Arctic Sea Ice Extent, Area, and Volume

[csnavywx]

The Chukchi-Laptev sector has been under withering fire for some time now. If this keeps up, there won't be an ESS "arm" of ice to be recirculated this year. About the only spot that's in halfway decent shape appears to be right near the pole. Some ponding there, but not too much -- yet. Ponding isn't quite as widespread as 2012 overall, but the open water fronts are generally in a more retreated position, with the open front from the Beaufort-Chukchi being opened very early and the Laptev bite being especially large and the fast ice and poleward pack ice in an advanced state of decay already. The Atlantic sector is in better shape than 2012 at this point and I think that's where most of the extra area/extent is located right now.

 

This year has a legit shot of seeing full open water at the pole, if nothing else due to the advanced state of the Laptev Bite.

One thing that does concern me considerably (for this year and future ones) is the amount of heat being pumped into the Chukchi. It is running extremely warm (4-8C SSTs already) and that water tends to be pumped under the halocline where it is stored from year to year. Once temps reach ~12C though, surface density drops below the fresher water at the top of the halocline, allowing it to be disrupted. It doesn't take a full disruption though. A weakened stability gradient is enough to cause some significant changes. So the heat pump that is running in overdrive this year will only serve to hasten the demise of the summertime Pacific sector in the future.

[csnavywx]

1 hour ago, SnoSki14 said:

The upcoming pattern is an absolute ice destroyer, massive blocking high over the Arctic. 

Extent will plummet late June into July. 

https://www.esrl.noaa.gov/psd/forecasts/reforecast2/teleconn/forecast.html

Some of the area flatline is due to cooler weather, but some of it is also due to melt pond draining as water-covered ice tends to be (incorrectly) counted as open water by the sensor. There tends to be a big drop initially as widespread melt ponding sets in, it rebounds somewhat as those ponds drain and then drops again as the ice breaks up.

[raindancewx]

My hunch is the AMO peaked for Summer-time SST warmth around 2012, and we'll continue to not beat the lows achieved that September. The periods near the prior AMO shifts tend to have stories like this if you look back in newspaper archives from the 1800s and 1900s. During the prior peak of the AMO warmth in the 1950s, there were reports that Summer sea ice extent was around 5 million square kilometers at peak melt. Other than 2012, that's not dramatically different than now. There were also reports earlier in 2019 of volcanic ash reaching near 50,000 feet above sea level, before the final data was corrected lower - eventually there will be a big volcanic eruption in the tropics, it's coming up on 30 years now since Pinatubo. Severe cold in the West & Plains, ala 2016-17 or 2018-19 during winter also tends to occur near AMO shifts historically. Look at 1932-33, 1935-36, or the winters around 1960.

https://trove.nla.gov.au/newspaper/article/58314725

[csnavywx]

Record low volume was 2016 (a near tie). Please tell me I'm misreading this and you're not trying to go down this "it's mostly natural variability" road.

That coffin has so many nails in it there's virtually no more room to fit another.

[aperson]

http://www.realclimate.org/index.php/archives/2019/06/unforced-variations-vs-forced-responses/

 

Quote

Until recently, the hypothesis that there are significant natural (unforced) ocean cycles with an approximate periodicity of 60-70 years had been widely accepted. The so-called Atlantic Multidecadal Variability index (AMV, sometimes called the AMO instead), but also the Pacific Decadal Variability index (PDV) have been touted as major factors in observed multidecadal GMST fluctuations (for instance, here). Due to the strong co-variability between AMV and GMST, both, the Early 20^th Century Warming (1915-1945) and the Mid-Century Cooling (1950-1980) have been attributed to low-frequency AMV variability, associated to a varying degree with changes in the Atlantic Meridional Overturning Circulation (AMOC). In particular, the uncertainty in quantifying the human-induced warming fraction in the early 20th Century was still substantial.

