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Kevin O'Neill

I think we're looking at timeframes a bit longer than we might intuitively expect.

The long-term trend in volume loss is 0.05 kkm^3/year. As Rob points out in the other thread, this loss incorporates all of the albedo effects to date. It also incorporates any changes in ocean warming, atmospheric warming and all other forcing or feedback changes.

Assume that we lose all ice by September 1st, what are the actual consequences? Other than a lot of publicity it really won't change anything. At essentially the very moment the ice disappears it will start refreezing. The year-to-year change won't be much different than we've seen over the past decade. We'll still see thousands of cubic kms of ice formed every winter, but, on average, a little less each year. And again, on average, every year it will disappear a little sooner.

If we look at the change mathematically, we are likely to see essentially all the ice melt out when max volume is around 19 kkm^3. Assume the arctic sea area is 12.5 Mkm^2, then an equivalent ocean surface layer would be 1.5 m deep and we would have the potential to raise it's temperature by 80°C if none of it were there at the beginning of the melt season.

This is a staggering amount, but it isn't quite as bad as it seems because that's not what would actually happen. Because of thermal diffusion the energy wouldn't be limited to the top 1.5m and it wouldn't all necessarily stay in the arctic. If we diffuse that over the top 200m we quickly drop the actual increase in ocean temperature down to a 0.6 degree. Unfortunately, that would be an accumulative increase each year.

Remember, these numbers were predicated on no ice at the beginning of the melt season just to show what the theoretical *potential* heating equivalent of melting all that ice would be - this is not something that's likely to happen, but it shows how dramatic the changes would be with a year-round ice-free arctic ocean.

Given this energy budget, a year round ice-free arctic ocean would seem to be a giant step towards a runaway greenhouse effect. Fortunately there seems little reason to suspect that ice will stop forming in winter :)

Kevin O'Neill

In the above:"If we diffuse that over the top 200m we quickly drop the actual increase in ocean temperature down to a 0.6 degree. "

Should read: If we diffuse that over the top 200m we quickly drop the actual increase in *ARCTIC* ocean temperature down to a 0.6 degree.

Bill Fothergill

@ Rob "... Thanks Bill. Incidentally, it is not really a coincidence that the albedo difference between ice and open ocean matches the ice melt numbers I mentioned ..."

Sorry, my train of thought often grinds exceedingly slow. Of course your numbers would match the amplification factor. mea culpa

What might be of interest to those participating in this debate is the addendum to NOAA's 2016 Arctic Report Card...
http://www.arctic.noaa.gov/Report-Card/Report-Card-2016/ArtMID/5022/ArticleID/326/2016-Addendum

Of particular relevance are these two paragraphs...
"Anomalously warm SSTs in September 2016 compared to the 1982-2010 September mean (Fig. A3c) were largely confined to regions that were ice-covered in the long-term mean, relative to ice-free regions in September 2016. In these regions near the marginal ice zone (i.e. near the edge of the sea ice cover), values were up to +2° C warmer in September 2016 compared to the September 1982-2010 mean. In addition to these regions, SSTs in the Barents Sea were up to +2° C warmer in September 2016 compared to the September 1982-2010 mean, and also warmer in Baffin Bay, and off the east coast of Greenland (Fig. A3c).

A similar pattern persists for October 2016 SST anomalies compared to the 1982-2010 October mean (Fig. A3d) with anomalously warm temperatures generally just to the south of the October 2016 ice edge; regions that were ice covered in the October 1982-2010 mean. In addition to these regions, SSTs in the Barents and Kara seas were up to +1° C warmer in October 2016 compared to the October 1982-2010 mean (Fig. A3d)"

wayne

Hi Rob,

Wikipedia's graph I cited is the NASA graph, taken from not cited link, if you do a weighted horizontal transect 66.3 to 90 North, there is no way the average is close to 100 w/m2, with photoshop grid, which I don't have or another software, the greatest area by far if 500 w/m2,
which makes 300 w/m2 more likely. I did a transect for 5 months and that was a mistake. The other graph you cited seems at odds with this other.

zebra

Kevin O'Neill,

You seem to be leaving out evaporation?

Kevin O'Neill

zebra, "You seem to be leaving out evaporation?"

