Arctic Sea Ice Bounce Wiped Out as 2015 Summer Tracks Third Lowest on Record

It’s been a rough summer for the Arctic sea ice. Extent values started off at record low levels during late spring, melt ponding and warming ramped up during early June, and July saw the ice pounded by intense high pressure cells located on the Greenland side.

Sea surface temperature anomalies

(Abnormally hot water surrounds the Arctic sea ice on all sides. High sea surface temperature anomalies in this range tend to aid in the maintenance of late season melt momentum. Image source: DMI.)

Warm Waters and Airs

Anomalously warm water invaded from almost every side. The Kara saw extreme sea surface temperature warming after an early ice recession, a flood of warm water from rivers, and a powerful albedo flip to dark ocean from white ice. The Chukchi, Beaufort, and East Siberian seas saw a continued influx of anomalously warm waters from the Pacific side — this flow was fed by the powerful and persistent blobs of warm water in the Northeast Pacific. A heat invasion that has been ongoing for that region since at least Winter. And in North Baffin Bay a pool of anomalously hot water has combined with an extended period of warmer than usual air temperatures to deliver heat to the remaining thick ice along the Northern Greenland and Canadian Archipelago boundary.

Warm Storms Smashing the Old Ice

By August, a series of storms had invaded the Beaufort, Chukchi and East Siberian Seas. Kicking up 20-35 mile per hour winds, they pushed 2-7 foot swells out through an expanding shattered ice zone. Though the storms cooled the air, they tapped heat from the ocean itself through the process of surface churning and the larger dynamic of cyclonic Ekman pumping. All this motion and heat energy created a very unfavorable environment for sea ice — essentially melting the ice rafts out from the water line on up.

Beaufort July 22

Beaufort August 4

(Top [July 22] and bottom [August 4] comparison of the same Beaufort grid showing large rafts of multi-year ice gradually being smashed to finer and finer pieces. Image source: LANCE – MODIS.)

Large pieces of multi-year ice were smashed together like rocks in the late 20th Century video game — asteroids. The ice, ground into ever-finer bits by these storms, then felt the heat of the moving waters and suffered an ongoing dissipation.

The result is that the Beaufort ice is being steadily hollowed out. A bank of thicker ice floes is expanding into the warmer waters of the Chukchi and near-shore Beaufort as it melts. This leading ice edge, though frail, is denser than the interior ice for scores of miles where three large polynyas are in the process of joining into one. If this keeps up for too much longer, the next ten-to-twenty days will see the Beaufort ice and the Chukchi boundary ice practically wiped out.

Melt Invading Past 80 North

Meanwhile, thinned ice and open water is gradually invading the Central Arctic past the 80 North Latitude line.

Arctic sea ice early Augustarctic_AMSR2_visual_small

(Arctic sea ice appears to be in a terrible state  in the AMSR2 visible measure. Beaufort and Chukchi ice continues dramatic thinning. Central Basin ice is retreating in numerous places behind the 80 North line. And the fabled Northeast Passage is open to shipping. Image source: Uni Bremen.)

Heat from the Atlantic side is eating away at the ice edge there. Laptev melt is biting in beyond the 80 North line. And the Beaufort storms are basally melting and dispersing the Central Arctic boundary ice. As a result, the monitors are showing sea ice that looks to be in a very unhealthy state overall. The Northeast Passage is open and the Northwest Passage appears to be just a week or two behind.

The Rebound is Wiped out in all Major Monitors

As a result of all this punishment, the sea ice monitors are looking increasingly bleak. Japan’s JAXA extent monitor is showing sea ice boundary measures in the same range as third lowest year on record — 2011. The National Snow and Ice Data Center measure is not too far behind at just a hair above 2011 and 2010 — now tracking at 5th lowest extent on record (a loss of two places since last week). These extent measures are swiftly catching up to the Cryosphere Today area totals that are now also just a hair above 2011 at 4th lowest on record. The area measure is also interesting in that overall area is at 4.13 million square kilometers — which is now starting to dip below the 2005 line.

But perhaps most concerning of all is the fact that sea ice volume, which showed a brief bounce back from 2012 record lows during 2013 and 2014, is now re-entering decline. For According to PIOMAS, the ongoing punishment we have visibly seen in the form of high atmospheric temperatures north of the Canadian Archipelago and in remaining thick ice being swept into the billiards pool that is the Beaufort has pushed that volume measure well below the 2014 line and back toward recent record low years.

