The 2015 melting season

[greatdying2]

2015 has moved into 3rd place, passing 2011 on this NSIDC extent graph.

That is 5 day average. For 1 day numbers it is into 2nd place:

Thanks. It will be interesting to see if it stays there.
(Note: I quite like approach of using multi-day averages. It weeds out a lot of apparent daily artifacts...)

[crandles]

(Note: I quite like approach of using multi-day averages. It weeds out a lot of apparent daily artifacts...)

I agree multi-day averages are better for most purposes. Shame it delays reporting things and I am (we? are) so impatient. 

[Jim Hunt]

That is 5 day average. For 1 day numbers it is into 2nd place:

Here's both charts:

http://GreatWhiteCon.info/2015/09/the-2015-arctic-sea-ice-minimum-extent/#comment-211714

A close run thing:

[ChrisReynolds]

Sorry, my mistake. I guess it comes from my drive to comprehend what is going on. As a lifelong nerd I have never really grasped the point of idle chatter.

But being rude is OK.

Got ya.

Here's my rude comment back: More than once in my life I have been ahead of the science. Implying we know enough of the complexity of the global/arctic system as to know what you, or the studies noted, claim, rather than it being educated guessing, essentially, is hubris defined.

It's fine to tell me the evidence is weak, it is another to impugn my approach.

And I repeat: Looks like is not is. Get that before bothering to respond again. You have literally added nothing to the discussion that wasn't already implied, rather implicitly, by the use of that simple phrasing. Say the evidence is weak, don't be patronizing about it.

Waddeva.

[ChrisReynolds]

The strongest evidence for a possible impending bifurcation has been within the extensive work of Ian Eisenman into simple models of the sea ice. This year Eisenman has published work showing that those modelled bifurcations are artefacts of the simple model, and by implication that the GCMs are correct in not showing bifurcation behaviour in the transition to a seasonally sea ice free state.

How can an artifact be evidence of anything?

I think that is the point Chris is trying to make, actually.

Is it? Then we're on the same page.

But I thought he suggested that the artifact implied something about other models being correct, which to me doesn't seem to follow.

if the bifurcation is just an artifact of the model, there's no reason to doubt the accuracy of other models which don't show a similar bifurcation. it doesn't show the GCMs are right, it just means you can't use the lack of bifurcation behaviour to argue that they're missing sth

Yes, exactly.

Have any of you read Wagner & Eisenman 2015 "How Climate Model Complexity Influences Sea Ice Stability" in its entirety?
http://www.researchgate.net/profile/Till_Wagner2/publication/276276426_How_Climate_Model_Complexity_Influences_Sea_Ice_Stability/links/5554c82108ae6943a871ae40.pdf

That paper conclusively shows that the GCMs are right and the simple models are wrong in showing a rapid crash to a seasonally sea ice free state.

[ChrisReynolds]

Chris:  If I understand the ice drift hypothesis correctly, it is that the Beaufort gyre takes (approximately) four years for one full "turn".

That means we can regard the gyre effectively as four quadrants, each of which may have different melt characteristics due to different proportions of MYI.  When a particularly "tough" quadrant rotates into the Beaufort, that year will have substantially reduced melt in that area - and when a particularly "delicate" quadrant is present, you see a high melt year in the Beaufort.

If so, then it should be quite easy to spot that in the ice age model.  If you take  the images from (say) April of each year, and average the age of the ice in the Beaufort region, is there a four-year periodicity, and does it correlate with high- or low-melt years?

Another possibility that follows from this model is that years with particularly high weather driven-losses in one region will impact other regions further down the line.  For example, if the Beaufort has high melt in year 1, then the Chukchi will have weaker ice in year 2 and be more susceptible to melt that year.  The next year, the ESS might in turn be more vulnerable, and so on.  This might show up in the general anomaly plots - is there a correlation between ESS extent in one year and Chukchi extent the previous year, or Beaufort extent the year before that?

Peter,

All reasonable suggestions but I have already decided to wait to see what happens next year to see whether it is worth investing time on. Anyway today I started a three day audit session to maintain our accreditation, so sea ice will have to take a back seat for the rest of the week.

[jai mitchell]

That paper conclusively shows that the GCMs are right and the simple models are wrong in showing a rapid crash to a seasonally sea ice free state.

from the paper's abstract.