In contrast to those earlier studies, we were able to reproduce effectively all the observed multidecadal temperature evolution, including the Early Warming and the Mid-Century cooling, using known external forcing factors (solar activity, volcanic eruptions, greenhouse gases, pollution aerosol particles). Adding an El Niño signal, we virtually explain the entire observed record (Figure 1). Further, we were able to reproduce the temperature evolution separately over land and ocean, and between Northern and Southern Hemispheres (NH/SH). We found equally high fractions of explained variability associated with anthropogenic and natural radiative forcing changes in each case. Attributing 90% of the Early Warming to external forcings (50% of which is due to natural forcing from volcanoes and solar) is – in our view – a key leap forward. To date, no more than 50% had been attributed to external forcing (Hegerl et al. 2018). While there is less controversy about the drivers of the Mid-Century cooling, our response model results strongly support the idea that the trend was caused by increased levels of sulphate aerosols which temporarily offset greenhouse gas-induced warming.

 

[ORH_wxman]

9 minutes ago, bluewave said:

The CPOM melt pond based outlook is going for a 2nd or 3rd place finish.

https://www.arcus.org/sipn/sea-ice-outlook/2019/june

https://www.arcus.org/files/sio/29427/cpom_david_schroederpan-arctic.pdf

We predict the September 2019 ice extent will be 4.3 +/- 0.5 million km2. This means there is a 68% likehood it will be among the lowest 3, 50% among the lowest 2, and 6% it will be a new mininum record. May 2019 has been the warmest and sunniest May in the Arctic since 2012 leading to melt pond fraction above average.
Brief explanation of Outlook method (using 300 words or less).
This is a statistical prediction based on the correlation between the ice area covered by melt-ponds in May and ice extent in September. The melt pond area is derived from a simulation with the sea ice model CICE in which we incorporated a physically based melt-pond model1. See our publication in Nature Climate Change http://www.nature.com/nclimate/journal/v4/n5/full/nclimate2203.html for details2.

 

This is in line with area numbers...which is a proxy for melt ponds. 

[bluewave]

1 hour ago, ORH_wxman said:

This is in line with area numbers...which is a proxy for melt ponds. 

This is the lowest that CPOM has gone since they began issuing outlooks back around 2014. While their forecasts usually finish within the error bars, they are often a little too high. 

CPOM June forecast compared September average NSIDC extent verification

Standard Deviations
+/- 0.5 mill. km2

2018...F...5.30....V...4.71

2017...F...5.00.....V..4.80

2016...F...4.50......V..4.70

2015...F...5.10......V..4.63

2014..F....5.40.......V..5.30

[ORH_wxman]

51 minutes ago, bluewave said:

This is the lowest that CPOM has gone since they began issuing outlooks back around 2014. While their forecasts usually finish within the error bars, they are often a little too high. 

CPOM June forecast compared September average NSIDC extent verification

Standard Deviations
+/- 0.5 mill. km2

2018...F...5.30....V...4.71

2017...F...5.00.....V..4.80

2016...F...4.50......V..4.70

2015...F...5.10......V..4.63

2014..F....5.40.......V..5.30

Area is basically in a dead heat with 2016 right now. We'll see if it can pull ahead before the end of the month.

Extent is harder to predict. It's a lot easier to predict final area. Extent obviously has the nuances of compaction...take 2015 vs 2010 for example. 2015 finished with greater area but far less extent since 2015 had an epic compaction occur in August/early September. That's probably why they missed the extent prediction the most of any of their forecasts. They correctly saw that there would likely be more ice area than some other years at the minimum but had no way of knowing how compacted it would be. 

