The 2018 melting season

[SteveMDFP]

As of now the storm is centered above the relatively compact, continuous CAB ice, where there is reduced capacity to generate wave action.  ...

What, if any, affect will Ekman pumping have on bottom melt under the 'continuous CAB ice'?

On smaller scales, cyclonic winds induce Ekman transport which causes net divergence and upwelling, or Ekman suction, while anti-cyclonic winds cause net convergence and downwelling, or Ekman pumping. Ekman transport is also a factor in the circulation of the ocean gyres.

Do I have this right:  the storm should cause (Ekman) downwelling? And the consequences for the ice?

I believe the quoted text is correct.  Low pressure systems cause divergence of the ice and upwelling.  The opposite for high pressure systems.  Pretty sure, anyway.  There are smarter experts around.

[Sciguy]

.       
You have a good track record and, given the current slow melt, I am inclined to agree that we will end this melt season around 5.00 M km2. 

I am continually gobsmacked by comments like this. Volume is taking a hammering. Bottom melt and fragmentation is going at a record pace. The fast changing weather systems and winds are sprawling the pack and mixing in the unprecedented incoming ocean heat like never before. Are people so stuck in their habits that they only make a skin deep quick look at extent and area figures compromised by incapacity to distingush between fields of shrapnel and solid ice, and charts drawn by the artist algorithm. And don't look at the underlying processes going on.
These Amsr2 datasets cannot resolve even sub 200m wide continuous leads of long length. And even thickness products are giving misleading results due to measurement of the gap between sea level and the tops of chunks of floating rubble.
Incoming heat is attacking the ice basin wide. The energy flux into the ice and sea surface is  enormous. It REALLY stands a chance of slushing into almost nothing in one major prolonged storm.

I think with the high snow cover, low level of melt ponding in May and June, the early cyclone over the Kara that brought in a lot of clouds and fresh show, that the amount of heat in the Arctic is probably less this year than in 2012, probably close to what it's been the past five years.  So I think a continuation of the long term trend is what we'll see, not anything exceptional this year.

[bbr2314]

.       
You have a good track record and, given the current slow melt, I am inclined to agree that we will end this melt season around 5.00 M km2. 

I am continually gobsmacked by comments like this. Volume is taking a hammering. Bottom melt and fragmentation is going at a record pace. The fast changing weather systems and winds are sprawling the pack and mixing in the unprecedented incoming ocean heat like never before. Are people so stuck in their habits that they only make a skin deep quick look at extent and area figures compromised by incapacity to distingush between fields of shrapnel and solid ice, and charts drawn by the artist algorithm. And don't look at the underlying processes going on.
These Amsr2 datasets cannot resolve even sub 200m wide continuous leads of long length. And even thickness products are giving misleading results due to measurement of the gap between sea level and the tops of chunks of floating rubble.
Incoming heat is attacking the ice basin wide. The energy flux into the ice and sea surface is  enormous. It REALLY stands a chance of slushing into almost nothing in one major prolonged storm.

I think with the high snow cover, low level of melt ponding in May and June, the early cyclone over the Kara that brought in a lot of clouds and fresh show, that the amount of heat in the Arctic is probably less this year than in 2012, probably close to what it's been the past five years.  So I think a continuation of the long term trend is what we'll see, not anything exceptional this year.

Why don't you post maps and analysis instead of observations that are completely lacking in support? The amount of heat import this year has been the worst ever. I would post maps but oren will yell at me so go to ESRL and look for yourself. Satellite data also shows the most open water in the High Arctic on record.

[oren]

.       
You have a good track record and, given the current slow melt, I am inclined to agree that we will end this melt season around 5.00 M km2. 

I am continually gobsmacked by comments like this. Volume is taking a hammering. Bottom melt and fragmentation is going at a record pace. The fast changing weather systems and winds are sprawling the pack and mixing in the unprecedented incoming ocean heat like never before. Are people so stuck in their habits that they only make a skin deep quick look at extent and area figures compromised by incapacity to distingush between fields of shrapnel and solid ice, and charts drawn by the artist algorithm. And don't look at the underlying processes going on.
These Amsr2 datasets cannot resolve even sub 200m wide continuous leads of long length. And even thickness products are giving misleading results due to measurement of the gap between sea level and the tops of chunks of floating rubble.
Incoming heat is attacking the ice basin wide. The energy flux into the ice and sea surface is  enormous. It REALLY stands a chance of slushing into almost nothing in one major prolonged storm.