I'm leaving out a lot more than that :)

These are just back of the envelope numbers. And like albedo there is evaporation taking place now - so the percent it affects the final result is already (partially) included even though not dealt with specifically.

We know feedbacks will change and obviously if there is a significant change in the net of all feedbacks, then these results cannot account for them. But to account for every feedback diligently would require a GCM that handles at least handles the arctic very accurately.

Perhaps Wieslav Maslowski's regional arctic model could do that, but we know how perilous it has been to trust GCMs on matters related to the arctic.

zebra

Kevin,

I just meant the actual energy going into the phase change, not any effect of the water vapor as a GHG or possible contribution to albedo through cloud formation.

In the simple model, this would be an additional brake on the temperature gain. When there's ice on the surface, evaporation would be much less of an issue.

Kevin O'Neill

zebra - I always by habit default to Energy Involved in the Phase Changes of Water to jog my memory for the energy conversions. It doesn't speak of evaporation in this context.

Geert Diederen

Hi guys, sorry I hadn't looked for an answer on my question since the 3rd of februari, and I see it brought many interesting answers...

Thank you for that!!! I appreciate everyones input very much!!

First of all I'm pretty new on these subjects, actually got interested and followed arctic forums since december 2015, when I suddenly realized something really odd was going on in the arctic...

Allright, to the point now..., what I am wondering is what the effect on seatemperature and airtemperature in the arctic (also above land, e.g. Greenland) will be when lets say in a few years in september all seaice is gone, and for instance a year later in August all ice is gone, and again a year later in July etc...

As my idea is that more and more heat will warm the arctic ocean but also the nearby land (such as Greenland)... but I'm wondering in what speed this will happen (how many degrees C will the arctic ocean and the land heat up each year, from the year that we start having an icefree summer, having each following year a longer icefree summer, e.g. Every following year a month longer icefree summer... which could happen because of the extra heat build up in the arctic Ocean every year...

Just the above I'm interested in when we further leave all other effects out, and suppose that all other changing effects (such as changings of wind directions or maybe faster water flowing out of the arctic, or extra vapour etc...)... stay the same (which they won't)... but to keep it simple...

Behind my question, if that could be adequately answered somehow, my second question is: given these supposedly increasing temperatures, what extra effect will this have on the accelleration of the melting of Greenland ice... and of course in the speeding up of sealevel rise...

In case you didn't know, I am living in the Netherlands at about 20 feet below sealevel... so, sealevel rise (everyone says oh that is just a few mm each year, but I think that could quickly speed up to some cm's each year in maybe a decade from now..., and where is the end of it...) is becoming an important issue very soon...

Rob Dekker

wayne said

Wikipedia's graph I cited is the NASA graph, taken from not cited link, if you do a weighted horizontal transect 66.3 to 90 North, there is no way the average is close to 100 w/m2, with photoshop grid, which I don't have or another software, the greatest area by far if 500 w/m2, which makes 300 w/m2 more likely.

There really is no contradiction here, wayne.
The NASA graph you quoted shows TOA insolation. To obtain annual average you need to indeed take a transect and integrate it over the year. For North Pole that integration actually becomes easy. Earth tilt is 24 deg, so PEAK insolation is 1362*sin(24)= 554 W/m^2.
The annual average (integral) becomes 1/pi * PEAK = 176 W/m^2 which matches with the TOA insolation at the NP in the figure I showed.

AT THE SURFACE this become 80-100 W/m^2.

Rob Dekker

Geert, regarding influence of Arctic sea ice on the Greenland ice sheet, there are many, many unknowns. I am not aware of any specific scientific papers addressing a link, but maybe somebody else does.

Even regarding sea ice retreat and how quickly that will progress (even after the first ice free Arctic summer occurred) is still hard to predict. I recommend you read Kevin O'Neil's post above ( February 07, 2017 at 08:25) since it presents a realistic picture.

Other than that, on sea level rise, let's hope for the best and prepare for the worst.

wayne

Thanks Rob

We are getting there

Would it be flawed to consider the average Arctic equinox sun elevation from latitude 66 to 90 which is Sin 0 to 24 degrees step n=1 being = .207 of which * 1360 w/m2 = 281 w/m2 TOA (is a confirmation of the graph rough evaluation with poor imaging software) . If you think of it, the equinox is the average insolation day for the entire season. Considering the dark long night as part of the daily average calculation is confusing.