 

[raindancewx]

I do think a lot of variability is still natural, how much is an open question. The Arctic is surely, what, half a degree to a degree warmer than in 2012 given that it is warming faster than the temperate zones? Something is counteracting that to change the patterns. Some of that is upper air patterns, but some of it is ocean temperature changes too. The AMO is not dramatically warmer anymore than it was in the prior peak of the AMO warm cycle.

https://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.mean.data

 1958   19.239   18.935   19.068   19.493   20.215   21.454   22.626   23.350   23.292   22.442   21.380   20.313
 1959   19.293   18.863   18.700   19.146   20.024   21.176   22.433   23.203   23.208   22.405   21.248   20.206
 1960   19.372   18.968   18.818   19.249   20.322   21.557   22.738   23.529   23.296   22.591   21.450   20.236

The prior peak produced AMO values in the 23.5-23.6C range in late Summer. We now get up to 23.8C, but the frequency of hitting 23.8C has been falling off in Aug/Sept since 2012, so I don't think I'm being too extreme in saying the AMO is holding back record low sea ice to some extent. The (black) ash landing on the highly reflective ice after the Arctic volcanic eruptions in 2011 couldn't have helped either.

 2017   19.579   19.135   19.055   19.593   20.491   21.704   22.927   23.661   23.593   22.886   21.709   20.620
 2018   19.529   18.974   19.022   19.376   20.179   21.387   22.645   23.467   23.408   22.599   21.240   20.199
 2019   19.344   18.995   19.014   19.439   20.270  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990

Presumably, we'll melt less ice if this coming in 3-5 years?

 1963   19.361   18.925   18.871   19.264   19.942   21.199   22.439   23.128   22.891   22.231   21.150   20.046
 1964   19.131   18.783   18.779   19.017   20.070   21.252   22.334   22.970   22.876   22.034   21.044   19.988
 1965   19.011   18.587   18.665   19.069   19.934   21.124   22.292   22.997   22.876   22.060   20.937   19.98

[bluewave]

The AMO has become more amplified as the climate warmed. So even natural variability is impacted by climate change.

https://www.nature.com/articles/srep40861

Amplification of the Atlantic Multidecadal Oscillation associated with the onset of the industrial-era warming

North Atlantic sea surface temperatures experience variability with a periodicity of 60–80 years that is known as the Atlantic Multidecadal Oscillation (AMO). It has a profound imprint on the global climate system that results in a number of high value societal impacts. However the industrial period, i.e. the middle of the 19th century onwards, contains only two full cycles of the AMO making it difficult to fully characterize this oscillation and its impact on the climate system. As a result, there is a clear need to identify paleoclimate records extending into the pre-industrial period that contain an expression of the AMO. This is especially true for extratropical marine paleoclimate proxies where such expressions are currently unavailable. Here we present an annually resolved coralline algal time series from the northwest Atlantic Ocean that exhibits multidecadal variability extending back six centuries. The time series contains a statistically significant trend towards higher values, i.e. warmer conditions, beginning in the 19th century that coincided with an increase in the time series’ multidecadal power. We argue that these changes are associated with a regional climate reorganization involving an amplification of the AMO that coincided with onset of the industrial-era warming.

[forkyfork]

both area and extent are in first place on AMSR2 data

[forkyfork]

too bad so sad

[etudiant]

Perhaps the difference reflects definitional parameters?   One is Arctic Basin only, the other possibly the AMSR2 total area?  Hard to discuss when the data is inconsistent.

Just seems that Arctic ice is a topic where every detail has to be agreed, is it area, is it extent, is it volume, what coverage percent is included, are the land masks constant etc etc.

[Gray-Wolf]

I'd caution your confidence over this matter esp when dealing with a measuring system that takes a 3.5km grid square and calls it 'fully ice covered' when 15% covered?

The system in use by NSIDC and others was invented to better capture the 'ice edge' and not to best capture the type of central basin ice we have seen evolve since 2012?

The reality ( for those who can be bothered to look ) is visible on any of the visible satellite platforms with vast areas nothing more than 'slush puppy' rubble studded with small floes.