Hyperion, I will be very surprised if this season ends at 5.0 Mkm2 or above. But your level of confidence is unjustified, and attacking others over it is not acceptable behavior IMHO.

[El Cid]

.       
 

Hyperion, I will be very surprised if this season ends at 5.0 Mkm2 or above. But your level of confodence is unjustified, and attacking others over it is not acceptable behavior IMHO.

Tru dat

[Hyperion]

While gfs seems to have backed off a little since yesterday in having the cyclone gear up to a basin wide coherent super cyclone by the 11th, it still is showing basin wide cyclonic circulation up until the twelfth presently. And of course could go either way that far out.
The main effect of this atmospherically seems to be over a week of: the record northeastern American heat being drawn in over the CAA. Westerlies from the Chukchi into the Beaufort. And prolonged strong southerlies sweeping up into the Arctic across the whole Atlantic entrance.
Looking at the SST, SSTA, and waves from two days ago. The most recent on nullschool, we can see that already the cold fresh blob out of the Labrador sea has been swept north to the Faroes Iceland shallow area. Not good news for latter, as it will be preventing underlying Gulfstream water from radiating and evaporating heat, while up taking energy from insolation and the atmosphere better. Also mixing into the saltier hot waters underneath will lighten them, making them more able to stay near surface as they reach the ice.
Waves were already reaching long periods near Svalbard on the sixth, the prolonged winds will bring an onslaught of waves and warm surface water head on into the ice of the Atlantic killzone.
In the Chukchi, similarly waves and high SST Pacific water, are already being pushed towards into Pago's ice bridge in the Beaufort direction two days ago. This should accelerate. And as any Nautical man knows, winds can move large volumes of water at the surface of the ocean very fast indeed.
In terms of temperatures and energy, the whole basin border from Bering straits, CAA, Greenland to western Russia looks up for over a week of well above zero temps and incoming energy.

[Hyperion]

.       
 

Hyperion, I will be very surprised if this season ends at 5.0 Mkm2 or above. But your level of confodence is unjustified, and attacking others over it is not acceptable behavior IMHO.

Tru dat

Apologies.
That was not meant as a personal attack, but a general encouragement to everyone to look at the deeper picture rather than the extent over which the floes are sprawling. Claiming this season has a slow melt this season kind of yanked my chain in the small hours of the long winter night, and I did get a bit ranty.

[Neven]

Storm at 968 hPa, and looks like it bottomed out, because 18z still has it at 968 hPa:

[Cook]

Ummm... What surface is that Canadian met surface chart say its measuring?

Pressure corrected to the sea level surface.

[Pagophilus]

I'm no saint, no prude and no stranger to vulgarities, but I can say definitively that I believe this sort of language and 'humor' has zero place in any scientific discussion.  Furthermore, I can see this sort of thing as being particularly distasteful to women, or to persons who have been victims of sexual assault or those who have loved ones who have suffered such assault. 

It doesn't matter if some people say "Oh, it's alright with me" -- all members of the forum need to be considered.  Nor is the intent relevant, nor I am interested in castigating who wrote it -- it is the presence of such language, used in this manner.  Neven, I respectfully request that you draw the line here. 

I think he meant ANALysis.

As in, ANALrapist.

[Wherestheice]

Neven please do something about bbr, like remove him or something. Pagophilus is right, this is starting to get unscientific.

[Michael Hauber]

Why don't you post maps and analysis instead of observations that are completely lacking in support? The amount of heat import this year has been the worst ever. I would post maps but oren will yell at me so go to ESRL and look for yourself. Satellite data also shows the most open water in the High Arctic on record.

As Neven posted a little while back the temperature in the Arctic was the 6th warmest ever.  Maybe you should post some data or analysis to back up your claims.

[Frivolousz21]

Drops mic:

[binntho]

The most recent on nullschool, we can see that already the cold fresh blob out of the Labrador sea has been swept north to the Faroes Iceland shallow area. Not good news for latter, as it will be preventing underlying Gulfstream water from radiating and evaporating heat, while up taking energy from insolation and the atmosphere better. Also mixing into the saltier hot waters underneath will lighten them, making them more able to stay near surface as they reach the ice.