If the associated parameters are set to values that correspond to the current climate, the ice retreat is reversible and there is no instability when the climate is warmed.

you think that this is conclusive???

 

[jdallen]

That paper conclusively shows that the GCMs are right and the simple models are wrong in showing a rapid crash to a seasonally sea ice free state.

from the paper's abstract.

If the associated parameters are set to values that correspond to the current climate, the ice retreat is reversible and there is no instability when the climate is warmed.

you think that this is conclusive???

 

Context, Jai.  If I understand, the author is talking about how the model behaves, not making conclusive predictions about climate.  Or are you referring to the model? 

[jai mitchell]

JD

it seems quite plausible that the new complex GCM that the author (and chris) believes are more accurate, that bifurcation is an artifact and that a rapid collapse will not occur seems to rely on parameters that severely overstate the impacts of meridional water vapor and heat transfer and the impacts of this and seasonal insolation variability on the arctic.

Any GCM that states that we can "reverse" the loss of sea ice at current (and future!) warming states is severely flawed.

period.

[seaicesailor]

Seaicesailor, To fact check the DMI I looked at a NOAA map that shows a part of that DMI SST chart.
NOAA shows 8 C SST to 70 degrees N of Pt. Hope and those temperatures align quite well with the DMI chart in that area. The King Island NOAA buoy is also recording 8C sea surface temps in the Bering Strait for a little more confirmation.
 The area south of ITP#85 has been open water for over a month now between the former arm and the pact that 85 sits in so insolation has had some time to do it's work. Although DMI blends the edges compared to the NOAA chart they seem to agree so I don't think you are seeing any satellite error. These waters are warm enough that if the pack is pushed back in that direction as Born from the Void suggests it will result in further melt . Extent up but maybe area down.

  http://www.ospo.noaa.gov/data/sst/contour/beringst.fc.gif

http://www.ndbc.noaa.gov/station_page.php?station=48114

I agree. Beaufort and Chukchi were the first regions to show open water and serious melting (within the Arctic Ocean) and will probably be the last to show serious refreezing.

I believe it is a fact that the Pacific has been very warm, and there have been plenty of weather systems that were able to bring heat from the Pacific into the Arctic during this melting season, hence the carnage. AGW at its best (or it worst).

[helorime]

Friday's forecast is interesting, warm over Alaska, a solid cyclone over Novaya Zemla, other low pressure areas.  I'm not sure if this will affect the Atlantic side or not.  We shall see.

[jdallen]

JD

it seems quite plausible that the new complex GCM that the author (and chris) believes are more accurate, that bifurcation is an artifact and that a rapid collapse will not occur seems to rely on parameters that severely overstate the impacts of meridional water vapor and heat transfer and the impacts of this and seasonal insolation variability on the arctic.

Any GCM that states that we can "reverse" the loss of sea ice at current (and future!) warming states is severely flawed.

period.

... Which then sounds like a second argument.  I actually tend to agree with you.  I'm not sure current carbon related forcing is reversible, short of taking it out as fast as we put it in. Even then, I think the current momentum will destroy the Arctic. 2015 is just the next bit of wobble before the top falls over.

[OldLeatherneck]

**********************SNIP******************************

I agree. Beaufort and Chukchi were the first regions to show open water and serious melting (within the Arctic Ocean) and will probably be the last to show serious refreezing.

I believe it is a fact that the Pacific has been very warm, and there have been plenty of weather systems that were able to bring heat from the Pacific into the Arctic during this melting season, hence the carnage. AGW at its best (or it worst).

I'm beginning to think that the Bering and Chukchi Seas will be the first Arctic areas to become essentially ice-free perennially. I don't know how many years it will take and how much of the current SST anomalies are due to El Nino and will soon revert back to more normal temps.

[LRC1962]

Friday's forecast is interesting, warm over Alaska, a solid cyclone over Novaya Zemla, other low pressure areas.  I'm not sure if this will affect the Atlantic side or not.  We shall see.

Null School has a L setting up over Laptev Sea that on Sat turns into a cyclone almost over the pole. What could be even more important is that Fri that L has 56 mph blowing in the direction the storm is traveling which could mean some big storm surge in front of it although not that big amount of room from land to ice to get very high waves.

