The 2016 melting season

[Neven]

How is 2016 doing now? My guess is we have fallen back to 2012-ish levels.

Nick, it's clearly lowest on the CAJAX graph, and lowest with 2012 and 2015 on the CAMAS graph:

[Neven]

And indeed, finally, some classic melting weather coming up (first time since I don't know when, April?). It has been interesting to see what a 2013-like year can do to the ice when it's not so cold as it was back then, but who knows what might have happened if there had been a period or two in June and July with a set-up like we're going to see in a few days:

[Ice Shieldz]

And indeed, finally, some classic melting weather coming up (first time since I don't know when, April?). It has been interesting to see what a 2013-like year can do to the ice when it's not so cold as it was back then, but who knows what might have happened if there had been a period or two in June and July with a set-up like we're going to see in a few days:

I had assumed earlier that the lack of sea ice extent going into the main melt season would kick-in weather like this.  Apparently not so much amidst broader synoptic patterns and any negative feedback that the ice and melting ice had on local arctic weather.  Well we missed peak insolation but this weather is not gonna help, especially given the increasingly bleak setup for building up winter ice.

[Michael Hauber]

And indeed, finally, some classic melting weather coming up (first time since I don't know when, April?). It has been interesting to see what a 2013-like year can do to the ice when it's not so cold as it was back then, but who knows what might have happened if there had been a period or two in June and July with a set-up like we're going to see in a few days:

We had a short dipole-ish period a week or two ago.  High pressure between Greenland and Pole with sunny skies and warm temps on the American side of the Arctic, but still cool on the Asian side.  Not basin wide enough to meet your criteria for classic melting weather?

The comparison to 2013 for 925 hp is interesting.  A couple weeks of heat in July sandwiched by cooler conditions either side.  But overall warmer with a higher peak, and weaker cool periods this time.  And with the current forecast the second cool period should end sooner than the corresponding cool period in 13.

[Tigertown]

A couple pennies short of a dollar today(SIE Drop), but the biggest drop in a while. Apolagies for not knowing how to convert that to Euros, but I think everybody gets the gist. The stuff's melting again.

[pearscot]

Every. single. year. The more I guess and feel as though I 'understand' the arctic, the more I am wrong. That's okay, sometimes one learns more from being wrong than being correct once." That said, I still see portions, that do look very broken up, in what I see as a 'rubble.'

[Rob Dekker]

Today is day # 213 of 365.  DMI N80 temps typically fall below 0°C around day 230.  To a rough approximation then, we can expect refreeze to match melt in another two weeks north of 80°.

Marginal ice zones next to open water (the Laptev bite and the Atlantic sector) could continue a bit longer, but the central CAB only has a couple of weeks to reduce extent before it starts refreezing.

After that, compaction events will not have as large an effect because the interstitial openings will start being filled with new ice.

Ktonine  I doubt very much that temps of 0'C will stop the melt . Last year the melt continued for a further 40 days in the CAB  , 2012 continued melting for another 50 days from now . Why would/should bottom melt etc halt in 14 days ?

I would like to second that opinion.
Into August, bottom-melt sustains and rules, as Steele et al 2009 quantifies
http://psc.apl.washington.edu/zhang/Pubs/Steele_etal_2009JC005849.pdf

Just remember that sea ice "area" is a better predictor for Sept extent minimum than sea ice "extent" itself. That is because sea ice "area" tells something about how much heat is absorbed in the ocean. And sea ice "area" is still running at an all-time minimum, even below 2012.

Which means that when "area" falls, "extent" is sure to follow...

[Neven]

We had a short dipole-ish period a week or two ago.  High pressure between Greenland and Pole with sunny skies and warm temps on the American side of the Arctic, but still cool on the Asian side.  Not basin wide enough to meet your criteria for classic melting weather?

Yes, you're right, that was a dipole too. But in my experience, built up over the last 7 years and probably not worth all that much, a dipole where the high is sitting over the Beaufort Sea (to really get that Gyre going) is the worst for sea ice extent/area - ie they drop fast. Especially in June and July because of melting momentum, but in August and September too because of compaction potential of which there is a lot right now.

As for what kind of weather is best/worst for the ice, I'm not so sure anymore. It doesn't seem to matter all that much if there's a lot of heat in the system.

