All posts tagged Neven Sea Ice

The Human World Has Never Experienced A Time When Global Sea Ice Was So Weak and Reduced

Neven — one of the world’s most beloved sea ice trackers — has again taken a break from his much-earned sabbatical to issue yet one more warning on the state of global sea ice.

His report, based on this month’s bombshell National Snow and Ice Data Center statement, can best be described as an urgent call for action on the part of the global community to redouble efforts aimed at reducing the wide-ranging and expanding harms caused by the terrible warming trend we have artificially forced upon our world.

Neven is a kind, honest, and open soul. He is also one of the smartest and decent fellow bloggers I have had the good fortune of encountering in my many travels during my last four years of covering the slow motion global train wreck caused by our widespread and vastly irresponsible burning of fossil fuels. In other words, the man, in my view, has the moral and intellectual authority that many lack. We should listen to him.

Before the World Warmed, This Would Have Been a 1 in 30 Billion Probability Event

For, sadly, on the crucial issue of sea ice, a general muting of the subject has tended to continue despite a jaw-dropping plunge in both the coverage and volume of a substance so crucial to maintaining a stable global climate:

(Global sea ice extent fell off a cliff during December of 2016. The measure has now bounced back a little. But the global average remains significantly below past record lows for this time of year. Loss of so much sea ice can be highly disruptive to the climate system and related atmospheric circulation and precipitation patterns. Image source: NSIDC.)

During December, global sea ice extent coverage fell to an amazing 4.4 million square kilometers below average. This is far, far outside the 2 standard deviation range — passing to fully 8 standard deviations beyond the typical yearly average.

Under past expectations of average, the statistical probability of such an event is approximately 1 in 30 billion. Of course, it’s pretty obvious at this time that a normal, natural variability is not the underlying cause of such a great loss of sea ice. That the warmth we added to the system has now greatly tipped the scales beyond anything representing what would have previously been considered a normal range. A range that since the year 2000 had already tended to dip below average more and more frequently. But one that has never seen so much ice lost.

Unprecedented Losses

This area of sea ice removed — enough to change how the face of our Earth looks from space — is approximately the size of two Greenlands (Note that sea ice loss does not directly contribute to sea level rise. But loss of protective sea ice can contribute to land ice melt — which does add to rates of sea level rise.). And it has been roughly split between the Arctic in the north and the Antarctic in the south.

If sea ice extent losses appear bleak, then sea ice volume losses seem even worse. Sea ice extent is a rough measure of the surface of the world covered by ice excluding gaps behind the leading ice edge. Sea ice volume, however, measures both the ice area — including gaps — and the ice thickness.

(Globally, we’ve lost about 1/3 of the total volume of sea ice since the 1980s. 2016’s record fall in the measure coincided with record hot global temperatures and an abnormal period of polar warming that continues on into 2017. Image source: Wipneus.)

Late 2016’s big drop included the approximate removal of 1/3 of the world’s sea ice volume when compared to 1981-2010 averages. In other words, 1/3 of all of the floating portion of the world’s cryosphere beyond the edge of anchored ice shelves had melted away during the period.

Record Global Temperatures as Prime Cause For North and South Pole Sea Ice Melt

In the north, extremely warm temperatures ranging from 2 to up to 7 degrees Celsius above average for the Arctic Ocean region have helped to drive these unprecedented fall and winter sea ice losses. In the south, warmer than normal surface conditions appear to have also helped to drive the amazing coordinate losses there. And overall, 2016 has shown warm to extremely warm conditions for both poles during a year in which global temperatures have spiked to around 1.2 degrees Celsius above 1880s averages.

(Extremely strong polar amplification during 2016 is the likely primary contributor to sea ice loss in both the northern and southern polar regions. Image source: NSIDC.)

Under polar amplification — a condition associated with the human-forced warming of our world — scientists expected that the polar regions would tend to warm faster than the rest of the Earth surface. And during 2016, this global warming related condition presented effects writ large. The damage to sea ice, so far, has been monumental. And these losses have continued into 2017 — even if they are somewhat less below the record low line than during their period of maximum departure this past December.