[sofouuk]

JD

it seems quite plausible that the new complex GCM that the author (and chris) believes are more accurate, that bifurcation is an artifact and that a rapid collapse will not occur seems to rely on parameters that severely overstate the impacts of meridional water vapor and heat transfer and the impacts of this and seasonal insolation variability on the arctic.

Any GCM that states that we can "reverse" the loss of sea ice at current (and future!) warming states is severely flawed.

period.

... Which then sounds like a second argument.  I actually tend to agree with you.  I'm not sure current carbon related forcing is reversible, short of taking it out as fast as we put it in. Even then, I think the current momentum will destroy the Arctic. 2015 is just the next bit of wobble before the top falls over.

the paper just says that meridonal heat transport means there won't be a sudden change to an ice free state - as temperatures gradually increase, the ice will gradually retreat. in theory if we reduced climate forcing the ice would grow back; that's not happening any time soon, of course

[jdallen]

JD

it seems quite plausible that the new complex GCM that the author (and chris) believes are more accurate, that bifurcation is an artifact and that a rapid collapse will not occur seems to rely on parameters that severely overstate the impacts of meridional water vapor and heat transfer and the impacts of this and seasonal insolation variability on the arctic.

Any GCM that states that we can "reverse" the loss of sea ice at current (and future!) warming states is severely flawed.

period.

... Which then sounds like a second argument.  I actually tend to agree with you.  I'm not sure current carbon related forcing is reversible, short of taking it out as fast as we put it in. Even then, I think the current momentum will destroy the Arctic. 2015 is just the next bit of wobble before the top falls over.

the paper just says that meridonal heat transport means there won't be a sudden change to an ice free state - as temperatures gradually increase, the ice will gradually retreat. in theory if we reduced climate forcing the ice would grow back; that's not happening any time soon, of course

I agree, there won't be a sudden transition to an ice free state.  Once ice free, it may take a greater reduction in forcing than dropping CO2 to 285PPM to get the ice to return. That I think is where My thinking differs, but I'm not relying on models; an entirely analog armchair analysis, and not one I'm prepared to argue too deeply, as I haven't assembled any particularly solid evidence for it.  Thus, it remains in the realm of conjecture rather than prediction.

[greatdying2]

The strongest evidence for a possible impending bifurcation has been within the extensive work of Ian Eisenman into simple models of the sea ice. This year Eisenman has published work showing that those modelled bifurcations are artefacts of the simple model, and by implication that the GCMs are correct in not showing bifurcation behaviour in the transition to a seasonally sea ice free state.

How can an artifact be evidence of anything?

I think that is the point Chris is trying to make, actually.

Is it? Then we're on the same page.

But I thought he suggested that the artifact implied something about other models being correct, which to me doesn't seem to follow.

if the bifurcation is just an artifact of the model, there's no reason to doubt the accuracy of other models which don't show a similar bifurcation. it doesn't show the GCMs are right, it just means you can't use the lack of bifurcation behaviour to argue that they're missing sth

Yes, exactly.

Have any of you read Wagner & Eisenman 2015 "How Climate Model Complexity Influences Sea Ice Stability" in its entirety?
http://www.researchgate.net/profile/Till_Wagner2/publication/276276426_How_Climate_Model_Complexity_Influences_Sea_Ice_Stability/links/5554c82108ae6943a871ae40.pdf

That paper conclusively shows that the GCMs are right and the simple models are wrong in showing a rapid crash to a seasonally sea ice free state.

Thanks for the reference. That seems like an interesting model. But I don't need to read it "in its entirety" to see that it shows just what we were already saying: that the instabilities suggested by some idealized models likely are artifacts of over-simplicity. However, such a result does not (and cannot) "show that the GCMs are right."

[Adam Ash]

JD

it seems quite plausible that the new complex GCM that the author (and chris) believes are more accurate, that bifurcation is an artifact and that a rapid collapse will not occur...

Interesting discussion on the ‘model’.  From an ‘engineer’s’ perspective (i.e. from one with a little practical sense combined with just enough scientific knowledge to be opinionated and annoying) I am reminded that there are many systems which can flick from mellow to Boolean (on/off, good / bad , +5 volts / -5 volts) even tho the components are not obviously inclined to such abrupt outcomes.

