DHACSOO - A Durable Arctic Hypothesis

[Phoenix]

Hypothesis (definition) - a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

The subject suggested to be explored here is not proposed to be a theory. The scientific method typically proceeds in the following order.

Observation => Hypothesis => Experiment => Review Results => Theory

Background

It is clear that there is a lot of interest in the future of the Arctic sea ice. Both within the context of a longer term future and within the context of a single melt season. This is obviously an important topic because Arctic sea ice is an important element of Arctic ecosystems and a component of N. Hemisphere weather systems.

The primary factors influencing the Arctic sea ice future appear to be the chronic progression of AGW and weather variation. Given the high degree of volatility in weather patterns, predicting the future of the sea ice with any degree of precision is not considered likely at this time (at least not by this author). Nonetheless, it's may be worthwhile to pursue inquiry which helps us to move in the direction of better understanding the factors which influence the progression of sea ice loss.

I've only been actively following the discussion here at ASIF since early 2019, prior to the commencement of the melt season. At the conclusion of the season, I asked myself the following questions. WHY is the ice remaining in the regions where it still existed and WHY did the other areas become ice free?

Observations

There was basically little or no ice remaining south of 75N.

There was no ice remaining adjacent to continental land masses in N. America and Asia, but there is a lot of ice adjacent to Greenland.

The areas where sea ice loss penetrated N. of 80N were primarily those where the ocean was of relatively shallow depth.

Hypothesis

What is the causation for the location of the sea ice at the minimum?

The hypothesis includes the rationale that there is no sea ice adjacent to N. America and Asia due to frequent warm air advection as the continents heat up during the spring and summer. Ice adjacent
 to Greenland and smaller land masses near the CAA are not subject to the same magnitude or intensity of warm air advection.

The hypothesis also includes the rationale that bathymetry influences the progression of melt. The low density cold fresh water on/near the surface provide a layer of defensive protection against warmer saltier water below. Without being an expert on the details, it seems possible that the deeper water is more resilient because there is more room for layer stratification.

The observations led me to question an alternative hypothesis that the Arctic will lose ice in the future at a linear rate which is reflected in losses from 1979 until today. The possibility exists that the remaining regions of the Arctic (primarily CAB, CAA and N. Beaufort) are fundamentally different from the regions that have lost ice in recent decades and future ice loss will be at a much reduced rate.

Note: just to be clear, I'd like to re-emphasize the distinction between that which I hope to better understand and predict (the chronic progression of AGW on sea ice loss) and that which I don't intend to try and predict (short-term weather variability).

Almost forgot - The acronym DHACSOO stands for Distant From Heat Advecting Continents and Shallow Open Ocean.

Why a separate thread ?

in order to determine if a hypothesis has any predictive value, you have to kick the tires. I welcome criticism and observations that might be disruptive on other threads.

The hypothesis heavily emphasizes the distinction on areas based upon their likelihood to retain ice at the annual minimum. The hypothesis might indicate that the 2020 melting season is currently substantially less advanced than the 2019 melting season at a similar point in time even though 2019 is ahead in aggregate Arctic ice loss.

It may be useful to explore alternatives measures of the strength of a melt season while it is in progress.

[SimonF92]

Cool stuff, I enjoyed the read.

Could you sum up your hypothesis in one or two sentences?

[Phoenix]

Cool stuff, I enjoyed the read.

Could you sum up your hypothesis in one or two sentences?

Basically, the hypothesis is that the incremental degree of difficulty in melting the final 4k km2 of Arctic sea ice represents a non-linear progression.

A BOE will always be theoretically possible in the short-term with unpredictable weather variation (2007, 2012, etc.) but not the result of the near term chronic progression of AGW.

I'll try an analogy....

When he was 20 years old, Novak Djokovic rose from a top 15 tennis player to top 5 and was rapidly improving. A linear progression would have seen rise to #1 within the next year. He quickly rose to #3, but it would take him 3 more years before he could surpass Federer and Nadal in the rankings.

In that case, the difference in quality between the #2 and #3 player was greater than the difference in quality between the #3 and #15.

Djokovic is the analog for AGW. Federer and Nadal are the CAB / CAA. We know who wins eventually, but the rate of future progression is dependent on the quality of the opponents who have yet to be conquered. The remaining Arctic has totally different physical characteristics from the previously conquered regions and should be evaluated independently.

[SimonF92]

 Ah okay, so we are talking about an exponential decay in the rate of loss? I agree with this statement, I think many people do.

Im more curious about your DHACSOO. It can be quite difficult to collate data but were you to regress the average velocity/direction of wind coming off the coastlines versus the ice area for the adjacent sea, I think it could be quite interesting. Is the Siberian side terrible at the moment because of current conditions? Or pre-conditioning last year.

Lots to think on.

Occams razor for your working hypothesis is that the ice just follows the mean ocean surface current and accumulates north of the CAA.

[oren]

Some advice:
As background, take a few minutes to study the dynamic behavior of past melting seasons and movements of multi-year ice.





To corroborate the working theory, find a way to quantify where indeed is ice more likely to survive at the annual minimum. This can be done by gridded computing, by animation, by picking certain locations and manually counting the years (e.g. since 2007) in which they were ice covered, or even by using crude regional area and volume statistics . But not quantifying this at all makes the hypothesis into an assumption.

Also, read the Slow Transition thread from start to finish, very relevant. When Chris Reynolds came up with that theory he quantified a lot of its underlying assumptions and postulations. You can also read the posts on his old blog, DosBat.

[Phoenix]

Thanks for your interest and suggestions Oren. I will peruse the blog and read the ASIF thread you suggest.

I have seen similar animations of sea ice export over past decades before I found my way to ASIF and acknowledge that ice export is a significant alternative means of transport. Instead of bringing heat to the ice, export transports ice to the heat. I certainly wouldn't rule out the possibility of massive export events leading to eventual BOE.

In terms of attempting to prove whether the hypothesis is accurate, I don't have a vision of a classical research paradigm where i'm a principal investigator doing all the work and then presenting my findings for someone else to read.

I'm thinking more in terms of a classroom setting where everyone puts themselves in the role of investigator and putting out an idea for them to consider as we all watch the experiment unfold together.

For example, Freegrass posted a 5 second gif today on the melting season thread which depicts the GFS 5 day wind and temperature forecast for the Arctic. It's a wonderful example which demonstrates the heat intrusion into the Arctic from multiple different sources and how the heat is more pronounced at the perimeter of the Arctic, especially in proximity to NA and Siberia. The general phenomena of heat from external sources dissipating as it approaches the center of the Arctic ice seems well documented. There are hundreds of examples of this to be observed every melting season with few exceptions.

A basic understanding of this seems to be accessible to most interested and curious lay people if they are guided to look for the source of heat and mechanism of transport into the Arctic.

The order in which the ice is lost is also instructive and already well documented. It is an annual recurring pattern that inner basin ice is lost first near the coast of NA and Asia and proceeds closer the pole as the season progresses. There are certainly exceptions to this general rule, but the general pattern doesn't seem to be too controversial and is easily accessible to a layperson through observation of recent history.

The situation of ocean heat intrusion is not as easily documented for a lay person. Here i would ask people to evaluate based upon less direct observation. Instead I would guide them to look at the result and use deductive reasoning. If a significant pause is observed where the ocean bathymetry transitions from shallow to deep, then there is reason to consider the connection. Especially given the understanding that stratification is relevant to melt.

I suppose the hypothesis has two separate elements. One element pertains to the outcome (slower rate of progression than the previous linear assumption) and the other relates to the root cause (distance from NA / Asia and non-linear bathymetry). The outcome has the potential to smash the entire hypothesis if the ice moves much further into the Arctic this decade.

If the coming years do not show much further progression of ice loss, then we can be right about the outcome and still wrong about the root cause. In that case, it would be important to evaluate alternative hypotheses which propose to demonstrate that other factors are more important than distance from land based WAA and the transition to deep bathymetry.

I hope others will take these ideas as an invitation to offer their own ideas as to why the melting stops where it does at seasons end. It's an interesting topic.

I care more about the outcome than the root cause. If the ice holds up longer significantly longer than people think based upon completely different factors, I will be very happy. During the interim between now and when the future reveals itself, I'll suggest that there may be merit in promoting possibilities that give people reason to hope that sea ice disaster will be averted. The presence or absence of hope could potentially be a factor in the outcome.

[Phoenix]

in the interest of not interrupting the melting season thread, I'll choose to reply to Binntho's comment (highlighted in bold below) here.

By way of background, I had previously commented on Freegrass' gif identifying the heat on the Pacific side as emanating from land and the heat from the Atlantic side being of indeterminate source, either from Scandinavia, the Atlantic or both. Since correctly identifying the origin or source of heat is important to understanding the hypothesis, I choose to reply here.