Albedo Losses and a Bad Set-up for Arctic Summer

Sea ice loss generates its own form of amplifying feedback — in which already prevalent polar warming can worsen further. Less ice coverage means that during summer more of the dark ocean surface is presented to absorb the sun’s rays. This replacement of a white, reflective surface with a dark blue, absorptive one means that still more heat will tend to be trapped in the polar environment. In addition, during winter, less ice cover means that the warmer ocean beneath will tend ventilate more heat and heat-trapping water vapor into the polar atmospheres. And it’s this kind of self-reinforcing cycle that can tend to lock in the dangerous changes like worsening severe weather, worsening heatwaves in the middle and lower latitudes, and the increasing rates of land glacier melt and sea level rise that scientists have been warning about for so long. And it’s this kind of disruptive longer term climate trend that we are being drawn into at this time.

(Freezing degree days for the crucial 80 N region have significantly departed into record low ranges. The less freezing degree days, the closer this region is to thawing. Image source: Tealight. Data Source: DMI.)

Nearer term, it appears that the polar heat which has already so greatly damaged the Arctic sea ice is set to stay. Over the next few days, the Arctic appears set to experience a powerful series of low pressure systems running in from the Barents side between Svalbard and Siberia. Neven warns that these storms will tend to push a considerable portion of the remaining thick ice out of the Arctic and through the Fram Strait. Over the next couple of weeks, global forecast models indicate that above freezing temperatures will tend to invade regions now covered by sea ice in Hudson Bay, Baffin Bay, and in the Chukchi Sea. Though the ice is trying to grow, such repeated insults will tend to keep ice coverage in record low ranges.

If this trend of warmth, storms and ice export continues through February, March and April — as it has during October, November, December and January — then the set up for the 2017 melt season would be about the worst we have ever seen. And that would tend to increase the likelihood of new record minimums being reached during September all while hastening the day when the Arctic experiences near ice free conditions. Lets hope that doesn’t happen. But, so far, the trends for the winter of 2016-2017, from pole to pole, have followed along the lines of a near worst case scenario.

Links:

Global Sea Ice Records Broken Again

National Snow and Ice Data Center Sea Ice News

Wipneus Sea Ice Graphs

NASA GISS Temperature Data

Polar Amplification

Tealight

DMI

Hat tip to Suzanne

Hat tip to Cate

Hat tip to Colorado Bob

235 Comments

by robertscribbler on January 13, 2017 • Permalink

Posted in Climate Change

Posted by robertscribbler on January 13, 2017

https://robertscribbler.wordpress.com/2017/01/13/the-human-world-has-never-experienced-a-time-when-global-sea-ice-was-so-weak-and-reduced/

Ten Mile Wide Chunks of Arctic Sea Ice are Disintegrating North of Svalbard

Over the past 10 days, the rate of sea ice extent loss in the Arctic has slowed down somewhat. And as a result sea ice extent measures, though maintaining in record low ranges, are much closer now to the 2012 line. Low pressure systems have come to dominate the Arctic Ocean zone. And the outwardly expanding counter-clockwise winds from these systems have tended to cause the ice to spread out and to thin. In the past, such events were seen as an ice preserving feature. But this year, there’s cause for a little doubt.

The first cause comes in the form of record Arctic temperatures for all of 2016. As Zack Labe shows in the compelling graphic below, not only has the first half of 2016 been a record warm six months for the Arctic, it’s been a record warm half-year like no other.

(The first half of 2016 is about 1.5 C hotter in the Arctic than the previous record hot year. It’s a huge jump to new record warmth that should cause pretty much everyone to feel a deep sense of concern about this sensitive region. Image source: Zack Labe.)

And if extra heat is guaranteed to do one thing — it’s melt frozen water. We can see that in the current near record low snow coverages for the Northern Hemisphere. We can see it in the fact that — despite what would be ‘bad melt’ weather conditions such as cloud cover and low pressure systems dominating the Arctic during the middle of June — Arctic sea ice extents are still in record low ranges and Arctic sea ice volume continues to track just below 2012’s record low trajectory. And we can certainly see it in the fact that despite the clouds that would normally promote cooler Arctic conditions during this time of year, surface temperatures have remained well above normal for the majority of June.

Overall, these conditions are unprecedented for the Arctic. And, in microcosm, we can tell a little bit of this story of heat by tracking the life of a ten mile wide hunk of ice that was recently blown away from the ice pack and into the warming waters north of Svalbard.

Ocean Zone North of Svalbard — A New Sea Ice Melt Field

(June 8 — a 10 mile wide hunk of sea ice exits the ice pack North of Svalbard. LANCE MODIS image.)