Still, with a bit more melting momentum built up during June, compounded during July, because of open skies instead of cyclones, this melting season would have been a real contender for the record. Although a lot of people seem to believe it still is, so maybe I'm wrong on that.

[iceman]

   ....
And this a line-up conducive for some Fram Strait export at t+192 h (less certain!):
   ....

Interesting prospect, let's see if that forecast verifies.
    The excess heat built up in Kara and Barents looks like a wild card for the remainder of the melt season.  So far it has been largely isolated from the main pack.  Yet I wouldn't be surprised if a big North Atlantic storm drew energy from that area.  If the low happened to stall near Franz Josef Land, it could shove a lot of ice out through Fram Strait.

[F.Tnioli]

The last two weeks in motion

Nice gif. My eyeballs see helluva lot of green now, - way more green than there was two weeks ago. And the way lots of that green can go is obviously below set % for extent (30% and such). Big cliff for extent numbers 2nd decade of August would not surprise me the least. Especially because there is also huge potential for compaction, and there is also that pattern Neven mentioned being formed. Heck, may be we'll see the largest extent numbers daily drop(s?) on record, soon. I wouldn't exclude such a possibility at all.

[lurkalot]

It looks to me as though the Amundsen NW passage route is just about open, passing east of Prince of Wales Island.

[A-Team]

It looks to me as though the Amundsen NW passage route is just about open, passing east of Prince of Wales Island.

See discussion of 31 July 16 opening of Northwest Passage at:

http://forum.arctic-sea-ice.net/index.php/topic,762.msg85125.html#msg85125
http://forum.arctic-sea-ice.net/index.php/topic,762.msg85127.html#msg85127

[NeilT]

Although a lot of people seem to believe it still is, so maybe I'm wrong on that.

Don't think so Neven.  We've only got about 4 weeks of reasonably strong melting followed by 2 weeks of lesser melting and wind rearrangement left in the season.

It's looking a lot like 2012 did before the GAC where all that ice just kept  lingering there but wasn't completely vanishing.  Whilst I'd be the last to say a GAC could not happen, it doesn't look like it with the weather patterns we've seen. The weather to date has been doing the dual function of dumping some heat whilst protecting from a lot more.

Should be top 4 for extent and something interesting for area.

[Neven]

We'll seen, Neil. I think it may still go either way. This year is somewhat unique.

BTW, this is Compaction with a capital C:

[jai mitchell]

Should be top 4 for extent and something interesting for area.

and volume?

[seaicesailor]

Although a lot of people seem to believe it still is, so maybe I'm wrong on that.

...
It's looking a lot like 2012 did before the GAC where all that ice just kept  lingering there but wasn't completely vanishing.  Whilst I'd be the last to say a GAC could not happen, it doesn't look like it with the weather patterns we've seen. The weather to date has been doing the dual function of dumping some heat whilst protecting from a lot more.
....

Funny, I think the storms combining June/July have made up for the GAC. They were passing once and again over the same areas! Breaking 20 km floes into 5 km pieces then 1km and so. Pushing the ice toward Beaufort and Atlantic heat, which took care of the 'castaways'. Dragging heat too. Good for the CAB ice that they came so early and kept it cloudy, but in the periphery the warmest year on record so far has been felt, except for the Laptev sea.
OTOH extent really matters and favours ice. It is not the same having a established melt front than thousand little holes in the CAB, IMO for many reasons too long to expose now.
So all in all no 2012 but very ugly.

[RoxTheGeologist]

I was intrigued by the Bathymetry link to the Barents Polar Front that A-Team pointed out and so read around the subject of oceanic currents. The export through the Fram is not only of ice, which can be blown around by prevailing winds, but also of cold surface water as a means of mass balancing the saline Atlantic waters that typically flow north and into the Arctic via the eastern Fram and through the Barents sea, cascading down the continental slope to from the stable halocline in the Arctic.

