Conditions Promoting Arctic Sea Ice Collapse Are Exceptionally Strong This Spring

It didn’t take long for Arctic sea ice to start to respond to a fossil-fuel based accumulation of hothouse gasses in the Earth’s atmosphere. For since the 1920s, that region of ocean ice along the northern polar zone has been in a steady, and increasingly rapid, retreat. Rachel Carson wrote about the start of the Northern Hemisphere ocean ice decline in her ground-breaking 1955 book — The Edge of the Sea.

But it wasn’t until the late 1970s that consistent satellite observations began to provide an unbroken record telling the tale of Arctic sea ice decline. The National Snow and Ice Data Center, The Polar Science Center (PIOMAS), Japan’s JAXA, The Danish Meteorological Institute, and others have since that time provided a loyal recording of the stark impact human-forced warming has had on this sensitive and critical region.

(Severe sea ice volume losses since 1979 illustrated in the above video by Andy Lee Robinson.)

Perhaps the most poignant and direct telling of this tale has been provided in the form of Andy Lee Robinson’s tragic and resonant re-rendering of sea ice volume declines as measured by PIOMAS. Others, like Neven over at the Arctic Sea Ice Blog, have heroically and often thanklessly provided the essential week-to-week analysis of this tragic decline. Rising to the task of a necessary telling of a key chapter in the human tale that our mainstream media sources have all-too-often neglected. Before we go on to today’s update on an Arctic Ocean ice cap that is now in a critically weak condition, I want to add one last mention — these scientists, analysts, experts, and creative and artistically inclined laymen have done the right thing. They were the modern-day prophets providing the critical warning that has been oft-ignored.

A Tale of Devastating Losses

It’s a warning that has been written in the record of the ice itself. A decline that since 1979 has followed a steepening descent curve. An overall downward trend punctuated by the abrupt and severe loss years of 2007 and 2012. A trend that has, nonetheless, featured a few weak challenges in the form of pseudo-recovery years like 2008, 2013, and 2014. A precipitous loss that, all too soon, will likely terminate with abrupt finality in temporally-expanding blue ocean events. Periods when little or no sea ice is observed on the surface of oceans and seas within the Arctic.

JAXA sea ice

(After the warmest Winter and early Spring period on record, Arctic sea ice extent, area and volume are now at or near new record lows. With abnormal heat persisting and with the ice showing an extraordinary lack of resiliency, there appears to be a heightened risk that Arctic sea ice will hit new record all-time lows by September and October of 2016. Image source: JAXA.)

Why should we talk about blue ocean events now? Well, we have only to look at the sea ice record to find that substantial losses have occurred during single years. Years when Arctic heat hit new peaks — lining up with severe adverse weather conditions to take a terrible toll on the ice. Years like 2007 when nearly 2 million square kilometers of ice was lost over the previous year and 2012 which featured about 800,000 square kilometers of extent lost below the 2007 low mark. And if a blue ocean event does happen, it will be during one of these severe loss years.

Extremely Frail Sea Ice During the Spring of 2016

2016 and 2017 could be years when such precipitous declines occur. Heat from an extraordinarily powerful El Nino already skipped over the weakening atmospheric wall of the Jet Stream to invade the High Arctic during Winter of this year. As a result, Winter and Springtime Arctic temperatures are currently at their warmest levels ever recorded.

All this extra heat is doing a number on the ice. Sea ice extent, volume and area, which had experienced a false recovery during the years of 2013 and 2014, have again retreated to seasonally record low levels. In particular, the new near record low seasonal volume measure is disturbing. For while area and extent measure the expanse of surface ice as visible from above, volume measures the ice in three dimensions — giving a better idea of overall resiliency or lack thereof. It’s worth noting that the PIOMAS volume measure is based on a model of assimilated observational data. And, as with any model, there are a few assumptions built in. But overall, PIOMAS has tended to provide data that has matched with other observational findings.

Broken Beaufort

(Extreme fracturing of Beaufort sea ice over recent days has come after a record warm Arctic Spring and Winter and during a period when a powerful high pressure system has been breaking and compacting the ice. Image source: LANCE-MODIS.)