Nope. There is nothing on Nullschool showing a "fresh blob" out of Labrador sea going towards the "Faroes Iceland shallow area" (which is what exactly?).

The currents go in the opposite direction, flushing the Labrador sea southwards, and SSTA's around Iceland and the Faroes Islands show normal fluctuation.

[cesium62]

You have a good track record and, given the current slow melt, I am inclined to agree that we will end this melt season around 5.00 M km2.

I think with the high snow cover, low level of melt ponding in May and June, the early cyclone over the Kara that brought in a lot of clouds and fresh show, that the amount of heat in the Arctic is probably less this year than in 2012, probably close to what it's been the past five years.  So I think a continuation of the long term trend is what we'll see, not anything exceptional this year.

What it's been in the past five years is pretty clearly less than 5M km2.  2013 and 2014 were barely above 5M km2.  4.5M km2 is much more in the middle of the past 11 years of minimums.  All other things being equal, we'ld expect 2018 to be a bit lower than the middle of the past 11 years given the amount of heat we've been pumping into the world's oceans.  A minimum of 4.75M km2 this year would make 2018 seem like a mildly exceptionally cold year to me.  A minimum of 5M km2 this year would seem exceptional.

[Hyperion]

Nullschool currently reporting waves of relatively long period, over three meters, heading north just South of the Svalbard hotspot. Yesterday measuring 16.2C peak. The shallows around Svalbard will act as a lens bending these divergent to the south of the islands waves, so they converge and cross in the kill zone to the north. Forming a field of pyramid waves. Examples below.
Also showing today shorter 1.5 m waves about where itp 108 is in the central Beaufort, headed toward the CAA, in a region of high salinity, -1.7 SST water.

[Hyperion]

The most recent on nullschool, we can see that already the cold fresh blob out of the Labrador sea has been swept north to the Faroes Iceland shallow area. Not good news for latter, as it will be preventing underlying Gulfstream water from radiating and evaporating heat, while up taking energy from insolation and the atmosphere better. Also mixing into the saltier hot waters underneath will lighten them, making them more able to stay near surface as they reach the ice.

Nope. There is nothing on Nullschool showing a "fresh blob" out of Labrador sea going towards the "Faroes Iceland shallow area" (which is what exactly?).

The currents go in the opposite direction, flushing the Labrador sea southwards, and SSTA's around Iceland and the Faroes Islands show normal fluctuation.

[Neven]

bbr2314 is now under moderation. And I'll repeat: Those making extraordinary claims, need to be able to take extraordinary criticism.

The cyclone highly likely bottomed out at 968 hPa, because it's 969 hPa now, according to EC.

[uniquorn]

Worldview Kara sea, jun24 and jul8. Quite resilient.

[binntho]

The most recent on nullschool, we can see that already the cold fresh blob out of the Labrador sea has been swept north to the Faroes Iceland shallow area. Not good news for latter, as it will be preventing underlying Gulfstream water from radiating and evaporating heat, while up taking energy from insolation and the atmosphere better. Also mixing into the saltier hot waters underneath will lighten them, making them more able to stay near surface as they reach the ice.

Nope. There is nothing on Nullschool showing a "fresh blob" out of Labrador sea going towards the "Faroes Iceland shallow area" (which is what exactly?).

The currents go in the opposite direction, flushing the Labrador sea southwards, and SSTA's around Iceland and the Faroes Islands show normal fluctuation.

Repeating your previous image is not proving anything. If you go back in Nullschool you can see that the SSTA in the area between Iceland and the Faroes fluctuates, nothing new happining now. If you set Nullschool to show currents, you can see that the currents from Labrador sea go southwards and there is simply no way that any cold or fresh water could be swept from Labrador sea to the east of Iceland.

It does feel like you are just spouting nonsense, stringing together a series of dubious claims and this particular claim is easily disproved.

[A-Team]

Since the wind is fairly strong and locally consistent, if the GFS forecast is correct, we might expect considerable dispersion to the south of the ice edge and immediate interior. Floes moving into the newly expanded Atlantification zone presumably will melt out over the course of a few days, leaving the ice edge where it is now but farther into the extruded Kara ice.