We have been heading to this point over half a decade with the numbers showing a very 'stable picture' of sea ice come ice min whereas a combination of winter conditioning and ever less ice has placed us at a point where high heat at max insolation will drive both melt and ocean warming leaving a very precarious 'bottom melt' 1/3rd of the season with isolated floes and warm 'kill zones' where the ocean has been under full sun since ice max?

The apparent disappearance of the 'June cliff' should tell folks something surely? This year again we saw 'gains' over a few days in June. Do folk really think this was 'real' new ice or a fragmenting ,spreading ,pack triggering the 15% or more rule for empty peripheral squares?

When floes fall below 100m the 'side melt' becomes greater than the bottom melt so floes go 'poof' real quick.

We'd better hope that ice rubble isn't just that eh?

[ORH_wxman]

34 minutes ago, Gray-Wolf said:

I'd caution your confidence over this matter esp when dealing with a measuring system that takes a 3.5km grid square and calls it 'fully ice covered' when 15% covered?

The system in use by NSIDC and others was invented to better capture the 'ice edge' and not to best capture the type of central basin ice we have seen evolve since 2012?

The reality ( for those who can be bothered to look ) is visible on any of the visible satellite platforms with vast areas nothing more than 'slush puppy' rubble studded with small floes.

We have been heading to this point over half a decade with the numbers showing a very 'stable picture' of sea ice come ice min whereas a combination of winter conditioning and ever less ice has placed us at a point where high heat at max insolation will drive both melt and ocean warming leaving a very precarious 'bottom melt' 1/3rd of the season with isolated floes and warm 'kill zones' where the ocean has been under full sun since ice max?

The apparent disappearance of the 'June cliff' should tell folks something surely? This year again we saw 'gains' over a few days in June. Do folk really think this was 'real' new ice or a fragmenting ,spreading ,pack triggering the 15% or more rule for empty peripheral squares?

When floes fall below 100m the 'side melt' becomes greater than the bottom melt so floes go 'poof' real quick.

We'd better hope that ice rubble isn't just that eh?

The thing is....NSIDC area is measured by SSMI/S and that particular satellite gets "tricked" by melt ponds into thinking it is water. It's been measuring like this for decades so we have a consistent database. So if we are a few hundred thousand sq km behind 2012 on this measurement, it's likely because we have less melt ponding than that year. Since melt ponding in June is the best predictor of final extent/area, we closely monitor the SSMI/S area numbers. 

[Gray-Wolf]

I think that , since the first Feb crackopalypse event in 2013, the large floes that used to hold extensive melt ponding have gone in favour of smaller individual floes that drain readily into the ocean.

No sooner had we sorted out a way of using the melt pond extent we lose it due to further changes in the basin!

 But yes , melt ponds and certain low level cloud type will fool sensors into seeing ice ( as will 'overwash' during choppy weather) but this 15% or more measure really does give scope for 'misdirection' from some who demand no real change to the basin since 2013.

All you can do is direct folk to sat imagery and ask them to compare shots for the same date of the year with the 'numbers' that are meant to capture that moment.

 

If you think that in year 1 the grid square could be 99% ice covered and so = 'ice covered'

Year 2 could be 75% ice covered and still ='ice covered'

Year 3 could be 40% ice covered yet still ='ice covered'

Year 4 could be 20% ice covered yet still= 'ice covered'

Year 5 could be 16% ice covered yet still ='ice covered'

Only on year 6 when ice cover goes below 15% do we see change as the grid square will then show 'ice free'

You can see that year 1 is very different to year 5 but to the algorithm they equate as 'equal'

With both the year on year degradation of the pack overall and this years extreme conditions some folk could be in for a big shock in late July/early Aug as the ice starting around 2m thick blinks out en masse

 

[ORH_wxman]

8 minutes ago, Gray-Wolf said:

I think that , since the first Feb crackopalypse event in 2013, the large floes that used to hold extensive melt ponding have gone in favour of smaller individual floes that drain readily into the ocean.

No sooner had we sorted out a way of using the melt pond extent we lose it due to further changes in the basin!