Sea ice frailty seen in the measures is also verified by current satellite observations of the ice surface. This frailty is particularly visible in the region of the Beaufort Sea north of Alaska and Canada. There, extensive fracturing of the ice is clearly visible in yesterday’s MODIS satellite shot. Here we find huge regions of thin ice and open water as the torquing influence of a powerful high pressure system has turned the greatly weakened Beaufort ice into a sea of ice cubes.

During recent years in the post 2012 timeframe, Beaufort ice has shown a considerable lack of resiliency to fracturing. This is particularly disturbing as, historically, the Beaufort Sea has tended to house the thickest, toughest ice in the Arctic. If such a great former bastion for the ice can now be torn to ribbons by the slightest fluxes of wind and weather, then the sea ice is, indeed, in a rather wretched state. And last year, just this kind of early fracturing and warm up in the Beaufort greatly contributed to an overall return to the trend of an Arctic sea ice death spiral in 2015.

Neven notes in a recent blog at his Arctic sea ice portal:

Last year’s April cracking event caused a lot of fragmented multi-year ice to be transported all the way up to the Chukchi Sea (see here), leaving a vulnerable looking barrier on the Pacific side of the Arctic. When this was followed by an early heat wave in May (see here), the ice in the Beaufort and Chukchi Seas received a beating it never really recovered from during the rest of the melting season. This was also because continental snow had melted out really quickly, making it possible for warm winds to blow in from the land.

Heating From Both Water and Land

Compared to last year, this year looks quite a bit worse. A wide-ranging Beaufort break-up is happening on the back of last year’s losses and is concurrent with new record and near record low sea ice extent, area and volume values and is happening during a period in which Arctic heat has hit new all-time highs. The result is a risk of compounding melt factors hitting the greatly weakened ice all at the same time.

Locally, the kind of widespread fracturing we now observe can result in a loss of protective reflectivity for the sea ice. As the Springtime sun rises and more of its direct rays fall upon the ice, darker thin ice patches and areas of open water will absorb more of the solar heat. That extra heat will then go to melting the islands of thicker ice that remain.

This situation can generate a compounding effect of ice losses if weather conditions and atmospheric temperatures line up. In addition, loss of the thicker sea ice cap during break-up can result in the ventilating of heat from the warmer waters beneath the ice. In fact, it is the heating of waters beneath the sea ice by means of current transport of warming ocean waters from around the world and into the Arctic that is one of the chief drivers of Arctic Ocean ice losses as the globe has been forced to warm by human fossil fuel emissions. So not only does an ice crack up in the Beaufort reduce the ice’s resiliency to the sun, it also tears the lid off the deeper ocean warming rising up from below.

Warmer Arctic Ocean Cooler Land

(Lower albedo due to ice fracturing results in more of the sun’s rays being absorbed into the ocean surface. A warmer Arctic Ocean surface then radiates more heat into the surrounding environment. Such conditions can result in periods when temperatures over the, previously colder and solidly frozen, Arctic Ocean are far warmer than even over land masses on the verge of tipping into a springtime thaw. Image source: Earth Nullschool.)

During Arctic Spring, when land surfaces are now retaining snow cover even as the sea ice breaks up, the effect of lower albedo and ocean heat ventilation can be found in the form of warmer temperatures over thin ice, broken ice, and in open water regions when compared to nearby land masses. Such a condition of newly added heat over ocean zones can have substantial impacts come Summer if melt-favorable weather patterns continue to hold sway. The result is a kind of melt synergy developing between the land, the waters, and the sun. Early on, during Spring, the warmer ocean zone weakens ice and provides warm air pools that aid in the initiation of snow melt over adjacent land. Then, as land warming ramps up, the warm winds coming from regions of early snow withdrawal provide further pressure to the already greatly weakened ice.

A Big Burly High as the Final Ingredient

Weather patterns that favor melt during Spring and Summer include powerful high pressure systems dominating large regions of the Arctic. And for much of the past week, an extremely intense high in the range of 1040 to 1045 mb has stooped over the Beaufort, torqued the ice, and developed the kind of strong clockwise wind flow that has tended to result in fracturing, ice compaction, and the opening of darker ice and open water areas (please read Neven’s fantastic recent blog on this observation here).

This kind of weather system is the last ingredient necessary to trigger an early, rapid melt for the side of the Arctic where the last of the thick, old ice now remains. And it appears that, for at least two weeks, such conditions will hold strong sway over the Beaufort.