Revisiting once again the aftermath of the early July local weather system examined in post #1795 with follow-up in #1881 which used GFS nullschool  from June 30th to July 4th to anticipate the effects of fairly strong and persistent north winds forecast for the ice edge and adjacent concentration above the Svalbard-FJL-SZ line, I’ve come to realize that (1) it’s better to wait until the system has passed so preliminary re-analysis can be used instead of forecasts (we’re here to study the ice, not reliability of GFS), (2) it takes a few days beyond the study boundary for effects to fully emerge, (3) attribution to the event will always be problematic, correlation not being causation — what the ice would have done “without” the weather system, and (4) comparisons to past year offer some idea of seasonal progression norms while introducing too much variation of their own.

At any rate, based on effects of similar wind event in early April and the presumed thinning of this ice since then, some ice edge dispersion drama and advance into the melt zone seemed a foregone conclusion. While there has indeed been some of that, it doesn’t come close to the mid-April aftermath.

That event (on Ascat) had a much longer duration (24 days vs 5), more erratic local winds but strong support from an ongoing basin-wide CW rotational pattern. Since a rigid ice pack transmits ‘action at a distance’, it seems (5) purely local considerations are insufficient as compressibility and motion of the whole pack must be considered.

Moving on, yesterday's cyclone was notable for its low pressure but not so much for winds which relate to pressure gradients rather than pressure per se. Nullschool does not go back as far as GAC2012 though winds were likely considered in the aftermath papers.

With Ascat, SMOS and JaxaRGB largely benched for the season, the remaining ice edge/concentration monitoring tool, UH AMSR2 3.125 km, has its own issues with bluish overlays from passing weather artifacts this time of year. We haven’t found a processing system, eg rolling averages, that entirely removes them quite as well as ocular observation of day-to-day feature persistence. However that leaves something to be desired from the quantitative and comparative perspectives.

The last ice of the Barents, seen uncurling around FJL as it rotates clockwise, melts and disperses is associated with deeper St Anna Trough bathymetry (reamed out by grounded ice streams during the last ice ages). This area is not so much affected by incoming atlantification and indeed serves somewhat as a control for regions that are.

The most noteworthy event of this melt season to date has been the apparent advance — some say tipping point — of atlantification shows up in the 2017-18 comparison out to July 7th.

https://tinyurl.com/y92mc8s2 free full text of Northern Barents tipping point paper
https://tinyurl.com/y96traq8    https://tinyurl.com/ya3v4kd2

[Hyperion]

The most recent on nullschool, we can see that already the cold fresh blob out of the Labrador sea has been swept north to the Faroes Iceland shallow area. Not good news for latter, as it will be preventing underlying Gulfstream water from radiating and evaporating heat, while up taking energy from insolation and the atmosphere better. Also mixing into the saltier hot waters underneath will lighten them, making them more able to stay near surface as they reach the ice.

Nope. There is nothing on Nullschool showing a "fresh blob" out of Labrador sea going towards the "Faroes Iceland shallow area" (which is what exactly?).

The currents go in the opposite direction, flushing the Labrador sea southwards, and SSTA's around Iceland and the Faroes Islands show normal fluctuation.

Repeating your previous image is not proving anything. If you go back in Nullschool you can see that the SSTA in the area between Iceland and the Faroes fluctuates, nothing new happining now. If you set Nullschool to show currents, you can see that the currents from Labrador sea go southwards and there is simply no way that any cold or fresh water could be swept from Labrador sea to the east of Iceland.

It does feel like you are just spouting nonsense, stringing together a series of dubious claims and this particular claim is easily disproved.

Stop spouting nonsense. Are you a troll or just willfully ignorant?
Have you heard of storm surges?
Not only them at work here, but likely the huge surge of Gulfstream waters into the north sea entraining the southward Labrador sea meltflow. And the negative sea surface anomaly in the arctic created by its evacuation, and the cyclonic dispersion and negative atmospheric pressure anomally in the Arctic are behind this situation.
The persistent Greenland vortex low pressure systems are a big part of it also

On a lighter note. Here's an example of a pyramid wave field caused by waves from the latest Greenland vortex low refracting around  Iceland. Some reflection off Greenland is culpable too.

[Hyperion]

A-Team: With Ascat, SMOS and JaxaRGB largely benched for the season, the remaining ice edge/concentration monitoring tool, UH AMSR2 3.125 km, has its own issues with bluish overlays from passing weather artifacts this time of year

.


