When will the Arctic Go Ice Free?

[D-Penguin]

To-date Arctic ice loss has been highly unpredictable and dependent on the relative effects of the many variable metrics that come into play each year. These metrics have invoked knowledgeable debate and sometimes heated exchages from the advocates of differing viewpoints. However, I strongly suspect, that these 'variable metrics' are about to be overcome by a 'single metric', the 'Global Heat Energy Inbalance'. This 'imbalance', I beleive, is at a 'tipping point' and the effect on Arctic ice will be devastating and rapid. The existing variable metrics will be secondary to the global increase in SST and solar insolation. In other words what goes into the Arctic by way of ocean currents and atmospheric advection will override all other metrics local to the Arctic. Obviously, the variable metrics are driven by AGW but the 'tipping point' determined by the Global Heat Energy imbalace will create a new 'physical state' in the Arctic.

The specific latent heat of fusion of ice is the amount of heat required to change 1 kg of ice to water without a change in temperature. The specific latent heat of fusion of ice is 0.336 MJ per kg. So, the future debate will be more about advection, ice thicknes and volume in the Artic Ocean. There is nothing new here, just a change of emphasis and the over riding consequences of a tipping point.

Many years ago on the ASI Blog I predicted (guessed) that the first BOE would occur in 2020 +/- 2 years, followed within 4 years +/- 2 years by an ice free Arctic summer, followed within 4 years +/- 2 years by an ice free Arctic winter. I see no reason, at the moment, to change my prediction (guess).

I do not subscribe to the idea that an 'ice free' Arctic seasons will be followed by periods of seasons that are not ice free and that the Arctic will eventually become 'ice free' over an extended period of time.

How might we know when the tipping point has been reached so far as it effects Arctic sea ice, I would suggest three consecutive years when the minimum date is on or later than 20 September.

Just interested to know if anybody is like-minded in their opinions.

[crandles]

X2 curvilinear regression.  R2 = 99.99% 
"1985" = midyear of 1979-1988, etc.

Year          Model estimate of Arctic Sea Ice volume at September minimum.
1985   21.41
1995   19.10
2005   15.34
2015   10.14
2025   3.49
2029   0.42
2030   "-0.37"

Conclusion:  If current volume loss trend continues, then around 2030-32, the September minimum will have virtually no Arctic Sea Ice.  Thus, all ice in following spring will be FYI from preceding winter.

How are you calculating that R2 figure?

That pattern shows accelerating loss of Sept ice volume. I don't believe that pattern is appropriate.

Following graph is not aggressive enough, but is a better fit and doesn't have R2 anywhere near 99.99%

[crandles]

Just interested to know if anybody is like-minded in their opinions.

You only want to hear from people who agree with you? Does this mean you want to live in an echo chamber?

Since you seem to be indicating that, I suppose I have already said more than enough.

[Shared Humanity]

Just interested to know if anybody is like-minded in their opinions.

So 10 years after the 1st BOE at minimum, you expect the Arctic to become perennially ice free?

Could be mistaken but others have said seawater begins to freeze at a temp of -2.0 C. Below is a chart that models the temps in the Arctic above 80 degrees. (Yes. I know this chart has serious issues and many here feel it is useless but I have nothing else to reference due to my limited knowledge.) In the long dark polar night, while temps are warmer in recent years, they still reach -20.0 C to -30.0 C degrees. Could you explain to me how seawater won't freeze in these conditions?

My very unscientific opinion? The Hudson Bay freezes every winter after melting out completely. We should expect the same with the Arctic Ocean.

[D-Penguin]

Posted by: crandles
« on: Today at 01:04:43 PM
QUOTE
"You only want to hear from people who agree with you?"

That is a statement and not a question.

QUOTE
"Does this mean you want to live in an echo chamber?"

That is a derogatory remark phrased as a question, unnecessary and lowers the tone of debate and exchange of ideas.

"Just interested to know if anybody is like-minded in their opinions." I added this comment at the end of my posting because contributors, with far more knowledge than I have, might be able to add quantitative or qualitative evidence regarding a 'tipping point' related to SSTs and advection and its effect on Arctic sea ice.

After all, I was expressing an opinion, just as you do with your graphs and statistics.

[El Cid]

Just interested to know if anybody is like-minded in their opinions.