So overall, more and more conditions are lining up to deliver a ramping up of melt pressure on the Arctic sea ice. Record atmospheric heat, early break-up, record low or near record low area, extent, and volume, and a powerful high pressure system over the Beaufort do not at all bode well. In fact, this looks like a near perfect early season set-up for a record melt in 2016 should this clearly ominous trend continue.

Links:

Beaufort Under Early Pressure

The National Snow and Ice Data Center

The Polar Science Center (PIOMAS)

The Danish Meteorological Institute

JAXA

Andy Lee Robinson

The Edge of the Sea

CIRES1

LANCE-MODIS

Earth Nullschool

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PIOMAS Volume Melt Slowed in May, Too Soon to Implicate Negative Feedbacks.

A slowing in sea ice area and extent melt during May has born out in the PIOMAS volume numbers. According to the most recent PIOMAS update, pace of Arctic sea ice volume melt remained about level during mid-to-late May. In past record melt years, 2011 and 2012 volume melt picked up by the end of May.

2013’s end May melt, however, was more gradual:

PIOMASmay2013

(Image source: PIOMAS)

As a result, sea ice volume has edged away from record low territory and is currently the third lowest in the measure.¬† It’s a number still quite close to record lows, sitting about 900 cubic kilometers above 2012 values. But closer yet is 2010, the 4th lowest year, which was about 200 cubic kilometers above 2013 by end of May.

Overall, Arctic sea ice volume is a bit more substantial, but still low enough to be worthy of concern. The reason is that, as noted before, the disposition of Arctic sea ice this year is, overall, thin and spread out. PIOMAS shows overall ice thickness just slightly above record low values. While Arctic Ice Blog Neven’s crude ice thickness calculator that simply divides PIOMAS volume by Cryosphere Today area shows ice currently at its thinnest on record:

Neven Ice thickness

(Image source: Neven)

It is also worth pointing out that Greenland and the Central Arctic above the 80th parallel has been somewhat cooler than average this May, despite large regions of substantial warming present in other areas. Whether this trend persists and whether it has an impact on melt for 2013, will be more readily apparent as June progresses.

Emergence of negative feedbacks?

A prolonged slow-down in sea ice volume melt would also begin to beg the question: have negative feedbacks started to emerge in the Arctic? Large influxes of fresh water from Greenland have been flushing into the Arctic since the early 2000s. So one wonders if such high volumes of cold, fresh water could be involved in rejuvenating the Cold Arctic Halocline (CAH) layer while at the same time pumping colder water into the North Atlantic.

This layer of cold water is a key protector of the Arctic ice pack. Over the past few decades, the CAH has been undergoing dramatic retreat. Its retreat is a primary reason why the sea ice is so vulnerable to impacts from a warming ocean beneath. (A number of scientific papers have been written on this subject. The Response to Climate Change of the Cold Arctic Halocline, Shielding Sea Ice from the Warm Deep Water Below is just one example.)

In the Antarctic, scientific research has shown that glacial melt on the Antarctic continent has provided a cold layer of protective water which, in turn, has made the sea ice more resilient there. So if 2013 melt does slow and we get a trend of slower sea ice melt years to follow, it will be worth investigating if such a negative feedback is currently active in the Arctic.

Evidence of Negative Feedbacks in Paloeclimate

An increasing pace of northern hemisphere ice sheet melt has also been implicated in past climate swings. The Younger Dryas period occurring about 12,000 years ago was initiated by the breaking of an ice damn in the Laurentide ice sheet which covered a large portion of North America. This ice damn collapse flooded cold water into the North Atlantic which initiated major swings in climate — setting off a period of colder temperatures that lasted for about 1,000 years.

Geological observations of such a large infusion of cold, fresh water provides an example of how large volumes of melt water can act as a negative feedback and cool the climate. Present day Greenland melt is substantial, averaging about 500 cubic kilometers per year, though certainly not as substantial as what occurred during the Younger Dryas. Nonetheless, Greenland and Canadian Arctic Archipelago glacial melt is likely to have an impact on both sea ice and climate as melt rates increase.

This will be something worth looking at if volume melt continues to slow and cooler conditions begin to persistently crop up in the Arctic. At some point, human greenhouse gas forcing is likely to achieve such an event. When this happens, Arctic temperatures are expected to cool even as warming increases in the lower latitudes. The weather consequences for such an event are quite dramatic (a subject worth exploring in another blog).