Actually I've been finding that comparing the results of the new SMOS processing algorithm with the recent weather systems quite informative A-team.
Cross post from Nev's SMOS thread:

Hyperion
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Re: SMOS
« Reply #19 on: Today at 10:52:18 AM »
QuoteModifyRemove
Today's SMOS is in,  and results are as expected.

On the seventh the Beaufort cyclone has already detached the blob of beige from mid CAA. And compacted the pack in the north Beaufort through dispersing floes in the direction of the pole.

The winds blowing out of Fram strait and around the top of Greenland have shifted the beige blob off the northeast tip of Greenland and compacted floes in the mouth of Nares.

Winds out of Bering straight are withering Pago's bridge in the Alaskan coastal Chukchi- Beaufort border.

In general, melt is progressing at pace around the whole periphery of the pack.

[jdallen]

4 day GIF of the western Kara illustrative of a phenomena I mused over on the area and extent thread - large stretches of ice disintegrating into smaller and smaller floes which continue to occupy approximately the same extent.
(click to animate)

[binntho]

The most recent on nullschool, we can see that already the cold fresh blob out of the Labrador sea has been swept north to the Faroes Iceland shallow area. Not good news for latter, as it will be preventing underlying Gulfstream water from radiating and evaporating heat, while up taking energy from insolation and the atmosphere better. Also mixing into the saltier hot waters underneath will lighten them, making them more able to stay near surface as they reach the ice.

Nope. There is nothing on Nullschool showing a "fresh blob" out of Labrador sea going towards the "Faroes Iceland shallow area" (which is what exactly?).

The currents go in the opposite direction, flushing the Labrador sea southwards, and SSTA's around Iceland and the Faroes Islands show normal fluctuation.

Repeating your previous image is not proving anything. If you go back in Nullschool you can see that the SSTA in the area between Iceland and the Faroes fluctuates, nothing new happining now. If you set Nullschool to show currents, you can see that the currents from Labrador sea go southwards and there is simply no way that any cold or fresh water could be swept from Labrador sea to the east of Iceland.

It does feel like you are just spouting nonsense, stringing together a series of dubious claims and this particular claim is easily disproved.

Have you heard of storm surges?

Are you suggesting a storm surge from Laptev Sea (against the prevailing currents) to the east of Iceland? How on earth does that work? Which storm did you have in mind? The current (2018-07-08 at 20:00 GMT) does blow out of the Laptev Sea but doesn't reach anywhere near the east of Iceland.

Not only them at work here, but likely the huge surge of Gulfstream waters into the north sea entraining the southward Labrador sea meltflow.

More nonsense. "Likely" the "huge" surge of Gulftsteam waters into the North Sea (? between the UK and Scandinavia?)

Anyway, the Gulf Stream flows up the other side of the Atlantic, nowhere near the Laptev Sea.

And the negative sea surface anomaly in the arctic created by its evacuation, and the cyclonic dispersion and negative atmospheric pressure anomally in the Arctic are behind this situation.
The persistent Greenland vortex low pressure systems are a big part of it also

Which situation? There is no situation - there is nothing happinening now with the SSTA around Iceland that hasn't been ongoing for the last several months. Some daily fluctuations, but that's it.

It takes a specific kind og hyperimagination to see cold freshwater being "entrained" 1500 km against surface currents on the basis of a slightly bluer than usual color in an SSTA map where the colors change daily anyway!

On a lighter note. Here's an example of a pyramid wave field caused by waves from the latest Greenland vortex low refracting around  Iceland. Some reflection off Greenland is culpable too.

Do you honestly think you can see pyramid waves on that picture? "Refracting around Iceland" ... please! Do you imagine it's a duck in a bathtub?

And when did the normal stream of low-pressure areas flowing up the Atlantic, as they do every year more or less non stop, become "caused by the Greenland vortex"? The lows flow all the time, non stop, all year round, and any purported "Greenland vortex" has nothing to do with it.

Currently the lows tend to flow in over Iceland because they are pushed to the west by the unusual high pressure area over the United Kingdom. Greenland has nothing to do with it.

[gerontocrat]

Currently the lows tend to flow in over Iceland because they are pushed to the west by the unusual high pressure area over the United Kingdom. Greenland has nothing to do with it.

Indeed they do. We were told this as kids at school in England in the early 1960s, and told that that meant hot sunny days in summer and cold sunny days in winter.

This pattern has been in operation for what feels like up to a month, and the UK Metoffice tells us is likely to continue for at least another two weeks.