So 10 years after the 1st BOE at minimum, you expect the Arctic to become perennially ice free?

Could be mistaken but others have said seawater begins to freeze at a temp of -2.0 C. Below is a chart that models the temps in the Arctic above 80 degrees. (Yes. I know this chart has serious issues and many here feel it is useless but I have nothing else to reference due to my limited knowledge.) In the long dark polar night, while temps are warmer in recent years, they still reach -20.0 C to -30.0 C degrees. Could you explain to me how seawater won't freeze in these conditions?

My very unscientific opinion? The Hudson Bay freezes every winter after melting out completely. We should expect the same with the Arctic Ocean.

I tend to agree with you but let's not forget that the Barents does NOT freeze now during winters despite a long polar night - simply because it gets fed warm Atlantic water. I do not know if the same will/can happen to the Arctic proper but if the answer is yes then there will be no ice even during winter. (The Hudson is almost like a lake, pretty closed for oceanic water intrusions)

[dnem]

Wow, Crandles, why so harsh?  He was just saying "What do others think?"  Do you really think he meant "If you don't agree, shut up?"  C'mon.

D-Penguin, everything you say may come to pass.  Except for the perennially ice free arctic.  There will be at least some winter freeze-up for decades, IMO.

[gerontocrat]

My theory hypothesis speculation that belongs to me follows very much that which is happening now in individual seas, to whit, for example, the Chukchi.

As the years have gone by, the minimum has reduced and the melting starts earlier and finishes later. This shows up on :
- the area graph profile morphing from a V to a U shape, i.e. wider & deeper,
- the number of days when ice area is less than, for example, 15% of maximum has increased.
- the open water percentage of the sea increases strongly in summer and slowly in winter until....
However, the sea still totally freezes up in winter.

The Bering Sea has reached stage 2, when winter sea ice area is well below 100%, but still forms. And that is despite being exposed to a warming North Pacific Ocean and warming North Pacific air temperatures.

You can see this process at various stages in all the seas.

So why should a warming Arctic Ocean behave any differently? i.e. melting earlier, freezing later, less winter ice. And my guess is that
- Hansen is right and the IPCC is wrong, i.e. Global temps up about 0.4 celsius per decade (not 0.2),
- Double that temperature rise for the Arctic, i.e. nearly 1 degree celsius by 2030,
- So a BOE of some sort before 2030,
- And maybe by then the annual average for the sea ice area of the 7 seas of the High Arctic Ocean drops to below 50% of total ocean area, i.e. the Arctic becomes more a maritime sea than an ice-covered desert.

[Klondike Kat]

Just interested to know if anybody is like-minded in their opinions.

So 10 years after the 1st BOE at minimum, you expect the Arctic to become perennially ice free?

Could be mistaken but others have said seawater begins to freeze at a temp of -2.0 C. Below is a chart that models the temps in the Arctic above 80 degrees. (Yes. I know this chart has serious issues and many here feel it is useless but I have nothing else to reference due to my limited knowledge.) In the long dark polar night, while temps are warmer in recent years, they still reach -20.0 C to -30.0 C degrees. Could you explain to me how seawater won't freeze in these conditions?

My very unscientific opinion? The Hudson Bay freezes every winter after melting out completely. We should expect the same with the Arctic Ocean.

I tend to agree with you but let's not forget that the Barents does NOT freeze now during winters despite a long polar night - simply because it gets fed warm Atlantic water. I do not know if the same will/can happen to the Arctic proper but if the answer is yes then there will be no ice even during winter. (The Hudson is almost like a lake, pretty closed for oceanic water intrusions)

The Barents is fed directly by the Atlantic.  It is also a rather open expanse.  Many other seas are more sheltered by land that will freeze more readily (like Hudson Bay).  The warm waters may continue flowing further into the central Arctic, but cannot melt the entire ocean - yet.  Even the Barents is partially ice-covered in March.

[binntho]

My theory hypothesis speculation ...

[D-Penguin]

Just interested to know if anybody is like-minded in their opinions.

So 10 years after the 1st BOE at minimum, you expect the Arctic to become perennially ice free?

Shared Humanity - Thanks for your feedback.

I do not know what the answers are to your questions. I simply do not have enough knowledge.

However, I will give it a go to explain in very general terms!

My idea is that there will be a 'tipping point' in AGW related to the Arctic and the effect it will have on the Arctic sea ice.