On June 8th, this ten-mile wide chunk of ice was ushered away from a thinning but concentrated grouping of ice about 80 miles to the North of the Island Archipelago of Svalbard. In past decades during June, the sea ice had tended to remain closer to Svalbard, often enveloping this Arctic island chain straddling the 80th parallel. But during recent years sea surfaces around Svalbard have dramatically warmed due to a human-forced heating of the atmosphere and oceans. And today, sea surface temperatures surrounding Svalbard range from 1 to 8 degrees Celsius above 20th Century averages.

That’s still cold water in the range of 32 to 46 F. At least to the human perspective — as neither you nor I would find it a pleasant experience to plunge into sea waters that are still relatively close to freezing. But to sea ice, this water is basically warm enough to represent an oceanic killing field.

(June 10 — the large ice island shatters in waters warmed by climate change. LANCE MODIS image.)

By June 10, our ten mile wide hunk of ice had been ejected about 30 miles into this warm water zone north of Svalbard. After only two days, the previously contiguous structure of the ice is riddled with cracks large enough to be plainly visible in the 250 meter satellite resolution. The sudden contact with warmer waters was more than enough to shatter the surface of this island-sized hunk of Arctic sea ice.

Export into warmer waters has long been a melt issue for ice moving out through the Fram Strait. And loss of ice in this fashion due to strong winds circulating clockwise around Greenland has become a growing concern. Ice originating in the thick (though much thinner than in past decades) ice pack north of Greenland can be funneled along the Greenland Coast and eventually propelled out into the warmer waters of the North Atlantic where it has no chance to survive.

(June 13 — the ice island breaks into tiny pieces. LANCE MODIS image.)

But this is exactly what happened to this 10 mile wide chunk of ice as it entered waters North of Svalbard. It exited the ice pack, lost access to the fresh water field protecting the ice. It entered 1-3 C surface waters. And it basically disintegrated.

Arctic Ocean Near Summer Melt Tipping Points?

Added Arctic heat is not just a measure, therefore, of atmospheric temperatures. It’s a measure of implied ocean surface heat and ocean heat lurking just beneath the surface. In the end, what we see is that new ways to lose sea ice are now emerging. And it appears that sea ice export into the northern Barents and near Svalbard waters is yet one more sea ice melt risk potential. It’s a matter worth bringing up due to the simple fact that this zone of ocean water was once frozen, was once a consistent part of the Northern Hemisphere ice pack. And after warming just enough, it’s a region that is now hostile to sea ice.

(More reliable US Navy ARCc model shows rapid thinning of remaining Beaufort sea ice taking hold over the next seven days. With so much heat baked into the Arctic over the past six months, we should remain vigilant regarding outlier melt possibilities for 2016. Image source: US Navy.)

Looking north, there’s risk that human caused climate change will drive that ice hostility zone into the near polar region itself. During the melt phase, broken ice can generate a bit of negative feedback by promoting cloud formation through increased water evaporation and reduced albedo as surface melt ponds are essentially dumped back into the ocean. But such floes are at the mercy of transport and waves. And they sit upon a warming surface ocean. A discontinuous floe can hit a melt tipping point pretty rapidly — covering a large region and then disappearing in a very short period. We’ve seen instances of such events during late June for Baffin Bay, Hudson Bay, and the Kara Sea.

Now, much of the Arctic Ocean is covered by these floes. And with so much heat in the system, it’s worth considering that the old rules no longer fully apply. It’s worth realize that the ice is dancing in an increasingly tenuous temperature zone between the warming waters below and the warming airs above.

Links:

LANCE MODIS

CIRES

NOAA’s Environmental Monitoring System

Zack Labe

Arctic Sea Ice Graphs

by robertscribbler on June 14, 2016 • Permalink

Posted in Climate Change

Tagged arctic sea ice, arctic sea ice melt, climate change, global warming, human warming, Neven, Neven Sea Ice

Posted by robertscribbler on June 14, 2016

https://robertscribbler.wordpress.com/2016/06/14/ten-mile-wide-chunks-of-arctic-sea-ice-are-disintegrating-north-of-svalbard/

“Massive” Arctic Heat Dome Sets Up to Bake Sea Ice

There’s a massive heat dome building over an Arctic sea ice pack that is looking increasingly fragile in both model forecasts and observations. In short, very bad weather for sea ice is rapidly settling in even as the ice pack, despite recent place gains in some measures, is looking increasingly weak.