All that said, the above is purely speculative and we would have to see a more consistent slow-down in volume melt as well as a regime of cooler Arctic temperatures to validate such an occurrence.

Not out of the Woods Yet

So it is worth emphasizing that we are not out of the woods yet. One month of slower than blindingly fast volume melt in the context of some of the thinnest ice on record does not a trend make.

More ice volume remains in areas outside the Central Arctic Basin and so will be more vulnerable to mid-to-late-season melt. In contrast, Central Arctic ice is much thinner than usual, also making it vulnerable. So volume numbers will be more telling once we start getting substantial melt in Hudson Bay, Baffin Bay, and the Kara Seas. Speculation for a major June melt, for various reasons, is running particularly high (An interesting and well-thought-out take is that of Chris Reynolds over at Dosbat.).

This fragile state makes end of June PIOMAS numbers an important indicator. If temperatures are cool, the edge ice stays more resilient, the central ice is able to hold together under the pounding of our Persistent Arctic Cyclone (PAC) of 2013, and the pace of overall melt remains slower as volume numbers remain somewhat higher by end of June, then it becomes a bit less likely we will see another record year in 2013. Were such an event to occur, we’d have to revise our end-of-year melt risk estimate downward.

We are still in record low territory. June is a volatile month. And we have the PAC of 2013 as well as the potential emergence of warmer waters from the depths to contend with. So June is likely to be a very, very interesting month.

PIOMAS November Update Shows Sea Ice Thinner Than Ever: Volume More Than 1000 Cubic Kilometers Below 2011

The November update of the Polar Science Center’s PIOMAS sea ice volume tracker shows Arctic sea ice volume remaining in record low territory for the month of October. By month’s end, sea ice volume was still about 1096 cubic kilometers below the previous record low set in 2011.

Volume recovery during the seasonal re-freeze was lower than in 2011. During that year, sea ice volume in fall and winter rebounded to levels near those of the previous year. This year, however, the gap between 2011 and 2012 is much greater.

A number of factors kept Arctic re-freeze lower than in previous years. Sea ice has been pushed so far back that it simply takes longer and longer to recover. Warm water ocean currents are traveling further north, transporting more warm water into the Arctic environment later and later in the year. Atmospheric circulation has also changed. Large blocking patterns dredge warm air up from the south and deposit it in the Arctic. These same blocking patterns dump cold air, which once tended to concentrate in the Arctic, into temperate regions. The result of all this ocean and atmospheric mixing is that the Arctic is much warmer than usual and sea ice recovery mostly lags.

In his Arctic Sea Ice Blog, sea ice blogger Neven has also pointed out that it is likely sea ice is also thinner now than ever before. His rough graph combines PIOMAS volume and NSIDC sea ice area data to provide an estimate for average thickness. This month’s graph shows average ice thickness of less than 1 meter over the entire Arctic lasting through November 5th.

Neven’s previous rough estimates had shown average sea ice thickness did not pass below the one meter threshold at any time since records have been established. This year, average sea ice thickness dropped below 1 meter on October 21rst and has remained at that record low level through to November 5th.

Increasing scientific evidence and consensus points toward massively reduced sea ice area and volume resulting in chaotic and damaging weather patterns. Meteorologists and researchers from climate and weather disciplines have attributed Superstorm Sandy’s size, intensity, and path, to influences that have been made worse and worse by human caused climate change. Furthermore, powerful blocking patterns that result from the deterioration of sea ice have been implicated in wide ranging weather extremes including the current historic drought, powerful heat waves in Europe, Russia, and the US, and extreme rain and storm events across the globe.

In addition, receding sea ice kicks off a number of powerful global warming feedbacks that are likely to amplify human-caused climate change, heating the Earth at a faster rate. Loss of insulating sea ice also puts Greenland and West Antarctica at increasingly severe risk of increased melt. The result, in these cases, is much more rapid sea level rise on top of increasingly powerful storms. We are experiencing only the first outliers of these impacts now. So rapid reduction in greenhouse gas emissions can help to prevent the worst of a large pack of climate troubles now forming.

Links:

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

http://neven1.typepad.com/

 

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