I think it is possible that atmospheric advection will so disrupt the Jet Stream that the heat energy balance of the Arctic will be radically changed based on the thermal capacity of the Arctic Ocean and a continuos advection.

Cold air will flow south (heat loss) to be displaced by hot air that will flow north (net heat gain). The thermal capacity of the Arctic ocean will gain and store heat energy at the surface (top layers of water) according to the water/air flux.

Also, increasing SSTs with advection of heat energy flowing into the Arctic ocean will greatly increasing the total heat energy at surface level and lower ocean depths.

The heat energy exchange calculations are way, way above my head but I would be very interested in reading any recent peer reviewed paper that might be informative on the subject of Heat Energy Exchange related to AGW and the Arctic region. If somebody could point me in the right direction I would be grateful.

So far as the Hudson Bay ice is concerned, all I can say is that advection from ocean currents would be limited and perhaps form part of the 1 M sq kM of remaining winter ice that defines an ice free Arctic.

I just feel that relevant events are now changing so rapidly that all the graph extrapolations and statistics are seriously behind the wave of events. Just a gut feeling that the total heat energy going into the Arctic from atmosphere and sea is monumental; that the 'tipping point' is very close.

I would love to be able to do the calculations based on a permanent annual perpurtration of the Jet Stream!

[Sterks]

Opposite to the CAB over deep water, which will take years before it melts below the 1 mill. mark, we have the sallow seas especially Laptev and ESS, which are adjacent to the cold Siberia, their low depth waters are not ventilated by Atlantic or Pacific currents in winter, and I don't see them remaining open in the long night of 180 days in our lifetimes (including the millenials reading)

[DrTskoul]

Just interested to know if anybody is like-minded in their opinions.

So 10 years after the 1st BOE at minimum, you expect the Arctic to become perennially ice free?

Shared Humanity - Thanks for your feedback.

I do not know what the answers are to your questions. I simply do not have enough knowledge.

However, I will give it a go to explain in very general terms!

My idea is that there will be a 'tipping point' in AGW related to the Arctic and the effect it will have on the Arctic sea ice.

I think it is possible that atmospheric advection will so disrupt the Jet Stream that the heat energy balance of the Arctic will be radically changed based on the thermal capacity of the Arctic Ocean and a continuos advection.

Cold air will flow south (heat loss) to be displaced by hot air that will flow north (net heat gain). The thermal capacity of the Arctic ocean will gain and store heat energy at the surface (top layers of water) according to the water/air flux.

Also, increasing SSTs with advection of heat energy flowing into the Arctic ocean will greatly increasing the total heat energy at surface level and lower ocean depths.

The heat energy exchange calculations are way, way above my head but I would be very interested in reading any recent peer reviewed paper that might be informative on the subject of Heat Energy Exchange related to AGW and the Arctic region. If somebody could point me in the right direction I would be grateful.

So far as the Hudson Bay ice is concerned, all I can say is that advection from ocean currents would be limited and perhaps form part of the 1 M sq kM of remaining winter ice that defines an ice free Arctic.

I just feel that relevant events are now changing so rapidly that all the graph extrapolations and statistics are seriously behind the wave of events. Just a gut feeling that the totally heat energy going into the Arctic from atmosphere and sea is monumental; that the 'tipping point' is very close.

I would love to be able to do the calculations based on a permanent annual perpurtration of the Jet Stream!

Those calculations are performed by the global atmospheric and oceanic circulation models, and none of them have shown anything close to what you are describing. Why do you think they exist?

[Archimid]

Those calculations are performed by the global atmospheric and oceanic circulation models, and none of them have shown anything close to what you are describing. Why do you think they exist?

Source?

[DrTskoul]

Those calculations are performed by the global atmospheric and oceanic circulation models, and none of them have shown anything close to what you are describing. Why do you think they exist?

Source?

I am not starting with you again...echo chambers are awesome ...I will stick with my understanding of the PDEs and properties involved...

[Shared Humanity]

My very unscientific opinion? The Hudson Bay freezes every winter after melting out completely. We should expect the same with the Arctic Ocean.