You may not be aware of the massive heat conveyor belt called the North Atlantic Current, and further south commonly referred to as the Gulf Stream. The oceans carry vast amounts of heat from mid latitudes northwards, both in the Pacific and the Atlantic, and the heat that makes the North Atlantic such a relatively balmy place has it's orgins mostly on the Caribbean and the Gulf of Mexico.

I'm aware of the AMOC. Let's see if we can make a connection to Freegrass' gif which is depicting what may happen in the next 5 days.

Over the ocean conveyor you wil often find a low-pressure conveyor, where one low pressure area after another is carried northwards, essentially being the mechanism by which the high temperatures of the ocean surface is spread outwards to warm the British Isles, Scandinavia, Iceland and Svalbard to temperatures that are far above what is found elsewhere at the same latitudes.

You are describing a general condition. Still no connection to the Freegrass's gif which demonstrates the current non-recurring event of atmospheric heat intrusion from the Atlantic. Said event is coming from a system dominated by high pressure over the area from the Atlantic to the Arctic, not the low pressure system you describe.

In the Pacific, the North Pacific drift carries heat from mid-latitudes north and east towards the Canadian Pacific coast and southern Alaska, again making those areas much warmer than they otherwise would have been. The warming effects of the oceans can be seen by comparing average temperatures on the western and eastern boundaries of the northern reaches of each ocean. The warm currents hug the eastern boundaries due to the Coriolis effect, keeping them considerably warmer.

Again, you are attempting to explain a general situation, not explaining the current activity which I have characterized as origininating from land based heat. If you want to dispute that conclusion, let's have the discussion.

The Arctic ocean, being as it is sheltered by landmasses on most sides, mostly misses out on this massive advection of heat from the southern oceans. The only real front open to the oceans is the Atlantic, with the shallow Barents sea and the Svalbard / Franz Josef Land barrier stopping the warm currents from properly entering the Arctic.

In my understanding this is simply incorrect. The Spitsbergen Current brings a steady supply of incoming Atlantic water into the Arctic unimpeded by land. There is enough warm water of Atlantic origin beneath the Arctic surface to melt the surface ice many times over. The impediment to this incoming water melting the ice is the cold fresh melt water lens at the surface.

https://oceancurrents.rsmas.miami.edu/atlantic/spitsbergen.html

If the Arctic was not so sheltered behind the massive landmasses of Asia and N.America with their cooling effect, we would probably see BOE every year.

Let's try to explain the Arctic as it is. Not hypothetical scenarios.

[oren]

I have seen similar animations of sea ice export over past decades before I found my way to ASIF and acknowledge that ice export is a significant alternative means of transport. Instead of bringing heat to the ice, export transports ice to the heat. I certainly wouldn't rule out the possibility of massive export events leading to eventual BOE.

The point of these videos was not to highlight export but to show the prevailing movement of ice from Siberia towards the CAA, thus explaining why the remaining ice ends up bunched against Greenland, Ellesmere and the CAA in September, with no need for the DHACSOO mechanism of distance from heat advecting continents and shallow open ocean as an explanation. A mechanism which I believe is not a good explanation and will not protect the ice from further warming and more mobility.

In terms of attempting to prove whether the hypothesis is accurate, I don't have a vision of a classical research paradigm where i'm a principal investigator doing all the work and then presenting my findings for someone else to read.

I'm thinking more in terms of a classroom setting where everyone puts themselves in the role of investigator and putting out an idea for them to consider as we all watch the experiment unfold together.

This could happen if more people felt DHACSOO is a viable explanation and predictor. I am not sure that is the case. If you can't put in the time to quantify your own theory, I expect others, with less conviction than you, will not invest much effort either.
My own initial reaction was skeptical and I've given some reasons (back when this was presented in the "when ice free" thread). Now I see no reason to spend time and effort investigating a theory I haven't seen proof of and am not convinced of its viability.
For example, I believe the location of remaining ice at minimum is not exactly as described in the initial post of this thread, and that deep/shallow plays much less of role than other factors. However, were I to be shown convincing quantified proof of this, I might be more inclined to investigate further.

I suppose the hypothesis has two separate elements. One element pertains to the outcome (slower rate of progression than the previous linear assumption) and the other relates to the root cause (distance from NA / Asia and non-linear bathymetry). The outcome has the potential to smash the entire hypothesis if the ice moves much further into the Arctic this decade.

If the coming years do not show much further progression of ice loss, then we can be right about the outcome and still wrong about the root cause. In that case, it would be important to evaluate alternative hypotheses which propose to demonstrate that other factors are more important than distance from land based WAA and the transition to deep bathymetry.

I hope others will take these ideas as an invitation to offer their own ideas as to why the melting stops where it does at seasons end. It's an interesting topic.

I care more about the outcome than the root cause. If the ice holds up longer significantly longer than people think based upon completely different factors, I will be very happy. During the interim between now and when the future reveals itself, I'll suggest that there may be merit in promoting possibilities that give people reason to hope that sea ice disaster will be averted. The presence or absence of hope could potentially be a factor in the outcome.

Others have indeed, already, offered their own ideas as to why the melting stops where it does, and why a collapse to BOE is not imminent. But the root cause - and not the end result - is the interesting part. Otherwise we just wait until one year the end result is different. OTOH, a good root cause can be used for prediction, and can be checked against unfolding events.
For example, Chris Reynolds predicted winter volume in the Inner Basin to stabilize, once the long-term process of MYI replacement by FYI is finished, due to freezing season length being stable, FDDs decreasing only slowly, and the low marginal effect of added FDDs on FYI thickening. And with winter volume stable, summer declines should take place much more slowly than expected at the time. A much more convincing and quantified theory than DHACSOO, though with its own weaknesses, exposed during the winter of 2016/17 when freezing was much delayed and Inner Basin volume fell to a new low.
I fear your theory will not see much traction and discussion without a strong initial quantification of its merit.

[oren]

Another thing to bear in mind is that temperature is a problematic indicator over the Arctic. As long as there is abundant sea ice, summer surface temps will be pinned to the ice melting point, while the ice might get thinner and thinner. Besides, the Arctic can get a lot of its melting energy directly from the 24-hour sun, with albedo and cloudiness playing an important mediating role in this process.

[binntho]

I agree, this is a better forum for these discussions.

On the other side of the screen you see a blast of warmth coming in from the Atlantic over Svalbard. That's coming from a long way away and it isn't getting any local land based boost. It's either coming from Scandinavia or the Atlantic (not sure which or both) with a lot of atmospheric assistance from a massive high pressure system that extends all the way from the mid-Atlantic to the Kara Sea and a low off the coast of Greenland.

The Arctic ocean, being as it is sheltered by landmasses on most sides, mostly misses out on this massive advection of heat from the southern oceans. The only real front open to the oceans is the Atlantic, with the shallow Barents sea and the Svalbard / Franz Josef Land barrier stopping the warm currents from properly entering the Arctic.

In the interest of keeping this thread on topic, I reply here if you want to continue.

https://forum.arctic-sea-ice.net/index.php?topic=3097.msg265708#msg265708

Regarding the concept that a land barrier is an impediment to Atlantic water entering the Arctic, I diagree. The Spitsbergen Current brings enough warm Atlantic water to the Arctic to melt all the ice many times over. The defense mechanism against the Atlantic water is the less dense fresh water lens at the surface. Uniquorn might be a good person to comment on this.

https://oceancurrents.rsmas.miami.edu/atlantic/spitsbergen.html

The reason why I wrote the above comment was your seeming ignorance of the possible origins of warm air entering the Arctic from the Atlantic. Which implies a lot of ignorance regarding ocean currents and how they move heat around the globe.

As for the land barrier, it is both the barrier and the changes in bathymetry that follow the same line that prevent the warm Atlantic currents from free entry into the Arctic. At the same time, the land barrier protects the inner Arctic from the massive storm generated swells that are common in the North Atlantic, and from storm waves in general, and waves are well known to not only break up the ice but to mix up the underlying layers.

Which is why I willl continue to point out that without the cold embrace of the surrounding continents, the Arctic would be ice free in summer every summer.

That the land protects the ice, while access to open ocean hinders the ice, becomes obvious when you compare the two sides, Atlantic and Pacific. The typical line of extent on the Atlantic side is where the Atlantic warm waters are forced to sink and / or deflect due to land and bathymetry. On the Pacific side, it is the landmass that is the delimiter. If the coast of Siberia or Canada were to move a 1000 km further south, the ice would follow, just as it forms every winter on the Hudson as far south as the latitude of London- another body of water in a continental cold embrace.

Continental summer heat does not travel well, and is therefore not a good source of the heat that melts the ice in summer. Ocean heat travels extremely well. But of course, by far the biggest melt effect in summer stems from insolation.