If one has detected a number of quasi-cyclic functions (variance in insolation, inclination of the planet’s orbit, the North Atlantic Oscillation, the Chinese share market [an important determinant of global GHG and particulates], sand storms from the Sahara et al) then as you throw those into the model pot you could see the output representing an oscilloscope chart of noise from a student party, until you throw in the last function and the whole thing goes straight-line high or low on you and you say ‘Wow how did that happen?!’.

Likewise, if you have found something like a square wave (we have ice/ we have no ice) you need to remember that situation can be readily derived from a mess of cyclic functions, which you can only detect by the meticulous (indeed the omniscient) deconstruction of the inputs.

In climate modelling we have a swarm of functions including the usual Knowns, Known Unknowns and of course the Unknown Unknowns.  It is/ will be very hard to guess whether the function which could tip the output from one state to another is going to be the rhythmic chest-thumping of the gorilla in the room, the faintest flappering of one of Jim Hansen’s Monarch butterflies, or a 'Honk!' from a black swan.

My point is that you can mess with models in the most well-intentioned ways, but still be hopelessly wide of the truth.  I know of many models which usually give plausible answers while using internal methods which are just plain wrong.  And likewise I am sure there are models which are very correct in their internal functions which never get near the ‘truth’ in their outputs because they lack some key ingredient which is required to turn warm winds and gentle waves into catastrophe. 

In particular I do not think that it is at all 'safe' to say '...bifurcation is an artefact and that a rapid collapse will not occur..' when in fact the complexity of your model is such that the potential end result of the sum of all the driving elements diverges exponentially from any cursory target by the power of the number of variables.

But keep up the good work, take care, and don’t take it all too seriously!

[Jim Hunt]

The latest edition of Arctic Sea Ice News has been published

http://nsidc.org/arcticseaicenews/2015/09/steady-decline-summer-minimum-approaching/

Arctic sea ice extent averaged for August 2015 was the fourth lowest in the satellite data record. Through 2015, the linear rate of decline for August extent is 10.3% per decade.

[Our] forecast places the upcoming daily sea ice minimum between third and fourth lowest, with fourth more likely. There is still a possibility that 2015 extent will be lower than 4.3 million square kilometers, the third lowest sea ice extent, surpassing the 2011 sea ice extent minimum, and a small chance of surpassing 2007, resulting in the second-lowest daily minimum. This assumes that we continue to have sea ice loss rates at least as fast as those of 2010. This was indeed the case for the final ten days of August 2015.

They also reveal that:

In support of the upcoming Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) mission, NASA recently deployed two instrumented aircraft to Thule Air Force Base, Greenland (near Qaanaaq) to collect data for the development of software to process the satellite data. Instrumentation for the three-week campaign (July 28 to August 19) included a laser altimeter called SIMPL and an imaging spectrometer called AVIRIS-NG.

[slow wing]

U. Bremen daily update shows action around the following longitudes:

• 105E (Laptev), the stub projection is expanding away from the Pole
• 165E (ESS) the forearm projection is shrinking towards the Pole
• between 120E and 150E there is a net recovery of peek-a-boo ice.

Click on gif for the comparison...

[Jim Hunt]

The latest view from O-Buoy 9:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#OBuoy9

[F.Tnioli]

...
I believe it is a fact that the Pacific has been very warm, and there have been plenty of weather systems that were able to bring heat from the Pacific into the Arctic during this melting season, hence the carnage. AGW at its best (or it worst).

Ain't no best/worst yet, i believe what we see there it's just a tiny little warming-up AGW does, if to compare with what will be (most likely) present in mere 50 years... Pun intended.

Null School has a L setting up over Laptev Sea that on Sat turns into a cyclone almost over the pole. What could be even more important is that Fri that L has 56 mph blowing in the direction the storm is traveling which could mean some big storm surge in front of it although not that big amount of room from land to ice to get very high waves.

56 _miles_ per hour? If so, it won't need "much" room to make big waves, i dare think.

[LRC1962]

OOOpps, let me wake up. Should have been KPH

[slow wing]

Spectacular!

The ESS Forearm being nibbled on by the low pressure system. MODIS Worldview, both Aqua and Terra. (Pardon my ignorance, they're two different satellites?)

To me the cloud swirl of the storm almost looks like one of those coal digging cylinders.

Some further cracking and disintegration of the forearm is apparent. And is the Southern tip just disintegrating - everything South of 76N? The latest U. Bremen concentration map for 2 September had relatively solid ice pack for at least another degree further South. Has it really lost more than a degree of length (degree of latitude=10,000km/90~111 km) or am I misinterpreting it?