I was therefore surprised to see this ice floe:

http://go.nasa.gov/2avkYRf

Disintegrate over a few days as an moved towards the Greenland coast. Clearly the water there is warm enough to melt a huge ice floe quickly. If the East Greenland current is flowing strongly, I would expect the surface water there to be too cold to melt anything! Has the East Greenland current slowed dramatically? It suggests more surface mixing between Atlantic and the cold fresh upper layers of the Arctic ocean and that the lack of Fram export is partly because the saline Atlantic water is warmer,  its rate of sinking is reduced and thus there is less potential energy to drive water out of the Arctic. Perhaps the stable halocline is not going to be quite so stable as heat is added to the Arctic and there is less ice to freshen surface water.

http://oceancurrents.rsmas.miami.edu/atlantic/east-greenland.html

[Ice Shieldz]

Highly anomalous SSTs surround pack on all sides, especially Atlantic.  Wondering how much the dipole will drive ice into the Atlantic?  Seems it will more likely cause compaction in the CAB. Maybe the ice north and east of Greenland will get pushed out with the low positioned as it's forecasted.

[werther]

I don’t know what temps over 80dN are up to, but DMI reports a pretty unusual excursion into anomaly lately:

[slow wing]

The U. Bremen ice concentration map is out for 1 August. This is one of the dates for which Neven has a year-to-year comparison plot - one of my favourite visual aids in trying to compare years:
https://sites.google.com/site/arcticseaicegraphs/concentration-maps/sic0801

[jdallen]

The U. Bremen ice concentration map is out for 1 August. This is one of the dates for which Neven has a year-to-year comparison plot - one of my favourite visual aids in trying to compare years:

Strikes me that there is a lot of similarity between 2012 and 2016.

[peterlvmeng]

The U. Bremen ice concentration map is out for 1 August. This is one of the dates for which Neven has a year-to-year comparison plot - one of my favourite visual aids in trying to compare years:

Strikes me that there is a lot of similarity between 2012 and 2016.

Yes, the difference is in the Laptev sea.

[seaicesailor]

A bit cherry-picking but fits the moment. Sun was shining a few hours ago. No much ice. The ship is near the boundary between Beaufort and Chukchi seas, west of the big block remains

[binntho]

I was therefore surprised to see this ice floe:

http://go.nasa.gov/2avkYRf

Disintegrate over a few days as an moved towards the Greenland coast. Clearly the water there is warm enough to melt a huge ice floe quickly.

I've followed this forum for the last couple of years and this year I've been wondering about the Fram strait in the light of what seems to be a general consensus, that this year Fram export is negligible and/or not important compared with other areas.

Two features seem to have been very persistent all summer: A tongue of ice going down the middle of the strait before veering towards the Greenland coast - this tongue shows very active melting along it's entire eastern side, with large swirls of slush moving rapidly south.

The second feature is a patch of open water at the northeastern extreme of the strait, along the Greenland coast. This patch has been very persistent since the beginning of June and I somehow reckoned that it was caused by, and kept open, by wind off Greenland or ocean currents eddying around the corner of Greenland.

But as RoxTheGeologist points out, there is actually a lot of melting going on in this open patch of water, and looking at Modis one can easily see this happening.

I would guess that any persistent features in a moving ice pack indicates consistent melting. I've made an animation showing Rox's icefloe over the last month or so, it originates in landfast ice on the northern Greenland shore, is carried into the Fram strait where it breaks up and the two largest pieces I could track end up over 100 km apart.

So there is clearly an eddy or gyre but given how the fast the ice melts within it makes it unlikely to be an eddy of the cold Fram current. Perhaps an upwelling of warm water originating further east? Looking at the last few years on Eosdis I can see the same features, except for 2012 where Fram export seems to have been nonexistent in July?

My tentative and entirely non-expert conclusion is that Fram export is very active and is contributing significantly to ice melt this season. But I've very little idea how this year compares with other years, again on Eosdis I don't see that much of a difference at this time of year over the last few years (except, as noted, for 2012).

The furthest piece moved some 250 km in 33 days, picking up speed slightly towards the end, covering some 120 km in the last 10 days.

Click to see the animation.

[Rob Dekker]

The U. Bremen ice concentration map is out for 1 August. This is one of the dates for which Neven has a year-to-year comparison plot - one of my favourite visual aids in trying to compare years:

Strikes me that there is a lot of similarity between 2012 and 2016.

Yes, the difference is in the Laptev sea.

The Laptev will melt out (Neven calls it a "piggy bank" IIRC).
The real action will be in the CAB. The CAB determines if it will be a "average low" minimum or a "record low" minimum come September.