Heat from continents is probably a distant third after insolation and heat transfer from the Atlantic and to a lesser extent the Pacific.

[Phoenix]

I fear your theory will not see much traction and discussion without a strong initial quantification of its merit.

You make lots of good points Oren and I hope to learn a lot from you. Of course, all of the factors that go into making ice disappear is such a complicated and perhaps impossible thing to completely reduce to math. I haven't the inclination to even contemplate such an undertaking. Instead I choose to focus on two simple variables which are accessible to most people through visual observation.

I don't expect heaps of discussion because the premise is so relatively simple. In an arena where there appears to be a) incredible interest in the future outcome and b) an absence of an accepted hypothesis.... one would hope that simple curiosity would motivate people to at least pay attention.

Not to be too nitpicky, but I appreciate if you refer to the concept as a hypothesis and not a theory. I understand the colloquialism, but the distinction of where this idea falls in the process of the scientific method is an important one. I think this is a concept that may be worthy of investigation. I don't want to represent it as having withstood nearly enough scrutiny to merit being labeled a scientific theory.

Giving the hypothesis some visibility with a melt season in front of us is a good way to enhance the observations from last year. I will watch more carefully and hopefully so will some others and perhaps kill the idea before the season is over.

[oren]

Sorry, laziness, theory is a shorter word to type.

[Phoenix]

The reason why I wrote the above comment was your seeming ignorance of the possible origins of warm air entering the Arctic from the Atlantic. Which implies a lot of ignorance regarding ocean currents and how they move heat around the globe.

As for the land barrier, it is both the barrier and the changes in bathymetry that follow the same line that prevent the warm Atlantic currents from free entry into the Arctic. At the same time, the land barrier protects the inner Arctic from the massive storm generated swells that are common in the North Atlantic, and from storm waves in general, and waves are well known to not only break up the ice but to mix up the underlying layers.

Which is why I willl continue to point out that without the cold embrace of the surrounding continents, the Arctic would be ice free in summer every summer.

That the land protects the ice, while access to open ocean hinders the ice, becomes obvious when you compare the two sides, Atlantic and Pacific. The typical line of extent on the Atlantic side is where the Atlantic warm waters are forced to sink and / or deflect due to land and bathymetry. On the Pacific side, it is the landmass that is the delimiter. If the coast of Siberia or Canada were to move a 1000 km further south, the ice would follow, just as it forms every winter on the Hudson as far south as the latitude of London- another body of water in a continental cold embrace.

Continental summer heat does not travel well, and is therefore not a good source of the heat that melts the ice in summer. Ocean heat travels extremely well. But of course, by far the biggest melt effect in summer stems from insolation.

Heat from continents is probably a distant third after insolation and heat transfer from the Atlantic and to a lesser extent the Pacific.

Rather than argue, I'll ask a few question.

Let's construct an example. There is a land based heat wave in Siberia near the Laptev Sea with 25C temps over land. The GFS weather map indicates a plume of heat into the Laptev with color coded gradations representing heat in degrees C. Immediately adjacent to the coast is a semicircle which extends 100 km into the Arctic at a temperature of 3C. A bigger area extends beyond to 300 km from the coast at a temp of 2C and a 1C plume extends out to 800 km from the coast.

How do you interpret that?

I see that the sun has warmed the earth and that the warm air from the earth is traveling out over the coast and dissipating as it gets farther away from the coast. Do you see the same thing?

[binntho]

Rather than argue, I'll ask a few question.

Let's construct an example. There is a land based heat wave in Siberia near the Laptev Sea with 25C temps over land. The GFS weather map indicates a plume of heat into the Laptev with color coded gradations representing heat in degrees C. Immediately adjacent to the coast is a semicircle which extends 100 km into the Arctic at a temperature of 3C. A bigger area extends beyond to 300 km from the coast at a temp of 2C and a 1C plume extends out to 800 km from the coast.

How do you interpret that?

I see that the sun has warmed the earth and that the warm air from the earth is traveling out over the coast and dissipating as it gets farther away from the coast. Do you see the same thing?

So you give me an imaginary anectdote and want me to say something other than the obvious? Of course there is warm air advection from Siberia to the Arctic at times, and sometimes quite significant, although of course, this is only air moving about, with very low heat capacity, and the reason it gets so hot is that it's not really moving very much in the first place. Because, you see, the sun doesn't shine any harder on continents than other ents.

Heat transfer from the continents is real but is very unlikely to rank higher than at best third place after direct insolation on the ice in first place, and ocean heat absorbtion and transfer (and increasingly, wave action) in strong second place when accounting for ice melt during summer. My own guess would be that third place is taken by low-pressure areas bringing kinetic energy from the southern oceans, stirring up heat from below and bashing the floes together.

The oceans have much higher heat capacity, are much more easy to move around than the continents, and have much lower albedo. So the oceans are the clear winners by far when it comes to collect, store and transfer the heat energy from the sun from anywhere to anywhere when compared to warm air over contintents.

And of course, the flip side of the continental hot summers are the very long and very cold continental winters. Were the Arctic not sheltered in the cold embrace of those massive continents, it would grow much more slowly in winter and disappear easily every summer.

[Phoenix]

So you give me an imaginary anectdote and want me to say something other than the obvious? Of course there is warm air advection from Siberia to the Arctic at times, and sometimes quite significant, although of course, this is only air moving about, with very low heat capacity, and the reason it gets so hot is that it's not really moving very much in the first place. Because, you see, the sun doesn't shine any harder on continents than other ents.

Heat transfer from the continents is real but is very unlikely to rank higher than at best third place after direct insolation on the ice in first place, and ocean heat absorbtion and transfer (and increasingly, wave action) in strong second place when accounting for ice melt during summer. My own guess would be that third place is taken by low-pressure areas bringing kinetic energy from the southern oceans, stirring up heat from below and bashing the floes together.

The oceans have much higher heat capacity, are much more easy to move around than the continents, and have much lower albedo. So the oceans are the clear winners by far when it comes to collect, store and transfer the heat energy from the sun from anywhere to anywhere when compared to warm air over contintents.

And of course, the flip side of the continental hot summers are the very long and very cold continental winters. Were the Arctic not sheltered in the cold embrace of those massive continents, it would grow much more slowly in winter and disappear easily every summer.

OK. I'm glad that we can at least reach a point where we can agree on the minimum, which is the existence of WAA.

Let's stick with land for now so the conversation doesn't get too unwieldy.

Next question. Why does ice adjacent to Siberia begin melting earlier than ice in the CAA which is at the same latitude? Insolation s/b the same +/- some cloud anomaly. Water temp s/b < 0 before the ice begins melting.

I see proximity to heat from land as the trigger to begin melting, preconditioning, etc. Perhaps you see it differently?

Also, many people make reference on the melting thread to snow levels in NA and Siberia. To me, I interpret this as important as it is impacting continental albedo which influences WAA from land. Do you think continental snow level is important? If not for its potential influence on WAA, what is the relevance to the sea ice discussion?

[oren]

Next question. Why does ice adjacent to Siberia begin melting earlier than ice in the CAA which is at the same latitude? Insolation s/b the same +/- some cloud anomaly. Water temp s/b < 0 before the ice begins melting. 

I see proximity to heat from land as the trigger to begin melting, preconditioning, etc. Perhaps you see it differently? 

I wish you would attempt to quantify your hypotheses.
Does the CAA start melting later than the ESS? I think not, judging by the AMSR2 area graph.
Why does the Beaufort start melting much earlier than the ESS? Same latitude, same proximity to landmasses, and deeper bathymetry.
The answer to all these questions is prevailing currents and ice movement.
Note if the CAA ice was not landfast, it would have been flushed south and melted much earlier every year. So the CAA is a really bad example.

[SimonF92]

Next question. Why does ice adjacent to Siberia begin melting earlier than ice in the CAA which is at the same latitude? Insolation s/b the same +/- some cloud anomaly. Water temp s/b < 0 before the ice begins melting.

I see proximity to heat from land as the trigger to begin melting, preconditioning, etc. Perhaps you see it differently?

I wish you would attempt to quantify your hypotheses.
Does the CAA start melting later than the ESS? I think not, judging by the AMSR2 area graph.
Why does the Beaufort start melting much earlier than the ESS? Same latitude, same proximity to landmasses, and deeper bathymetry.
The answer to all these questions is prevailing currents and ice movement.
Note if the CAA ice was not landfast, it would have been flushed south and melted much earlier every year. So the CAA is a really bad example.

I agree, if you can it would be great to see some kind of data. Most of the time a hypothesis has underlying pilot data. Something other researchers can use to make their own judgements.

I know we all have busy lives outside of ASIF, so please dont interpret this as pushy!