I tend to agree with you but let's not forget that the Barents does NOT freeze now during winters despite a long polar night - simply because it gets fed warm Atlantic water. I do not know if the same will/can happen to the Arctic proper but if the answer is yes then there will be no ice even during winter. (The Hudson is almost like a lake, pretty closed for oceanic water intrusions)

While the Arctic does have points of entry for large amounts of warm water on the Atlantic side and warm water intrusions from the Atlantic side are the Achilles Heal, I think the Hudson is a better representation of how the Arctic will behave in the near future than the Barents. The Kara Sea melts seasonally, is located on the same shallow shelf as the Barents with half of it south of 75 degrees and yet it freezes over like Hudson Bay because Novaya Zemlya protects it from warm Atlantic currents that have made the Barents perennially ice free.

While Svalbard, Franz Josef and Severnaya Zemlya do not offer the same measure of protection from currents, they do serve as pinning points for ice trying to exit the Arctic as can be seen by the current state of the ice today. Some of the highest thickness anomalies remaining in the Arctic are along their northern coasts. As we finally reach a seasonally ice free Arctic Ocean, I expect that topographical features in the Arctic will have the biggest impact on ice regrowth in the winter. The channels in the CAA will ice over which will favor the refreeze of the CAB directly to the north which is almost entirely north of 80 degrees. The Kara and Laptev will continue to refreeze, beginning at the coasts and moving outward. Where they are less sheltered from Atlantic currents, the refreeze will be more difficult.

I know someone here has argued that once we arrive at an annually ice free ocean at minimum, the winter refreeze will see the shallow areas surrounding the CAB covered with ice and a central CAB that is stormy with ice rubble strewn across it. Looking at the topographical map, I think I agree.

[Shared Humanity]

- So a BOE of some sort before 2030,
- And maybe by then the annual average for the sea ice area of the 7 seas of the High Arctic Ocean drops to below 50% of total ocean area, i.e. the Arctic becomes more a maritime sea than an ice-covered desert.

I think this is correct although a BOE might occur later. I think your individual ice free days analysis gives us a window to the future.

[Shared Humanity]

Just interested to know if anybody is like-minded in their opinions.

So 10 years after the 1st BOE at minimum, you expect the Arctic to become perennially ice free?

Shared Humanity - Thanks for your feedback.

I do not know what the answers are to your questions. I simply do not have enough knowledge.

However, I will give it a go to explain in very general terms!

Please don't take offense but everything that followed sounded like supposition to me.

[crandles]

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/monthly/images/04_Apr/N_04_trend_v3.0.png

40 years to get Barents outside of Novaya Zemlya plus some of Okhotsk to retreat at winter maximum. The central Arctic basin is rather larger than this area of retreat, .... so time for winter ice to retreat is multiple times longer than 40 years?

Above assumes that longer periods of darkness do not make it harder as you get further North.

[Shared Humanity]

As a follow up to the impact that topography will have on the refreeze of a seasonally ice free Arctic, I've attached a map of the entire Canadian Archipelago with Greenland. Imagine the Hudson Bay if you will.

During the winter the entire CAA (Hudson Bay as well) will refreeze and become snow covered due to their being protected from the currents from larger bodies of water. Combine this with a Greenland ice sheet which will be a stable topographical feature for the foreseeable future and I think we will see a new, relatively stable state where the winter cold pole shifts south and sits over northeast Canada and Greenland.

I love reading all of the posts here that cover the PV, jet stream, stuck weather patterns, NAO etc. and understand none of it. What will our climate/weather look like with a cold pole shifted south?

Please excuse me in advance if this belongs in the Stupid Questions thread.

[crandles]

The heat energy exchange calculations are way, way above my head but I would be very interested in reading any recent peer reviewed paper that might be informative on the subject of Heat Energy Exchange related to AGW and the Arctic region. If somebody could point me in the right direction I would be grateful.

...

I would love to be able to do the calculations based on a permanent annual perpurtration of the Jet Stream!