And here is the CAB's ice "area" :


The question is if the CAB area will follow the 2015 high line, or the 2012 low line...
Hard to say right now, but JDallen's remark is a case in point.
If that ice in the ESS will get cut-off from the main pack, we will see 2012-line progression, and if not, and August will be cold as it was in 2015, we may see 2015-line progression.

Personally, I think 2016 will be in between.

Either way, 2016 promises to be fascinating during the "end-game" that is starting right now.

[seaicesailor]

The ECMWF ensembles keep agreeing on the position and intensity of the anticyclone in five days but disagree on the intensity of the low pressure system. The main forecast put it lower at 985 hPa

[Andreas T]

I was intrigued by the Bathymetry link to the Barents Polar Front that A-Team pointed out and so read around the subject of oceanic currents. The export through the Fram is not only of ice, which can be blown around by prevailing winds, but also of cold surface water as a means of mass balancing the saline Atlantic waters that typically flow north and into the Arctic via the eastern Fram and through the Barents sea, cascading down the continental slope to from the stable halocline in the Arctic.

I was therefore surprised to see this ice floe:

http://go.nasa.gov/2avkYRf

Disintegrate over a few days as an moved towards the Greenland coast. Clearly the water there is warm enough to melt a huge ice floe quickly. If the East Greenland current is flowing strongly, I would expect the surface water there to be too cold to melt anything! ....

http://oceancurrents.rsmas.miami.edu/atlantic/east-greenland.html

This area of open water on the northeast corner of Greenland has been a feature for many years. You can see the floe circulating in a clockwise eddy, which is typical for floes entering this area. The bathymetry shows that the deep trench where the main outflow from the arctic occurs passes further east and there is a shelf under that area of water which makes it plausible that shallower water recirculates up north along the coast. This northward movement while southward flow predominate further east can also be seen a little further south where ice has broken up recently inside Belgica bank. My guess that the warmer water is atlantic water which flows back out at depth below 200m but is brought to the surface by the shelf and coriolis effect

The norwegian hovercraft Sabvabaa spent some weeks there in 2015, these weekly reports make interesting reading: https://sabvabaa.nersc.no/node/368
If your browser allows it is also interesting to look at the area in IR band worldview images with a narrow colour scale https://worldview.earthdata.nasa.gov/?p=arctic&l=MODIS_Terra_CorrectedReflectance_Bands367(hidden),MODIS_Terra_CorrectedReflectance_Bands721(hidden),MODIS_Aqua_CorrectedReflectance_Bands721(hidden),VIIRS_SNPP_CorrectedReflectance_BandsM3-I3-M11(hidden),VIIRS_SNPP_CorrectedReflectance_BandsM11-I2-I1(hidden),VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor,MODIS_Terra_CorrectedReflectance_TrueColor,AMSR2_Sea_Ice_Brightness_Temp_6km_89V(hidden),Aqua_Orbit_Asc(hidden),Graticule,AMSR2_Sea_Ice_Brightness_Temp_6km_89H(hidden),Coastlines,MODIS_Aqua_Brightness_Temp_Band31_Night(hidden,palette=rainbow_1,min=250.2,max=279.9,squash),MODIS_Aqua_Brightness_Temp_Band31_Day(hidden,palette=rainbow_1,min=250.2,max=282.5,squash),MODIS_Terra_Brightness_Temp_Band31_Day(palette=rainbow_1,min=260.3,max=283.1,squash),MODIS_Terra_Brightness_Temp_Band31_Night(hidden,palette=rainbow_1,min=240.1,max=285,squash)&t=2016-08-01&v=-114649.27580048237,-1239704.9125953487,1284134.7241995176,-564888.9125953487

[Rob Dekker]

binntho, Thank you for the animation of this flow around Greenland.
However, there are several indications that Fram export has been minimal this melting season.
For one, the ice extent in the Greenland Sea has been running at a record low all season (suggesting it was not supplied with much ice).

And then Wipneus animation today
http://forum.arctic-sea-ice.net/index.php/topic,382.msg85116.html#msg85116



shows quite clearly that whatever little Fram export happened, the ice quickly melts out.

