Holy Sh!t: Year-Round Arctic BOE Imminent

[Wherestheice]

I think once we get a BOE, that's when the heat in the ocean will have it's biggest influence.

[crandles]

It's a good question how long to go before you can establish a trend, in this case. In most cases for climate you need decades. This certainly does not meet that standard.

*Exactly*,  and thank uou.

Decades is about establishing a reliable number for a trend i.e. a number. Steepening or flattening is a binary choice. That is a different ball game. 2^11 = 2048. No, I agree that doesn't really work, I believe there is much more than a 1 in 2048 chance of the trend now steepening. However, maybe that is about the future which is hard whereas this is about observations to date.

If there were only 6 years after inflection point, I would believe that the process of fitting the curve was essentially data mining the residuals for an overfit of the data. So it appears to me to be more like 2^(11-6)=32 and 31/32 is more than a 95% confidence level but only a little more.

Perhaps better than guessing that number 6 used above, instead model a linear downward trend with noise to match the data 200 times. What would the 10 5 percentile model that is best at showing a slowdown in the rate look like? Would it be more or less convincing than my graph?

Waiting 20 or 30 years data before declaring whether the trend is flattening appears to me to be misuse of the valid reason for wanting that much data to get a reliable trend rate number.

(Edit: I meant 5 percentile or 10th most flattening data set)

[sark]

If anyone doesn't like the title of the thread

I thought it was very well done, but I've come to expect content titles to be useful instead of extremely accurate. 

You go from a study title of "Warming of the interior Arctic Ocean linked to sea ice
losses at the basin margins"

to a science mag title of "'Archived' heat has reached deep into the Arctic interior, researchers say"

and nobody shows any interest in any of that, and the discussions never begin, and scientists remain safely silo'd and strictly literal, and 20 years goes by and scientists are blaming themselves for not properly communicating the accelerating demise of global habitability

maybe it's not the job of scientists to communicate climate change science into mitigation & adaptation policy

I'd like to apologize to any scientists who would risk their career by sharing space with someone who talks loose about arctic sea ice, and I thank you for teaching.  I'm not here to argue my darling theories.  I am not married to my suspicions..  I just don't know how to expect the arctic to refreeze after a few BOE in late summer.  How do you propose the cold upper halocline layer of the Arctic will be maintained, after weeks and months of no ice cover?

[FishOutofWater]

What's important is the slow but increasing northward push of warm, salty Atlantic water into the subarctic seas and the Eurasian side of the Arctic ocean. Increased release of ocean heat in the dark and dim months through the thin-ice covered Arctic is important. The increase in advection of warm humid air into the Arctic from the Atlantic and Pacific basins is important. The lengthening of fall and the shortening of winter is important. Increasingly vigorous stratospheric warmings are important.

Arguments about how fast a trend is established are academic. They have value in debunking crap like "the Hiatus". However, they are quite irrelevant to the developing ecological and human catastrophes that are being caused by the warming climate and declining sea ice.

[Ned W]

which is why there is not much more to say hence the rest is chatter and noise about something nobody can predict except the fact that year-round is not imminent.

Yes, well, that's pretty much it.  Despite the thread title, a year-round BOE is not imminent, so we fall back on speculating about when the Arctic might become ice-free in the summer.  And you're right that this has already been the topic of many threads, sometimes multiple ones simultaneously.

Will you qualify "imminent?"  what about 2035?

Whether 2035 is "imminent" is a matter of opinion, obviously.  But that's more of a realistic date for an ice-free September, not an ice-free year, surely.

Models suggest that when the ice extent becomes low enough there's a fairly rapid shift to a seasonally ice free Arctic (meaning a large chunk of the summer, not just a few days). But that doesn't then tip into a perennially ice free Arctic.  Bringing that about is a lot harder.  I would say "not this century" and therefore "not imminent" but YMMV.

https://www.sciencedirect.com/science/article/pii/S0277379113004162

[Wherestheice]

Possibly depends whether you expect serious consequences from a BOE that was just due to natural variability?

I don't expect "serious consequences" from a BOE per se, given that we've defined a BOE as just crossing some arbitrary threshold (1 million km2 extent or 1 thousand km3 volume).  Going from 1.1 to 0.9 in either case will be small in effect, compared to the much larger change that has already happened.  In fact, I think the whole concept of "eek, a BOE!" is misplaced.  What matters is the long-term decline.  But people want excitement and drama...

Once the ice is gone, the impacts will be very serious. I agree that the whole 1 million threshold doesn't mean much, but once we lose the majority of the ice.....shit will go down, so really its all about when we have that year. As long as there is volume in the ice, there will be extent, the volume is dropping, there will come a point here soon when the volume is to low and most of the ice will melt out. Probably gonna happen in the next hand full of years, unless there is a flattening in the trend of volume decline, tho i see no evidence to support the notion of a flattening.

[FishOutofWater]

Interesting article, Ned. In the present the increase of GHGs causes a planetary increase in radiative forcing compared to the summer forcing in the Arctic caused by orbital effects ~10,000 yr bp.

That means that this time around that atmospheric transport of heat from the Atlantic and Pacific oceans, and oceanic heat transport in the Atlantic are more important than they were in the early Holocene.

That would make today's situation more unstable.

[Dharma Rupa]

a) year round will take a long time (intentionally don't name my idea of how long)

b) is certainly NOT IMMINENT ?

Toss out the imminent part.  I say that when you get a BOE in mid-August you'll have BOE year round.  (Not sure about it if the BOE is at the very end of what is currently the melt season.)  All you need are long fetches to roll the water.