Perhaps
The large‐scale energy budget of the Arctic
Serreze et al 2007
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006JD008230


I don't really have much idea how much the atmospheric heat flows would be changed by jet stream going wildly meridonal and away from zonal flow. However I suspect the heat capacity of the Arctic ocean is such that it would swallow such changes for many years in order to be noticeably warmed. And even if warmed enough such that ice cover gets thinner, then lots more heat flows out in the Arctic winter.

or per Tietsche et al 2011
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL045698

In our perturbation experiments, we observe how different feedbacks in the Arctic compete to enhance or dampen a strong negative anomaly in sea ice, equivalent to a strong positive anomaly in oceanic heat content. In summer, the oceanic heat anomaly is enhanced by the ice–albedo feedback, but in winter the excess oceanic heat is lost to the atmosphere due to a lack of insulating sea‐ice cover. This leads to an anomalously warm atmosphere, which in turn causes increased heat loss by longwave radiation at the top of the atmosphere and decreased heat gain by atmospheric advection from lower latitudes. A lasting impact of the ice–albedo feedback is not possible because the large‐scale heat fluxes quickly adapt to release the excess oceanic heat from the Arctic.

[Shared Humanity]

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/monthly/images/04_Apr/N_04_trend_v3.0.png

40 years to get Barents outside of Novaya Zemlya plus some of Okhotsk to retreat at winter maximum. The central Arctic basin is rather larger than this area of retreat, .... so time for winter ice to retreat is multiple times longer than 40 years?

Above assumes that longer periods of darkness do not make it harder as you get further North.

Thank you Crandles. Makes sense. I've always struggled with anyone who argued that a perennially ice free Arctic was eminent. My uninformed position is many centuries from now at the earliest.

[Archimid]

In our perturbation experiments, we observe how different feedbacks in the Arctic compete to enhance or dampen a strong negative anomaly in sea ice, equivalent to a strong positive anomaly in oceanic heat content. In summer, the oceanic heat anomaly is enhanced by the ice–albedo feedback, but in winter the excess oceanic heat is lost to the atmosphere due to a lack of insulating sea‐ice cover. This leads to an anomalously warm atmosphere, which in turn causes increased heat loss by longwave radiation at the top of the atmosphere and decreased heat gain by atmospheric advection from lower latitudes. A lasting impact of the ice–albedo feedback is not possible because the large‐scale heat fluxes quickly adapt to release the excess oceanic heat from the Arctic.

The bolded part is the exact opposite of observations.

[crandles]

In our perturbation experiments, we observe how different feedbacks in the Arctic compete to enhance or dampen a strong negative anomaly in sea ice, equivalent to a strong positive anomaly in oceanic heat content. In summer, the oceanic heat anomaly is enhanced by the ice–albedo feedback, but in winter the excess oceanic heat is lost to the atmosphere due to a lack of insulating sea‐ice cover. This leads to an anomalously warm atmosphere, which in turn causes increased heat loss by longwave radiation at the top of the atmosphere and decreased heat gain by atmospheric advection from lower latitudes. A lasting impact of the ice–albedo feedback is not possible because the large‐scale heat fluxes quickly adapt to release the excess oceanic heat from the Arctic.

The bolded part is the exact opposite of observations.

What observations of sea ice removal are you talking about?

[Archimid]

Those calculations are performed by the global atmospheric and oceanic circulation models, and none of them have shown anything close to what you are describing. Why do you think they exist?

Source?

I am not starting with you again...echo chambers are awesome ...I will stick with my understanding of the PDEs and properties involved...

Over at the other thread I pointed out exactly why the IPCC models were wrong using the references given. You didn't like it, started insulting and abandoned the science. I see that crandles, by quoting Tiesche, is also ignoring the huge defects on that model. He is in fact using the worst part of the model to justify the wrong conclusion that no threshold behavior is expected.

For everyone else who is not aware, the IPCC uses models that run cold as evidence for no threshold behavior.  Even when they used cold models to simulate and Arctic, the Arctic still exhibits memory. Upon even the slightest scrutiny the models used to justify the "no tipping point" fall flat on their face. 

[crandles]

Alternative interpretation: A couple of us try to explain the science to Archimid and he fails to understand and prefers his own feelings of what is right to what the papers are saying.

Anyone want to try reading
https://forum.arctic-sea-ice.net/index.php/topic,2818.msg216275.html#msg216275
Decide on the matter as you will.

[Archimid]

A summary of the basic facts because that thread is TLTR

Tiesche et al has the following defects:

1. It runs cold. Contrary to most recent result, Tiesche et all produces and ice free Arctic by 2070

The probability for an ice free Arctic using RCP 8.5  is less than 1%



Crandles asked for evidence that 2070 was too late and I gave it to him. He has to ignore it to maintain his argument.


