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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