So what has been, could be, might be, the effect so far on the Arctic of this continuous movement of wettish air (and surface water currents?) up North twixt Scandinavia and Greenland?

I attach some 5-day images from cci-renalyzer that seem pretty typical of the weather story for the last month and maybe the rest of July. If nothing else these images are pretty.

[Thawing Thunder]

4 day GIF of the western Kara illustrative of a phenomena I mused over on the area and extent thread - large stretches of ice disintegrating into smaller and smaller floes which continue to occupy approximately the same extent.
(click to animate)

Right now compactness is at an all time record low – probably because of that effect of disintegration. Add to this all the ice left in peripheral areas like Hudson, Baffin and Kara, and there still could be a surprise in the cards. And right now the July cliff seems to start: Late but with a vengeance. The end of this month will be the moment of reckoning IMO ...

Below a strongly enhanced image of the actual state of the ice:

[Hyperion]

You are deliberately polluting this forum bintho. Go away.

Anyone confused by bintroll. Pyramid waves are the result of waves crossing and reinforcing.
And the Labrador sea is halfway round the world from the laptev on Arctic Siberian coast.

[Neven]

You are deliberately polluting this forum bintho. Go away.

Like I've said. If you make extraordinary claims, you need to be able to take extraordinary criticism. That may not be fair (we'll only know in hindsight), but that's how it works.

I'm not going to have the atmosphere on this forum spoiled for the sake of extraordinary claims.

Anyone confused by bintroll. Pyramid waves are the result of waves crossing and reinforcing.
And the Labrador sea is halfway round the world from the laptev on Arctic Siberian coast.

I'm more confused by your writings than by bintroll. I mean, what are pyramid waves with regard to oceanography or Arctic sea ice? Please, keep it short or respond elsewhere, as this is off-topic.

[Often Distant]

Large algal blooms appear to be occurring also entirely across eastward to the British Isles as well as east off Iceland and north of the Scandinavian Peninsula 30°E. Area where sea surface is warmer than a fridge.

The volume of warming water encroaching through the Atlantic is most concerning given the way the ocean has tended over recent years to confront and expose gigantic glacial ice fronts northeast of Greenland ever more earlier, increasing the likelihood inevitable substantial sea level rise occurs comparatively soon. There will never be another dull season, if ever was a thing. The year could yet be quite dramatic. Cannon balls need dodging.

[magnamentis]

4 day GIF of the western Kara illustrative of a phenomena I mused over on the area and extent thread - large stretches of ice disintegrating into smaller and smaller floes which continue to occupy approximately the same extent.
(click to animate)

that's been my point for long and i started (try) to look into the use of different thresholds for extent and their impact on older data.

for now it looks like if one would increase the 15% threshold to 35% that before 2015 when the ice was mostly a homogeneous sheet that mostly disintegrated at it's edges, hence in a limited strip around the big "arctic floe" that the impact would be minor, almost non-distinguishable, while for the last 3 years that 35% threshold would show significant difference in extent and IMO represent the current state of the ice better than the 15% threshold.

since i'm just an layman with ideas there would have to be a skilled scientist looking into this to either confirm, propse a longterm adoption or come to the conclusion that it's utter non-sense.

just bringing it up on various opportunites and since the impact on older date appears to be negligible that would let the history literally intact.

any ideas form someone with an appropriate background ?

[Aluminium]

July 4-8

[binntho]

I'm more confused by your writings than by bintroll. I mean, what are pyramid waves with regard to oceanography or Arctic sea ice? Please, keep it short or respond elsewhere, as this is off-topic.

Well, this "bintroll" is quite happy to stop posting in this forum in favor of those that actually know what they are talking about. Perhaps others should consider doing the same? 

<Sorry, I should've put that label between quotation marks as well. No offense; N.>
None taken!

[deconstruct]

You are deliberately polluting this forum bintho. Go away.

No he is not. He is just correcting much of the stuff you write, as it clearly is not correct.

[Quantum]

New snow for the next 10 days predicted by the ECM. Consistent with a PAC type situation? Seems like conditions are quite good for retention over the CAB with most precipitation falling as snow. A mixture of snow and rain in the ESS/laptev but mostly snow in the beaufort.

[Neven]

No better weather conditions than this for ice retention:

[bbr2314]

The mass of first year ice is now visibly giving way in most peripheral sectors.