[Shared Humanity]

And of course the deeper and more important questions are: if there is a 'flattening,' what is causing it?  and what are likely to be the main forces driving extent and volume numbers over the next decade?

Purely speculative on my part but I think that the flattening of the melt season minimum and the decline of the freeze season maximum are both related to a shift in the year round Arctic climate, from a bitter cold, cloudless desert climate to a cloudy, humid relatively higher precipitation climate. This is caused by the wide expanse of open water.

[Shared Humanity]

It's a good question how long to go before you can establish a trend, in this case. In most cases for climate you need decades. This certainly does not meet that standard.

In any case, isn't there always a distortion at the end of any smoothed graph toward the beginning and end since the the few years at the end have an outsize effect on the smoothed curve?

And of course the deeper and more important questions are: if there is a 'flattening,' what is causing it?  and what are likely to be the main forces driving extent and volume numbers over the next decade?

The cause may be climate change itself.  Warmer temperatures have led to greater cloud cover.  Greater cloud cover leads to warming in the Arctic winter, due to less heat loss during clear skies.  This has been quite prevalent in recent years.  Greater cloud cover in the summer leads to cooling, as less sunlight reaches the surface.  This has also been evident in recent years, although to a much less degree than winter warming.  Cooler summers in the Arctic may be the reason for the observed flattening.

Said better than me.

[Shared Humanity]

Increased GHG levels, increased water temperatures, increased air temperatures, any other forcings,  internal variability, and feedbacks both positive and negative.  That covers everything, right?   

A few more considerations, ...

Natural / internal variability, hmmm. Is there any unnatural/external variability? 
Do aliens aiming meteors at the Arctic count as unnatural? 

As humankind is the stuff of nature, wouldn't climate forcing due to CO2 emissions be natural variability?

[Shared Humanity]

If anyone doesn't like the title of the thread, though, they are of course free to start their own thread with their own more sensible title, and then they can enjoy being the target of slings and arrows of skeptics! 

I like the title and, if we stay on topic, suggesting that a year round BOE could be just years away is rather nonsensical IMHO.

I do think we need to look at the peripheral seas that are increasingly ice free in the winter to understand the processes that are likely going to play a large role in us transitioning into a year round BOE environment. The Atlantification of the Barents and the Bering Sea behavior are test labs.

[Shared Humanity]

I just don't know how to expect the arctic to refreeze after a few BOE in late summer.  How do you propose the cold upper halocline layer of the Arctic will be maintained, after weeks and months of no ice cover?

Salty sea water freezes when the temperatures drop low enough. The Hudson is ice free every summer and freezes every winter with temperatures far higher than what we see in the central Arctic.

[Shared Humanity]

a) year round will take a long time (intentionally don't name my idea of how long)

b) is certainly NOT IMMINENT ?

Toss out the imminent part.  I say that when you get a BOE in mid-August you'll have BOE year round.  (Not sure about it if the BOE is at the very end of what is currently the melt season.)  All you need are long fetches to roll the water.

The Hudson Bay experiences a BBE every year and continues to freeze reliably in the dead of winter. Explain to me the mechanism that will prevent temperatures from plunging below the freezing temperature of sea water in the long polar night.

Don't misunderstand me. I am not saying no such mechanism exists. I am just saying I don't know what it would be.

[Dharma Rupa]

a) year round will take a long time (intentionally don't name my idea of how long)

b) is certainly NOT IMMINENT ?

Toss out the imminent part.  I say that when you get a BOE in mid-August you'll have BOE year round.  (Not sure about it if the BOE is at the very end of what is currently the melt season.)  All you need are long fetches to roll the water.

The Hudson Bay experiences a BBE every year and continues to freeze reliably in the dead of winter. Explain to me the mechanism that will prevent temperatures from plunging below the freezing temperature of sea water in the long polar night.

Don't misunderstand me. I am not saying no such mechanism exists. I am just saying I don't know what it would be.

Actually, I'd expect the Hudson to continue to freeze over long after the Central Arctic no longer does.  I think WACCy weather will become the norm for awhile before equable climate.  So I'd also expect the peripheral seas to freeze over in Winter for a number of years after the CAB becomes a foggy sea instead of a desert -- at least the seas close to Canada and Russia.

[Darvince]

The Hudson Bay experiences a BBE every year and continues to freeze reliably in the dead of winter. Explain to me the mechanism that will prevent temperatures from plunging below the freezing temperature of sea water in the long polar night.

Don't misunderstand me. I am not saying no such mechanism exists. I am just saying I don't know what it would be.

IIRC, the Hudson Bay is fully mixed and brackish at all depths whereas the Arctic Ocean has a cold fresh layer about 100 to 300 meters thick (dunno specifically, haven't read about its oceanography in detail recently) with a relatively warm (4 to 6C ish) salty layer below that. The idea is that the warm salty layer is mixed with the fresh layer by large storms on an open sea Arctic, although I would think the cold layer is too thick for that?

[Dharma Rupa]

The Hudson Bay experiences a BBE every year and continues to freeze reliably in the dead of winter. Explain to me the mechanism that will prevent temperatures from plunging below the freezing temperature of sea water in the long polar night.

Don't misunderstand me. I am not saying no such mechanism exists. I am just saying I don't know what it would be.

IIRC, the Hudson Bay is fully mixed and brackish at all depths whereas the Arctic Ocean has a cold fresh layer about 100 to 300 meters thick (dunno specifically, haven't read about its oceanography in detail recently) with a relatively warm (4 to 6C ish) salty layer below that. The idea is that the warm salty layer is mixed with the fresh layer by large storms on an open sea Arctic, although I would think the cold layer is too thick for that?

https://en.wikipedia.org/wiki/Arctic_Ocean#Water_flow

In large parts of the Arctic Ocean, the top layer (about 50 m (160 ft)) is of lower salinity and lower temperature than the rest. It remains relatively stable, because the salinity effect on density is bigger than the temperature effect.