 But yes , melt ponds and certain low level cloud type will fool sensors into seeing ice ( as will 'overwash' during choppy weather) but this 15% or more measure really does give scope for 'misdirection' from some who demand no real change to the basin since 2013.

All you can do is direct folk to sat imagery and ask them to compare shots for the same date of the year with the 'numbers' that are meant to capture that moment.

 

If you think that in year 1 the grid square could be 99% ice covered and so = 'ice covered'

Year 2 could be 75% ice covered and still ='ice covered'

Year 3 could be 40% ice covered yet still ='ice covered'

Year 4 could be 20% ice covered yet still= 'ice covered'

Year 5 could be 16% ice covered yet still ='ice covered'

Only on year 6 when ice cover goes below 15% do we see change as the grid square will then show 'ice free'

You can see that year 1 is very different to year 5 but to the algorithm they equate as 'equal'

With both the year on year degradation of the pack overall and this years extreme conditions some folk could be in for a big shock in late July/early Aug as the ice starting around 2m thick blinks out en masse

 

Area already takes into account lower concentration. So if the pack is very fragmented, we will get lower area readings. I don't see any clear evidence why we should treat area as different than we normally do. 

This year is already quite low on area, so it isn't like area is showing something drastically different than what we'd expect given the very warm conditions thus far. If we get very hostile weather from here on out, we could still see a new record low this year. Right now, I'd bet against it, and settle on something in the top 3 or 4 instead. But there is still time for things to change. 

[Gray-Wolf]

I'm seeing developments over the ice as very worrying right now. The numbers may not be currently showing it but the ice is taking a real battering and I think this will begin to present over July when sub 2m ice blinks out. By the start of Aug the bulk of the 2m ice ( majority of our ice at max?) will fail and go.

The foundations of this 'cliff' are being laid now by the aggressive melt across many sea ice areas?

'Melt momentum' takes a lot to suppress and , unlike 07'/2012, we had open waters around our ocean entrances from the get go?

The warming , all season, of the waters in these area merely aid the imported warm/salty waters to maintain temp as they push in toward the central basin. These 'kill zones' mean any late season weather ( lows) can scatter ice into these 'new' zones of ice destruction so take ice that used to survive until re-freeze.

We saw some of this behaviour in 2012 when the line just kept falling at rates not seen before that late in the season.

So in basin 'kill zones' and sub 100m ice floes will add a difference to late melt season losses so we may have seen the 'June Cliff' fade with 'collapse and spread' causing us to see 'upticks' in ice cover where once we saw rapid losses ( when the central ice was still continuous floes so did not 'collapse and spread')

But every glint of open water sees that remarkable switcheroo from 90% energy reflected back into space to 90% of the energy gobbled up by the ocean? so the central pack , over peak insolation is offering up a new heat dump for the solar now the pack is so thin and fragmented as to 'collapse and spread' in June.

I've also heard folk bemoan the low angle of the sun and infer reflection of the incoming solar right back into space. Only if the ocean surface were mill pond calm as any ripples present a steeper angle for that incoming solar to strike ( think of German vineyards on the southern facing slopes?) so that 24hr sun's massive amount of energy is getting gobbled up right now ready to melt out the ice and delay re-freeze before flooding the autumn arctic atmosphere with warm , moist air, to mess with the set up of the polar night Jet and begin another torrid autumn/early winter for lower lats.

 

 

[bluewave]

The big story this year is the record warmth and low sea ice extent in the Pacific sector. But you can see 2012 ahead of 2019 in the Atlantic sector. Overall, 2019 is a bit behind the pace of 2012 to date.

https://mobile.twitter.com/AlaskaWx/status/1143202863633448960

The northern Bering & southern Chukchi Seas are baking. Large areas away from land with ocean surface temperatures more than 5C (9F) above the 1981-2010 average. Impacts to the climate system, food web, communities and commerce

https://mobile.twitter.com/AlaskaWx/status/1142829854930296832

Chukchi and Beaufort Seas combined #seaice extent remains the lowest of record (

@NSIDC

passive microwave data since 1979), 21 percent below the 1981-2010 median. Lower concentration of ice will be easily moved by winds this week.