[binntho]

binntho, Thank you for the animation of this flow around Greenland.
However, there are several indications that Fram export has been minimal this melting season.
For one, the ice extent in the Greenland Sea has been running at a record low all season (suggesting it was not supplied with much ice).

And then Wipneus animation today
http://forum.arctic-sea-ice.net/index.php/topic,382.msg85116.html#msg85116

shows quite clearly that whatever little Fram export happened, the ice quickly melts out.

Thanks for the reply. I've been looking at Fram all summer, runnig Eosdis back and forth to see the movement of the ice, and it is erratic to say the least, with a lot of back and forth movement.

But I guess my main point is this: All summer there has been a lot of melt on the edges of that tongue of ice going into Fram. But the tongue is still there ... which means it's being replenished constantly. The actual size of the tongue could just as well be a sign of more melt than as of less transport - I've no idea how to determine which is which - but again, looking at Eosdis and scrolling back and forth indicates ice moving very fast, and melting very fast as well. So I'm not convinced that Fram export is somehow negligible ...

[binntho]

This area of open water on the northeast corner of Greenland has been a feature for many years. You can see the floe circulating in a clockwise eddy, which is typical for floes entering this area. The bathymetry shows that the deep trench where the main outflow from the arctic occurs passes further east and there is a shelf under that area of water which makes it plausible that shallower water recirculates up north along the coast. This northward movement while southward flow predominate further east can also be seen a little further south where ice has broken up recently inside Belgica bank. My guess that the warmer water is atlantic water which flows back out at depth below 200m but is brought to the surface by the shelf and coriolis effect

Thanks for that Andreas, it's certainly an interesting feature.

[Thawing Thunder]

I was therefore surprised to see this ice floe:

http://go.nasa.gov/2avkYRf

Ah! RTG! I learned how to toggle between the days on NASA Worldview! That's a cool feature, as motion is so essential for understanding the ice (newbee-comment  )

[NeilT]

and volume?

Because most volume is modelled rather than observed, I tend to find it responds on the modelled path rather than an observed path.  So sudden shocks can't be reflected in the model because it can't allow for it until after they have been observed for the first time.

I suspect the volume models will be the last to fall when the ice suddenly vanishes.

I see Volume as a good indicator but not a metric which you can observe on a year to year basis in the same way during the melt season.

[A-Team]

Below is the 01 Aug 16 sea ice concentration map from UH AMSR2 3k showing bin lumping (watch the palette). This may provide some sort of end-of-season heuristic (though it neglects ice movement).

Because bin occupancy is so low at low concentrations, these were filled 4 bins at a time whereas at the higher concentrations only one bin at a time. At the end, the remaining ice is divided between melt and left-over.

As a technical aside, the overall Arctic at AMSR2 scale does not fit well within the 700x700 pixel forum framework, so it had to be reduced at the very end. The full size version, which will not animate without a click is also attached in the following post, with the end frame showing initially, for those wishing to download the gif frames and make variants.

[A-Team]

This is the full size version, it cannot be co-displayed with the first and won't animate without opena click or new browser tab.

[Gray-Wolf]

Not liking this 'spike' in temps on the DMI?

 I thought melt was supposed to peg temps around freezing and only when the ice was gone could temps rise?

I've looked back and cannot find similar over past years ( you can see the temp maintain as heat is shed into the first part of Autumn but no 'spikes'?)

[Dundee]

What I find intriguing in the latest Bremen concentration (#3769) plots is the region north of Greenland. Looking at the plot and the calendar, it is not hard to imagine a (if only hypothetical) circumnavigation voyage around the island. Has Greenland ever melted free from the pack in, say, the last hundred years?

I am a newbie, but the current volume of discussion of the Fram Strait surprises me. My brief look at the (sparse) summertime record leaves the impression that in summer months export volume is at its weakest and most variable. Is not the real power of Fram export that it is capable of removing large volumes of ice from the equation (though they may not actually melt for many weeks) while the Arctic is firmly frozen?

[RoxTheGeologist]

What I find intriguing in the latest Bremen concentration (#3769) plots is the region north of Greenland. Looking at the plot and the calendar, it is not hard to imagine a (if only hypothetical) circumnavigation voyage around the island. Has Greenland ever melted free from the pack in, say, the last hundred years?