OK
Also albedo

This includes both clouds, sea ice with or without snow, from experience sea ice cover is roughly 80% with snow: having 90% albedo, and 20% without: 50% albedo

With Clouds 40% coverage goes like this:

summer 0.8 before ice contact which seems to be a better number

http://www.earthobservatory.nasa.gov/Features/ArcticReflector/arctic_reflector4.php

, remains .2 split 80-20 gives total albedo 0.91, fascinating since even with much fewer clouds the albedo would be close to 0.9.

Rays hitting sea ice at 100/m2 gives potential melt 39,381 km3 which is roughly amplification factor of 2

269 w/m2 gives about 3 times more ice melt potential , so I concede 100 w/m2 seems the better number. Is an explanation TOA reduction to surface atmospheric absorption?

At any rate this is quite a revelatory piece of maths. It definitely shows a great melt potential. And also other factors at play , namely top of sea temperatures.

wayne

Rob,

The graph you cite is a bit not conform to the Arctic long day and night, the sum total of 100 watts average a day throughout a 365 year is what counts, therefore during the long day, 6 months long
the surface input is in fact about 200 watts/m2 per second,

182.5 X 200 = 365 X 100

Top of atmosphere reduction by atmospheric absorption accounts for the difference close to my equinox calculation.


zebra

Kevin O'Neil,

Wait, wait-- you are confusing me with Elisee Reclus, who suggested boiling oceans!

http://www.engineeringtoolbox.com/evaporation-water-surface-d_690.html

I admit to being too lazy to dig up numbers myself to plug in but in the simple model, the air will be pretty dry at the beginning of the ice-free period at least.

On further consideration, I would have to think water vapor should not be excluded, since it will also affect the freezing season.

Elisee Reclus

I suggest you suspend your contempt for M. Recluse until AFTER the first ice-free winter.

zebra

ER,

Come on, there's no contempt at all in that-- if you can't take some good-natured joking you would have a very hard time with actual insults.

You and I mostly agree on being cautious about extreme predictions. I'm just doing what I do, which is trying to build up a sound first-approximation framework from first principles.

Elisee Reclus

Thank you for taking the time, Zebra, and making the effort. And I'm reassured that you feel the same way I do about cautious predictions.

I recognize now my boiling equator scenario was not very well thought out, but I see its origin, a reaction to unalloyed doom and gloom from some of our other contributors, is not out of place at all. In fact, it is the only way to approach this problem politically, which is what really matters now.

If I fail to participate in the cocktail napkin math, it is only because I believe the future will be the result of second and third order effects we cannot even foresee. After all, how successful have our first order calculations been at explaining the changes we have documented since the early 1980s? If we can't explain the past, we should be wary of predicting the future.

No one can predict the future, but we do have the evidence of billions of years of history on this planet that runaway climate catastrophes are damped by natural feedback mechanisms. It is not the end of the world, nor is it the extinction of all life on the planet. It may be the end of modern civilization as we know it, though, so if we really wish to influence our society into doing something about it we should be cautious in our remarks. Our enemies toil endlessly to ridicule and discredit us.

This is what prompted my very first post here, that even though our looming climate situation is grave and very threatening, exaggerating its potential effects is not only over-dramatic, it is counter-productive in the political arena. Until our understanding of the world climate engine improves, our best strategy as scientists is to communicate to the public the statistical trends which are starting to become abundantly clear. Those monthly NSIDC SIE graphs are much more dramatic and persuasive than any algebra we can crank out here.

It is most likely the climate crisis will not manifest itself initially as massive coastal flooding, raging methane fires in the tundra, or an ice age in Northern Europe. It will probably start as a gradual collapse in agricultural production caused by deterioration in the weather system. This will lead to famine, vast refugee movements, civil strife, conflict and war.

What is forseeable, even likely, is bad enough. There is no need to cry wolf or act the Cassandra. I may feel differently if I see an ice-free Arctic winter in my lifetime
(I am 69) but until I do, I counsel restraint, and be gentle with those who do.