[Phoenix]

I wish you would attempt to quantify your hypotheses.
Does the CAA start melting later than the ESS? I think not, judging by the AMSR2 area graph.
Why does the Beaufort start melting much earlier than the ESS? Same latitude, same proximity to landmasses, and deeper bathymetry.
The answer to all these questions is prevailing currents and ice movement.
Note if the CAA ice was not landfast, it would have been flushed south and melted much earlier every year. So the CAA is a really bad example.

It is interesting to consider how one would attempt to quantify such a hypothesis. Let's consider....

One would probably have to begin with a database which conforms to the NSIDC or Jaxa pixel level dataset.

For each pixel, one would have to add some data fields which provide information regarding ocean depth, distance from land and any desired additional attributes which provide more refined understanding. Then for each year one wanted to go back and evaluate, one would have to populate  each pixel with a value which represents the presence or absence of sea ice at the minimum.

If that attribute data is not already present, it involves a lot of research. 

If someone wanted to go back 10 years, then they would have to populate 10 years x the # of pixels in the dataset. Ten years is not a statistically significant sample size and going back 10 years is a pretty different environment with CO2 levels 20-25ppm lower than today. We are in an environment where data from older years is rapidly losing relevance as a barometer for what will happen going forward as we constantly reinvent the atmosphere.

What I did was look at the year which most resembles the current environment and formulated a simple hypothesis which fit just last year's observed minimum. I'm not representing any predictive value at this point because the hypothesis was made after the fact to fit the outcome.

It doesn't make sense to invest a ton of effort into attempting to quantify the hypothesis at this point when there is the possibility of easily disproving it with another season of observation. Especially when the range of observations can be augmented by a bunch of other observers, many of whom which would like to see it disproven.

Another season of observation with many eyes and opinions will yield a better hypothesis than anything I came up with on my own. If it still has merit, someone else may have better aptitude than I in the number crunching aspect. It's not written in stone that the person providing the initial observation also be the PI.

If I were pressed to come up with some quantification, I would start with the following variables...

1) a distance from NA or Siberia expressed in km or degrees latitude
2) distance from the border between the Nansen Basin / Atlantic shelf
3) ocean depth

The unusual nature of CAA is of course taken into consideration. That's why the acronym is DACHSOO and not DACHSO. SOO stands for shallow OPEN ocean. CAA is shallow, but not open and therefore distant from shallow open ocean.

The reasons Beaufort might start melting before ESS is not essential to the hypothesis. I'm attempting to explain the factors which best differentiate between those areas which retain ice at the minimum. Both of these areas are pretty much guaranteed to melt out before the minimum. Again, I'm not pretending to be offer the unified holy grail of all melting processes. I'm simply offering some thoughts which represent an alternative possibility to the linear hypothesis that some offer when projecting BOE.

The linear hypothesis is similar to mine in some respect. It's based on looking backward and fitting the projection to the prior outcome. The linear hypothesis has no intuitive resonance for me. i see an annual process which resembles the siege of a castle. The ice outside the basin is analagous to the farm land, the basin is the outer castle walls and the last remaining ice is the fortified keep. The tactics and artillery necessary to penetrate the keep might be different than those employed earlier.

I'm interested in investigating the difference and quality of the defense mechanisms which the as yet unconquered Arctic has to offer. The linear hypothesis doesn't require anyone to consider the quality of the defenses of the remaining Arctic. It assumes the incremental difficulty is proportional to the increase in strength of AGW. It assumed that Djokovic would pass Nadal and Federer within 2-3 months of becoming the world #3, not the 3 years it actually took.

Let's be patient. I've just introduced an idea. Let's watch a melt season unfold with this idea in mind and see where it leads. It may die a natural death within a few months.

[oren]

Thanks, well explained.
The pixel-level analysis you described is something I have wanted to do a long time ago and still want to, however I currently lack the skills and especially time to do so. I know the data is available and that it is a feasible calculation, if I have a couple of free months I know I can do it including acquiring the programming skills. Won't ever happen probably.
For each pixel, what is the probability of being ice-covered or ice-free (or % ice concentration), for each given date, looking at statistics from the last 10 years (since 2010 when the Arctic sea ice statistics seem to have stabilized a bit). Best displayed as a color-coded map of probability, animated over the days of the year.
Even better would be to compare this animated map with one containing the data of previous decades (2000-2009, 1990-1999).
A map for AMSR2 data (since 2012 or 2013), and for NSIDC data (full data available), as these have different pixels and vastly different resolutions.
Missing data would have to be interpolated from preceding and following days.
By the time I get down to actually doing it, the Arctic will probably be post-BOE...

I have made do with aggregated regional data, especially the finer AMSR2 data from Wipneus, but also the NSIDC area data. This gives some crude conclusions and insights but is mostly unsuitable to the huge and diversified CAB, in fact to any region that is made up of different ice behaviors or geographies.
Let's wait and see what this season will bring. If I have further contributions to add, I will post them here or in the "when ice free" thread.

[Phoenix]

Maybe you can advertise for a willing student who wants to do some research and get some programming experience.

Help the next Zach Labe get started.

[Phoenix]

i'll editorialize a bit today to try and give some sense of the rationale behind the revelance of the hypothesis.

I'm naturally drawn to observe systems of all kinds and try to understand the processes which govern them in order to understand where the world is heading. One of the principles which is common to all systems is entropy. All systems come apart in the end.

There is an abundance of history to draw upon which provides parallel examples to help us understand humanity's present situation. For example, we can look at the US situation as a declining empire and draw understanding empire and see parallels to the entropy of previous empires. We can look at the unsustainable disease of wealth concentration and understand the parallels in events like the Great Depressions, rise of Nazi fascism, French Revolution, etc.

AGW and associated ecological collapse provides a somewhat unique feature to human experience in the potential to trigger global collapse of human civilization. That's not a novel concept at ASIF. Intellectually, that's a view that the majority of people here probably share. The pattern of civilization collapse itself is not new, there are plenty of regional examples. One of the things that makes the current situation unique is that it involves a global resource threat.

Understanding that humans have been around for ~ 10,000+ generations, there is a certain surreal element to grasping the possibility that we might not get many more. In the abstract, its not that shocking. All systems end and some people will inevitably be there at the end. Why not us? But there is a conflict with the instinctual human condition to fight for our survival and protect the people we love.

Each of us has our wiring system which determines how we act and react to the situation. There is no right or wrong way. Each of us follows our nature.

My nature instructs me to choose hope that we can somehow adapt and salvage something. Some others might characterize that as hopium in the face of such inertia. I can't fault the full doomers for taking their path. It may be too late to avoid disaster. Alternatively, salvage may still be a technical possibility, but it is unrealistic to expect that the inertia of human systems involving billions of people will evolve on a timely basis. Again, I can't fault that skepticism. It's rational.

I believe the odds aren't great, but I hold out hope that the survival instinct will prevail and there will be some kind of viral awakening that results in a transformation of political priorities.

My understanding of the consequences of a BOE are incongruent with the concept of salvage. The incremental entropy associated introduced into the system as a result of something close to BOE is not something fun to contemplate. The belief that BOE is inevitable and coming in the near term is anti-hope for the future and diminishes the rationale to work for the political transformation which could potentially promote salvage.

I have a pro-salvage agenda. In the absence of certainty, I'm going to compete and promote the outlook that salvage is possible. I'm not proud of that...it's simply where my programming leads me. I've tried surrender and it just doesn't work for me. The durable Arctic hypothesis is a manifestation of that competition and an attempt to persuade people that there is hope.

There is obvious and natural tension that manifests in this competition. On the melting thread, Friv is the avatar for doom. He is also funny and entertaining and very knowledgable about the sea ice and contributes good forecast content and insights. If something adverse for the ice is on the horizon, its a good bet that Friv will be on top of it before most people and amplifying the threat. He reminds me of the Woody Harrelson character in the movie 2012 who is determined to bear witness to the Yellowstone Caldera eruption in person. He's rooting for it and wants to see it even if it means the end of the world. And if it's inevitable, why not enjoy the show ??

My contributions to this forum should be understood as those of someone who wants to promote the belief that doom is not inevitable in the coming decades.  I have a psychic vested interest in the outcome. I'm biased.

[Phoenix]

A lot of signals of increasing climate volatility right now.

Anomalous input with covid-19 aerosol reduction. We just experienced the strongest tropical cyclone in Bay of Bengal history. Multiple May named storms in the Atlantic. Possibly the all time most active May melt season in the Arctic. CO2 levels hitting daily peak levels later in the calendar. ENSO 3.4 index shifting extremely quickly from positive to negative.

So much volatility makes interpretation more challenging with so many variables up in the air.