I am a newbie, but the current volume of discussion of the Fram Strait surprises me. My brief look at the (sparse) summertime record leaves the impression that in summer months export volume is at its weakest and most variable. Is not the real power of Fram export that it is capable of removing large volumes of ice from the equation (though they may not actually melt for many weeks) while the Arctic is firmly frozen?

I'm a newbie too, but I opened my discussion because of the rapid melt of ice adjacent to the North East Greenland coast. I haven't been able to find a single reference to a northward flow of a current along the shelf. The assumption seems to be that the shelf region is part of East Greenland Current that flows south along the western side of the Fram strait. The eastern Fram strait has a northward flow of warm Atlantic Water, the West Spitzbergen Current, (WSC). About 50% of the WSC turns south at the "Molly Hole Gyre" around 79.5°N  to 80°N, and joins with Polar Water (Cold fresh surface water) and deep Arctic water in the ECG and flows south.

http://onlinelibrary.wiley.com/doi/10.1002/2016GL068323/full

The observation is that the recently broken fast ice is moving north adjacent to the coast, and ice is melting north of there.

The water where the ice is melting cannot be comprised of cold fresh polar water, or it wouldn't melt. As far as I know the only 'warm' water in the mix is Atlantic Water, but the question is how is it appearing on the Western side of the EGC? My guess, for what it is worth, is that not all the Atlantic water is turning south, and some is making it all the way across the strait beneath the polar water. It appears on the Greenland shelf, probably being pushed to the surface as it encounters and flows up the continental slope.

[Ice Shieldz]

Not liking this 'spike' in temps on the DMI?

 I thought melt was supposed to peg temps around freezing and only when the ice was gone could temps rise?

I've looked back and cannot find similar over past years ( you can see the temp maintain as heat is shed into the first part of Autumn but no 'spikes'?)

As far as firsts go, I don't think there was a time when SSTs were so anomalously warm across more area of ocean surrounding the arctic than now.  Also weather continues to bring record or close to record hot air masses up from lower latitudes.  The gotcha here is that most of the heat from weather and SSTs can clearly be seen affecting areas south of 80° but not really north of 80°.  As some have suggested, all that extra heat must be advecting into the ocean, ice and air north of 80°. it's basic physics, we just need greater clarity with more measurements and deeper understanding of the specific mechanisms of heat transfer.

Edit:  Here is a current nullschool of surface temps and wind patterns.

[seaicesailor]

What I find intriguing in the latest Bremen concentration (#3769) plots is the region north of Greenland. Looking at the plot and the calendar, it is not hard to imagine a (if only hypothetical) circumnavigation voyage around the island. Has Greenland ever melted free from the pack in, say, the last hundred years?

I am a newbie, but the current volume of discussion of the Fram Strait surprises me. My brief look at the (sparse) summertime record leaves the impression that in summer months export volume is at its weakest and most variable. Is not the real power of Fram export that it is capable of removing large volumes of ice from the equation (though they may not actually melt for many weeks) while the Arctic is firmly frozen?

It is in winter as shown in the plot below, but in a bad year like 2007 (sorry I cannot find the data now) the Fram Export keeps on and might be double as usual for summer, which is very bad for obvious reasons.
There is another thing: a high Fram Export in summer may indicate that prevailing weather is pushing and compacting the ice from Pacific toward Atlantic. In that case, the high export is also an indication of the bad weather for the ice in the whole Arctic.

[jai mitchell]

I see Volume as a good indicator but not a metric which you can observe on a year to year basis in the same way during the melt season.

I disagree.  The monthly average values of the model are quite robust so, even though the results are delayed and are not a direct observation of visual imagery that can be observed on a day to day basis, the monthly and annual minimum values can be compared accurately and provide good insights.

indeed, the uncertainty associated with SIE and (especially) SIA makes them even poorer for comparison values than the monthly average volume estimates.

[Kethern]

It is working fine with this link

Bear in mind that the model underlying ACNFS is admittedly not "working fine" at present:

http://forum.arctic-sea-ice.net/index.php/topic,1602.msg84108.html#msg84108

Regardless of any model problems, the snapshot archives are showing that the last run was on July 29th so there would appear to be some issue with the website or underlying software as well.