* * * * * *

First the somewhat good news… Arctic sea ice extent has backed off to about 8th lowest on record. Arctic sea ice area is at about 4th lowest on record. And Arctic sea ice volume, according to DMI, is in the range of 3rd lowest on record (PIOMAS looks even better). This report may sound rather bad, but when compared with late May and early June when sea ice extent measures were at or near new record lows the data could arguably be characterized as an improvement. Yeah, there’s been some big area drops recently, but all in all, not too terrible, right?

Probably wrong… Because the Arctic is gearing up for a very powerful heat wave over the coming week. One that is likely to spike maximum summer temperatures in the High Arctic, a region that seldom shows much variance on the side of hot or cold at this time of year, by 0.5 to 1.5 C above average. A heatwave my somewhat more reserved fellow ice observer, Neven, has called ‘HUGE’ (note that Neven seldom uses caps lock) and is characterizing as something he’s not seen in all of his five years of sea ice observation. From The Arctic Sea Ice Blog Today:

…However, there is one big difference compared to last year and that’s heat. Despite a very cold start, there have been several outbreaks of warm air over the ice, slowly but radically shifting the balance between extent and area data. The impact is felt on the surface of the ice pack, but doesn’t translate directly into a decrease. Not yet. In theory, it should percolate through after a while, especially if the heat persists. And right now the Arctic sea ice pack is undergoing a massive heat wave which shows no signs of letting up.

I find myself in agreement with Neven. The massive heat build in the Arctic predicted for this week is likely to be a significant event with potentially wide-ranging impact. But to understand why, it helps to get an overall picture of the broader context in which this particular heatwave is occurring. And that context includes two other stories as well — the story of human-forced climate change and the story of a still developing and potentially monstrous El Nino.

Ocean Warming Injects Heat into the Arctic

To get an idea how warming in the Equatorial Pacific and over-all greenhouse gas based warming can have such a far-flung impact, particularly on the currently building Arctic heatwave, it always helps to take a look at the behavior of the circumpolar Jet Stream. Large areas of persistently warmed water, like the one we have seen now for two years over the Eastern Pacific, have a tendency to generate high amplitude ridges in the Jet. Ridges that serve as open avenues for heat transport into the Arctic. Specifically yesterday a huge pulse of heat was traveling north along just such a high amplitude and ocean-warmed ridge:

(Amazing high amplitude Jet Stream wave punching all the way through to the High Arctic on the back of the Eastern Pacific’s Ridiculously Resilient Ridge. Image source: Climate Reanalyzer.)

Our particular heat transporter should by now be very familiar — a ridiculously resilient ridge (RRR) — extending northward and buttressed by multiple high pressure cells stubbornly entrenched over abnormally hot water in the Eastern Pacific. Yesterday (Monday, July 6) the ridge elongated. South to north winds over-riding northward flowing warm, salty ocean water. Running up through Alaska, the heat pulse set off all-time daily highs in places like Anchorage (81 degrees and breaking the record set in 1972). The heat then spilled into the Bering, Chukchi and Beaufort Seas where it met with adjoining, though lesser heat pulses over-riding Greenland and the Laptev. A gathering pocket of hot, thick air that is now pooling in the so-called sea ice ‘safe zone’ just north of Greenland.’ A precursor to the very intense high pressure cell we see developing now.

But before we go on to tell the tale of our gathering Arctic heatwave we should first take a closer look at ocean surface temperatures. As these give us a rather clear picture of the Arctic’s current vulnerability — providing for us a hint as to why heat will intensify most strongly to the north of the Canadian Archipelago and Greenland. For it is ocean surface heat that built the road that warm air followed:

(Heat plume running all the way from Equator to Pole clearly reflected in this July 6 NOAA/ESRL SSTA anomaly map.)

Taking a look at NOAA’s July 6 Sea Surface Temperature Anomaly (SSTA) map, we find a massive plume of much warmer than normal (1971-2000) waters extending up from a plainly visible El Nino pattern, all throughout a large sweep of the Eastern Tropical Pacific. Moving northward, these steamy waters spill into two hot blobs off the Mexican, US, and Canadian coasts — a heat pool that again punches up through the Chukchi and Beaufort Seas. An Equator to Pole expanse of ominously hot water that is enabling both sea ice melt in the regions directly impacted as well as a broader invasion of warmth into even the sea ice’s most secure haunts.