[oren]

I do think we need to look at the peripheral seas that are increasingly ice free in the winter to understand the processes that are likely going to play a large role in us transitioning into a year round BOE environment. The Atlantification of the Barents and the Bering Sea behavior are test labs.

Yes indeed. And it seems that while we are dutifully following the surface behavior, the depths of the Arctic have been undergoing a steady heat accumulation. This change is invisibly pressuring the surface and will hasten the upcoming summer BOE, even without all that warmth magically pumped upwards by some huge storm.
My everlasting consternation at the stupidity of humanity is that we do not monitor these depths sufficiently, even though the technical solutions are available and the cost not very high AFAIK.
As to the year-round BOE, IMHO it will take a long time after the first September BOE, decades or centuries, even if we continue the BAU trajectory (which we probably won't due to collapse, but that's for a different thread).

[Dharma Rupa]

As to the year-round BOE, IMHO it will take a long time after the first September BOE, decades or centuries, even if we continue the BAU trajectory (which we probably won't due to collapse, but that's for a different thread).

Which of us is right is entirely up to the Fresh Water Lens.  If it stays there you are right.  If it drains away I am right.

The survival of civilization is probably a topic for a different Forum, not just a different Thread.

[marcel_g]

wili, I think the title is fine.


My questions about the timing of a summer BOE are:

• how reliably is the open water going to create cloudy conditions that preserve the ice by preventing pre-conditioning? Every summer? What happens if there is a sunny summer? (Ice goes poof?)
• how fast is the Atlantification of the Arctic Ocean that FOOW is talking about going to go?
• how likely are large storms that can cause enough mixing/upwelling to melt out the remaining ice? 

Given those questions, I'm inclined to guess that a summer BOE is going to be arrived at abruptly, rather than gradually. The trend of poor refreezing in the winter, combined with a summer with sunny weather and then some well timed storms could do it in the next 5-10 years. At least that's my guess.

How long it takes before we have a year round BOE is another question, but I suppose we could get an indication of when that would happen by postulating an open water arctic with fully mixed surface water (no halocline), and calculating how much heat loss there is when there's a lot more water vapour in the air in winter, and if that heat loss is enough to refreeze the ocean. I don't have the ability to calculate that, but I suspect that it's in decades rather than centuries.

Someone upthread said there wouldn't be significant impacts? I may have read that wrong, but we're already having significant impacts to Northern Hemisphere jetstream and weather, and they will only get more extreme and worse as the Arctic melts.

Isn't an ice free Arctic supposed to radically warm land areas up to 1500km from the coast? That will melt a lot of permafrost.

[jdallen]

If anyone doesn't like the title of the thread, though, they are of course free to start their own thread with their own more sensible title, and then they can enjoy being the target of slings and arrows of skeptics! 

I like the title and, if we stay on topic, suggesting that a year round BOE could be just years away is rather nonsensical IMHO.

Agree.  Going back to my "trajectories", freeze season maximum volume has dropped about 2500KM3 a decade going back to the late 70's.  Assuming a similar trend, we're looking at 80 years +/- a couple of decades before we have a year round BOE - at a minimum.  Because of other attenuating effects I think it could be quite a bit longer, possibly as much as a couple of additional centuries.

Even then, I'd say it would be several more decades before that became permanent, as follow on years I think could still have significant refreezes.

[Tor Bejnar]

So, there we have it:  year-round BOE sometime between

• within a decade or so

to

• minimum 80 years to a couple centuries

As a geologist (by education and heritage), these are both "imminent".  My pessimistic outlook has me leaning toward the "any year now - probably not this one" stance, but I regularly guess less ice will survive the summer than what actually survives (except for 2012). 

I understand adequate heat is nearby, so year-round BOE is feasible; that heat is just not currently affecting the surface of the CAB.  A few of the mechanisms that could make the heat accessible include 1)Atlantification, 2) longer-fetched wind-driven waves with opening peripheral seas, 3) a pair of true GACs (I like the recent suggested definition, paraphrased 'more consequential [longer/deeper] than the previous one') strategically placed during the melting season, and 4) 'draining the swamp' (woops, that's political language), I mean, draining the Beaufort Sea of its fresh water cap down the CAA sieve (not garlic press, 'cause somebody doesn't like that term - aren't I nice?).

[Shared Humanity]

draining the Beaufort Sea of its fresh water cap down the CAA sieve (not garlic press, 'cause somebody doesn't like that term - aren't I nice?).

 

[bluesky]

I understand adequate heat is nearby, so year-round BOE is feasible; that heat is just not currently affecting the surface of the CAB.  A few of the mechanisms that could make the heat accessible include 1)Atlantification, 2) longer-fetched wind-driven waves with opening peripheral seas, 3) a pair of true GACs (I like the recent suggested definition, paraphrased 'more consequential [longer/deeper] than the previous one') strategically placed during the melting season, and 4) 'draining the swamp' (woops, that's political language), I mean, draining the Beaufort Sea of its fresh water cap down the CAA sieve (not garlic press, 'cause somebody doesn't like that term - aren't I nice?).