[NeilT]

I disagree.  The monthly average values of the model are quite robust so, even though the results are delayed and are not a direct observation of visual imagery

Even if they were.  The models can't estimate a year with exceptionally strong bottom melt where there is still area or even extent being recorded.  They take the area and apply the model created by the record of the observed record.

Yes PIOMAS does an amazingly good job even then.  However when a step change happens it will come up short.  You can already see the drift from Cryosat2 data posted on the blog by Chris Reynolds.  It's not that huge right now but it's definitely there and Cryosat2 is not modelled, it was calibrated very extensively when it was commissioned.

[werther]

The latest model plot coming from ECMWF for the next ten days confirms an awful first decade of August for Arctic Sea Ice.
On top of compaction- and dipolish low level configuration, a strong 500Mb ridge builds up over Baffin Bay/Greenland.
In it's own way, this configuration might well produce a '12-like' race to 5Mkm2 SIE around 10-12 August.
First effects should be visible on MODIS by thursday. In the numbers by friday.
In the meantime, it will be quite freightening if today's CB should be followed by others tomorrow etc. If so, a spectacular slide might be in pocket when the ECMWF forecast unfolds....

[ktonine]

Not liking this 'spike' in temps on the DMI?

 I thought melt was supposed to peg temps around freezing and only when the ice was gone could temps rise?

There's a lot of Atlantic Sector ocean exposed with high temp anomalies.  This could well be the reason for the uptick.

[Villabolo]

A little off topic but I see something scary in this site's graph's page. Where I expected to see Hycom's ice thickness chart I now see a blank page and a link to a Russian website. 

[Feeltheburn]

I was intrigued by the Bathymetry link to the Barents Polar Front that A-Team pointed out and so read around the subject of oceanic currents. The export through the Fram is not only of ice, which can be blown around by prevailing winds, but also of cold surface water as a means of mass balancing the saline Atlantic waters that typically flow north and into the Arctic via the eastern Fram and through the Barents sea, cascading down the continental slope to from the stable halocline in the Arctic.

I was therefore surprised to see this ice floe:

http://go.nasa.gov/2avkYRf

Disintegrate over a few days as an moved towards the Greenland coast. Clearly the water there is warm enough to melt a huge ice floe quickly. If the East Greenland current is flowing strongly, I would expect the surface water there to be too cold to melt anything! Has the East Greenland current slowed dramatically? It suggests more surface mixing between Atlantic and the cold fresh upper layers of the Arctic ocean and that the lack of Fram export is partly because the saline Atlantic water is warmer,  its rate of sinking is reduced and thus there is less potential energy to drive water out of the Arctic. Perhaps the stable halocline is not going to be quite so stable as heat is added to the Arctic and there is less ice to freshen surface water.

http://oceancurrents.rsmas.miami.edu/atlantic/east-greenland.html

Rox, thanks for the explanation of the possible effect of cold less saline water mixing with warmer more saline water on currents and Fram export.  One thing that occurred to me is the fact that frozen sea ice, which is made mostly of fresh water, has a density of 0.917 g/cm3 while salt water has a density of 1.03 g/cm3, meaning there is substantial volumetric contraction when ice melts and mixes with salt water of about 10%.  Expansion and contraction of air in canyons causes winds, so perhaps contraction of water through relatively narrow straits between large land masses contributes to currents.  If so, might the observed current lack of ice and concomitant melting in the Fram strait slow down Fram export?  Isn't this consistent with previous years when a lot of ice in the Fram strait correlated with high ice export and right now when the lack of ice in the strait correlates with low export?

Of course, I am already prepared to be shouted down for proposing something (perhaps) new.

[Rob Dekker]

The furthest piece moved some 250 km in 33 days, picking up speed slightly towards the end, covering some 120 km in the last 10 days.

Thanks binntho,
120km over 10 days, or 12km/day is indeed quite a lot.
But I noticed that most of that movement of the ice floe is eastward.
Very little moves south (and contributes to Fram Strait export), and That eastern front is also much larger than the Fram Strait opening.
So it seems to me that melt on the eastern front (as pointed out by A-team and others) this year is quite a bit more significant than Fram Strait export.

[binntho]

The furthest piece moved some 250 km in 33 days, picking up speed slightly towards the end, covering some 120 km in the last 10 days.