Bill Fothergill

@ Kevin

I agree with much of what you said in your post yesterday (at the top of page 2), but there was one bit I would take you task over. You stated that ...

"... The long-term trend in volume loss is 0.05 kkm^3/year... "

However, I think that this is an understatement. If one looks at the PIOMAS trend chart from Washington University, the trend is about 3,000 km^3 per decade [+/- 1,000 km^3 per decade]
http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/


I don't know if this is just a typo, or if you have used a different source, with a different trend. There is a factor of ~ x6 between these values.

Elisee Reclus

While you guys have your slide rules out...

Since the beginning of the industrial revolution, average global temperature has gone up on the order of 1 or 2 degrees (Kelvin).

This is less than a percent, on the Absolute scale,and yet just since the early 1980s, summer Arctic sea ice extent has dropped by about 40%. There seems little doubt that the two are causally related, but how do we account for such a substantial effect being driven by such a minor cause?

True, the proportional increase in atmospheric CO2 concentrations is on the order of the physical changes we see in the Arctic, but the global temperature itself has changed relatively little. It seems that if we could understand this mechanism in detail we would be in a much better position to predict its future behavior.

I grasp the concept that the polar regions are very sensitive to changes in planetary weather, and that they serve as a barometer on the health of the climate (canary in a coal mine, etc), but it also seems to me that if the poles serve to help regulate planetary weather, then their extreme sensitivity even to minor changes in average temperature would imply that as a purely regulatory mechanism they are not very effective. A flywheel that flies apart at the slightest increase in RPM is not a very effective long-term smoothing influence on a motor. Rather than being subject to forces that keep it stable, the global climate should be oscillating erratically on very short time scales.

We subconsciously seem to be operating on the notion that the icecaps serve as a regulatory mechanism that smooths out minor
variations in planetary temperature, helping to maintain the entire system relatively stable. The conventional wisdom is that any change in the system sets in motion counter-pressures that tend to bring the system back into stability and equilibrium. But what we actually measure is that a minor temperature change over a short period of time causes an immediate and drastic variation in the physical characteristics and morphology of the icecap. The intuitive notion and the observed behavior contradict each other.

Am I missing something? Yeah, I know it has a name, Arctic Amplification, but does that really mean we understand it?

zebra

Elisee Reclus,

You are indeed missing something, and I now see why you may have misunderstood some earlier comments of mine.

You have cause and effect reversed.

Global mean surface temperature is the result of local surface temperatures, not the other way around.

This is what I was talking about with respect to complex, non-linear systems.

Energy in the system is not evenly distributed to begin with, so you have to think of the magnitude of the total added energy compared to the magnitudes of energy in sub-systems like the Arctic, and with respect to the coupling mechanisms that already exist to transfer energy among those systems (e.g storms and currents).

That's what's going to break first. The question, which we hit upon just above, is whether individual parts and couplings breaking will lead to a catastrophic cascade, or whether the system as a whole will sputter along.

james cobban

Elisee said:

...if the poles serve to help regulate planetary weather, then their extreme sensitivity even to minor changes in average temperature would imply that as a purely regulatory mechanism they are not very effective. A flywheel that flies apart at the slightest increase in RPM is not a very effective long-term smoothing influence on a motor. Rather than being subject to forces that keep it stable, the global climate should be oscillating erratically on very short time scales.

And it is, on very short geological timescales.

I recall reading in one of James Lovelock's books on the Gaia hypothesis that the planetary system entered a period of chaotic instability two million years ago, when the ice ages began. He discussed this in terms of a complex system entering a chaotic state (or leaving a stable attractor), and says that the ice ages represent the wild oscillations of a complex system seeking a new attractor that will continue indefinitely unless and until the system settles around a new attractor. The ice ages and interglacial periods are symptoms of this chaotic behaviour, and in no way can be interpreted as regulators promoting a stable state; they are the very definition of an unstable state. He thinks that it is unlikely that a new stable state will be reached, because the sun itself has aged and changed enough over the Earth's history to usher in the beginnings of an old age for the Earth system itself. He thinks this will last for a billion years or so, while the sun gradually expands, and that this period will be characterized by continued chaotic instability, which will find the Earth becoming increasingly less resilient to shocks than it was during the previous five mass extinctions. If correct, this bodes ill for a robust or rapid (on the order of two million years)recovery after the sixth mass extinction plays out.