Sea ice Volume Losses PIOMAS

(PIOMAS volume measure takes a nose-dive in July. Continued losses at this rate would put sea ice volume in the range of lowest years recently observed. Image source: PIOMAS.)

It’s a steep nose dive. One that will start to challenge the upper boundary of record low years without a slowing in the rate of losses soon.

Storms, Ocean Surface Warmth, El Nino Heat Transport, and Beyond 80 North Melt Drive Late Season Loss Risk

With a month and a half of melt still to go, we could see a softening in this high rate of loss and an adjustment that brings use closer to 2014 for end season. Or we could see the steep rate of loss continue to challenge the 2011 boundary in some measures and possibly even break lower to challenge 2007. But given the melt momentum coming out of July, it is very unlikely that measures return to 2014 levels. As a result, it looks like the summer of 2015 is wiping out the post-2012 sea ice bounce which, given the massive pace of human-forced warming and failing to see large enough melt from Greenland to counter that trend in the Arctic, appears to have been inevitable.

Looking forward there appears to be four factors that will play out their final hands for 2015 melt. The first are those very warm sea surface temperatures we mentioned earlier. The second is the fact that this is an El Nino year featuring a very warm Northern Pacific and a strong northward heat transport through the Canadian Archipelago and Alaska. The third involves the weak sea ice and persistent storms in the Beaufort, Chukchi, and ESS. And the final major factor involves the strong advancement of melt into the Central Arctic and the higher likelihood that the below 80 North boundary ice will be wiped out in the coming weeks.

sst.daily.anom

(The northward propagation of anomalously warm ocean surface waters is bad news for late season sea ice. Extremely warm Northeastern Pacific surface waters and an associated El Nino warming of the Eastern Pacific equatorial waters creates a pathway for warm air transport into the Arctic over Alaska and Canada during late summer. Such a situation may result in an extension of late season melt beyond the September 15 date. Image source: NOAA ESRL.)

Abnormally warm sea surface temperatures plus the atmospheric feedback of El Nino hint that more energy to melt ice may remain in the Arctic for longer than during a typical year. Current transport of that abnormally warm water into the Chukchi, East Siberian Sea, and the Beaufort will continue. And the El Nino tendency to push warm air up over Alaska and the Bering will be reinforced by the strong warming in the lower Chukchi. These factors will tend to extend late season melt. Over on the Atlantic side, a similar dynamic is starting to come into play. Warm waters in the Laptev and Barents are increasingly being driven against the edge ice past the 80 North boundary line by warm southerly winds and through the action of storm systems invading the upper North Atlantic. Over the past few days a pattern has emerged in the models indicating an influx of these storms past Iceland and into the Barents near Svalbard. Swell propagation and warm water driven north will have a deleterious effect on the ice there.

As storms rise up from the North Atlantic, storms are predicted to continue to plague the ice in the Beaufort, Chukchi and East Siberian seas. According to GFS model runs, this tendency continues through at least the next five days. And with warm air firmly in place over Alaska and the Chukchi, while cooler air sits over the Beaufort, the gradient necessary to fuel these storms will remain in play. Ocean state forecasts pick up seven foot swells in the East Siberian Sea tomorrow, nine foot swells in the Chukchi on Friday, and 3-4 foot swells ranging the thick ice billiard room in the Beaufort on Sunday. Swells in the Laptev open water are also predicted to hit 6-7 feet over the coming days.

Stepping back and looking at the overall distribution of the sea ice, we find that much of the beyond 80 North region is invaded by melt. A substantial amount of weak boundary ice remains in the Beaufort, the Chukchi, the East Siberian Sea, near the land regions of the Laptev, and within the waterways of the Canadian Archipelago. Ice in these outlier regions is traditionally more vulnerable to rapid melt and it is doubtful that much of it will remain by end season.

Wipneus amsr2 graph

(Arctic Ocean sea ice extent measures are tracking in the range of 2012 according to the above graph by Wipneus. Low values that, entering final stage melt for August and September, may swing the overall measures lower come end season. Image source: Wipneus.)

Meanwhile, the beyond 80 North melt invasion is substantial to the point that we are now very close to the 2012 melt trend line in that key region. In fact, pretty much all the interior Arctic Ocean seas show extent values tracking near the 2012 record low line.