Thanks binntho,
120km over 10 days, or 12km/day is indeed quite a lot.
But I noticed that most of that movement of the ice floe is eastward.
Very little moves south (and contributes to Fram Strait export), and That eastern front is also much larger than the Fram Strait opening.
So it seems to me that melt on the eastern front (as pointed out by A-team and others) this year is quite a bit more significant than Fram Strait export.

Thanks for the answer Rob. I am sure that Fram strait export is of lesser significance now than before because of that eastern-front melting. But on the other hand I'm not convinced that Fram export is small or insignificant. I've seen some attempt to quantify the export, but so far the most common argument for small export seems to be that the tongue of ice is smaller than usual. Which to me could just as well indicate that it is melting faster than before.

The block of ice I marked in the animation is heading for the Fram strait, and the bit that ends furthest south is in the middle of the ice tongue. The entire block ends in the Fram strait, i.e. it crosses a line between the norht-east corner of Greenland and the north-west corner of Svalbard, where it then melts.

The tongue of ice going into the strait shows very significant melt along its entire length, on both sides, as well as in the middle, and yet the tongue persists through the summer which indicates that a large amount of ice is being exported. But how much ice compared to the entire eastern front? I've no idea - a rough measure of the length of the tongue compared to the rest of the eastern front (from north-western Svalbard to south of Ostrov Komsomolest island) gives a ratio of 1/2, i.e. the east-facing side of the tongue is roughly half the length of the rest of the eastern front. Given that the tongue is actually melting from both sides (and in the middle) this would indicate that the Fram strait is at least providing half the melting on the Atlantic front?

Another thing to consider is that the ice being exported into Fram over the last month originates to the north of Greenland, presumably being thick MYI - while the rest of the eastern front is mostly thinner FYI.

Reading the above I can't help thinking that I'm missing a major point here: That Fram export is usually considered to be the steady flowing of ice on a cold current going much further down the coast of Greenland where it eventually melts (particularly in winter). But as RoxTheGeologist has pointed out, something else might be happing in the Fram strait - possibly indicating that instead of the normal cold surface waters flowing south in the western half of the Fram strait it is now being mixed with a tongue from the warmer Spitzbergen current? The rapid melting of the much-mentioned ice floe off the coast of Greenland certainly indicates that the surface waters there are warm, which doesn't really fit well with a cold polar current.

In the end it doesn't really matter - the ice melts or it doesn't. But a lot of the fun of this forum is people trying to predict what the ice will do, and if Fram strait export is indeed significant, and mostly MYI, then this could affect these predictions.

[Andreas T]

The North East Water polynya probably deserves a thread of its own. There is research around if you search under that name.
quoting one abstract from 1993: http://link.springer.com/article/10.1007/BF00240265

Physical observations of the North East Water (NEW) polynya, located near the north-eastern corner of Greenland, are presented. Data were collected in June 1991 by RV Polarstern. An idea is put forward to explain how the NEW is generated. A northward coastal current interacts with a persistent shelf ice barrier under which water can flow but that retains ice floes and therefore protects the NEW area from ice advection. Since in summer, the combination of currents, barrier and air-sea heat balance gives rise to a polynya. The distribution of upper water column vertical stability in the NEW is also influenced by its generation process. Surface melt water is retained by the shelf ice barrier, causing neutral vertical stability in its lee. Sea ice melting and land runoff then act as two distinct sources of vertical stability enabling the development of plankton blooms, especially in the northern part of the NEW.

something to note about binntho's animation is that the rapid reduction in size of the floe is not entirely due to melting but of course break up in the first instance. Melting no doubt is part of this process but it is not quite as rapid as it appears.
Obuoy9 went into this area last year and the video  of its melt out is still available here: http://obuoy.datatransport.org/monitor#buoy9/movie

[Adam Ash]

ENS shows a southbound current moving at about 20 km per day (0.23 m/s) to carry the ice into the Atlantic, and a tongue of 12.8 degrees C water pushing north to welcome any block of ice which gets sent that way.

I don't know how well ENS works, but 12.8C sure seems warm out there.  I don't have any history on this tho - may be routine situation.

https://earth.nullschool.net/#current/ocean/surface/currents/overlay=sea_surface_temp/orthographic=-15.59,82.11,2708/loc=6.224,77.778