There is enough cases for a "perfect storm" at any time, and there has not been a perfect storm for some years now, so would it mean BOE could happen any year? Unless there are unknown low level negative feedback (well not so unknown as higher cloud cover could explain the temporary stable curve)

[Wherestheice]

I understand adequate heat is nearby, so year-round BOE is feasible; that heat is just not currently affecting the surface of the CAB.  A few of the mechanisms that could make the heat accessible include 1)Atlantification, 2) longer-fetched wind-driven waves with opening peripheral seas, 3) a pair of true GACs (I like the recent suggested definition, paraphrased 'more consequential [longer/deeper] than the previous one') strategically placed during the melting season, and 4) 'draining the swamp' (woops, that's political language), I mean, draining the Beaufort Sea of its fresh water cap down the CAA sieve (not garlic press, 'cause somebody doesn't like that term - aren't I nice?).

A perfect storm is all we need at this point, or just the continued decline in volume

There is enough cases for a "perfect storm" at any time, and there has not been a perfect storm for some years now, so would it mean BOE could happen any year? Unless there are unknown low level negative feedback (well not so unknown as higher cloud cover could explain the temporary stable curve)

[gerontocrat]

There is enough cases for a "perfect storm" at any time, and there has not been a perfect storm for some years now, so would it mean BOE could happen any year? Unless there are unknown low level negative feedback (well not so unknown as higher cloud cover could explain the temporary stable curve)

There was a  warm sunny summer in the Arctic in 2012. Extent was heading for a record low before the GAC. All the GAC did was add some impetus to that event, i.e. make the record low even lower. But it was the warm and sunny summer that did the real damage. So maybe all this GAC and perfect storm talk is a red herring.

[GoSouthYoungins]

If anyone doesn't like the title of the thread, though, they are of course free to start their own thread with their own more sensible title, and then they can enjoy being the target of slings and arrows of skeptics! 

I like the title and, if we stay on topic, suggesting that a year round BOE could be just years away is rather nonsensical IMHO.

Agree.  Going back to my "trajectories", freeze season maximum volume has dropped about 2500KM3 a decade going back to the late 70's.  Assuming a similar trend, we're looking at 80 years +/- a couple of decades before we have a year round BOE - at a minimum.  Because of other attenuating effects I think it could be quite a bit longer, possibly as much as a couple of additional centuries.

Even then, I'd say it would be several more decades before that became permanent, as follow on years I think could still have significant refreezes.

What about the fact that the GHG effect delta from baseline has more than doubled since the late 70s (and is exponentially increasing)? Is that not the cause of all this melt? (AND THERE IS A SIGNIFICANT LAG)

I really don't understand this opinion. Even if it had some validity, it is the equivalent of being in a burning building but estimating that the fire won't reach this room for quite some time. The fire might reach this room at any time, and that's the only reasonable way to teach such a situation. Imminent.

[bluesky]

According to this paper, the Arctic ocean stratification seems to be quite stable, and the 2012 GAC did not fundamentally mix the halocline and other layers below. Which may imply that the full year BOE will be much difficult to achieve before quite some time:


"Wind-driven mixing at intermediate depths in an ice-free Arctic Ocean"
Ben J. Lincoln et al , 2016
Geophysical Research Letters
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2016GL070454

"Abstract Recent seasonal Arctic Ocean sea ice retreat is a major indicator of polar climate change. The Arctic Ocean is generally quiescent with the interior basins characterized by low levels of turbulent mixing at intermediate depths. In contrast, under conditions of reduced sea ice cover, there is evidence of energetic internal waves that have been attributed to increased momentum transfer from the atmosphere to the ocean. New measurements made in the Canada Basin during the unusually ice-free and stormy summer of 2012 show previously observed enhancement of internal wave energy associated with ice-free conditions. However, there is no enhancement of mixing at intermediate depths away from significant topography. This implies that contrary to expectations of increased wind-induced mixing under declining Arctic sea ice cover, the stratification in the central Canada Basin continues to suppress turbulent mixing at intermediate depths and to effectively isolate the large Atlantic and Pacific heat reservoirs from the sea surface."

[bluesky]

There is enough cases for a "perfect storm" at any time, and there has not been a perfect storm for some years now, so would it mean BOE could happen any year? Unless there are unknown low level negative feedback (well not so unknown as higher cloud cover could explain the temporary stable curve)

There was a  warm sunny summer in the Arctic in 2012. Extent was heading for a record low before the GAC. All the GAC did was add some impetus to that event, i.e. make the record low even lower. But it was the warm and sunny summer that did the real damage. So maybe all this GAC and perfect storm talk is a red herring.

Apologies, I did not express myself clearly, a perfect storm in my mind was "a perfect storm climatic condition" like the 2007 weather type condition leading to prolonged sunny period and high frequency of transpolar drift, or 2012 type  no necessarily needing the GAC... so agree with you

[Tor Bejnar]

Boy, bluesky, your report on that research will conservatize [yah, that's a made up word meaning truning me more mainstream] me and lead me to someday believe "any year now - probably not this one or the next".

[bbr2314]

There is enough cases for a "perfect storm" at any time, and there has not been a perfect storm for some years now, so would it mean BOE could happen any year? Unless there are unknown low level negative feedback (well not so unknown as higher cloud cover could explain the temporary stable curve)

There was a  warm sunny summer in the Arctic in 2012. Extent was heading for a record low before the GAC. All the GAC did was add some impetus to that event, i.e. make the record low even lower. But it was the warm and sunny summer that did the real damage. So maybe all this GAC and perfect storm talk is a red herring.

This is somewhat incorrect. The warm and sunny summer was what ultimately provided the knockout blow. But the difference between 2018 and 2012 is that 2012 was seemingly some kind of tipping point in that the conditions preceding summer were excellent for melt.