The later rise in CO2 has the antennae on alert. Definitely want to see that go down soon. Hoping the negative ENSO diminishes the atmospheric heat available to the Arctic.

Increasing volatility is not a surprise to anyone paying attention, but there is a different in the intellectual expectation of an event and the actual experience when the outcomes begin to manifest. It's scary.

[Phoenix]

https://www.windy.com/-Show---add-more-layers/overlays?temp,2020-06-07-00,76.660,157.148,3,m:fMCajzE

Here's a nice clean example of warm air advection into the Laptev in the euro forecast.

Easy to see the that the source of warmth is the daytime heat from Siberia and the low over the Siberian islands is providing the wind to propel the heat into the Arctic. Clicking on the various sections of the Laptev, it is easy to see the dissipation of heat as you get farther away from the coast. Close to the coast, you see 4-5C temperatures which you will probably never see in the CAB.

This paradigm plays out so frequently that one has to try hard not to see it. The relationship between heat distribution and proximity to land with land based advection is clear.

The counter argument is that just because the WAA demonstrated here is visible and common, that doesn't mean it is greater in magnitude than the things we can't see. Insolation and currents beneath the ice are not shown on the this imagine.

But  let's be clear, those locations close to the coast are also getting more insolation than in the CAB as they are at lower latitude and have longer intervals of open water. They are also more like to get warm current as they are shallower (less space for stratification) and coriolis force tends to push incoming ocean current along the coast line.

The linear hypothesis proponents have work to do to demonstrate how heat can be expected to ROUTINELY reach into the ice fortress into the DHACSOO regions to justify an expectation of near term BOE.

Freak weather like long term dipoles, massive export scenarios, GAC's and delayed Mackenzie River discharges are not predictable in advance and I don't see any math anywhere which justifies the chronic forces of AGW ramping up enough in ten years to do the trick. The freak weather hunch may come true, but there doesn't seem to be a serious effort to quantify the likelihood.

[oren]

Quantifying: in the last 10 years there were two August GACs - 2012 and 2016. Both years are also lowest in NSIDC area, similar to each other and far ahead of other years.
Thus, chance of GAC is ~20%/year. Not freak. To break the area record it is probable another GAC will be needed. Ergo, chance of new area record is 10%-20% per year. Or 15%-25%, depending on your assumptions about other factors.
Note: 2012 has a huge lead in min extent, thanks to freak Sep compaction. But area is IMHO more representative of energy in the system.

[Phoenix]

Quantifying: in the last 10 years there were two August GACs - 2012 and 2016. Both years are also lowest in NSIDC area, similar to each other and far ahead of other years.
Thus, chance of GAC is ~20%/year. Not freak. To break the area record it is probable another GAC will be needed. Ergo, chance of new area record is 10%-20% per year. Or 15%-25%, depending on your assumptions about other factors.
Note: 2012 has a huge lead in min extent, thanks to freak Sep compaction. But area is IMHO more representative of energy in the system.

i'm cool with area as a better measure at the minimum when the melt pond noise is gone. I also like it better now for momentum because i know to take the melt pond issue into consideration.

If record chance is 10-20% per year, that gives us 1-2 expected records between now and 2030. Those need to be great big leap(s) forward in order to get BOE.

Reading analysis recently that GAC was much less impactful than the Mackenzie discharge and points to the whole flukiness of the outcomes. That 2012 discharge had a huge impact because it was delayed by late land ice breakup. That water sat at lower latitude in the shallows accumulating extra heat. If melt years had a personality, 2012 was the mad scientist coming up with novel approaches to get heat to the CAB surface. It should be government policy to proactively break that fast ice to make sure that doesn't happen again.

I think your assumption that comparable cyclones will appear from time to time is fair. But the evidence that they will have the requisite impact to push toward BOE is a reach at this point.

One thing BOE proponents have is the unknown. We keep seeing new things that we couldn't  / didn't predict before they happened. Covid based aerosol reduction? Who saw that coming? I think it's more likely to get BOE from some feedback mechanism taking off that we couldn't predict than a linear extrapolation of AGW forcing.

It's all interesting. Appreciate your engaging and giving me an opportunity to voice my perspective here.

[The Walrus]

A lot of signals of increasing climate volatility right now.

Anomalous input with covid-19 aerosol reduction. We just experienced the strongest tropical cyclone in Bay of Bengal history. Multiple May named storms in the Atlantic. Possibly the all time most active May melt season in the Arctic. CO2 levels hitting daily peak levels later in the calendar. ENSO 3.4 index shifting extremely quickly from positive to negative.

So much volatility makes interpretation more challenging with so many variables up in the air.

The later rise in CO2 has the antennae on alert. Definitely want to see that go down soon. Hoping the negative ENSO diminishes the atmospheric heat available to the Arctic.

Increasing volatility is not a surprise to anyone paying attention, but there is a different in the intellectual expectation of an event and the actual experience when the outcomes begin to manifest. It's scary.

Please refrain from making exaggerated statements.  Amphan was the strongest cyclone in the Bay of Bengal SINCE 1999!  Five other years experienced multiple May storms in the Atlantic.  Possibly the most active.  Possibly not.  Volatility is a difficult measure.

[Phoenix]

A lot of signals of increasing climate volatility right now.

Anomalous input with covid-19 aerosol reduction. We just experienced the strongest tropical cyclone in Bay of Bengal history. Multiple May named storms in the Atlantic. Possibly the all time most active May melt season in the Arctic. CO2 levels hitting daily peak levels later in the calendar. ENSO 3.4 index shifting extremely quickly from positive to negative.

So much volatility makes interpretation more challenging with so many variables up in the air.

The later rise in CO2 has the antennae on alert. Definitely want to see that go down soon. Hoping the negative ENSO diminishes the atmospheric heat available to the Arctic.

Increasing volatility is not a surprise to anyone paying attention, but there is a different in the intellectual expectation of an event and the actual experience when the outcomes begin to manifest. It's scary.

Please refrain from making exaggerated statements.  Amphan was the strongest cyclone in the Bay of Bengal SINCE 1999!  Five other years experienced multiple May storms in the Atlantic.  Possibly the most active.  Possibly not.  Volatility is a difficult measure.

walrus, please don't accuse someone of making exaggerated statements w/o first fact checking.

Amphan had record sustained winds of 165 MPH (145 kts), beating the old record of 160 MPH shared by the 1999 storm and one other. I follow the big storms with the weather nerds elsewhere.

https://earthobservatory.nasa.gov/images/146749/amphan-batters-india-bangladesh

https://en.wikipedia.org/wiki/1999_Odisha_cyclone

I indicated the two named storms in May as being "rare", not unprecedented. That it has happened 4 other times in 120+ years of record keeping is in my opinion, rare. You are free to disagree if you like.

I'm sorry that the truth doesn't suit your liking.  I don't invent the truth, just try to lead people in that direction and understand that the truth is often unwelcome. The truth of climate breakdown is hard to digest. Even for me as I have explained above. I wish it were otherwise.

i truly value the ASIF forum as one of the rare places where we can speak freely with intelligent people about these unpleasant truths.

[Phoenix]

Just for reference, Post # 1229 in the melting season thread provides some math involved in the calculation of potential daily land based WAA. Thanks to Aluminum for the contribution.

The figure is 50 km3 / day. I acknowledge that I'm not in a position today to evaluate this. Something to come back to.

Let's point out that WAA isn't inhibited by albedo and is active during the entire melt season. Insolation makes a relatively minor impact in the period preceding melt ponding and gets a lot of help from WAA in the process that initiates melt ponding.

[igs]

Interesting not to say annoying how each time when I and hopefully others have a great read after someone invested time and energy to write instersting stuff like i.e. the creator of this thread frequently does, that immidiately someone has to nitpick/cherrypick anything irrelevant, often prone to opinion and/or definition of terms, to spoil the party.


So I have high respect for those who post reapeatedly such informative stuff who do not get discouraged by the "oppositon adicts".


I for my part gave up long ago and just enjoy reading most of the time, need my energy for my loved ones


 

[Phoenix]

Thank you igs for the supportive comment. It's nice to know someone is getting value from these posts. A buddhist teacher once told me we add as much suffering to the world by taking offense as by giving it so i try not to let it bother me. Criticism is welcome when we pursue science.

Let's pivot back to the content of the thread for benefit of those interested. If the 50 km3 of daily WAA melting potential that Aluminum suggests is in the ballpark, then 50*180 day melting season is 9,000 km3 pool of season potential. If we immediately give this a 50% haircut to put it in a more conservative frame, 4,500 km3 is still a very significant fraction of basin melt which is in the range of 15-20k km3 total in a given year.

Observing the process repetitively reveals that the heat plume from land WAA dissipates as it moves away from the land so the potential causative relationship between the distance from land emerges as a clearer possibility to consider.