Hudson and Kara continue to hold out as well (though slowly they are caving). This will give additional momentum as we head deeper into the summer / July and the ongoing cliff in numbers should only worsen.

I think people here may be misreading what is happening. I would suggest looking at the 2M temp maps for the GFS and CMC as they illuminate a major discrepancy between what is forecast for the upper levels and the reality at the surface (where oceanic SSTs are now blazing, especially in the Laptev).

The amount of water that opened up during the ongoing GAC was substantial and vast swathes of ice are now undergoing bottom melt. With open water occurring simultaneously we now have wide areas of very low temperatures as the melt is ongoing. I would agree that on the upper levels it may appear similar to 2013 + 2014 but I think that the sheer lack of volume in many peripheral CAB regions vs. those years portends a different outcome than we saw previously, alongside the oceanic SSTs.

I would argue that the phenomenal anomalies witnessed this June over Siberia and much of the Arctic are further proof that the oceanic SSTs are overwhelming all other feedbacks in some regions, and even the residual snow cover anomalies were insufficient to blunt ^^^ this year (no matter how substantial). If that can happen on land, perhaps the same may occur over much of the Arctic proper as we head into September.

[Gray-Wolf]

Hi Neven!
My concern is that we will enter a time where such conditions will be conducive to ice loss? If we continue to see early opening of peripheral areas and warming of the waters there then any L.P. will act like my old record deck with my toy soldiers stood on it on it when I hit 78rpm!!

We have seen Beaufort go from ice nursery to ice graveyard and I worry that so much more that used to aid the basin will flip 180 under the continued warming forcings ( does it not have to?)

With decreasing floe sizes and open water the mechanical erosion of choppy waters is something the old contiguous pack never used to face.....

I have been with you through the melt seasons of high cloud low temp but I'm not sold on a 'pause' or minor recovery. I think we are just seeing a reorganisation of processes impacting the basin and one of these years the ice will be so poor from the winter re-freeze that any type of summer will take our ice.

Before then I feel we will see one of these 'good for the ice' synoptics devastate the remaining ice!

[uniquorn]

Worldview, Kara sea jul7-9. Not looking quite so resilient today without the low cloud.

[F.Tnioli]

No better weather conditions than this for ice retention:

There is a line of thought in ecology which recognises one important feature of ecosystems: they affect environment in ways which prolong ecosystem's stability. Then comes a point when this compensation is no longer possible, and things collapse. Recently mentioned in the topic algal blooms may have more with weather conditions you just mentioned than we think; possibly, algae affect local climate chemically, much like corals do. What you think? Feasible? Significant?

[sinocentric]

<snip, this question was moved to a more appropriate thread; N.>

[jdallen]

No better weather conditions than this for ice retention:

2013 didn't have the big storms, but it does look like feedbacks are in play in a similar broad sense.  Greater heat in the system = more atmospheric moisture.

[Neven]

I have been with you through the melt seasons of high cloud low temp but I'm not sold on a 'pause' or minor recovery. I think we are just seeing a reorganisation of processes impacting the basin and one of these years the ice will be so poor from the winter re-freeze that any type of summer will take our ice.

Before then I feel we will see one of these 'good for the ice' synoptics devastate the remaining ice!

That's definitely possible, but somehow I don't feel that this is the year.

There is a line of thought in ecology which recognises one important feature of ecosystems: they affect environment in ways which prolong ecosystem's stability. Then comes a point when this compensation is no longer possible, and things collapse. Recently mentioned in the topic algal blooms may have more with weather conditions you just mentioned than we think; possibly, algae affect local climate chemically, much like corals do. What you think? Feasible? Significant?

It's possible that some negative feedback is causing the warm winters and cloudy summers. The ice has been as vulnerable as ever the past three melting seasons, but weather conditions don't come even close to years like 2007 or 2012. It could also be some cycle at play.

But maybe it's just weather. I don't know. I just take it one melting season at a time, and hope scientists are able to make more hay when it comes to long(er)-term processes.

I'm holding out with any definitive statements about this melting season, but as things currently stand, I'd be surprised if the minimum makes the top 3. But you never know. 2016 also had a final sprint.

[Dharma Rupa]

It's possible that some negative feedback is causing the warm winters and cloudy summers. The ice has been as vulnerable as ever the past three melting seasons, but weather conditions don't come even close to years like 2007 or 2012. It could also be some cycle at play.