Snowfall across the continents was low enough in 2011-2012 (in fact NYC's last winter with barely any snow) that by March, the snow line was already well into Canada (this year, it was May). Two months of springtime without large areas of continental albedo primed the system for an enormous injection of heat that only continued until winter 2012-13 when evidently enough heat / open water existed to "flip" us into where we are today.

In spite of its snowcover, 2018 has still seen severe high latitude melt (and no refreeze of Bering). I think viewing 2012 as an inflection point of sorts gives it much more value re: reading into our current state (e.g., we finally hit a point (which keeps getting higher as GHG emissions keep rising) where lack of sea ice results in enough water vapor to equal +++springtime snowfall and even out anomalies). 2013 and 2014 didn't happen in a vacuum, after all.

I think our two "recovery" years after 16-17 foretell a similar situation, where 17-18 and 18-19 may be the "+WV / albedo couplet comeback" and 19-20 could be bad a la 15-16 but with way more oceanic heat accumulated in the periphery. But if 2017 was to 2013 as 2018 is to 2014, then the upcoming winter is going to be b-r-u-t-a-l over huge swathes.

[bluesky]

… but this paper seems to go in favour of potentially more mixing of Canadian bassin sea due to increased near inertial wave field leading to a weakened stratification of the upper halocline, although a relatively slow ramping up process with time:

https://journals.ametsoc.org/doi/pdf/10.1175/JPO-D-15-0056.1

"Dynamics of the Changing Near-Inertial Internal Wave Field in the Arctic Ocean"
HAYLEY V. DOSSER AND LUC RAINVILLE, 2015

ABSTRACT
"The dynamics of the wind-generated near-inertial internal wave field in the Canada Basin of the Arctic Ocean are investigated using the drifting Ice-Tethered Profiler dataset for the years 2005 to 2014, during a decade when sea ice extent and thickness decreased dramatically. This time series, with nearly 10 years of measurements and broad spatial coverage, is used to quantify a seasonal cycle and interannual trend for internal waves in the Arctic, using estimates of the amplitude of near-inertial waves derived from isopycnal displacements. The internal wave field is found to be most energetic in summer when sea ice is at a minimum, with a second maximum in early winter during the period of maximum wind speed. Amplitude distributions for the near-inertial waves are quantifiably different during summer and winter, due primarily to seasonal changes in sea ice properties that affect how the ice responds to the wind, which can be expressed through the ‘‘wind factor’’—the ratio of sea ice drift speed to wind speed. A small positive interannual trend in near inertial wave energy is linked to pronounced sea ice decline during the last decade. Overall variability in the internal wave field increases significantly over the second half of the record, with an increased probability of larger-than-average waves in both summer and winter. This change is linked to an overall increase in variability in the wind factor and sea ice drift speeds, and reflects a shift in year-round sea ice characteristics in the Arctic, with potential implications for dissipation and mixing associated with internal waves."

"The near-inertial internal wave field in the Canada Basin has become increasingly energetic and variable over the last decade, reflecting a fundamental shift in year-round sea ice characteristics in the Arctic Ocean. As the properties of the sea ice continue to change, the internal wave field will continue to evolve as well. This has important implications for mixing in the upper ocean due to wave overturning and dissipation, as the most energetic waves are those most likely to become unstable and break. Any resulting increase in mixing would influence the vertical flux of heat and nutrients, and weaken the stratification of the upper halocline."


Physical process of near inertial waves (unfortunately paywall access):

https://www.annualreviews.org/doi/abs/10.1146/annurev-marine-010814-015746

[Phil.]

The disturbing thing about this winter was along with the Bering not freezing was the absence of the cold water pool that hitherto has prevented the migration into the Arctic ocean of cod and pollock.  As you can see below this wasn't expected to happen this soon.
"Water along the ocean floor where pollock live has been kept cold by the layer of sea ice that forms every winter on the surface of the northern Bering Sea. That ice is expected to persist even with climate warming. Cold water sets up below the ice layer and remains cold throughout the summer.

“What it looks like at the moment is that the northern Bering Sea — and north to us is north of St. Matthew Island — looks like it is going to stay cold,” said physical oceanographer Phyllis Stabeno of NOAA’s Pacific Marine Environmental Laboratory in Seattle.
This year the cold pool didn't form and the pollock distribution changed, another year of this might indicate that the N Bering sea has entered a new phase.

[magnamentis]

As I say in the first post in the thread, if you want to replace 'imminent' with 'could basically happen any time' that's fine, and I think the evidence still supports the statement.

There has always been a vast body of relatively hot and salty water below the freshwater 'lens' in the Arctic Ocean that makes sea ice possible.

We now know that this vast body of hot salty water has gotten much hotter (and presumably saltier...do we know about that?).

And as the authors of the study also point out, they expect major disturbances of the layering structure that has been keeping the hot, salty lower water from interacting with the surface, fresh(er)-water lens...basically at any time.

The article also points out that there is enough heat (and salt, presumably) in that lower level to keep the region ice-free for most of the year.

Add those all together, and I think you can defend at least a version of the title of the thread, especially since at the same time 'Atlantification' and plain old feedbacks are also assaulting the same ice from every other direction.

If anyone doesn't like the title of the thread, though, they are of course free to start their own thread with their own more sensible title, and then they can enjoy being the target of slings and arrows of skeptics! 

if you mean "could happen any time" together with "year round" it's a clear now, can't happen and this is physics, calculating the energy needed to melt all the ice and keep the arctic ice-free in winter is simply not there and can come from nowhere in such a short time that the terms "imminent" or "could happen any time" are valiid and quite far from it.

also to does not matter if some insist that "everything is possible" and find millions of cherry picked arguments to feed their bias. nothing helps if basic physics is involved.

year round BOE will not happen any time soon while BOE in summer will happen soon but not during the next 5 years, except if some would start to invent thresholds again that are nowhere to meet the term but their bias, 1M km2 for example, totally arbitrary and 1M km2 has nothing to do with ice-free, because 1M km2 a certain average thickness is  A LOT of ice and not "NO ICE".