I'm not expert enough to vouch for the accuracy of Aluminum's calculation, but this represents an opportunity for those so inclined to participate and satisfy themselves.

Now that the basics of the relationship between land and ice minima have been presented, I'll move over to the bathymetry argument which is a little harder for the layperson like myself to observe.

[Phoenix]

Now that we've made the case for land based WAA and distance from land, we can await more critiques and move to the proposed connection to bathymetry. The SOO element of DHACSOO.

Observation

Let's begin with the observation of 2019. If we look at a bathymetry map of the Arctic and a map of the 2019 minimum, we easily see the correlation.  The dividing line where the ice begins and ends is very highly correlated to the dividing line between the respective perimeter shelves (Kara, Barents, Laptev and ESS) and the deep inner basins.

This is not a potential correlation that first dawned on me only after the 2019 season. During the course of the 2019 season I noted a connection between an advanced projection of melt in the Chukchi and a shallow depth feature called the Chukchi Plateau (CP).

The Chukchi Plateau exists in the 75N - 79N range of the Chukchi Sea on the side of the Chukchi adjacent to the Beaufort Sea. The ocean floor in the same latitude under the Chukchi which is adjacent to the ESS is much deeper.

If we look at the outcome in the Chukchi in 2019 as represented by Aluminum's image in post #6470 from last year....

https://forum.arctic-sea-ice.net/index.php?topic=2591.6450

....we can see the correlation between the outcome of the ice melt and the location of the shallow ridge. The melt advances noticably further toward the central basin directly over the ridge and less so over the deep section adjacent to the ESS.

So, we either have funky coincidence or connection. I very strongly suspect causation here but I'm in no hurry to prove it. We repeat the experiment again every year and we can watch it again together in a few months unless 2020 is a dog in the Pacific and doesn't get that far.

Corroboration

One thing we know about the Arctic is that stratification matters. We know that there is plenty of heat beneath the Arctic surface to melt the surface, but in our transportation paradigm, there is a road block preventing the heat from getting to the surface.

Stratification is based upon a density hierarchy. The highest density water is at the ocean floor and the lowest density water is at the surface. In general, hot water is less dense than cold water and fresh water is less dense than salty water. So what happens when we compare cold fresh water to warm salty water?

It turns out that the salt contributes a more influential component to density than temperature in this instance and the warm salty water settles in below the cold fresh water layer and is blocked from melting the ice.

( One of the reasons that 2012 was such a successful melt season was the Mackenzie River discharge which supplied an influx of water which was both warm and fresh. This influx would have been even less dense than the common surface layer and wrought havoc on the surface ice. )

It stands to reason that traffic management with the various layers becomes more challenging when the amount of space is reduced. if there are x # of stratified layers, then the warmth must be compressed closer to the surface and more likely to reach the surface in a shallow water environment. The difference between 100 feet and a steep drop off to  several thousand can reasonably be inferred to make a difference in the size and depth range of the various layers.

This is of course not proof. It is simply demonstrating that there is a cogent argument here and a reasonable cause to investigate the connection.

In an ideal world, we would have lots of weather buoys set up at the boundary between the shallow and deep water which provide information about what is going on at the interface. Perhaps a skilled investigator such as Uniquorn can better piece this puzzle together.

In the meantime the rest of us....

What to look for....

According to DACHSOO, it will be more difficult for melt to proceed from the shallow regions to the deeper regions.

1) We can already see open water in the shallow CAB regions on the Atlantic side between 80-82 around Svalbard, FJL and SZ. If DACHSOO is accurate, then this front is not going to make rapid progress across the boundary. The same holds for the boundary in the Laptev and ESS.

2) Keep in mind that this is proposed as a secondary factor in melt outcome. The proximity to large land mass is also important and takes precedence so we expect deep sections which are close to the coast such as the Beaufort to melt out.

3) Watch the Chukchi Plateau region if 2020 gets there.

Suggestions

There is a proposed disconnect between the way data is organized by the measuring agencies and the interests of the user community.

The measuring agencies organize the information according to surface geographical features and I would posit that the users are more interested in insight that informs them as to the prospects for the ice.

In a perfect world, I would extend the barriers of the Kara and Laptev out to the edge of their respective shelves so that they incorporate the easy to melt section of the CAB which is already showing open sea. That's dream land. Those agencies aren't going to orbit around us.

As a compromise and given the fixed constraints of the agency data, I might gently suggest that the data thread consider a different way of looking at the Arctic. Instead of having a High Arctic grouping which categorizes based on surface geography, create categories according to end of season expectation. This might avoid the current situation where 2020 is leading in area losses and giving rise to an expectation of a fantastic low minima when it is performing mediocre to date in some key regions and super strong in some regions which we know are less relevant to the outcome.

Since over 90% of the season ending ice is expected to be in the CAB, CAA and Beaufort, it would be a simple tweak to create a category for the sum of these three seas instead of the current High Arctic grouping.

Alternatively, I could attempt to report this information. But I don't want to be "that guy" who is raining on the parade of all the people rooting for a record low.

[Jim Hunt]

Also, read the Slow Transition thread from start to finish, very relevant.

You took the words right out of my mouth Oren!

[oren]

Two comments off the cuff:
* In the Chukchi and in the Svalbard-JFL line, we have not just a shallow shelf but also an incoming oceanic current which is warm and salty. These current are prevented from sinking below the cold fresh water, thus enhancing ice melt. Ignoring the effect of prevailing currents in general, and these two currents in particular, can lead one to the conclusion that shallowness is a factor in itself.
Other shallow regions do not have these currents and do not have the tendency of enhanced ice melt. Specifically, the ESS is the shallowest Arctic sea and also the most difficult to melt. OTOH, the deep Beaufort is continually fed by thick ice from the CAB during the melting season, as can be seen in the long-term animations upthread and in animations from various melt seasons. Thus its resilience is partially a mirage of ice import.
* I know you do not consider quantification an essential tenet of the hypothesis. However, once a quantification has been served by others I think it shouldn't be ignored.
"Since over 90% of the season ending ice is expected to be in the CAB, CAA and Beaufort, it would be a simple tweak to create a category for the sum of these three seas instead of the current High Arctic grouping."
I have posted data in the Melting Season thread showing that on average more ice survives in the ESS than in the Beaufort. Besides, 90% of the Beaufort and ESS ice is expected not to survive a given melt season. And what about the Greenland Sea? Thus I think your proposed "survivable ice" measure would not be quite helpful.

[Phoenix]

Two comments off the cuff:
* In the Chukchi and in the Svalbard-JFL line, we have not just a shallow shelf but also an incoming oceanic current which is warm and salty. These current are prevented from sinking below the cold fresh water, thus enhancing ice melt. Ignoring the effect of prevailing currents in general, and these two currents in particular, can lead one to the conclusion that shallowness is a factor in itself.
Other shallow regions do not have these currents and do not have the tendency of enhanced ice melt. Specifically, the ESS is the shallowest Arctic sea and also the most difficult to melt. OTOH, the deep Beaufort is continually fed by thick ice from the CAB during the melting season, as can be seen in the long-term animations upthread and in animations from various melt seasons. Thus its resilience is partially a mirage of ice import.

Your point is well taken Oren. As I have indicated previously, I am not representing anything close to a unified explanation of all the factors influencing melt. I am also not representing this hypothesis as an endpoint in the pursuit of explaining the factors which influence the annual minimum. Just a start.

I certainly appreciate that factors below the surface are working in conjunction with depth to influence the outcome. The level of complexity associated with these subsurface factors is potentially infinite and the data is not necessarily available or easily understandable to a layperson, which is my intended audience.

Your point that there the combination of current and shallow water influences the minimum offers the potential for a more refined hypothesis which you are of course free to do. I don't regard that as contradicting what I have offered as you don't seem to be refuting that depth is an important element of the outcome.

Your point that other regions have shallow water which are not subject to "enhanced ice melt" (due to lack of currents) is potentially outside the scope of my intended investigation. I am trying to address an understanding of only the regions which have yet to become ice free (as represented by 2019 minumum). If you can identify which area you are thinking of, perhaps I can better respond.

* I know you do not consider quantification an essential tenet of the hypothesis. However, once a quantification has been served by others I think it shouldn't be ignored.

I don't feel like I am 'ignoring' quantification. I think I'm being straightforward in acknowledging that i don't have the quantification that you or others might prefer. Acknowledging the shortage of quantification is a nice way to allow others to step in and try to fill the gaps as Aluminum did on an unsolicited basis. I took care to acknowledge my own lack of qualification in validating the data he provided.