These low Arctic Ocean values imply a deeper vulnerability to hitting lower end season totals. A vulnerability the overall measures, so far have missed.

Links:

DMI

LANCE – MODIS

Uni Bremen

Arctic Sea Ice Graphs

Neven Sea Ice

JAXA

NSIDC

Cryosphere Today

PIOMAS

NOAA ESRL

Wipneus

Earth Nullschool

Advertisements

Arctic Sea Ice Now Below 2014 in All Major Measures — Warm Storm Settles In

When looking at Arctic sea ice melt, there are trends and there are bounces. The great 1979 to 2015 melt we call a trend. The 2013 and 2014 rebound from all-time record lows during 2012? That we call a bounce. But it’s starting to look more and more like the bounce is ending and the long-term melt trend is starting to, inexorably, reassert.

Over at the Guardian, Arctic Sea Ice expert Neven comes to similar conclusions, he notes:

…something more important for the longer term could be happening. If this weather keeps up – and according to the current forecasts, it will for at least another week – that thicker multi-year ice could receive such a beating that the slight rebound from record low levels is essentially wiped out by the time winter sets in again (see also an excellent related article by Dana Nucitelli here).

Overall, it was a decent rebound. By September, minimum seasonal ice popped up by about 3,500 cubic kilometers in the PIOMAS volume record, by about 1.4 million square kilometers in the Cryosphere Today area measure, and by 1.5 million square kilometers in the NSIDC extent measure. A decent rebound, but still about 11,000 cubic kilometers lower in volume than 1979 (more than a 55 percent loss), about 1.9 million square kilometers lower than 1979 in area (more than a 36 percent loss), and about 1.9 million square kilometers lower than 1979 in extent (about a 30 percent loss).

PIOMAS Volume Trend

(Sea ice volume rate of decline as measured by PIOMAS.)

Sadly, a bump of this kind does not a trend make. Looking at the overall volume loss line (above), we can clearly see that the 2013 and 2014 rebound after 2012’s record low was plainly within the melt progression’s boundaries. Moreover, out of the last 8 years, 2014 is the only year above base-line rate of loss at 3,200 cubic kilometers per decade. A rate of loss that, if it continues would bring us within striking distance of a dreaded ‘blue ocean’ type event for the Arctic by the early 2020s.

Since this trend is polar amplification driven — an underlying aspect of phase 1 climate change forced by human greenhouse gas emissions — the only major driver with the potential to challenge Arctic melt is a large outflow of fresh water from Greenland. Such an outflow would temporarily reduce ocean ventilation of heat through the sea surface in the fresh water outflow region. The result being that surface temperatures would, for a short time, cool in the outflow zone. This would have an effect of regenerating sea ice in a larger counter-melt-trend feedback. It’s likely that melt outflows from Greenland would need to be significant enough to have profound impacts on the Arctic environment as a whole. To hit anywhere near these levels, we likely need to see in the range of at least a half centimeter of sea level rise from Greenland melt alone each year. And we are, as yet, nowhere near that rate of loss (although we might get there in a decade or two or three).

So though the recent 2012 Greenland melt high mark was likely enough to push AMO negative, to further weaken AMOC, to develop a cool pool in the ocean south and east of Greenland, to back a super hot Gulf Stream up to the US East Coast during the winter of 2014-2015, and to set off a slew of nasty weather impacts for the North Atlantic from 2012 through 2015, it was nowhere near enough to upset the overall long-term, human heat-driven Arctic melt trend. If such an event were to occur, what we would likely see is a signature not only of a North Atlantic cool pool but also of more ice in Baffin Bay, more ice in the North Atlantic itself and more ice on the Arctic side near Greenland. A signal that we do not fully see at this time.

It is thus more likely that we will see a re-assertion of the overall Arctic sea ice decline trend. And there are a growing number of indicators that some of this re-assertion is starting to come about during the summer of 2015.

All Major Monitors Now Below 2014

For the Summer of 2015, melt has been consistently strong — especially for July. During most of the month, strong high pressure systems dominated. This situation led to compaction, storm formation at the sea ice edge, and a degree of sea ice export. It amplified solar insolation at a time when the sun was near its seasonally highest angle — enhancing surface melt and melt ponding.