Heat Directly North of Greenland, Canadian Archipelago

Warmth that today aided in the formation of an Arctic high pressure ridge hitting significant heights of 1030 to 1035 mb directly between the Pole and Greenland. At 1245 Eastern Standard Time, the ridge had already intensified to 1032 mb. And for at least the next seven days both the GFS and the Euro model shows a 1025 to 1035 mb high pressure cell dominating the same region.

(Left frame shows strong, 1032 mb high pressure system settling in to the region just north of Greenland on July 7. By July 10 [right frame], this ridge is predicted to have greatly warmed the Central Arctic zone between Greenland and the Pole. Image source: Earth Nullschool.)

This persistent ridge will remove cloud cover in a large area between North America and the Pole. Sunlight, at its seasonally most intense, will multiply already widespread melt ponds on the sea ice surface. The combined solar forcing and loss of albedo will push surface temperatures higher as the ridge remains in place. And by Friday a broad band of 2-4 C temperatures is predicted to form in a bulge over the Arctic Ocean north of Greenland and the Pole. Abnormally warm temperatures and direct sunlight that will, over the next week, increase melt pressure over the last remnant of thick sea ice left to the Arctic.

In addition to reducing cloud formation and enhancing the melt-forcing impact of sunlight on the sea ice, high pressure cells in this region will have a couple of further influences. First, they will tend to compact the sea ice overall — drawing in the fringe ice while generating warm water upwelling at the ice edge. And second, the clockwise motion of air circulating around a strong high pressure cell will nudge sea ice out of the Central Arctic toward the gateway of the Fram Strait. Add in the significant impact due to reduced cloud formation allowing sunlight to contact sea ice during a period of peak solar radiative forcing and we end up with a substantial overall blow to the sea ice.

(Extraordinary high temperature anomalies are predicted for the Arctic from July 7-17. A departure more typical for winter when human greenhouse gasses have the greatest heat-amplifying impact. Image Source: meteomodel.)

Taking a look at the meteomodel anomaly map above, we find a very extreme warming of the Central Arctic predicted over the next ten days. A heat pulse to rival 2012 for this period. A melt multiplying heatwave that is predicted to push anomalies for the entire Arctic above +1.5 C beyond the early July average. A polar amplification similar to what is typically a winter manifestation of human emissions-driven anomalous warmth — this time anomalously occurring during a period when heat for the region is approaching peak intensity.

Impacts to Sea Ice Could Be Substantial

In the face of this oncoming weather, ice pack strength would be a deciding factor lending resiliency during melt-promoting conditions or a shift to a much more rapid rate of decline. Though some indicators, including a seemingly slower rate of decline during late June, may point toward more ice resiliency, a growing number of satellite reports and model analysis hint at a general and overall weakness throughout the ice pack.

This weakness can best be described as model indication of thin or low concentration ice, already widespread melt ponding, and visual indication of ice weakness in the satellite shot.

(The US Navy’s GLBb model has always been unfriendly to sea ice. But other models are now starting to agree. Image source: US Navy.)

For low concentration ice, no model is more stark than the US Navy’s experimental GLBb sea ice thickness ensemble. I colloquially think of this as the ‘holy crap’ sea ice model. This label due to the fact that if sea ice state is really as bad as the model indicates, then the ice is basically toast. Starting in June, this model displayed a great overall weakness in the sea ice and, according to its analysis, the situation has progressed from bad to worse with most of the remaining Arctic Ice possessing a thickness of 1.2 meters or less. Easily thin enough for any nudge by weather to really start rapidly bringing the ice down and opening up very large expanses of open ocean.

If the GLBb ‘holy crap’ model were the only sea ice model making us want to say ‘holy crap!’ then we could probably breathe a bit easier. Unfortunately, another US Navy model is now also tending to elicit this response in reaction to its predictions for the next 7 days and more specifically for the next 3 days:

(The US Navy’s ARCc sea ice concentration model predicts a very rapid rate of sea ice decline over the next few days. Image source US Navy.)