[bbr2314]

As I say in the first post in the thread, if you want to replace 'imminent' with 'could basically happen any time' that's fine, and I think the evidence still supports the statement.

There has always been a vast body of relatively hot and salty water below the freshwater 'lens' in the Arctic Ocean that makes sea ice possible.

We now know that this vast body of hot salty water has gotten much hotter (and presumably saltier...do we know about that?).

And as the authors of the study also point out, they expect major disturbances of the layering structure that has been keeping the hot, salty lower water from interacting with the surface, fresh(er)-water lens...basically at any time.

The article also points out that there is enough heat (and salt, presumably) in that lower level to keep the region ice-free for most of the year.

Add those all together, and I think you can defend at least a version of the title of the thread, especially since at the same time 'Atlantification' and plain old feedbacks are also assaulting the same ice from every other direction.

If anyone doesn't like the title of the thread, though, they are of course free to start their own thread with their own more sensible title, and then they can enjoy being the target of slings and arrows of skeptics! 

if you mean "could happen any time" together with "year round" it's a clear now, can't happen and this is physics, calculating the energy needed to melt all the ice and keep the arctic ice-free in winter is simply not there and can come from nowhere in such a short time that the terms "imminent" or "could happen any time" are valiid and quite far from it.

also to does not matter if some insist that "everything is possible" and find millions of cherry picked arguments to feed their bias. nothing helps if basic physics is involved.

year round BOE will not happen any time soon while BOE in summer will happen soon but not during the next 5 years, except if some would start to invent thresholds again that are nowhere to meet the term but their bias, 1M km2 for example, totally arbitrary and 1M km2 has nothing to do with ice-free, because 1M km2 a certain average thickness is  A LOT of ice and not "NO ICE".

Year round BOE is a fallacy. the impact of summer BOE + extant ice sheet over Greenland = we snowball back to glaciation well before we approach BOE all year.

I would give credence to the notion that 2017-18 was a fluke re: SWE except it happened in an environment where GHGs are like +50% vs 100 yrs ago (yet we saw coldest April ever over parts of N America). The only explanation is catastrophic shifts in ocean currents + the SWE happenings. Therefore it is NOT an anomalous happening but a point in a continuum that will get much more dramatic as we approach 0 volume. If this were not the case, we would've hit BOE after 2012 + continued the trend since the late 90s, but that was the inflection point, IMO.

[Wherestheice]

As I say in the first post in the thread, if you want to replace 'imminent' with 'could basically happen any time' that's fine, and I think the evidence still supports the statement.

There has always been a vast body of relatively hot and salty water below the freshwater 'lens' in the Arctic Ocean that makes sea ice possible.

We now know that this vast body of hot salty water has gotten much hotter (and presumably saltier...do we know about that?).

And as the authors of the study also point out, they expect major disturbances of the layering structure that has been keeping the hot, salty lower water from interacting with the surface, fresh(er)-water lens...basically at any time.

The article also points out that there is enough heat (and salt, presumably) in that lower level to keep the region ice-free for most of the year.

Add those all together, and I think you can defend at least a version of the title of the thread, especially since at the same time 'Atlantification' and plain old feedbacks are also assaulting the same ice from every other direction.

If anyone doesn't like the title of the thread, though, they are of course free to start their own thread with their own more sensible title, and then they can enjoy being the target of slings and arrows of skeptics! 

if you mean "could happen any time" together with "year round" it's a clear now, can't happen and this is physics, calculating the energy needed to melt all the ice and keep the arctic ice-free in winter is simply not there and can come from nowhere in such a short time that the terms "imminent" or "could happen any time" are valiid and quite far from it.

also to does not matter if some insist that "everything is possible" and find millions of cherry picked arguments to feed their bias. nothing helps if basic physics is involved.

year round BOE will not happen any time soon while BOE in summer will happen soon but not during the next 5 years, except if some would start to invent thresholds again that are nowhere to meet the term but their bias, 1M km2 for example, totally arbitrary and 1M km2 has nothing to do with ice-free, because 1M km2 a certain average thickness is  A LOT of ice and not "NO ICE".

To say it won't happen in the next five is a bit ignorant. Unless the decline in volume decides to flatten out.

[Shared Humanity]

Supposition with no supporting research.

[Dharma Rupa]

if you mean "could happen any time" together with "year round" it's a clear now, can't happen and this is physics, calculating the energy needed to melt all the ice and keep the arctic ice-free in winter is simply not there and can come from nowhere in such a short time that the terms "imminent" or "could happen any time" are valiid and quite far from it.

All the energy is right there.  It might not be within snorkeling distance, but it is within SCUBA diving distance of the ice.

[jdallen]

if you mean "could happen any time" together with "year round" it's a clear now, can't happen and this is physics, calculating the energy needed to melt all the ice and keep the arctic ice-free in winter is simply not there and can come from nowhere in such a short time that the terms "imminent" or "could happen any time" are valiid and quite far from it.

All the energy is right there.  It might not be within snorkeling distance, but it is within SCUBA diving distance of the ice.

It's all about the Arctic heat budget and rate of heat transport. 

A BOE requires a sufficiently large heat budget combined with a rate of transport (into and out of the Arctic) that exceeds the ability of local conditions to maintain temperatures that overwhelm the ice.