 

 

 

[ORH_wxman]

2019 is still in the running, but will need a strong finish to June:

 

2016: +70k

2012: -190k

2010: -300k

2007: +5k

 

You can see how 2010 was actually running ahead of 2012 here for melting, but it then stalled near the end of the month and it continued into early July....putting an end to any chance of a nuclear finish like 2012 had.

 

The guidance this year has a very impressive dipole to finish the month of June...so we might have a legit shot here. The big question will be if we can turn that into a big blocking high over the CAB or if it retreats more to the Asian side and becomes a reverse dipole, which would probably put an end to our chances at a record....the guidance is kind of split on that idea for the longer term.

 

This melt season might finally have some drama after the colder early summers we've seen in recent years.

[csnavywx]

Now that the forecast range is much shorter, it looks like 2019 can snipe pole position over the next week or so. 2012 had a very impressive dipole at the end of June to about July 10th as well, so it'll be close, like ORH said. We're still a bit behind melt ponding in 2012 overall, but that looks to close up quickly with this upcoming pattern. The Atlantic sector and the area of untouched ice/snow in the central CAB are the only things holding this up at the moment and both look to start retreating soon. Substantial area drops are already underway due to the warm advection from the Siberian side, but with this upcoming dipole, we should see some big area drops from the CAB for the first time this season. 

After July 10 or so, 2012 never did get back to the mega-dipoles over the basin, but the damage was pretty well done by that point as virtually the entire pack was riddled with ponds and the momentum alone was enough to cruise in comfortably to a record.

[Gray-Wolf]

I find it odd to be comparing such different ice packs with our current pack?

In 2007 we still had paleocryistic ice in the basin and included in that year ice min figures.

08' and 09' had their final numbers plumped up by the collapse and spread of the last of this type of ice before its removal from the basin in 2010.

in 2012 prof Barber introduced 'rotten ice' into the sea ice classification

The ice since 2012 has progressively become younger , more fragmented and thinner.

Much of the ice in today's basin would melt out/rapidly be exported under 2007 forcings.

As it is much of the ice that saw ice max with only 2m thickness has been under high melt conditions for a while now and most areas are seeing ready fragmentation ( so opening of dark water around the floes).

As sat images also show most of the basin ice from pole to Barentsz had been flushed into Fram before melt season began (and Nares gobbled up Lincoln sea ice) leaving late grown FY as a replacement.

This pack began this melt season warmer/more fragmented/thinner than any pack thus far.

Proof of this will come when the 2m ice goes 'poof' at some point in late July.

Then we will have a lot of open water and less ice cover. Any storms entering/growing in the basin will put extra melt pressures on the remaining ice through swell/waves and the overwash/tumbling the ice fragments will see.

Not only do we have a good shot a 3rd lowest and above but also, should the right combination of weathers present, a B.O.E ( IMHO)

[ORH_wxman]

1 hour ago, Gray-Wolf said:

I find it odd to be comparing such different ice packs with our current pack?

In 2007 we still had paleocryistic ice in the basin and included in that year ice min figures.

08' and 09' had their final numbers plumped up by the collapse and spread of the last of this type of ice before its removal from the basin in 2010.

in 2012 prof Barber introduced 'rotten ice' into the sea ice classification

The ice since 2012 has progressively become younger , more fragmented and thinner.

Much of the ice in today's basin would melt out/rapidly be exported under 2007 forcings.

As it is much of the ice that saw ice max with only 2m thickness has been under high melt conditions for a while now and most areas are seeing ready fragmentation ( so opening of dark water around the floes).