The top image in this up and down comparison shows the US Navy’s ARCc model’s interpretation of sea ice concentration for July 6 of 2015. Note the extensive green regions showing a 40-50 percent sea ice concentration. It’s a huge swath of ice including large sections of the Chukchi, the Beaufort the ESS, the Laptev, as well as remaining ice in the Kara Sea, and Baffin and Hudson Bay. Now watch what happens to those large sections of lower concentration ice from July 7 to July 10 in the ARCc model 30 day history and forecast summary. Almost all that green is wiped off the map. It’s like losing about 1 million square kilometers of extent and 600,000 kilometers of area in just 72 hours. Or about 10,000 square kilometers of ice per hour. A precipitous fall that would mark an extraordinary and likely unprecedented rate of loss should it emerge as the Navy model predicts.

But you know what they say about models — no model is perfect and every model ends up wrong in some manner or another. So the question here is — how likely is it that the Navy models could be correct or incorrect this time?

To try and tease this answer out we could also look at other sea ice concentration maps. Notably all the major ones including Cryosphere Today, Uni Bremen, and NSIDC currently show sea ice looking either thin or very thin. Specifically, Uni Bremen has shown some amazing contrast over the past 48 hours:

(AMSR2 model analysis of sea ice surface state shows very rapid thinning in the Beaufort and Chukchi Seas during the past 24 hours. Image source: Uni Bremen)

The left image in the above comparison is from the AMSR2 model analysis for Arctic sea ice concentration on July 5. The right image is the same analysis but for July 6. Note the substantial change in the sea ice concentration for the Beaufort and Chukchi seas over just one day. A change that is consistent with the pulse of warm air and water riding up through the Eastern Pacific and through Alaska, the Bering and the Chukchi. Another holy crap moment, and not at all of the good variety. To say the least, a similar response north of Greenland and the CAA would be devastating.

Moving away from models and back to observations we find that from the satellite vantage the entire Arctic Ocean displays an ice pack in various shades of azure. By color analysis alone we can readily see that the 2015 ice (July 6 MODIS image) is far more melt pond embedded than 2014 or 2013. 2012 is a tough comparison due to NASA-MODIS’s format change from that year. But the widespread melt ponding alone hints at a reduced resiliency for the ice when compared with recent years.

(Arctic sea ice turns blue color characteristic of widespread proliferation of melt ponds on July 6. Also note very thin and diffuse sea ice in the Beaufort and Chukchi. Image source: LANCE-MODIS.)

Turning to the Chukchi and Beaufort, we see a visible confirmation of the weakness indicated in the US Navy and Uni Bremen models. Beneath the smoldering outflow of the Alaskan fires we can plainly see the decayed state of ice. The floes greatly disassociated with widening gaps appearing between diminishing ice clusters.

As satellite gives us an overall view of the Arctic from above, local observations can help provide a sense of the sea ice state at the surface. During recent years, cameras mounted on buoys throughout the Arctic have provided us with a first-hand account of the story of Northern Hemisphere sea ice decline. And during recent days almost every camera-based buoy has shown an extensive expansion of melt ponds and open water. (Extensive melt ponding extends as far north as the Pole).

In the swiftly thinning ice pack of the Beaufort even the contrast of a single day can be quite stark.

(Warm storm kicks up under the gradient imposed by a building heat dome of the Arctic. Top and bottom frame provides a stark tale of impacts in just one 24-hour period. Image source: USIABP.)

In the above top-bottom comparison of RACS#2 ice buoy photos we find that wide but placid areas of sunlit open water in the Beaufort Sea on July 6th (top frame) have rapidly transformed to wind-driven 1-2 foot waves whipped up by 15-25 mile per hour winds on July 7th (bottom frame) in association with a tightening gradient around the strengthening high pressure in the Central Arctic. Waves of this kind can deliver a significant amount of melt forcing to the ice — mixing cooler surface waters with warmer waters below as well as rocking through the ice floes with a rain of incessant, ice-breaking blows.

Conditions in Context: Rapid Melt Likely On the Way

Increasing model agreement indicating rapid sea ice melt, observations of sea ice weakness via satellite and buoy based systems throughout the Arctic, and predictions of a substantial Arctic heatwave all point toward a high and rising risk of rapid sea ice melt. Larger global trends, particularly heat transport from the Equatorial Pacific all the way to the northern Polar zone through the mechanisms of El Nino, human based greenhouse gas heat forcing, and the associated Ridiculously Resilient Ridge, heighten this risk even further. Finally, a wide array of observations indicate that such rapid melt is already starting to set in. Given this increasing agreement and confluence, it appears that the late June ice dispersal is likely over and that serious trouble for Arctic sea ice has now set in and will remain in play for at least the next seven days.