2. Tiesche et al claims that maximum albedo effects are reached in July first. He does this without any good justification except the model results. A model that we now KNOW  runs very cold

Here is what he Tiesche et al says:

The start date is chosen such that the effect of the perturbation is maximal: starting from ice‐free conditions earlier in the year leads to immediate re‐freezing, and hence both earlier and later start dates imply shorter exposure of open water to sunlight, and a less pronounced ice–albedo effect.

The coldest point in the Arctic, N80 reaches maximum teperature towards the end of may, beginning of June. Solistice is on June 21st. CAB melt starts at the end of may. Tiesche is wrong about maximum perturbation.

3. Worst of all Tiesche et al claims that the WAA will help winter refreeze, yet what we are seeing is the Hemisphere encroaching into the Arctic accelerating melt and decreasing ice creation.

[binntho]

Does anybody have open access to Arctic Climate Tipping Points by Timothy M. Lenton?

[D-Penguin]

Just interested to know if anybody is like-minded in their opinions.

Please don't take offense but everything that followed sounded like supposition to me.

Absolutely no offense taken. And, you are absolutely correct the opinion I expressed was entirely supposition.

The problem that I have with 'current thinking' is that it is mostly based on what has happened when the published science is usually 3 or 4 years behind the present. Whereas, in real life you also have to assess what happens 'if' and 'or' and even then there is no certainty viz. The global economic crash, it was not predicted and a short term event that transitioned the global economy in days, not weeks, months or years.

I have actually read Tietsche et al 2011 many years ago; the suggested reference Posted by: crandles
« on: Today at 04:24:19 PM »

Again the paper was based on references to other papers going back further than 10 years to the best of my recollection. It certainly did not address the questions 'if' and 'or'. Tietsche's calculations were based on a 'current state' of the Arctic environment with significant constants assumed. Also, again to the best of my recollection radiant winter heat loss calculations ignored cloud cover over the Arctic, the potential extension of melting season and reduction of freezing season, Pacification and Atlantification of the Arctic ocean and so on.

I would be very interest to see Tietsche's calculations applied to current conditions and where the Polar Jet Stream did not exist. At least we could then apply interpolation instead of extrapolation.

But you are right, this is all supposition!

[El Cid]

...

During the winter the entire CAA (Hudson Bay as well) will refreeze and become snow covered due to their being protected from the currents from larger bodies of water. Combine this with a Greenland ice sheet which will be a stable topographical feature for the foreseeable future and I think we will see a new, relatively stable state where the winter cold pole shifts south and sits over northeast Canada and Greenland.

I love reading all of the posts here that cover the PV, jet stream, stuck weather patterns, NAO etc. and understand none of it. What will our climate/weather look like with a cold pole shifted south?

I totally agree with you and have often wondered what changes this will bring to the atmospheric circulation. And this process is already happening and that might be one of the reasons why we have seen winter cooling around Hudson/E.Canada/Great Lakes, and let's not forget bbr's pet theory either. So the NEW COLD POLE will have significant effects on climate but who knows exactly what?

[Steven]

Does anybody have open access to Arctic Climate Tipping Points by Timothy M. Lenton?

Full text of that paper can be found here:
http://www.homepages.ed.ac.uk/shs/Climatechange/Arctic%20ice/Lenton%20Arctic%20cllimate%20tipping%20points%202.pdf

[Klondike Kat]

...

During the winter the entire CAA (Hudson Bay as well) will refreeze and become snow covered due to their being protected from the currents from larger bodies of water. Combine this with a Greenland ice sheet which will be a stable topographical feature for the foreseeable future and I think we will see a new, relatively stable state where the winter cold pole shifts south and sits over northeast Canada and Greenland.

I love reading all of the posts here that cover the PV, jet stream, stuck weather patterns, NAO etc. and understand none of it. What will our climate/weather look like with a cold pole shifted south?

I totally agree with you and have often wondered what changes this will bring to the atmospheric circulation. And this process is already happening and that might be one of the reasons why we have seen winter cooling around Hudson/E.Canada/Great Lakes, and let's not forget bbr's pet theory either. So the NEW COLD POLE will have significant effects on climate but who knows exactly what?

This also may explain why Europe has experience more warming in recent years than the United States and Canada.