Increasing ocean enthalpy increases that heat's accessibility to transport.  The only argument right now over is how soon that heat "spills" out of its deep reservoir and how fast it moves.

[Dharma Rupa]

A BOE requires a sufficiently large heat budget combined with a rate of transport (into and out of the Arctic) that exceeds the ability of local conditions to maintain temperatures that overwhelm the ice.

Into and out of???   The heat has been building there since at least 1800.  The issue is transport up and down, not in and out.

[jdallen]

A BOE requires a sufficiently large heat budget combined with a rate of transport (into and out of the Arctic) that exceeds the ability of local conditions to maintain temperatures that overwhelm the ice.

Into and out of???   The heat has been building there since at least 1800.  The issue is transport up and down, not in and out.

Yes, heat has been building for a long time, I'm aware of that.

Yes, for the heat *currently in the Arctic Ocean* the reason why it hasn't melted the ice and kept it off year round has to do with the mechanics of vertical transport of heat in the water column.

All else being equal, if the system were static, that heat would never arrive at the surface in sufficient quantity to melt out the ice.

My point was and is, that those dynamics are changing, and what will make more of that heat accessible - and contribute first to a summer BOE - later to a year round BOE - is the continued transport and accumulation of heat in the ocean. 

The heat *has* to accumulate in the system until such point as one of two things happen:

(1) It exists in sufficient quantity that the current vertical transport mechanisms can move enough of it that it overwhelms the ice or

(2) The volume of heat itself changes the dynamics of the system such that it is present at the sea surface in enough quantity that outgoing heat loss is insufficient to lower temperatures to where it will freeze.

The annual heat budget - heat imported via currents, captured via insolation, delivered by precipitation, and how fast it exits the atmosphere as radiation - will determine how soon one of those two events takes place.  Eventually the total heat will be sufficient that a pendulum swing (the weather) will take out the ice. 

Absent massive intervention, the only argument right now is how soon that will take place.

-J

[Hefaistos]

Year round BOE is a fallacy. the impact of summer BOE + extant ice sheet over Greenland = we snowball back to glaciation well before we approach BOE all year.
...

I doubt that dramatic statement.
Can you give a reference to some scientific research on this?

[Klondike Kat]

As I say in the first post in the thread, if you want to replace 'imminent' with 'could basically happen any time' that's fine, and I think the evidence still supports the statement.

There has always been a vast body of relatively hot and salty water below the freshwater 'lens' in the Arctic Ocean that makes sea ice possible.

We now know that this vast body of hot salty water has gotten much hotter (and presumably saltier...do we know about that?).

And as the authors of the study also point out, they expect major disturbances of the layering structure that has been keeping the hot, salty lower water from interacting with the surface, fresh(er)-water lens...basically at any time.

The article also points out that there is enough heat (and salt, presumably) in that lower level to keep the region ice-free for most of the year.

Add those all together, and I think you can defend at least a version of the title of the thread, especially since at the same time 'Atlantification' and plain old feedbacks are also assaulting the same ice from every other direction.

If anyone doesn't like the title of the thread, though, they are of course free to start their own thread with their own more sensible title, and then they can enjoy being the target of slings and arrows of skeptics! 

if you mean "could happen any time" together with "year round" it's a clear now, can't happen and this is physics, calculating the energy needed to melt all the ice and keep the arctic ice-free in winter is simply not there and can come from nowhere in such a short time that the terms "imminent" or "could happen any time" are valiid and quite far from it.

also to does not matter if some insist that "everything is possible" and find millions of cherry picked arguments to feed their bias. nothing helps if basic physics is involved.

year round BOE will not happen any time soon while BOE in summer will happen soon but not during the next 5 years, except if some would start to invent thresholds again that are nowhere to meet the term but their bias, 1M km2 for example, totally arbitrary and 1M km2 has nothing to do with ice-free, because 1M km2 a certain average thickness is  A LOT of ice and not "NO ICE".

To say it won't happen in the next five is a bit ignorant. Unless the decline in volume decides to flatten out.

Do you mean more so than it already has?

[SimonF92]

Year round BOE is a fallacy. the impact of summer BOE + extant ice sheet over Greenland = we snowball back to glaciation well before we approach BOE all year.
...

I doubt that dramatic statement.
Can you give a reference to some scientific research on this?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306672/

That paper describes the potential positive feedback of a warming Arctic Ocean on "colder" landmasses and by inference increased glaciation.

[binntho]

Year round BOE is a fallacy. the impact of summer BOE + extant ice sheet over Greenland = we snowball back to glaciation well before we approach BOE all year.
...

I doubt that dramatic statement.
Can you give a reference to some scientific research on this?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306672/

That paper describes the potential positive feedback of a warming Arctic Ocean on "colder" landmasses and by inference increased glaciation.

The above mentioned paper is not really saying anything that others haven't pointed out already: Decrease in Arctic Sea Ice is, at least partially, responsible for increase in snowfall during autumn in the Northern Hemisphere.

But there is a big difference between increased autumn snowfall and "snowballing back to glaciation" - and the above mentioned paper makes no such claims.

Autumn snow has been increasing these last several decades, winter snow cover is more or less flat, spring snow cover has been decreasing - all as expected in a warming world with more moisture.

[Dharma Rupa]

Absent massive intervention, the only argument right now is how soon that will take place.

I don't have much to say on when a Summer BOE will happen.  My main contention is that Winter BOE will follow Summer BOE almost immediately (Equable Climate).  I base this mostly on the geologic evidence that climate change tends to happen suddenly in steps, not slowly and continuously.

I do think the Summer BOE will be soon, but I don't have any good reason for thinking that.

