2012, the year with the lowest September ice extent, up to 34% of the sea ice is covered by ponds.

Neven over at the Arctic Ice Blog recently provided an excellent assessment of the impact of melt ponds which is available here.

Massive interconnection of sea ice melt ponds

(Major expanse of dark sea ice melt ponds in the Chukchi Sea during June of 2010. Image source: The Polaris Project.)

Achilles Heel For the Arctic During the Summer of 2014

The most recent hot pulse for this region may just be the first of many as the spring and summer melt season progresses. Jet Stream patterns continue to remain fixed, delivering much hotter than normal temperatures throughout the Western Canadian, Alaskan, and East Siberian regions. Furthermore, snow cover losses for these regions are particularly well advanced further enhancing the likelihood of warm air invasions from these rapidly heating continental zones. Anomalously large and extreme early season fires may also result in a degree of albedo loss as smoke and soot is drawn northward to darken both remaining snow cover and sea ice.

As such, this zone represents a kind of sea ice Achilles heel as the 2014 melt season progresses. If we do see major losses and a progression toward record melt, it will likely come as a result of extreme weather patterns emerging from the continental zones spanning East Siberia, Alaska and Western Canada.

Links:

LANCE MODIS

Arctic Sea Ice Forums

University of Maine

Global Forecast System Model

More on Melt Ponds

September Sea Ice Minimum Predicted By Sea Ice Melt Pond Fraction

 

 

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