As of yesterday, the major extent monitors — JAXA and NSIDC — as well as Cryosphere Today’s area monitor were all below or well below the 2014 line. The ongoing and rapid July melt drove JAXA below the 2014 line late last week while NSIDC hit below 2014 just yesterday. As a result, NSIDC sits at 7.2 million square kilometers extent or 7th lowest on record (a decline of 2 places since last week) and JAXA shows a 6.79 million square kilometer extent or 5th lowest on record in the measure (also a decline of 2 places).

Cryosphere Today’s area measure, meanwhile, continued to drop — showing increasing divergence from the 2014 line and hitting a 4th lowest area on record for the 27th (a one place dip from last week).

chart(4)

(Sea ice area dips to 4.67 million square kilometers or the fourth lowest on record in the July 27th Cryosphere Today measure. Note the 2015 sea ice area trend line is indicated in yellow, the 2014 sea ice area trend line in red. Image source: Cryosphere Today.)

Neven’s most recent post over at the Arctic Sea Ice blog provides a bit more detail regarding these trends. Of particular interest to me was the most recent and significant drop-off in the CAPIE index. A drop off of this kind indicates both a high degree of melt ponding and large gaps and areas of open water behind the sea ice edge. We particularly see this now in the Beaufort and Chukchi seas — both regions that have been turned into ice cube ponds over the past month. Perhaps more concerning, however, is the impact of high heat and transport in the regions of thickest ice north of Greenland and the Canadian Archipelago. Ice fracturing there is notably high as is melt ponding. But even more concerning is the development of a large polynya that now extends through most of the thick ice region.

Overall, these drop-offs are consistent with a returning to the long-term melt trend in 2015. But it does not yet place 2015 in striking distance of new all-time record end melt season lows set during 2012. And we’d be quite surprised if it did. Larger ocean and atmospheric teleconnections tend to drive increasing heat in the Arctic ocean waters and airs and to increase sea ice transport to compound ice weakness during El Nino year +1 and El Nino year +2. The most recent record lows both occurred 2 years after El Nino (2007 and 2012). Given the large ocean and atmospheric drivers related to this trend, we may look to next year or, more possibly, 2017 as potential new record low years.

Weather Change on the Way

All that said, it doesn’t mean that 2015 cannot surprise us or (2005, an El Nino year, was also a record low year), at least, serve up some interesting features. Notably, there’s a change in the weather on the way.

Throughout July, we saw what was, perhaps, the worst possible atmospheric regime for sea ice melt during that month. Atmospheric heat was relatively high, clear skies dominated allowing for enhanced surface melt through direct solar heating, and the persistent high pressure systems helped to drive compaction and export. Though the action of gyres moving ice out of the Fram Strait was relatively moderate, overall melt conditions were very strong.

In particular, a synergy between the high pressure driven pole-ward pull of sea ice away from the Siberian side of the Arctic and a significant influx of warm water northward from the Pacific Ocean and through the Bering and Chukchi Seas had a marked impact. You can see the amazing melt progress led by these two influences in the excellent animation provided by The Great White Con below:

Now, however, the high pressure is sliding increasingly to the Siberian side of the Arctic. Meanwhile, a persistent storm is beginning to take hold over the Beaufort Sea and Central Arctic. Overall, it’s an increased storminess for the Arctic. One that is now driving 25-35 mph winds through the shattered ice sections of the Beaufort Sea.

There’s some argument that storms are friendly to sea ice. And, perhaps, this is more true during the June time-frame when storms can reduce insolation and melt ponding. When they can spread the sea ice out to increase overall albedo. But in the current melt regime, sea ice is, overall, far more fragile. There is more latent heat in the Arctic Ocean that is available for storm systems to tap in order to melt ice. And it is this condition that is most at play as we enter late July and early August.

image

(A storm is predicted to persist over the Beaufort for at least the next five days. Image source: Earth Nullschool.)

Over the next five days, the current storm is predicted to persist over the Beaufort. It will rumble along, sending its 20-35 mph winds out over the fractured multi-season ice and large stretches of open water. It will linger, gobbling up little storms rushing north over Alaska and the Bering. And it will lash the ice there with increasing wave action, breaking the surface cool water cap and pumping warm water up toward the ice from below.

In addition, this Beaufort low will form a kind of dipole with a high pressure system that will tend to remain on the Kara Sea side of the Arctic Ocean. The net effect of the dual circulation of the high over the Kara and the low over the Beaufort will be to lift the thick ice away from its base of support along the Northern Canadian Archipelago. The result is likely to be a continued widening of a large polynya already developing there.