Links:

The Arctic Sea Ice Blog

Cryosphere Today

Uni Bremen

NSIDC

The Polar Science Center

Hat Tip to Neven

Hat Tip to Frivolous

Hat Tip to Jim Hunt

Hat Tip to Climate Hawk

104 Comments

by robertscribbler on July 7, 2015 • Permalink

Posted in Climate Change

Tagged Arctic Heat Dome, Arctic heatwave, arctic melt, arctic sea ice melt, Climate, climate change, environment, extreme weather, global warming, Human Hothouse, human warming, Neven, Neven Sea Ice, sea ice, warming, weather

Posted by robertscribbler on July 7, 2015

https://robertscribbler.wordpress.com/2015/07/07/massive-arctic-heat-dome-sets-up-to-bake-sea-ice/

Arctic Sea Ice Area Drops 340,000 Square Kilometers in Just One Day

Sea ice researchers like to talk a lot about what they call ‘Century Drops.’ Days when Arctic sea ice area or extent values fall more than 100,000 square kilometers. In the past, daily Century Drops were relatively rare — with steepest rates of loss occurring during late June through early August and featuring, perhaps, a handful of days in which 24 hour losses exceeded 100,000 square kilometers. But the record melt years of 2007 and 2012 showed a proliferation of daily drops that exceeded the 100,000 square kilometers daily threshold.

Well, a couple of days ago a three Century Drop showed up in the Cyrosphere Today measure. And it may just be something we’ve never seen before (UPDATE: actually the last time was 2008, see Neven’s comment below). At the least, it’s an event that’s pretty amazingly rare — or it should be, without the heat added to the Arctic by human fossil fuel emissions.

On Tuesday evening, the Cryosphere Today site showed Arctic sea ice at about 8,986,000 square kilometers. The next day the measure stood at about 8,646,000 square kilometers. That’s an extraordinary loss of 340,000 square kilometers in just one day.

(Cryosphere Today sea ice graph shows that losses basically went vertical on Tuesday, June 16. Image source: Cryosphere Today.)

340,000 square kilometers gone in a single 24 hour period. That’s an area of sea ice the size of the state of New Mexico gone in a single day. In the above graph, you can see the drop as the vertical turn in the yellow line denoting 2015.

The massive single day drop temporarily brought sea ice area in the Cryosphere Today sea ice area chart into the range of second lowest on record for the date. Area losses of around 70,000 square kilometers for Wednesday resulted in a retreat to around 4th lowest on record. But any period in which drops of this size become frequent would easily transport the measure into new record low territory.

(LANCE MODIS showing the tell-tale blue of melt ponds all over the Arctic Ocean and most concentrated in edge zone regions. Proliferation of melt ponds during early season, especially when combined with the impact of human caused global warming, can increase risk for new record lows by end season.)

The cause of such a large single day drop is likely due to a combination of factors. Lately, storms have been more prevalent in the Arctic Ocean proper and such storms have a tendency to spread the ice out more, opening gaps in the ice called polynyas which tends to push the sea ice area measure lower. In addition, there is melt pressure now in Baffin Bay, Hudson Bay, the Kara Sea, the Laptev Sea, the Beaufort Sea, the Chukchi Sea, The East Siberian Sea, the Canadian Archipelago waters, and in the Barents border region. This basically composes the entire border zone of the Arctic sea ice.

Finally, the NASA MODIS satellite composite for recent days has shown a marked shift toward a light blue coloration for the entire Arctic Ocean zone and especially for the border zones. Such a shift is indicative of a proliferation of melt ponds. Major snow cover losses over sea ice during the past two weeks have removed insulation to the sea ice pack and probably aided in the formation of these melt ponds. Melt ponds are a strong indicator for sea ice health throughout the melt season — so a proliferation of melt ponds at this time may be a sign of sea ice melt vulnerability (see more over at Neven’s Arctic Sea Ice blog where they do a bang-up job tracking seasonal melt ponds and their potential impacts).

Though a three Century drop occurred, melt overall still has some catching up to do to make 2012 levels. So though this massive daily drop occurred, we are not yet in the red zone for sea ice area. Sea ice extent measures, on the other hand, remain in the range of second to third lowest on record and are still very close to all time record low levels. So this particular melt season is certainly one to still keep watching.

Links:

Cryosphere Today

LANCE MODIS

The Arctic Sea Ice Blog

Hat Tip to Neven