I don't propose that ultimately arriving at a mathematical proof of concept is necessary for this inquiry to be useful. In the absence of data which is either not easily available, unreasonably burdensome to assimilate or too complex for the layperson, I am trying to appeal to the deductive reasoning of the layperson and arrive at a simple argument which makes sense.

At some point in the process, the discussion becomes like a situation where a friend is asking to borrow some money. If you don't have any, then no matter how much you want to help them, you can't. I don't think I have what you are looking for in terms of quantification. Perhaps I am misunderstanding what you mean by quantification and there is something I can provide. if you can provide a straw man as a suggestion of something you think is realistic, then maybe there is something possible. It's not exactly clear to me what you are looking for.

I have posted data in the Melting Season thread showing that on average more ice survives in the ESS than in the Beaufort. Besides, 90% of the Beaufort and ESS ice is expected not to survive a given melt season. And what about the Greenland Sea? Thus I think your proposed "survivable ice" measure would not be quite helpful.

Let's separate my suggestion into two elements. The first element is the suggestion that we should strive for proactive measures which give a better sense of what the season portends. The second element is the specific suggestion that the measure be (CAB + CAA + Beaufort).

As far as the second suggestion, I would consider it to simply be a straw man. If the best minds think ESS or Greenland Sea s/b included, I think that's a step in the right direction and would be very pleased with that 5 sea indicator of intra season progress relative to the end game.

As far as the first element, what are your thoughts there ? Do you think this is a direction to pursue? How do you feel about the 5 sea comparison which I infer that you might like better? You are the moderator here, I'm happy to defer to your judgement.

[Phoenix]

I think we are at a point where we can attempt to triangulate the arguments a bit.

As pointed out previously, there are multiple ways to get energy to the ice.

1) There is direct short-wave IR (insolation) directly to the ice.

2) There is a indirect long wave IR absorbed by land or water and then subsequently transferred to the ice via atmosphere or water.

3) There is mechanical transport aided by wind which moves ice to the locations where heat is present. (this is a technically a subset of #2 above)

There is clear consensus that the march toward BOE is proposed to be a result of advancing AGW and i think that it's pretty clear that AGW is not influencing the amount of sunlight entering the earth atmosphere.

AGW is increasing the long wave IR stored in the primary heat sinks on earth which are the ocean and atmosphere.

I am putting forth the hypothesis that the land to air (WAA) to ice is a materially important transport mechanism.  I don't have the math at this point and consider challenges to that hypothesis legitimate.

What I want to point out is that the only other real alternative that we are left with is that all of the significant incremental heating is going to come from the water to ice transport route or from atmospheric anomalies that allow more sunlight to the surface.

If incoming sunlight is fixed and the land to ice route were hypothetically insignificant, then all of the material increases in future melt must come from the water to ice pathway (with atmosphere as a potential intermediate). We can't rule this out, but we should be clear that there is no math case that I am aware of for this either.

As we observe the robust onset of the 2020 season, we see a relative strength is in early reduction of albedo. Let's evaluate the pathways which are responsible.

We can immediate rule out the direct water to ice pathway as a material source of the early season start of albedo loss in places like the CAB. Rain can be a factor but none was observed. That leaves us with increased sunlight as a result of low cloud cover or WAA as the trigger of the surface snow melt.

Next step is to look at the evidence gathered in the melting season thread for connection between WAA and melt pond formation. Will melt ponds form in sub freezing temperatures or do they require the presence of WAA to commence? I don't seem to be coming up with any examples of melt pond formation in sub freezing weather, but maybe I'm missing something.

In the absence of math equations, I'm trying to employ deductive reasoning and process of elimination. The alternative hypotheses don't have a proponent who is being held up to any burden of making an argument to substantiate that case.

I am presenting logic w/o proof. The linear case presents neither.

[Phoenix]

Also, read the Slow Transition thread from start to finish, very relevant.

You took the words right out of my mouth Oren!

I have perused the Slow Transition thread. It doesn't seem like a discussion that is designed for the lay person.

[Phoenix]

The 5 seas most likely to retain ice at the minimum, 2019 v. 2020

2020 is more advanced in area loss in the CAB (47k) and ESS (22k)

2019 is more advanced in the Beaufort (201k) CAA (30k) and Greenland Sea (3k)

Net difference is 165k, 2019 is more advanced.

[Phoenix]

We may have a bit of a breakthrough in the trail of evidence.

In the new thread titled Arctic energy balance...

https://forum.arctic-sea-ice.net/index.php/topic,3106.msg266345/topicseen.html#msg266345

In post # 11, Aluminum has submitted what I posit to be a previously unconsidered (by me) and valuable source of information.....a chart showing daily PIOMAS volume losses.

Aluminum shared the chart to bolster his math regarding the potential contributions of WAA to the ice melt. The chart depicts the extremely robust ice losses of mid June 2019 which can IMO easily be correlated to land based WAA documented in the 2019 melting thread here...

https://forum.arctic-sea-ice.net/index.php/topic,2591.1650.html

This is an example of a potentially valuable route to quantify the contribution of land based WAA.

If we look at the daily data from PIOMAS we can potentially see the signal from WAA by investigating the root cause of the daily fluctuations. Looking at the pixel data can be used to quantify the relationship between distance from land and resultant impact of WAA events....we could theoretically measure dissipation.

By comparing the volume losses during cold intervals with minimal or no WAA, we can aim to separate the signal of WAA induced melt from insolation or water induced melt.

In the chart that Aluminum presents, volume loss increases by 200 km3 per day (peak to trough) over a two day period in response to the onset of the WAA.

In summary, taking the PIOMAS data and quantifying attribution of melt to the various transport mechanisms / weather events seems to be a good investigative route to take. The 3D should be infinitely more informative than the 2D.

Edit: It is important note the importance of WAA as both a melting mechanism and as a facilitator of direct insolation based melt. WAA is an important trigger of the early season albedo reduction which enhance the efficiency of insolation.

[oren]

Let's separate my suggestion into two elements. The first element is the suggestion that we should strive for proactive measures which give a better sense of what the season portends. The second element is the specific suggestion that the measure be (CAB + CAA + Beaufort).

As far as the second suggestion, I would consider it to simply be a straw man. If the best minds think ESS or Greenland Sea s/b included, I think that's a step in the right direction and would be very pleased with that 5 sea indicator of intra season progress relative to the end game.

As far as the first element, what are your thoughts there ? Do you think this is a direction to pursue? How do you feel about the 5 sea comparison which I infer that you might like better? You are the moderator here, I'm happy to defer to your judgement.

We have discussed it on the forum in the past. My position was and still is that as far as area data goes, the most relevant data is an aggregation of all the seas connected to the Inner Basin with import-export ties, plus the CAA because of its peculiar geography and ice retention. This is because the ice in these seas can move to the CAB, or be received from the CAB, thus making them one interconnected system. The same applies to energy and enthalpy in these regions. Seas that should be excluded are seas that mostly see export from the Inner Basin due to prevailing currents and winds and due to high local melt: Baffin, Barents and Greenland Sea. These seas may retain ice at minimum but that ice is not the ice that is there now, rather it's ice that will be exported to them in August or September.
Funnily enough, this is exactly the index tracked by the relentless Gerontocrat in his area updates and other updates: the High Arctic + CAA. Not because I am a moderator (irrelevant) or because that is my position, but because this has been discussed in the past and it makes sense. And because it's Gerontocrat's position of course. I track this index too in my regional PIOMAS updates, when I get around to making them. Wipneus has an Inner Basin chart that excludes the CAA. Each person that publishes statistics regularly can choose his or her own index to track, feel free to do the same. But if the stats are considered irrelevant by most of the forum, such contributions should be short and to the point and not cause too much noise and clutter. 2-3 lines of daily text and data are welcome, loads of text and repetitive analysis every day will be frowned upon. This happened in the past with some users.
Things change in August: the CAB starts crashing, and the single most important index by then is the CAB itself. But changes in the CAB will be a result of 2D developments that took place in the surrounding seas, and 3D processes in the CAB itself, all unseen in the CAB 2D data. Until August, all you see in the CAB area and extent data is noise (and the local variability of the sector near Svalbard-FJL, which should have been excluded from the CAB).
Note the best 2D index IMHO would be a pixel-level aggregation of ice concentration multiplied by the difficulty of clearing ice from that location, as measured by the statistics from the past 10 years. Thus a year that melts ice near the North Pole (such as 2016) gets more points than a year with early advances in the southern Kara. But this index is currently unavailable.

[oren]

On another note, you seem intent on proving that WAAs are very important to the Arctic, and that they do matter. I am not sure why you think this needs proving, it's quite obvious. The question raised by this thread is whether locations that do not often receive WAAs (away from continental landmasses) are highly likely to retain ice at minimum over the next decade, thus enticing a slow transition. To prove this, even just logically with no supporting quantification, requires more than just proving that WAAs are important.