[SimonF92]

Year round BOE is a fallacy. the impact of summer BOE + extant ice sheet over Greenland = we snowball back to glaciation well before we approach BOE all year.
...

I doubt that dramatic statement.
Can you give a reference to some scientific research on this?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306672/

That paper describes the potential positive feedback of a warming Arctic Ocean on "colder" landmasses and by inference increased glaciation.

The above mentioned paper is not really saying anything that others haven't pointed out already: Decrease in Arctic Sea Ice is, at least partially, responsible for increase in snowfall during autumn in the Northern Hemisphere.

But there is a big difference between increased autumn snowfall and "snowballing back to glaciation" - and the above mentioned paper makes no such claims.

Autumn snow has been increasing these last several decades, winter snow cover is more or less flat, spring snow cover has been decreasing - all as expected in a warming world with more moisture.

You are avoiding acknowledging that while extent has been flat in Winter and Spring, SWE has not been flat.  These are two different things.

Though we can both agree high-Arctic SWE positive anomalies, which cause delayed melt-outs, (and have been causing these in the CAA) are going to contribute much more to glaciation than some extra southerly snow in North America.

It is very important when reading papers not to over-stretch what one takes from them, but its also dangerous to ignore the bigger picture of their discussions. We're all very keen to point out the inferences of albedo on the Arctic Ocean and where it will lead us. So why not discuss this too?

[binntho]

You are avoiding acknowledging that while extent has been flat in Winter and Spring, SWE has not been flat.  These are two different things.

I'm not sure i'm "avoiding acknowledging" anything. Spring winter snow extent has not been flat, it has actually declined. Winter snow extent has been flat, while autumn extent has increased.

SWE may or may not have increased in winter, it's not an easy metric to establish, but this paper seems to say that it has decreased (or at least not increased).

Though we can both agree high-Arctic SWE positive anomalies, which cause delayed melt-outs, (and have been causing these in the CAA) are going to contribute much more to glaciation than some extra southerly snow in North America.

Well, I'm not sure what I'm supposed to agree on here. Positive SWE anomalies are not contributing to glaciation, as there are is no imminent glaciation. For glaciation to happen, both high SWE and increases in extent in spring and summer are necessary.

It is very important when reading papers not to over-stretch what one takes from them, but its also dangerous to ignore the bigger picture of their discussions. We're all very keen to point out the inferences of albedo on the Arctic Ocean and where it will lead us. So why not discuss this too?

Any change in extent affects albedo - SWE make no difference. And it doesn't seem to me that there has been any increase in snow albedo, since winter extent has been flat, and autumn increase is cancelled out by spring decrease.

All in all, I can't how bbr's hypothesis can supported by recent trends or by the paper you linked to.

[jdallen]

...For glaciation to happen, both high SWE and increases in extent in spring and summer are necessary...

Any change in extent affects albedo - SWE make no difference. And it doesn't seem to me that there has been any increase in snow albedo, since winter extent has been flat, and autumn increase is cancelled out by spring decrease.

All in all, I can't how bbr's hypothesis can supported by recent trends or by the paper you linked to.

I agree, I really can't see how any re-glaciation hypothesis has any foundation to stand on.  Increased *local* albedo in northern Quebec is no where near a strong enough forcing to resist increased heat elsewhere.  Put in metaphor, the hypothesis' "refrigerator has no insulation".  A net increase in reflected insolation of 15-20% will not prevent melt out of the snowpack, as imported atmospheric heat and moisture will overwhelm it.  There's no way to keep the heat out so ice can be established.

[SimonF92]

You are avoiding acknowledging that while extent has been flat in Winter and Spring, SWE has not been flat.  These are two different things.

I'm not sure i'm "avoiding acknowledging" anything. Spring winter snow extent has not been flat, it has actually declined. Winter snow extent has been flat, while autumn extent has increased.

SWE may or may not have increased in winter, it's not an easy metric to establish, but this paper seems to say that it has decreased (or at least not increased).

Though we can both agree high-Arctic SWE positive anomalies, which cause delayed melt-outs, (and have been causing these in the CAA) are going to contribute much more to glaciation than some extra southerly snow in North America.

Well, I'm not sure what I'm supposed to agree on here. Positive SWE anomalies are not contributing to glaciation, as there are is no imminent glaciation. For glaciation to happen, both high SWE and increases in extent in spring and summer are necessary.

It is very important when reading papers not to over-stretch what one takes from them, but its also dangerous to ignore the bigger picture of their discussions. We're all very keen to point out the inferences of albedo on the Arctic Ocean and where it will lead us. So why not discuss this too?

Any change in extent affects albedo - SWE make no difference. And it doesn't seem to me that there has been any increase in snow albedo, since winter extent has been flat, and autumn increase is cancelled out by spring decrease.

All in all, I can't how bbr's hypothesis can supported by recent trends or by the paper you linked to.

Though I don't speak for bbr, and i'm sorry should he take this personally, but I think his statement was somewhat tongue-in-cheek, as opposed to a serious hypothesis.

However, though exaggerated, he does make a valid point. The paper I attached discusses how decreasing ASI cover leads to increased Autumn snowfall. I know you have seen the crazy SWE maps for last year. It started snowing early, and the volume ended up literally off the GCW scale by mid-winter.

Glaciation is driven by a either a combination of lower summer temperatures and increased Autumn/Winter/Spring snowfall versus control, or an overwhelming contribution from one factor. The paper sets out a reasonable argument for the latter of these two mechanisms. Maybe, some areas in the CAA may see positive SMBs as a result of this, in the years and decades to come (Greenland has seen this effect for the last 2 years). I dont think my argument is invalid, or I wouldn't make the point- though you may well prove to be correct.