Elisee:
We subconsciously seem to be operating on the notion that the icecaps serve as a regulatory mechanism that smooths out minor
variations in planetary temperature, helping to maintain the entire system relatively stable.

On Lovelock's theory, then, the icecaps, far from being a regulatory mechanism, are a symptom of a complex system already behaving chaotically and unstably.

Elisee Reclus

Thank you, gentlemen. There's a lot to consider there.

Pursuing this line of questioning further, what sort of instability is the global system exhibiting?

There are several possibilities:

1) Minor random excursions and returns to a mean.
2) One or more, possibly several, oscillations, possibly with harmonics.
3) A continuous departure from stability, perhaps superimposed on random variations as in 1).
4) An asymptotic approach to some "attractor" representing stability
5)A runaway, exponential or logarithmic curve curve, leading to eventual collapse (Mars or Venus)?
6) Perhaps other modes, singly or in combination. Some which converge to a solution, and others which don't...

No, I really didn't expect an answer, I don't think anyone knows, or could know, at our current state of ignorance. Also the stability mode could look very different at different temporal resolutions.

The only reason I being this up is because the nature of the instability is going to have a profound effect on how the system reacts to a sudden outside stress (like a spike in greenhouse gases in the atmosphere).

Tor Bejnar

I rather thought that Arctic ice was doing a fantastic job at moderating a couple hundred years of greenhouse gas emissions, by "slowly" melting more than what freezes back each year. But even a fantastic great flywheel will slow down with 200 years of neglect. We may very well be at the brink of the flywheel's bearings seizing up.

Bill Fothergill

@ Elisee "While you guys have your slide rules out...

Since the beginning of the industrial revolution, average global temperature has gone up on the order of 1 or 2 degrees (Kelvin).

This is less than a percent, on the Absolute scale,and yet just since the early 1980s, summer Arctic sea ice extent has dropped by about 40%."

I don't know what possible relevance you see in that comparison. The freezing point of fresh water is 273.15 Kelvin, and below that, it would have been pretty tough for multi-cellular life to have developed.

A far more meaningful comparison is to consider that the temperature range (global) from the Last Glacial Maximum to pre-industrial was only in the order of 5 Kelvin.

See here...
http://www.cesm.ucar.edu/publications/jclim04/Papers/PWG1.pdf

or here...
https://www.gfdl.noaa.gov/bibliography/related_files/bush9901.pdf

Elisee Reclus

@ Bill

So the surface of the earth has been able to support microbial life for billions of years, and Metazoa for half a billion years, with its average temperature varying only a handful of degrees. That's really remarkable.

That certainly sounds like some pretty effective self-moderation has been going on for a length of time of roughly the same order of magnitude as the age of the Universe itself.

That seems to me to be highly relevant.

Rob Dekker

Elisee, that "pretty effective self-moderation" is called Stefan–Boltzmann law.
https://en.wikipedia.org/wiki/Black-body_radiation
Which keeps the temperature of a planet in check, and vary only minor with changes in GHG forcing.
And then there are feedbacks.
But I guess you already knew all that.

Rob Dekker

@ Kevin
In an otherwise excellent post, there is another oddity :

If we diffuse that over the top 200m we quickly drop the actual increase in ocean temperature down to a 0.6 degree.

Based on insolation, the Arctic receives some 3 GJ per melting season.
If that is all put to warming the ocean, we are looking at 37 C increase down to a depth of 20 meters (the mixed layer).
If diffused down to 200 m, that is still 3.7 C over the season, not the 0.6 C you assert.

Rob Dekker

Sorry, that is 3 GJ/m^2.

Elisee Reclus

@ Rob

The Earth is not a black body radiator. Its thermodynamic behavior involves much more than simple radiative transfer and cannot be understood fully on the basis of Planck's Law, of which Stefan-Boltzmann is itself only an approximation. S-F only works precisely for idealized Planckian cavity radiators, of which none actually exist in nature. But I guess you already knew all that.