Also, read the Slow Transition thread from start to finish, very relevant.

You took the words right out of my mouth Oren!

I have perused the Slow Transition thread. It doesn't seem like a discussion that is designed for the lay person.

And regarding that thread - many posters on this forum began their residence as lay persons, myself included. To most intents and purposes I am still a lay person, but I make it my business to learn anything I can, enhancing my own understanding and hopefully enabling some more personal contribution. Despite great difficulties in my first year on the forum, and lots of things being total gibberish to me, I recall trying to follow the discussion and even to post some useful(?) questions in that thread at the time. Make it your business to understand the detailed and difficult stuff, and your contribution to the forum will grow accordingly. Skip the hard stuff, and your contribution will be limited to lots of words with no supporting evidence.
Be aware, anyone can calculate simple formulas learned on the forum, and most anyone can use Excel or OpenOffice to make some statistics. It doesn't take a PhD, it's not difficult, but one must decide they want to invest the time and make the contribution.

[Phoenix]

All of your points are well taken Oren.

My vision are of which seas serve best as a leading indicator of the minimum presupposes that the boundary from shallow Arctic into deep Arctic is a difficult boundary for chronic melting forces to penetrate. I acknowledge that I may be jumping the gun in that regard. Not trying to budget for the potential import / export exchange which would seem hard to predict.

I am trying to demonstrate that WAA is important because several others have questioned its importance. In the process of exploring that, I've learned a bit from users like Aluminum. 

Proof that the as yet unconquered areas will not melt out in the near term is not a reasonable objective. We will never rule out the unknown and weather variability.

My goal is to present a logical case to contrast with the logic of the linear assumption. I don't want to prove the CAB will last, just want to indicate that the argument for it lasting is as good or better as the argument for it's quick disappearance based upon the chronic progression of AGW.

I'm presenting the halocline and limits of WAA as logical barriers to the center of the Arctic. I do believe that AGW will eventually overcome them, but I don't see the logical case for it happening quickly.

I would like this hypothesis to be judged against the standard of the linear assumption, which at this point I'm seeing as more of a default assumption than a logical argument.

At this point in time, I'm a minimalist. I don't own a computer, just a small device that allows me to access the internet. I'm evaluating my footprint in terms of necessity and the cost / benefit to the world of my buying another computer every few years doesn't make sense to me right now.  I'm content to contribute what I can and don't imagine myself an island. I can contribute ideas and observations as part of a larger effort that others will augment with their resources.

I'm doing my best to respect the norms of the melting season thread and trying to be circumspect in my posts there. I'm using this thread as more or less a notebook of ideas and observations related to the ability to assess the future of the sea ice. I highly value the privilege to participate here at ASIF.

[binntho]

I am trying to demonstrate that WAA is important because several others have questioned its importance. In the process of exploring that, I've learned a bit from users like Aluminum. 

If you are unable to point out any flaws in my post Arctic energy balance then you will have to give up this WAA hypothesis.

According to my calculations, the amount of heat that can possibly be advected via WAA is so miniscule that it cannot be used to explain anything. This is mostly because of the vast imbalance between the specific heat of air and the latent heat of ice - any amount of warm air that can be advected from Siberia can only melt a miniscule amount of ice.

Unless my math is totally wrong. So please try and work it out for your self. Or accept that your hypothesis is dead in the water.

[oren]

In short, WAA can melt snow, reducing its albedo and letting in the real monster, sunlight. So you cannot completely discount it no matter what calculations show regarding total energy transferred.

[Phoenix]

https://journals.ametsoc.org/doi/10.1175/JCLI-D-11-00113.1

 Large Decadal Decline of the Arctic Multiyear Ice Cover
Josefino C. Comiso (2012)

5. Connections with surface temperature, sea level pressure, and winds
a. Surface temperature

...
Scatterplots of sea ice area versus surface temperature for each of the five sectors (not shown) show negative linear patterns indicating strong correlation between the two variables. The results of regression analyses show that the data in the Bering Sea Sector actually have the highest correlation, with a correlation coefficient of −0.796, while those of the Kara/Barents, Greenland, and Okhotsk Seas following closely at −0.784, −0.754, and −0.732, respectively. The high correlation between the two variables is a manifestation of the strong connection of surface temperature with that of the sea ice cover.

[Phoenix]

https://www.smh.com.au/world/europe/europe-s-heat-wave-is-about-to-melt-the-arctic-20190727-p52bam.html

(articler regarding summer 2019 heat wave)

Zack Labe, a climate researcher at the University of California at Irvine who focuses on Arctic climate change, said the upcoming Arctic heatwave could have major ramifications and may push sea ice to another record low at the end of the melt season.

"This appears to be a very significant event for the Arctic," he said of the upcoming weather pattern.

"A massive upper-level ridge will position itself across the North Atlantic and eventually Greenland in the next few days. This negative North Atlantic Oscillation-like pattern will be associated with well above average temperatures in Greenland. In fact, simulations from the MARv3.9 model suggest this may be the largest surface melt event of the summer," Labe said, referring to a computer model projection of surface ice melt in Greenland.

(fwiw -congrats to zach labe on earning his PhD last week)

[Phoenix]

Last one of these....

https://forum.arctic-sea-ice.net/index.php?topic=2533.1500

Post # 1503 from Friv on last years data thread..

Told ya all.

Never underestimate or ignore surface temperatures.

They are the end all be all.

2019 might not finish the lowest but it will be close.

[be cause]

indeed .. when all the ice is gone you will be able to swim ..

 but WAAt is that I see at the end of the gfs run ? .. 2m temps above 0'C spreading across the 'ice' .. and 4'C+ .. and 8'C+ all in the ESS and Laptev ..

  ..https://modeles.meteociel.fr/modeles/gfs/runs/2020053012/gfsnh-9-384.png?12 

same forecast last year .. .. perhaps this is a recovery year ?

https://modeles.meteociel.fr/modeles/gfs/archives/2019053012/gfsnh-9-384.png?12
 
Not sure that gfs takes into account future melt at time of forecast so it could be warm enough to jump in in 2 weeks

the 850hpa temps are outrageous throughout the forecast run :

  https://modeles.meteociel.fr/modeles/gfs/runs/2020053012/gfsnh-15-6.png?12

..https://modeles.meteociel.fr/modeles/gfs/runs/2020053012/gfsnh-15-192.png?12

https://modeles.meteociel.fr/modeles/gfs/runs/2020053012/gfsnh-15-384.png?12

  b.c.

 p.s. ..as you can see I choose not to force you to see the forecasts unless you really really want to .

[Phoenix]

What's your opinion about how it ends bc? Do you think the future march to the pole will just be a smooth continuation of what we saw from 1979-2012 or does AGW have a tougher adversary to crack in the remaining ice?

Does it mean anything that the ice / water boundary at the Sept 2019 minimum is lined up parallel to the line that separates the shallow Atlantic CAB from the deep CAB or did the weather gods just put it there to make me curious?

[binntho]

In short, WAA can melt snow, reducing its albedo and letting in the real monster, sunlight. So you cannot completely discount it no matter what calculations show regarding total energy transferred.

Absolutely. As can many other things. The fallacy inherent in this WAA discussion is that continental mainland is somehow more effecient at transferring heat to the Arctic than the open ocean.

Nobody is disputing that continental heat waves can transfer heat to the Arctic, my contention is that this is an effect that is mostly negligible except for the short window of time where Siberian or Alaskan WAA kan cause rapid near-shore melt.

And my calculations seem to show that it is propably not the heat transferred by the  WAA that is the main cause of near-shore melt (the effect is truly small), but most likely the clear skies that follow those situations where WAA is stronges, allowing for much more insolation, and yes, helping that insolation along by wetting the surface.

Once the near-shore ice is gone, the vast heat transfer ability and energy distrubing potential of open ocean kicks in. Clear skies over the EES, Laptev and Chukchi are probably much more important here than any occasional WAA.

The Arctic happens to be near surrounded by continental land masses. Any warm air advection from the south is going to cause melt. But the net effects of the continents is to retard melt and increase ice formation, while the net effect of open ocean is to accelerate melt and decrease ice formation.

Just consider snow cover on the mainland - open ocean has no snow cover. So warmth from the south has to battle accross the accumulated snow on the mainland before it can begin to have any effect on the Arctic. This is obviously not the case where the ice is bordered by open ocean all year round!

[binntho]

Phoenix, I tend to consider the method of argumentation that is based on just publishing links and extracts from research papers found on the internet as not very effective, basically just the nerdy version of arguing with youtube clips. The papers (and youtube clips) may contain oceans of truth and unfathomable depths of wisdom, but if you can't say yourself what you think they are saying, then I won't bother trying to find that out for you.