[El Cid]

"This also may explain why Europe has experience more warming in recent years than the United States and Canada"

Exactly. I attach the past few years' winter temps. Europe was warm. Alaska also very warm, E.Canada/Great Lakes cold, Interior Siberia also cold.

[kassy]

Anyone worry about what storms might do if we have several months of open water over large parts of the deep central Arctic seas?

If they would mix out the fresh water layer that should make refreezing harder?

[gerontocrat]

Anyone worry about what storms might do if we have several months of open water over large parts of the deep central Arctic seas?

If they would mix out the fresh water layer that should make refreezing harder?

Extracts from a really old paper but IN PLAIN ENGLISH - https://www.whoi.edu/fileserver.do?id=92424&pt=2&p=44107

Ekman transport – the movement of ocean water caused by wind blowing steadily over the surface layers – is one of the most important variables in the study of oceanography. Its convergence or divergence can induce upwelling, linking subsurface oceanic processes with the surface mixed layer where air-sea and sea-ice interactions take place.

The Arctic Ocean Cold Halocline Layer is a cold water mass that lies between a cold, low-salinity surface mixed layer (ML) and a warm, salty Atlantic Water Layer (AWL) originating from the Atlantic Ocean. The CHL prevents the surface layer from mixing with the vast reservoir of heat
in the AWL, therefore, helping to maintain the perennial sea-ice coverage in the Arctic Basin.

Hydrographic observations have indicated that the CHL retreated in 1990s in the Eurasian Basin,
which consists of Nansen and Amundsen Basins (Figure 1). The retreat enhanced upward heat
flow and was estimated to result in an additional melting of sea ice in a range of 15-25 centimeters per year.

Any upwelling of warmer water is going to accelerate melting of ice that is there and delay refreezing in open water. It is interesting that the author writes  by wind blowing steadily over the surface layers, i.e. that a brief period of high winds not so effective?

I now await comment from those who know what they are talking about.

[petm]

Yes, that seems to have the potential to be a huge positive feedback, which is currently almost non-existent. 2012 may be a taste of what's to come.

(A) early melt -> open water -> (heat -> storms -> mixing)^repeat -> late freeze -> thin ice -> goto (A)

If & when this happens, the Arctic may suddenly and permanently move into a new state. At least it seems possible to me, but who knows?

___

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JC012624:

Figure 8. Map of the linear trends in vertical Ekman velocity for the period 1979–2014 with significance level p ≤ 0.05.

Figure 11. The time series of monthly mean vertical Ekman transport. The color dots indicate the (a) maximum and (b) minimum values of up/downwelling for each year with the month shown in black numbers. Gray lines/black dots, pink lines/red dots, and light blue lines/blue dots represent the total Arctic, Canadian, and Eurasian regions, respectively. The 36 year mean (±1 stand deviation) and linear trend slopes are printed on the plot.

[DrTskoul]

A lot of papers discussed previously have ventured to answer the question. A sudden transition ( bifurcation ) has not been found.

[petm]

How strong is the evidence against it? I don't put much faith in current climate models, which are struggling to cope even with continuous changes to known processes, let alone predicting tipping points. I'll believe it if we have the majority of the arctic as open water for several weeks, and if we then see no subsequent dramatic change in melting / refreezing.

[DrTskoul]

When it comes to the existence of bifurcations a well posed simple model is very useful and sufficient. Theoretical analysis has also shown the same thing :

[petm]

Interesting, thanks for the article. But I'm not convinced it supports a conclusion that mixing can't be a tipping point. They only study ice-albedo feedbacks in response to increased energy inputs, and they do find a tipping point with enough energy input:

When the model is further warmed (F0 = 23 Wm2), a saddle-node bifurcation occurs, and the wintertime sea ice cover abruptly disappears in an irreversible process.

Why do you think mixing isn't a plausible source of such an energy input?

[Klondike Kat]

Yes, that seems to have the potential to be a huge positive feedback, which is currently almost non-existent. 2012 may be a taste of what's to come.

(A) early melt -> open water -> (heat -> storms -> mixing)^repeat -> late freeze -> thin ice -> goto (A)

The only problem is that late freeze has not been shown to occur with low ice extent.  In 2012, the freeze onset occurred similar to preceding and succeeding years.  By December, the ice extent was similar.  In fact, the maximum extent in 2013 was higher that the average of the preceding ten years, and the melt that year was late.  Granted this is a very small sample, but it does go against your speculation.