As sat images also show most of the basin ice from pole to Barentsz had been flushed into Fram before melt season began (and Nares gobbled up Lincoln sea ice) leaving late grown FY as a replacement.

This pack began this melt season warmer/more fragmented/thinner than any pack thus far.

Proof of this will come when the 2m ice goes 'poof' at some point in late July.

Then we will have a lot of open water and less ice cover. Any storms entering/growing in the basin will put extra melt pressures on the remaining ice through swell/waves and the overwash/tumbling the ice fragments will see.

Not only do we have a good shot a 3rd lowest and above but also, should the right combination of weathers present, a B.O.E ( IMHO)

The chance of a blue ocean event this year is 0%. 

[Vice-Regent]

1 hour ago, ORH_wxman said:

The chance of a blue ocean event this year is 0%. 

Is that 100% ice-free? 90% ice-free is regarded as largely the correct definition. Once that happens the rest is not far behind. The Arctic effectively turns into a sub-tropical ocean basin with persistent cloud cover in the winter. It is the primary mechanism for the tipping point.

[ORH_wxman]

Just now, Vice-Regent said:

Is that 100% ice-free? 90% ice-free is regarded as largely the correct definition. Once that happens the rest is not far behind. The Arctic effectively turns into a sub-tropical ocean basin with persistent cloud cover in the winter. It is the primary mechanism for the tipping point.

I think "ice-free" has been defined as less than a million sq km of ice extent. I'm not sure if blue ocean event is the same thing but I'd assume it is. 100% ice free will never happen in this century because there will always be some residual ice clinging to northern Greenland or chunks of ice breaking off the Greenland glaciers. 

[Vice-Regent]

5 minutes ago, ORH_wxman said:

I think "ice-free" has been defined as less than a million sq km of ice extent. I'm not sure if blue ocean event is the same thing but I'd assume it is. 100% ice free will never happen in this century because there will always be some residual ice clinging to northern Greenland or chunks of ice breaking off the Greenland glaciers. 

Hansen Et. al. The meltwater injector.

[chubbs]

From Amy Butler's twitter. Unusual coupling of the stratosphere and troposphere this summer. Models at times too eager to end pattern.

[bluewave]

You can see why the Arctic Basin is at record low levels of extent. Blocking and record warmth focused over the Pacific sector. This is the opposite of 2012 when the harshest conditions were centered closer to the Atlantic regions. While 2019 has an Arctic Basin lead over 2012, the 2012 Atlantic extent was low enough to maintain a small overall advantage.

 NSIDC extent

6-26-19....9.819

6-26-12....9.712

[Gray-Wolf]

I think the move toward a more 'fragmented pack' leaves it all open to rapid transit if forcings arise. Currently the models are looking at a di-pole setting up so we should see gains in Barentsz/Greenland seas over the coming weeks as ice is thrown into the N.Atlantic.

To me part of the conditioning for a seasonal pack we have seen this past 5 years has been this mover to ever more fragmented, so mobile, ice. Even our older floes are riddled with scars of past fragmentation so have inbuilt weaknesses where 'new ice' glued the floe back together.

Both the low resilience of the 'glue ice ' and mechanical weathering ( jostling with other floes?) will see this pack become ever more broken up and heading for the 'less than 100m' sized floes where the side melt , not bottom melt, becomes the largest area of loss via ocean warmth taking floes out ever faster.

As for 0% chance of a blue ocean event ( less than 1 million sq km)?

Never say never eh?

Changes to the pack has seemingly done away with the June cliff in favour of June 'Gains' as the central ice fragments and flows into open waters.

Such ice is doomed and goes to fuel the July cliff where both it, and peripheral areas, are rapidly melting out. Todays century losses on JAXA may prove an early start to this 'cliff' ( due to recent high temps over sections of the pack?)

Again I would suggest that the folk relying on numbers alone take a comparative look at today's pack alongside other years for this date?

[chubbs]

Looking more and more like a 2 horse race