  The low pressure system is now going to bowl right through the forearm, with wind speeds exceeding 10 m/s ~ 22 mph.

EDIT: and another, more intense, low pressure system is forecast to follow the same path about two days later - this one with peak wind speeds around 20 m/s ~ 45 mph!

[greatdying2]

The latest edition of Arctic Sea Ice News has been published

http://nsidc.org/arcticseaicenews/2015/09/steady-decline-summer-minimum-approaching/

Their SST map is quite interesting:

 

[Jim Hunt]

Both GFS and ECMWF now show a 990 hPa low over the Central Arctic at the weekend:

http://GreatWhiteCon.info/2015/09/the-2015-arctic-sea-ice-minimum-extent/#comment-211728

[Jim Hunt]

Their SST map is quite interesting:

Yup - Much more info available from:

http://psc.apl.washington.edu/UpTempO/

IIRC lots were installed as part of last year's MIZ program:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/summer-2014-imbs/#MIZ

P.S. Yup - See: http://www.onr.navy.mil/reports/FY14/agsteele.pdf

[BornFromTheVoid]

The 5 day NSIDC extent is now equal to the 2008 minimum and below the 2010 minimum, which means we've now reached at least the 4th lowest minimum on record. The next minimum is 2011, which is 241k away.

[F.Tnioli]

Both GFS and ECMWF now show a 990 hPa low over the Central Arctic at the weekend:

http://GreatWhiteCon.info/2015/09/the-2015-arctic-sea-ice-minimum-extent/#comment-211728

That's a big one. Funny shape, too. I propose to name it WAC - "weird" arctic cyclone. Now to see how whacky big WAC will be, eh.

[Lord M Vader]

Most interesting things right now is:

A) how much damage to the sea ice will the cyclone in 2-3 days do?

B) Will the minor ice pack in Laptev melt out completely?

C) Will the ice in Foxe Basin in Hudson Bay and Davis Strait in baffin Bay melt out?

D) Will the small pockets of ice in Beaufort melt away before refreezing?

E) Will Parrys Channel be ice free before refreezing occurrs?

and....

F) will Queen Maud in the CAA north of Kugaruuk be ice free?

My opinions: the ice in Laptev will melt out. The ice close to the Alaskan coast should do so too. I also believe that the ice in Foxe basin and Davis Strait should have a decent chance to melt out before the refreezing.

I'm highly doubtful that Parrys Channel including Queen Maud, both in CAA, will get ice free before refreeze starts there.

Best, LMV

[TerryM]

Spectacular!

To me the cloud swirl of the storm almost looks like one of those coal digging cylinders.

Spectacular turn of phrase!!

This late in the season those swirls often leave little behind other than warm waters stirred up by Ekman Pumping.
If the forecasts hold, Healy may be in for a rough ride. A few years back Dr. Francis was close to the Pole when swells came through the ice to such an extent that some of the crew complained of sea-sickness. This could be a replay.

You're correct of course re. Terra & Aqua
Terry

[Jim Hunt]

I've just stumbled across what seems to be a MASIE based extent comparison chart:

http://GreatWhiteCon.info/2015/09/the-2015-arctic-sea-ice-minimum-extent/#comment-211736

It also shows 2015 as second lowest after 2012:

[jai mitchell]

In particular I do not think that it is at all 'safe' to say '...bifurcation is an artefact and that a rapid collapse will not occur..' when in fact the complexity of your model is such that the potential end result of the sum of all the driving elements diverges exponentially from any cursory target by the power of the number of variables.

Thanks, that was exactly what I was saying, but also in the knowledge that we have locked in 2.3 Degrees of globally averaged warming (above pre-industrial) at 400 PPMv CO2 and 1750 PPBv CH4 (in the absence of anthropogenic aerosols associated with fossil fuel consumption).

I am also absolutely certain that any model that projects a return of arctic sea ice to 1980 levels at current temperatures, in absence of global or regional climate modification, and ESPECIALLY in a scenario of continued future warming is not representative of reality.  That is what this paper implies.

Good luck with that shift in the MDO. . .

[ktonine]

In particular I do not think that it is at all 'safe' to say '...bifurcation is an artefact and that a rapid collapse will not occur..' when in fact the complexity of your model is such that the potential end result of the sum of all the driving elements diverges exponentially from any cursory target by the power of the number of variables.