I don't think I would call H2O vapor a negative feedback, but it might have a short-term leveling effect.

[jdallen]

I think we are just seeing a reorganisation of processes impacting the basin <snippage>

That's definitely possible, but somehow I don't feel that this is the year.

Reorganization?  I think almost definitely.  There are too many factors which have changed for the Arctic to be using the same playbook - total system heat, ice mechanics, salinity, hotter peripheral conditions on the continents, greater seasonal moisture inputs - all change.  Otherwise I agree with Neven; I think total system enthalpy will be key to the final melt out, as it establishes the "floor" over which our "multi-armed pendulum" is swinging.

There is a line of thought in ecology which recognises one important feature of ecosystems: they affect environment in ways which prolong ecosystem's stability. Then comes a point when this compensation is no longer possible, and things collapse. <snippage>

It's possible that some negative feedback is causing the warm winters and cloudy summers. The ice has been as vulnerable as ever the past three melting seasons, but weather conditions don't come even close to years like 2007 or 2012. It could also be some cycle at play.

But maybe it's just weather. I don't know. I just take it one melting season at a time, and hope scientists are able to make more hay when it comes to long(er)-term processes.

I'm holding out with any definitive statements about this melting season, but as things currently stand, I'd be surprised if the minimum makes the top 3. But you never know. 2016 also had a final sprint.

I think the key features supporting F.Tnioli's musing are the physical chemistry of water and the total heat content of the Arctic oceans.

As we've seen over several years with DMI's 80N temperature chart, atmospheric temperatures over the CAB are increasingly pulled back towards freezing.  I don't think this is an accident of weather; I suspect its a mechanism driven by increasing open water internal to the pack proper which permits more active direct heat exchange between the ocean at -1.8C and atmosphere.  As long as the Arctic ocean remains at or near freezing, it will be a huge buffer against intrusions of heat from further south. 

That buffer both protects the ice - which once brine extraction has taken  place, will tend to have a higher melting point than the water temperature - and cools the atmosphere via heat uptake that takes place either through direct thermal exchange or indirectly via evaporation.

Neven - I think your reference to 2016's "sprint" is very relevant, and I think it's reflective of the new behavioral regime the Arctic is transitioning into.  Extent now is definitely not the same as Extent pre-2007.  At the end of the season now we are seeing vast stretches of ice broken into fairly small floes, much of which is under 1M in thickness.  With that degree of vulnerability along with increased mobility, it doesn't take much of a shock to turn extent like that into slush.  That's something that I think we will see more rather than less of.

I leave you again with one of my favorite memes for chaotic systems

Edit:  This one's even better....

[Stephan]

It's possible that some negative feedback is causing the warm winters and cloudy summers. The ice has been as vulnerable as ever the past three melting seasons, but weather conditions don't come even close to years like 2007 or 2012. It could also be some cycle at play.

But maybe it's just weather. I don't know. I just take it one melting season at a time, and hope scientists are able to make more hay when it comes to long(er)-term processes.

I'm holding out with any definitive statements about this melting season, but as things currently stand, I'd be surprised if the minimum makes the top 3. But you never know. 2016 also had a final sprint.

Is there any multi-year record of "days of sunshine" or "percentage of cloudiness" in the arctic, comparable to the DMI chart "temperature above 80N", available?
If this were the case, another evaluation of "super melting years" (like 2007 and 2012) or "low melting years" like 2013 or this year might be possible.

[RoxTheGeologist]

Is there any multi-year record of "days of sunshine" or "percentage of cloudiness" in the arctic, comparable to the DMI chart "temperature above 80N", available?
If this were the case, another evaluation of "super melting years" (like 2007 and 2012) or "low melting years" like 2013 or this year might be possible.

The temperature north of 80° is buffered at 0°C. It doesn't give an indication of the amount of heat reaching the ice. Perhaps if we could compare volume data with cloudiness we might find a good correlation to build an hypothesis on.

[gerontocrat]

.....one of my favorite memes for chaotic systems

Edit:  This one's even better....

Horribly hypnotic - I was the rabbit paralysed by the snake.

[Neven]

I've never seen an ice floe move like that. 

[Hyperion]

A strange attractor indeed. Mortality Salience artwork here? Any thing will do to distract from confronting the reality of near term death of the cryosphere?