[DrTskoul]

Interesting, thanks for the article. But I'm not convinced it supports a conclusion that mixing can't be a tipping point. They only study ice-albedo feedbacks in response to increased energy inputs, and they do find a tipping point with enough energy input:

When the model is further warmed (F0 = 23 Wm2), a saddle-node bifurcation occurs, and the wintertime sea ice cover abruptly disappears in an irreversible process.

Why do you think mixing isn't a plausible source of such an energy input?

Forcing,  ...with extra forcing and it has to be sustained. Mixing is not forcing just transports heat from one place to another. You cannot boil the pot just by mixing it without sufficient heat input.

[petm]

Granted this is a very small sample, but it does go against your speculation.

True enough.

But my thought was more that 2012 may be a hint of what's to come rather than an example. What might happen in, say, a decade or two, once the ice cover is getting towards zero over most of the CAB for several weeks? If (highly debated) 2012 shows us that even that one strong storm when most of the ocean was still ice covered can result in a large spike of mixing-induced melt, then what could several weeks of storms on a mostly ice-free ocean result in?

[petm]

it has to be sustained

Can't storm-induced mixing be sustained? And what about affiliated feedbacks, such as increased water vapor, clouds, and advection of air masses from the south (weakening jet stream)? All of these seem to go hand-in-hand and it's hard for me to convince myself that they're not important.

[DrTskoul]

You got to get the heat from somewhere else. Cannot be sustained without more heating. The winter night in the arctic is going to be cold. NH at winter is cold. There are no heat flows to keep ice melting in the winter night unless there is no more winter in NH.

[Archimid]

1. 2012 was colder world with less Arctic amplification.
2. The GAC stirred up the ice real good melting more ice than the world was ready to melt.
3. That produced record ice growth in 2013. Since then ice growth has never been the same.
4. The world warmed since then. Arctic Amplification has gone berserk.
5. Atmospheric patterns are changing. WAA is becoming persistent.
6. 2016 happened at peak global warming with both the Pacific and North Atlantic at peak oscillation.
7. 2019 is happening with a cold cycle north Atlantic, and a barely warm pacific.
8. CO2 shows no signs of slowing down.

[Archimid]

From DrTskoul paper:

The theoretical treatment presented here is constructed to facilitate simple conceptual interpretation, and to this end many processes have been neglected. Factors including possible sea ice-cloud feedbacks (refs. 21–23 and D.S. Abbot, C.C. Walker, E. Tziperman, unpublished manuscript), the dependence of sea ice surface albedo on snow and melt pond coverage (24, 25), ocean heat flux convergence feedbacks (6, 26), changes in wind-driven ice dynamics (7), and changes in ice rheology (27) in a thinning ice cover (28) could potentially lead to other bifurcation thresholds or smooth out the threshold investigated here, akin to the smoothing of a first order phase transition because of statistical fluctuations (29).

You sound like you got this all figured  DrTskoul. So you must have already ruled out all the caveats the paper you posted warn us about. Can you please lead us to the links that complete talk about the factor that were left our on the link you posted? You do that and, if they check out we can stop talking about this. 

[petm]

You got to get the heat from somewhere else. Cannot be sustained without more heating. The winter night in the arctic is going to be cold. NH at winter is cold. There are no heat flows to keep ice melting in the winter night unless there is no more winter in NH.

Increased radiation from water vapor and clouds is a heat input.

And yes, the continents are cold in winter, but not nearly as cold as the Arctic inside the jet stream, when it is functional. The "polar vortex", which is causing colder winters outside the Arctic, is also causing warmer winters inside it. Furthermore, if the weather systems permit air masses to move from the Atlantic or Pacific into the Arctic during the winter, what then?

[Klondike Kat]

You got to get the heat from somewhere else. Cannot be sustained without more heating. The winter night in the arctic is going to be cold. NH at winter is cold. There are no heat flows to keep ice melting in the winter night unless there is no more winter in NH.

Increased radiation from water vapor and clouds is a heat input.

Actually that is not so much a heat input as a reduction in heat output.

[Archimid]

Actually that is not so much a heat input as a reduction in heat output.

It is both and input and a reduction of heat output, depending on context.

But really, when you have more heat, and a reduction in heat output, looking at it as input is probably a good thing.