Thanks, that was exactly what I was saying, but also in the knowledge that we have locked in 2.3 Degrees of globally averaged warming (above pre-industrial) at 400 PPMv CO2 and 1750 PPBv CH4 (in the absence of anthropogenic aerosols associated with fossil fuel consumption).

I am also absolutely certain that any model that projects a return of arctic sea ice to 1980 levels at current temperatures, in absence of global or regional climate modification, and ESPECIALLY in a scenario of continued future warming is not representative of reality.  That is what this paper implies.

Good luck with that shift in the MDO. . .

Some really, really, need to read what the authors wrote and attempt to understand it.

There was evidence from simple models that a 'tipping point' (instability, irreversibility) was possible.  This paper shows that the simple model was *too* simple and that the instability was an artefact of the model.  Hence, one cannot claim evidence for instability or irreversibility by citing the simple model.

This was Chris' original point: sufficiently sophisticated models show stability vis a vis known forcings.  *STABILITY* means no tipping point.  It means the ice will act in predictable ways given specific forcings.  Reversibility means that if the forcings reduce, the ice will return.  With tipping points it's very difficult to reverse - in some cases impossible - once the tipping point has been reached.

Most here are arguing against strawmen of their own creation -  either saying nothing at all about the actual paper or misunderstanding the results and what they mean.  This is science.  If you don't want to believe the science, fine.  Argue intelligently with a scientific rebuttal.  Otherwise  this forum might as well be known as WUWT with a focus on the arctic.  Personal beliefs that contradict the known science backed up with zero evidence is the typical reaction on just about every denier blog I've ever visited. I'd rather not have to read it here as well.

[OSweetMrMath]

The discussion of "How Climate Model Complexity Influences Sea Ice Stability" and whether August sea ice is exhibiting cycles or bifurcations has clearly gotten off topic for this thread. I've created a new thread Discussion of "How Climate Model Complexity Influences Sea Ice Stability" to continue discussing the paper.

The first post, up now, quotes and summarizes the discussion so far. I am currently working on my own post about the paper, which I will put up shortly.

ETA: As usual, once I start typing, I can't stop. But I now have several posts on my read on the paper and the conclusions it draws on the possibility of sudden sea ice melt.

[Gonzo]

Jim Hunt

I've just stumbled across what seems to be a MASIE based extent comparison chart:

Cool.

[slow wing]

The U. Bremen daily update shows the ESS forearm projection being twisted around by the low pressure system passing through. Further along the Siberian coast, towards the Atlantic, the ice pack edge is instead bulging outwards at the moment.

In a day or so, a much stronger low pressure system is due to pass through the same region in the same direction, with wind speeds briefly reaching around 20 m/s.

Not much left now of the Beaufort Arm and shoulder.

Click on gif for the comparison with yesterday's map...

[F.Tnioli]

Any PIOMAS updates?

I read the report that July 2015 was definitely the hottest global month on record since 1880, in particular in terms of SSTs. We know it was particularly warm in Arctic, as well. We know this means lots of warm waters, which should lead to extra bottom melt through August. We see massive extent loss in Beaufort and elsewhere, etc. In the same time, DMI shows net volume _gain_ for the month of August, but as discussed above in the topic, this seems to be HYCOM-CICE artefact. Thus it's quite interesting what PIOMASS will say about August. When exactly they normally do their monthly update?

[iceman]

  ....
In a day or so, a much stronger low pressure system is due to pass through the same region in the same direction, with wind speeds briefly reaching around 20 m/s.
  ....

It looks like the track of the low will cause more compaction than dispersion, which is atypical for a cyclone.  That means further above-normal extent drops over the next several days, though it could reduce the likelihood of a late minimum.

[seaicesailor]

  ....
In a day or so, a much stronger low pressure system is due to pass through the same region in the same direction, with wind speeds briefly reaching around 20 m/s.
  ....

It looks like the track of the low will cause more compaction than dispersion, which is atypical for a cyclone.  That means further above-normal extent drops over the next several days, though it could reduce the likelihood of a late minimum.

The weather maps and the CICE drift model predict three days maximum of some compaction.

A comeback of more favorable conditions for compaction before end of September cannot be discarded (or can it?). Even when refreezing starts, the broken ice in the Pacific side seems very mobile.