Earth is not just a "gray body", it is a highly complex, chaotic, non-linear convective fluid heat engine, a system which can be pretty robust and stable (as in the case of Earth) but which also has the potential to break down altogether (Mars and Venus).

It is unlikely we will ever be able to describe the mechanics of climate with any comprehensive theory based on simple assumptions and a priori appeals to physical law. At best, we may be able to make a few short-term predictions by using complex mathematical simulations, but even they will probably require continuous modification as new data comes in, i.e., algorithmic computer models.

All I'm trying to say is that the global climate, (at any temporal resolution) cannot be predicted with a few simple equations accessible to those who made it through high school algebra. Even the crudest approximation is going to involve solving systems of partial differential equations.

There is some value to the "cocktail napkin calculation". As I mentioned before, it allows us to critically examine extreme values, and establish constraints in our more complex models. They serve to suggest avenues of research, and as a reality check on our more detailed calculations. But they are not really going to tell us anything we don't already know.

zebra

Elisee Reclus,

I think you are chasing a strawman here, but you are being too equivocal to be sure what you are actually saying.

I don't think people are trying to model "the climate", whatever that is supposed to mean.

Again, "the climate" is made up of parts, and for the recent past (millenia), the global characteristic of energy balance (in-out) has stayed within relatively narrow bounds, as that retained energy moves through the system.

It is obviously the excursions of the local systems that will cause humans the most difficulty in the short term.

And, again again, the overall system energy balance (for which global mean surface temperature is a proxy) can hold ~constant while all hell is breaking loose locally.

That's why they call it an average.

So, if the people here want to play around with energy inputs and heat capacity and evaporation (get on that, guys), for the Arctic, it seems like a nice educational endeavor for those lurking.

This is actually how physics is supposed to be done; it's only a problem when you jump ahead to predictions outside the scope of the first approximation.

Elisee Reclus

@Zebra

Now, THAT makes sense.

I'm sorry if I've been a little too vague and overgeneralized here, but maybe its because I've detected a bit too much certainty, too much trees and not enough forest.

Basically, we're faced with a problem where we don't know all the parameters, much less all the solutions. What we do have are powerful interests and agendas and the solutions we must adopt soon are political and social, not technical.

Our most powerful tool is not what we can prove, or what we think might happen, or why we believe it will happen. The data trends alone should be convincing enough. What got me interested in AGW issues is those monthly Sea Ice Extent time series graphs published by NSIDC. There is no doubt something very nasty is going on.

As for doing the physics, "you don't need a weatherman to know which way the wind blows".

Rob Dekker

Elisee said

I'm sorry if I've been a little too vague and overgeneralized here, but maybe its because I've detected a bit too much certainty, too much trees and not enough forest.

Yes. You are very vague, and this latest remark is even more so.
Can you specify what exactly you have 'detected' with exactly which remarks here in this thread ?

Elisee said

Basically, we're faced with a problem where we don't know all the parameters, much less all the solutions.

I disagree. We know the parameters good enough to know what the problem is, and we already know the solutions too.

zebra

ER,

When you say "that makes sense", I still have no idea what you are talking about.

I'm going to do this one more time, and that's it.

Bill F made an excellent point about the glacial cycle, which quantifies what I just said.

What appear to be small changes in the energy input minus output of the system produce large changes in how energy is distributed within the system.

We know very well the parameters of this-- while we shouldn't make predictions, we can in fact make projections that describe potential outcomes.

We can describe the progression that will occur as we continue to increase energy "incrementally" (relative to the total, as manifested by your observation about degrees Kelvin).

-We will get what is described in the IPCC scenarios at least: The system is pretty much the same but there are more extremes.

-Then, parts of the system will really break. Three months of blue Arctic? I wouldn't try to predict it myself, but sure, it is a very reasonable projection. Six months? Yeah, why not? Will the Indian Ocean monsoon go outside 2 standard deviations? Can't predict it, but you can't exclude it. And so on.

-And then you move into the end-times, when the changes in the sub-systems begin to radically affect the global energy balance itself, through feedbacks and cascades.

You seem to acknowledge that we can know this, and then you turn around and say "well, but we don't know...".

This smacks of some kind of Nirvana Fallacy, or Unreasonable Expectation.

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