Polynya CAA

(Winds cycling between a high pressure over the Kara and a storm over the Beaufort may further widen a large polynya north of the Canadian Archipelago over the next few days. Image source: LANCE MODIS.)

Meanwhile, milder compaction and sea ice retreat is likely to continue on the Siberian side with ice recession particularly likely in the Kara, Laptev, and East Siberian Sea regions.

Overall, these factors should continue to drive melt enough to keep the monitors at or below the 2014 line with particular risk of increased divergence in the area measure over the coming week due to storm activity in the Beaufort. There is an outside, though not entirely negligible, risk that Beaufort storm activity will greatly impact the already very fragile ice along the Chukchi Sea boundary toward the Siberia side. Such an impact would result in still greater area and extent impacts. But more likely is an enhanced winnowing of the remaining multi-year ice together with a widening of the large polynya north of the Canadian Archipelago.

Links:

PIOMAS

LANCE MODIS

JAXA

Earth Nullschool

Melt Season Won’t Break Records But Could Wipe Out Bounce

Arctic Sea Ice Update 5: Late Momentum

Cryosphere Today

NSIDC

The Great White Con

The Arctic Sea Ice Blog

Hat tip to Humortra

(Please support publicly funded, non special interest based science like the fantastic work done by NSIDC, NASA, PIOMAS and JAXA which made this report possible)

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.

image

(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

 

 

At Start of 2015 Melt Season, Arctic Sea Ice is in a Terrible State

Strong Polar Amplification. With human-forced climate change, it’s normally something you’d tend to see during winter time. By spring, the increase in solar radiation in the Mid-Latitudes would tend to force a more rapid pace of warming there. The snow and ice cover, recently refreshed by winter, would be at highest annual albedo at winter’s end. That high albedo would create a warming lag from the upper Latitudes. The resulting increase in temperature differential would then tend to reinforce the Jet Stream — giving it a strengthening kick and providing the polar north with a kind of ephemeral haven. At least for a brief window during early spring time.

Not so with 2015. This Spring, the Jet has been a basketcase. A mess of meanders like a river finding its way through a wetland prior to joining the sea. Strong south to north flows have persisted over the North Atlantic and well into Western Siberia. These meridional patterns have repeatedly delivered heat into the Arctic — particularly through the oceanic gateway between Greenland and the Yamal region of Russia.

Unusually Warm Spring for The Arctic

For the past week, this pattern intensified and the result is a bulge of extreme heat extending on toward the North Pole in the broad zone between Greenland and Northwest Siberia:

21 h Thursday April 9 Arctic T Anomaly Map

In the above image, provided by Climate Reanalyzer, we find a classic polar vortex disruption type pattern (a rather odd event for April, as both polar amplification and vortex formation have both tended to fade by this seasonal period) in which the cold core is essentially ripped in half by warm air invading from the south. In this case, we see a massive warm air flood emerging from Eastern Europe, Western Russia and the North Atlantic riding up and over the polar zone across a warm frontal boundary. This greater warm air influx is joined with a lesser one emerging off the Ridiculously Resilient Ridge pattern off the US and Canadian West Coasts and flooding up over Alaska and the Mackenzie Delta region of Canada.

The cold cores are thus shoved aside. One has fled to a dubious haven over Eastern Siberia. The second has taken a stronger hold over Greenland. For the Greenland region, surface winds have encircled the new, displaced, cold pool, generating a temperature boundary that is sharply visible in the anomaly map. The dangerous weather-wrecking “Storms of My Grandchildren” Greenland melt and polar amplification pattern — featuring a Greenland cold pocket beside a meltwater-cooled North Atlantic zone surrounded by angrily warming regions.

High anomaly departures in the range of 15-20+ degrees C above average cover about 1/3 of the high Arctic region above 80 degrees North Latitude. Laptev, Kara, Barents and the Arctic Ocean proper are all included in the heat bulge. Temperatures in this zone today spiked to near or above the point at which sea ice melts at the surface (-2.5 C) with temperatures in the Kara in the 0 to -2 C range, temperatures in the Laptev in the -2 to -4 C range and temperatures within 100 miles of the pole hitting around -3.8 C. For this region, these are readings more typical to June or even July.

Record Low Start to Melt Season

The impacts to sea ice have been nothing short of unprecedented for early season melt.