If such weather comes, otherwise, the melting season ends next week.

[solartim27]

One coal digging machine later....

[slow wing]

Nice comparison! That shows the forearm has lost some ice off the top and looks like it has fattened as it has shattered into large fragments.

And now the BIG digger has arrived!

Twice the wind speeds so 8 times the wind power. Winds at up to 61 kmh (~40 mph; 17 m/s) at the moment - see Nullschool plot below, that wind speed is at the small circle.

What sort of wave action on the ice pack should be expected from this storm?

Isn't the ocean shallow there for quite some distance from the land? Would that prevent wave build-up for a while and lessen the effective reach?

http://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-35.44,100.85,1844

[slow wing]

The Beaufort Arm is almost gone in the U. Bremen update, with lots of action in the Chukchi Sea.

Click on gif to crossfade through the past 4 days...

[werther]

I think this is about it for this years' melting season. There will be some turmoil for the next seven days, lows entering on the Bering side. But temps are now dropping steadily and there's some new snow covering the melee and smaller leads over most of the CAB.
By next sunday ECMWF prognoses a strong High over the CAB. No doubt, Climate Reanalyzer will line up with associated strong freeze. For friday it already forecasts <-10dC around the Pole.

Extent will be hovering around 4.35Mkm2, maybe a tad lower, reflecting the compaction from the above mentioned storm in the Laptev Sea and another one some days later.

I think NSIDC extent is still a bit over 4.5Mkm2, so it will be interesting to see whether the last week produces enough losses to get into the 4.25-4.5 box I voted for on the poll-thread. I have a hunch I'll be proven wrong again....

[Adam Ash]

I think this is about it for this years' melting season...

You really think this season is going to end significantly earlier than recent ones?  I think there is still a bit of life in the old dog yet.  EarthNull shows some serious activity in the north Pacific, which could still spin north, continued import of warm air from the Atlantic, and winds pushing ice into the warm bath of the Beaufort Sea through the Chukchi towards Bering Straight over the next few days.  Pushing and pulling in all directions - so difficult to anticipate the net result.

As others have said, the reduction in stock of MYI is setting things up for an interesting 2016 season,  including (IMHO) much more action north of the CAA due to the absence of the blocking action of MYI to north-bound and west-bound currents coming through between the islands.  We shall see...!

[Jim Hunt]

What sort of wave action on the ice pack should be expected from this storm?

http://GreatWhiteCon.info/2015/09/the-2015-arctic-sea-ice-minimum-extent/#comment-211792

[seaicesailor]

I think this is about it for this years' melting season. There will be some turmoil for the next seven days, lows entering on the Bering side. But temps are now dropping steadily and there's some new snow covering the melee and smaller leads over most of the CAB.
By next sunday ECMWF prognoses a strong High over the CAB. No doubt, Climate Reanalyzer will line up with associated strong freeze. For friday it already forecasts <-10dC around the Pole.

Extent will be hovering around 4.35Mkm2, maybe a tad lower, reflecting the compaction from the above mentioned storm in the Laptev Sea and another one some days later.

I think NSIDC extent is still a bit over 4.5Mkm2, so it will be interesting to see whether the last week produces enough losses to get into the 4.25-4.5 box I voted for on the poll-thread. I have a hunch I'll be proven wrong again....

Me too, although the broken ice in the Pacific side is between a rock and a hard place. Wind blows from America, and it gets compacted, it blows from Asia and it get dispersed in -1 C to above zero warm waters. Either way it will take time. Plus the wind is blowing strongly.

[seaicesailor]

The Beaufort Arm is almost gone in the U. Bremen update, with lots of action in the Chukchi Sea.

Click on gif to crossfade through the past 4 days...

That was real flash melting.

[greatdying2]

Paul Beckwith makes an interesting claim in this video (at 9:35): that El Nino is causing a difference in sea surface height, resulting in increased water flow through the Bearing Straight and increased melt on the Pacific side. Comments?

! No longer available

[Gonzo]

greatdying2

Paul Beckwith makes an interesting claim in this video (at 9:35): that El Nino is causing a difference in sea surface height, resulting in increased water flow through the Bearing Straight and increased melt on the Pacific side. Comments?

Very interesting. They say that the sea level has risen along the east coast of America and Canada due to warmer waters there now.