In the extent measure we find that for the past month running we have been at or near new record lows. Over recent days, consistent with the strong surge of polar heat amplification, extent values have again plummeted past previous record low values. Dropping by more than 50,000 square kilometers for each day in the April 6-8 timeframe, the melt rate is exceedingly steep for this time of year. With April 8 achieving a new record low extent of 14,073,000 square kilometers — 95,000 square kilometers below the previous record low of 14,168,000 set in 2006.

Sea Ice Extent April 9

(Arctic Sea Ice Extent as recorded by NSIDC through April 9 of 2015. We are at the descending curve of the upper arc on the left in the image. The bottom dark blue line represents 2015 sea ice extent. The light blue and pink lines are 2007 and 2006 [previous record low years for springtime]. The upper dark blue line represents 1979 sea ice extent. The dotted green line represents 2012. Note how the 2015 line has consistently trended in record low range during the past month. Image source: NSIDC.)

As heat and sunlight build in this record low ice extent environment, greater stretches of dark, open water will trap more sunlight. This will tend to have a heat amplifying effect — pushing for greater ice losses as melt season gains traction. Weather trends will tend to have an impact as well. And Arctic Oscillation (AO) is expected to again hit a strongly positive level over the next couple of days — providing further melt pressure to sea ice already at record lows. Wind patterns have also tended to facilitate ice export through the Fram, Nares and Bering Straits this year. Given a predicted continuation of these conditions, the long term-trend seems to be melt-favorable through end of April.

Kara Melting Early, Beaufort Cracking Up

In the satellite shot the impacts of these much warmer than normal Arctic conditions are clearly visible. Particularly, the Kara Sea near Northwestern Siberia and the Beaufort are showing signs of melt stress and ice fragility.

For the Kara, melt is proceeding well in advance of typical seasonal thaw. Large polynyas have opened up even as the ice edge has retreated. Much of the ice in this zone appears broken, thin, and disassociated — making it vulnerable to both increasing solar radiation and to the periods of more intense warmth to come.

Kara Sea April 9

(The Kara Sea showing reduced sea ice coverage on April 9 of 2015. Image source: LANCE-MODIS.)

With 2015 showing a tendency for strong south to north air flows in this region, the Kara continues to be at risk of early melt through spring and into start of summer.

But perhaps more disturbing is an ongoing and widespread break-up of sea ice in the Beaufort. Starting in late March and continuing on through April, very large cracks have opened up throughout the Beaufort Sea. Given that air temperatures remain in a range cold enough to freeze surface water (-12 to -25 C), the resulting gaps have quickly frozen. However, this crack-up is occurring directly at melt season start. Warmth is building, the sun is at an ever higher angle, and the lower albedo cracks may well serve to capture more heat in an already vulnerable region. In addition, temperatures in the Mackenzie River Delta — a region that, when thawed, will dump above freezing water into the already broken Beaufort — are approaching the melt point (-4 C readings today and 0 C for widespread thaw).

Beaufort Breaking Up

(Large cracks and polynyas throughout the Beaufort Sea on April 10 of 2015. Left side of frame is somewhat covered by cloud, but a large polynya [partially frozen] is visible through the coverage. Image Source: LANCE MODIS.)

These cracks are very extensive and include multiple large breaks. A scene reminiscent of the winter 2013 break-up. But the current timing at melt season start is far more likely to enhance ice vulnerability as spring progresses toward summer. Also, the fragile behavior of this broad section of Beaufort ice illustrates how thin sea ice in this region has become even as it hints at the potential that warm water (which is increasingly prevalent at depth throughout the Arctic Ocean) may be upwelling to melt some of this sea ice from below.

Together, the warm air influx and very high temperature anomalies, the rapid melt at the edge zones, the record low extent levels, and the massive crack-up ongoing in the Beaufort all point to extreme sea ice weakness at the start of melt season. With weather patterns remaining neutral to melt-favorable over the next few weeks and with winds favoring export through the Fram, Bering and Nares, risks remain high that Arctic sea ice will remain in record low territory over the coming weeks. Sea ice fragility in certain regions, especially the Beaufort, also bear watching for possible unpleasant surprises.

Links:

Climate Reanalyzer

NSIDC

LANCE-MODIS

The Storms of My Grandchildren

The Arctic Ice Blog

%d bloggers like this: