« A new Arctic feedback (?) | Main | PIOMAS March 2017 »

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

zebra

Glenn,

It is correct that more energy will be absorbed. However, open water will be subject to evaporation and radiative losses as well. It's all about "how much".

What happens in the transition to "winter" is the interesting question. If we observe a lower maximum, as we seem to be experiencing now, is it the result of that excess accumulated energy (the net, due to the increased insolation, minus losses), or to "weather" bringing in warm air and water vapor?

You really have these two different mechanisms, which may be coupled to some degree as in the J Francis hypothesis, that have to be characterized.

My point being that extent, area, and volume, data are not going to resolve the physics involved in those phenomena.

For example-- you might just get more snow on Greenland.

Glenn Doty

Zebra,

It's true that there would be more evaporation, and hence some transfer of of energy from the sea surface to the upper atmosphere... But there's no way the scales should balance.

At ~3 C, the vapor pressure of water is still only 752 Pa.. so it's not like there will be a massive boil-off of the ocean. I cannot but believe that the amplification impact of reducing albedo from 0.8 - ~0.1 would far overshadow the energy loss from evaporation (more than half of which would be returned).

The presence of higher water vapor content in the Arctic atmosphere would then add more greenhouse forcing, and could lead to net higher pressure for the region keeping the skies clear in the summer.

I also cannot imagine how the possibility of increased snowfall in Greenland could outpace the increased melt-rate caused by waters that would absorb additional energy in the multiple EWh scale.. The increased attack on the foundation of the Greenland Ice shelf would lead to calving of ice masses that tower hundreds or even thousands of feet above the ocean. What is a few additional feet of snowfall going to do to compete with that?

Obviously, we don't know all things, and I know far less than many. I understand the physics well and the basic feedback mechanisms involved in climate change at large... and I'm struggling to understand the cryosphere - which I imagine most of the contributors here know far more than I.

But I cannot see any feedback mechanism within the cryosphere that can outpace the amplification caused by albedo loss from the disappearance of the ice. The vast majority of feedback mechanisms that I see in that area would only serve to further amplify warming even still.

I've lurked for quite some time, and am only now starting to post to seek answers for what I don't understand... So I'll welcome any additional knowledge or perspective and I don't claim expertise.
But I cannot see how the items you listed will significantly slow the runaway spiral.

zebra

Glenn,

On the previous thread I was trying to make the point to ER that the following two things are compatible, and we should not confuse or conflate them, as the Denialists often do. (I think Bill is talking about similar points in the preceding comment.)

-We can be very confident about longer term projections.

-We can't be very confident about shorter-term predictions.

So, to narrow down the physics here you have to be more definitive. For example: Are you talking about three days below the "ice-free" threshold, or three weeks, or three months?

As I've said previously, I think having this kind of discussion is a great educational opportunity, (for myself as well of course), but you have to pin down the first approximations before you can move on to more refined predictions.

And, to repeat: Just area, extent, and volume data are not going to tell us much about Greenland glaciers melting and calving.

NeilT

There was a substantial increase in absorbtion in 1991 and 1992 which has some impact by flattening the trend line

Yep, Mt Pinatubo really skewed the figures. But we won't see that happening more than once every 50 years or so.

This week NOOA updated the CO2 Global figures.

2015 2.98
2016 3.36

2016 is provisional till mid next month when the December figures come in. However it's almost certainly going to be over 3ppm for 2016 even with the ending of El Nino and the roll on effects rather than the direct effects during it.

If you take NSIDC Chartic and remove everything but 2017 and 2007, you see a similarity. Looking forward, a 2007 style melt and export year with 2017 volume should be.... Interesting.

AbbottisGone

I found this as a resource for daylight hours: http://www.timebie.com/sun/janmayenno.php

(It had Jan Mayen and I thought that was pretty cool/I couldn't resist because I've heard of that thanks to this forum and blog and had to share!)

Is there a more appropriate resource for investigating daylight hours in the Arctic at any latitude one would care to choose?

Thanks!

Elisee Reclus

AbbottisGone wrote:

"Is there a more appropriate resource for investigating daylight hours in the Arctic at any latitude one would care to choose?"

The celestial navigation data page is an automated calculator which will give you solar elevation above the horizon at any lat/lon as a function of the date and Universal Time.

It is essentially an online Nautical Almanac.

http://aa.usno.navy.mil/data/docs/celnavtable.php

wayne

"-We can be very confident about longer term projections.

-We can't be very confident about shorter-term predictions."

Hi Zebra

That is the most overstated nonsense well out there, not doing the science of predictions, or more fundamentally the basic understanding of scientific process. which is observe, evaluate and predict, any good.

Are we suppose to believe that in climate science we are incapacitated in the short term domain from some strange nebulous reason? Not at all, we confuse weather chaos with climate very easily, but even the weather prediction domain has made huge strides in success within the last few years, by the predictions most GCM models are recently calculating spectacularly. Hurricane Sandy for instance.

With sea ice we confuse very easily extent with compaction, melting with scattering, but the end product has been extremely predictable, yearly daily average extent numbers always give a downward death spiral, easily understood by numbers, not always so by the "looks".

Unto this we have the "dumb dumbs" as I call them, mostly bright people, who choose to lobotomize introspection just to play dumb for the sake of their polluting beliefs. They mock reality like Trump grasps reality, they pounce AGW at every cold spell, they laugh at how hysterical "alarmists" are correctly portraying the sequence of events leading our planet in rather a sad state.

I do believe we can predict in the short term just as much as the long term, but the resources to do 15 days in advance are simply enormous, but as computer memory and processing speed grows, GCM's will surprise some folks even further.

The basic argument 'dumb dumbs' always fail to achieve, is what they call sea ice "recovery" , again and again their long term predictions, supposedly easier, of such events have always failed. Need we remind their claims does not apply to correct science work but to themselves and their adherence to faulty methods disrespecting the basic precepts well integrated in the models.

wayne

The greatest question about 2016 melt season was why it was so strong?

It was, as many have written, quite a cloudy summer. There is a very good AGU paper published 2015 which has confirmed many of sea ice horizon refraction observation. They found the intriguing fact that sea ice albedo changes with clouds redirecting thermal rays more vertically, this was actually observed regularly:

http://eh2r.blogspot.ca/2017/02/summer-greater-cloudiness-thermal-flux.html

Refraction observations, I dare say, are cheaper than the equipment they used, but I can confirm their work as they confirmed mine, fun! But the science conclusions also include thinner sea ice albedo, which was found to be between .17 and .21, remarkably low.

zebra

Yo, Wayne,

And I thought I was a master of understatement! :-)

I am perfectly happy to discuss shorter-term projection (not prediction) as long as we maintain some first-approximation rigor.

So, I asked Glenn the obvious question:

Is your proposed outcome (e.g. greater Greenland SLR contribution) based on being below the "ice free" threshold for

-three days
-three weeks
-three months

?

For me, that's where you start-- properly stating the question you are trying to answer. What often happens is that you see the answer right away and move on to a more interesting hypothesis.

So far, I don't know what the death spiral actually means in the shorter term. As I said previously, we have the (real scientific) debate (between actual scientists) about cause and effect:

Are Arctic conditions leading to more intrusion of Tropical systems, or are increasingly energetic Tropical systems overwhelming the protective vortex? (Or, of course, some combination.)

The timeline is important here. Also, the actual configuration of the "end state" that you are imagining. For example, Greenland surrounded by the last vestiges of sea ice is not the same as the last vestiges lurking in some other locale.


wayne

Zebra

"So far, I don't know what the death spiral actually means in the shorter term. As I said previously, we have the (real scientific) debate (between actual scientists) about cause and effect:"

In this case it literally means a spiral to which an end will eventually arrive. It is calculable as some have done estimates based on available extent numbers, a mathematical result from the actual thermal balance machinations produced by Earth itself is available to all to review.

"Are Arctic conditions leading to more intrusion of Tropical systems, or are increasingly energetic Tropical systems overwhelming the protective vortex? (Or, of course, some combination.)"

That is correct, the polar vortex, the entire vortex consists of vortices, usually 2, rarely up to 5 or 6 at times, When the 2 main vortices are huge it is because it is a very cold winter. If they are much smaller, in yesterdays case, there was barely one on the extreme Norther Ellesmere edge on the North American side, warm cyclones have an easier ride Northwards.

NeilT

Is your proposed outcome (e.g. greater Greenland SLR contribution) based on being below the "ice free" threshold for

-three days
-three weeks
-three months

From everything I've read, that is far too narrow a definition.

Greenland SLR is three things.

A consequence of the climatic change which is destroying the sea ice
A disruptor of Arctic sea ice melt due to sea desalination locally
A long term consequence of the loss of albedo due to the long term loss of sea ice.

Personally I think it's daft to try and allocate blue ocean at the pole, in terms of weeks, as to Greenland SLR. Greenland is _already_ massively impacted just by the ice loss to date and will only be impacted _more_ and more rapidly by increasing sea ice loss.

Greenland is also massive. So any impact will be delayed by that mass. The rapidity of ice loss will be felt years after the fist blue ocean event and then will mount up more and more rapidly thereafter.

One of the reasons climate scientists have been clamouring for people to listen now and act NOW. Because once you can prove the impact it is far, far, too late.

GrayWolfBG1

I'd have to agree that we have already entered the age of the 'blue Ocean climate Disruption' as it does not demand a technical ice free ocean but a long period of open water throughout the basin as we saw last year. If this years ice is so weakened as we believe then this year will also be plagued with open water throughout the season. I fear the paid deniers will play games with a technical 'ice free' definition whilst Rome burns?

AbbottisGone

Thank you so much Elisee.

GrayWolfBG1,
I don't think the deniers will be able to play simple definition games if 'The Blue Ocean Climate Disruption' eventuates.

To me the rates of change of important indicators will indicate the event itself and simple false dichotomies surrounding semantic arguments will find it hard to combat the assumed quantitative argument.

Jim Hunt

From the darkest depths of Soggy South West England comes the latest news concerning the Trump administration's "Alternative Facts" assault on NOAA:

"Climategate 2 - Episode 3 of David Rose's Epic Saga"

Let’s see if we can discover if Peter Stott has any recollection of being interviewed last week by the Mail on Sunday and/or The Mail’s leading fantasy fiction writer shall we?...

Do you suppose that David [Rose] & Judy [Curry] have another “whistleblower” embedded deep within the Hadley Centre?

wayne

Hi Jim,

It came to my attention that David Rose timing is simply off,

https://www.theweathernetwork.com/us/videos/gallery/record-warmth-for-presidents-day-long-weekend/sharevideo/5326923742001

When set hard to mislead, timing is key, 10 days ago NYC got a taste of the NWWO, the New World Weather Order, darn , fake skeptics should at least watch the weather Networks. They predicted this warming days ago.

I did write, in this New World of Weather

http://eh2r.blogspot.ca/2017/02/new-world-weather-order-nwwo-blankets.html

things change fast, ahead of when it indeed changed fast, happened exactly as expected. Unlike Rose who can't know anything about the future since he can't get a solid grasp of the past! Accusing the met office of a cover up is like denouncing Hitler to be a pacifist. Therefore a firm shaky denial of reality is based on wasting time on false flags operations at the met office cafeteria table next to the washroom door. The perspective of a fake skeptic is based on reinforcing to self that science has trouble with 1 week ahead predictions, can't be good for next month or 10 let alone 100 years. That is because as we learn, they can't get their facts strait, yes the strait of reality, a narrow passage of facts enforcing cognition to strive, evolve and make great things, like Leonardo's Mona Lisa, Einstein's greatest equations and brilliant sketches by most 5 year olds you can find at any Kindergarten.

But why does anyone must endure, the dizzying backwards cats endlessly chasing their own tails? Is it because it is funny?


wayne

Marcus Rex and Polarstern want to do Nansen with modern equipment:

https://www.theguardian.com/world/2017/feb/20/scientists-to-repeat-19th-century-fram-ships-crossing-of-polar-ice-cap

Brilliant! Fantastisch!

Except they will need to keep pace with the faster drift, otherwise a shorter journey ahead...

Jim Hunt

Wayne - David Rose was apparently able to predict the HadCRUT4 numbers for January 2017 before they were published by the Met Office. He possesses a most impressive "crystal ball", I'm sure you agree?

Regarding the future MOSAIC expedition, don't forget that Tara did something similar not so very long ago. DAMOCLES!

http://geography.exeter.ac.uk/opensource/cryosphere/documents/Trapped_in_the_ice_OER_2.pdf

Robert S

Wayne: Love it. Just one minor correction: those dizzying backwards cats are being endlessly chased by their own tales, not vice versa, and not tails. Somehow a very apposite image for the Trumpian worldview...

Elisee Reclus

Dear AbbottisGone

The Celestial Navigation calculator I mentioned at

http://aa.usno.navy.mil/data/docs/celnavtable.php

provides not only solar elevation and azimuth but corrections for refraction which can be pretty substantial. The extreme temps and pressures at high latitudes can further exaggerate refraction, this might alter estimates of insolation substantially.
Also don't forget to correct for dip (height above sea level) if you are working on the Greenland icecap.

The sun is often visible long before it has actually risen due to this refraction! Since the sun's path will be almost parallel to the horizon for long periods of time during the polar day, you might want to allow for these effects. They may turn out to be significant.

wayne

Genius correction Robert S! Love it.

"a most impressive "crystal ball", I'm sure you agree?"

Opaque Bowling ball Jim,

With out of control bad reporting spinning towards the dark ages of ignorance, in the right lane for a ' pin head' science correspondent job at FAUX news.

wayne

3...... Pathetic.... So far 3 important but short lived anticyclones this Arctic Ocean winter, the latest one a "bridge" of clear air formed between land based Northeast Siberia and NWT Canada, Forecasted to last , alas, less than one week.

zebra

For Wayne,

I don't know if someone has done this before, but this might be the next step after thinking about a yearly average.

http://woodfortrees.org/plot/nsidc-seaice-n/from:1980/every:12/trend/plot/nsidc-seaice-n/from:1980.5/every:12/trend

It is a rough approximation to be sure, but it adds some important information about the future of winter and summer.

It is the kind of analysis I am talking about-- not supercomputer modelling, but quantitative in a way that people might find accessible.

Glenn Doty

Zebra,

I've been away a few days, and the conversation has kind of wandered a little from where we left off.
:)

But I wanted to get back to it for a second.

When you said this:
"Are you talking about three days below the "ice-free" threshold, or three weeks, or three months?"

I am concerned that you might be "missing the forest for the trees".

I'm not talking about 3 days or 3 weeks. I'm talking about 3 seconds.

Right now, the continual additional heating from blue ocean amplification is going towards melting sea ice. So as weather has fluctuated year-by-year, we've seen an average of ~300 km3 of ice disappear from the arctic cap/year. That level of energy absorption works out to only ~28 PWh. That really doesn't SEEM like that much net increase for the arctic system... it's about 7 times the total electrical energy generated in America in a year.

But that number is so small (!!!) only because of the short time duration that significant amplification is experienced, since most of the area is restored every year during the winter. The actual power from potential amplification is insane. A blue ocean event would drop the area to below 1 million km2. This from the former average low of >4.5 million.

If you assume only ~200 W/m2 insolation during September (a shot in the dark on my part, I couldn't find it through a quick google search), then a single hour of blue ocean at 90 degrees N would result in over 4 PWh of energy injected into the waters of the arctic. As that cycles around, some portion of that energy - enough to melt ~43 km3 of ice - will be transferred to the underwater support of the glaciers of the Greenland Ice Sheet.

That's ONE HOUR. A single day of such amplification would result in (considerably) more melting of Greenland ice than is currently averaged all year.

Of course, 100% of it wouldn't be transferred to Greenland, much of it would just be retained in the form of far warmer water, which would more rapidly degrade ice thickness.

This tipping point is so massive that after literally years of trying to wrap my head around the scope of it I have continually failed. It's terrifying. It is a complete paradigm shift.

And it's possibly going to happen this year.

Glenn Doty

Bah!

I shouldn't type things out so quickly without checking numbers.

:)

A single hour would only result in additional amplification of ~1.5 PWh - assuming my shot-in-the-dark guess of ~200 W/m2 was about right.

Oh well. Rambling quickly is how I typically blog, which is why I tend to lurk instead.
;)

zebra

Glenn,

Glad to see you didn't fall through the ice!

But look..."rambling quickly"...

That was my point exactly. I would like to follow your reasoning, but so far I am pretty confused.

My concern in all this is education and communication, just in case there are a few people out there who have not taken sides and want to understand what's going on. To me, that means organizing the argument in a systematic way.

I can't really conclude anything from your numbers, (assuming you got them right finally :).) You seem to be confusing terms like amplification and insolation, and using different methods to do your calculations.

It's not my place to tell you how to work things out for yourself, but as you communicate it, it sounds like you are overreacting to the big numbers without thinking about the structural (physics) details of the system.

There is no forest without the trees, and it is a common problem in this climate business that people make the most elementary "fallacy of division"-- attributing characteristics of the whole to the parts.

Glenn Doty

zebra,

Attempting to mock me for mistyping a number into the calculator doesn't make your position any more firm nor make my position any less so.

I did not (and do not) mistake power and energy. There was no mistake between insolation and absorption. Please do not belittle a comment because of a typo in the calculator entry so that you can dismiss it without consideration. I will henceforth double-check my quick calculations before posting in this forum (which - to my chagrin - doesn't allow editing).

Your concern for the internal system flows causes me to remain concerned that you are indeed missing the system at large.

The "structure" of the system flows cannot change the fact that there are only three major pathways by which the heat can be removed from the arctic: radiation into space, "sunk" into the deeper ocean waters, and absorbed by the phase change of melting ice.

The rate at which this energy is radiated into space will not increase quickly without a subsequent increase in surface/atmosphere temperature.

Very soon after nightfall in the arctic the atmospheric temp drops sufficiently to sharply reduce evaporation losses to the atmosphere. A reasonably thin layer of ice would sharply reduce conductive losses to the atmosphere...

So the winter shouldn't see a massive increase in total radiation losses that would correlate to the added energy absorption from amplification throughout the summer.


The action of sinking water into the depths, from what I understand, is a result of brine rejection in the formation of the ice, the brine being heavy and carrying some of the heat from the surface layers down with it... But as the ice thins, this avenue seems likely to decrease, and the energy absorbed by the upper ~5-20 meters of ocean is likely to stay there.

That leaves the final avenue - melting ice, or preventing ice formation.

Big picture, the amplification effects from the disappearance of the arctic icepack are terrifying.. because there's not likely to be any place for the energy to go unless the temperature warms considerably or unless the warmer water swirls around Greenland and is cooled by melting that ice.

Don't just dismiss this by saying "you have to nail down the first approximations". Please explain what I fail to understand, or at least attempt to point me in the right direction.

I'm not asking to be ignored and belittled, I'm coming here in full recognition that I understand the physics and chemistry perfectly well, but understand the cryosphere far less than most other people posting here, and I wish to understand more.

(And please don't just wave your hand and dismiss my post by saying I somehow mistook amplification, insolation, and absorption... I wouldn't have done such a thing since my early college years, and indeed did not do that here.)

John Bilsky

Glenn Doty,

Please take a chill pill and slow down a bit before you start casting aspersions on people.

Zebra stated " I would like to follow your reasoning, but so far I am pretty confused."

As a person of science, I can say that a statement like this means that there is a communication error somewhere and the proper thing to do is to determine where the communication breakdown happened. Being defensive and assuming you were attacked is not good science. May I suggest backing up a bit and determining where the communication broke down? We are here to learn & question & investigate. Egos should be checked at the door.

A master carpenter (my Dad) once told me that if you have a lot to get done, it's necessary to take your time. You'll get a lot more done that way. In other words, measure twice and cut once.


Glenn Doty

John Bilsky,

That is a fair rebuke.

I apologize, to zebra and this forum.

Rob Dekker

Glenn said

If you assume only ~200 W/m2 insolation during September (a shot in the dark on my part, I couldn't find it through a quick google search), then a single hour of blue ocean at 90 degrees N would result in over 4 PWh of energy injected into the waters of the arctic.

Insolation in September over the Arctic is about 50 W/m^2 :
http://2.bp.blogspot.com/-k_S7N0VlMRg/UH4RNvJ3cjI/AAAAAAAAFjk/lqjQhGqLWOk/s1600/insolation_latitude.gif

It is clear from this graph that the insolation during summer is much more important than insolation in September.
Needless to say that albedo amplification is much stronger during the summer months than it is during September.

zebra

Rob Dekker,

Very useful plot, thanks.

Perhaps you could explain something which may be part of the problem with my not understanding Glenn.

What is "albedo amplification"?

I know how "Arctic amplification" is usually defined-- it refers to the fact that the Arctic is warming faster than the planetary average.

I also understand the concept of "albedo feedback" as it relates to sea ice; as ice melts it reduces albedo so that more energy is absorbed rather than reflected, which of course melts more ice.

The only usage I could find in a quick search of "albedo amplification" is a paper on modifying agricultural practice to increase planetary albedo.

Bill Fothergill

@ Zebra "What is 'Albedo Amplification'?"

I'm sure Rob will answer for himself, but when I use that particular terminology, I am referring specifically to the component of Arctic Amplification caused by the +ve feedback introduced as a direct result of Albedo reduction.

See here, for example...

https://www.skepticalscience.com/What-causes-Arctic-amplification.html

Bill Fothergill

Oops!! A trifle premature with the "Post" button...

See also...

http://earthobservatory.nasa.gov/IOTD/view.php?id=81214

https://nsidc.org/about/monthlyhighlights/2009/09/arctic-amplification

http://ossfoundation.us/projects/environment/global-warming/arctic-polar-amplification-effect

Glenn Doty

@ Zebra,

I got the terminology from Bill. As stated, I've been lurking here for some time, and I think that the term "albedo amplification" succinctly describes what I see as the scariest feedback mechanism.

@ Rob Dekker,

Thank you. When Neven first posted this article, I immediately thought "we're going to have blue ocean at north pole this year".

I still think that the basic energy flows should result in most of the additional energy being trapped in the arctic until it is absorbed by melting ice. And I still hope that someone might be able to explain why my assumption is wrong on that...

But at least the net energy would be far less than I was thinking.
:)

zebra

Glenn,

I appreciate your reply to John Bilsky. No need to apologize; this is not my first internet "debate" rodeo.

First, I think others had previously made the point I was trying to make, which is that momentarily crossing the "no ice" threshold does not in itself represent some kind of "tipping point".

There is already lots of "blue ocean" when we hit the minimum last year. Something like 11 million square kilometers, if we just subtract about 4 from about 15, using the extent graph.

1) I suggest you calculate the net energy absorption for 24 hours as that number increases by say 1 million at a time, until you get to 15, and plot your results.

2) It would also make sense for you to think about the fact that all that blue ocean does re-freeze. Maybe a little less each year, but there is no catastrophic cascade going on at this point. So, where is the great accumulation of all the stored energy you are talking about?

Robert S

Zebra: The great accumulation of stored energy appears likely to be in the total arctic ocean system, including water and ice - essentially warmer water and less ice volume. Without the albedo changes etc. this energy accumulation would probably be pretty much a straight line graph. With albedo changes, clathrate emissions, higher cloud cover, etc., it does start to take on the shape that I think could fairly be called a cascade.

Glenn Doty

zebra,

A response to this:
"So, where is the great accumulation of all the stored energy you are talking about?"

The disappearance of >300 km3 of ice per year over the past ~38 years shows exactly that accumulation of energy.

In truth, the long term average isn't nearly as instructive as the more recent average, which is nearly twice that. But right now we're just witnessing (mostly) the phase change of floating ice. Once the floating ice is no longer available to absorb that energy, then the energy must manifest in a different way. That's the scary part. Rather than the blue ocean absorbing more energy and having that energy be immediately transferred into phase change, if there is no floating ice to soak up that energy... what then?

The radiation losses will not significantly increase in the winter because the surface WILL re-freeze, even if the warmer water below will keep the ice sheet thin.. I don't believe there will be anywhere near a commensurate increase in radiative losses, because the thin ice in the winter will keep conductive losses too low to heat the surface and atmosphere to such an extent that the total radiated energy can balance.

As soon as this tremendous amount of energy influx can no longer be transferred into melting floating ice, it will have to be transferred somewhere else. That is the tipping point that I see.

We are seeing the greater energy absorption and have been for years, but so far the vast majority of the energy imbalance has gone towards melting the icepack. When the icepack is gone..?

It seems most likely to me that some portion of that energy will be directed to the underwater portions of the Greenland Ice Shelf, and some portion of that energy will continue to reduce the thickness of the ice - which will further worsen the next year's amplification...

zebra

Glenn, Robert S,

This kind of physics involves being able to characterize temporal and spatial relationships, propose a causal narrative based on fundamental principles, and establish (simple) quantitative models therefrom.

I've tried to give some guidance on how you might constructively "do the math", but if you aren't interested in that elementary level of rigor, I can't force you to try.

wayne

The most revealing calculation made yet indicates solar energy capable of melting the thickest sea ice cover imaginable. This with 90% albedo. I think this leads to top of sea layer minima temperature depth. If for instance there is -1.8 C going down 200 meters instead of 4, the amount of heat required to bring up the sea water column from -1.8 to 0 suggests latent heat may be very important as well. The focus should agree on how many cubic kilometers may theoretically melt first, then we leave to the sea to do the compensation, how much cubic kilometers of sea water is doing the current job of keeping sea ice?

AbbottisGone

https://www.youtube.com/watch?v=hZdhPnsp4Is

This is a good video with some different numbers!

AbbottisGone

Niagra Falls = The Nasty Dilemma

Hans Gunnstaddar

Watched the video AG and it was very interesting - thx for the link. I just thought a partial transcript of some of the highlights might be helpful for those not having the time to watch the entire presentation:

One of the tidbits said was for the two billion poor people not participating to rise up into the middle class would require a 3.5 times increase in energy used, and from poor to a high level is an increase of 7 times. That's an interesting point because the economic push worldwide is in part to bring the poor up so they can participate, however the trade off is more carbon emissions i.e. unless that's achieved with renewables.

Another bullet was when he said, "We're at a point with Arctic sea ice when abrupt climate change can occur." The timelines for abrupt climate change from past ice cores can be as fast as 1C increase a year for 5 straight years, then it levels off for a few years only to rise later by another series of 1C a year for 5 years for a total of 10C!

He also said he didn't think 2C was a good limit, that the threshold for abrupt change is probably a lot less than that. But 2C is a consensus that was agreed upon, but maybe more for political reasons than scientific. I think we all know that once sufficient momentum begins in a direction it's hard to stop.

Robert S

Zebra: You asked "where is the great accumulation of all the stored energy you are talking about?" I suggested some possible answers to your question. I take it now that want you wanted to request was "please provide me with a detailed quantitative model of energy flows into and out of the arctic to demonstrate where the increased energy is being stored." That's a great request, but it wasn't what you had asked... and as I think you know, we're unfortunately short of data to really nail it, although some of the models out there take a crack at it. But those models are based on exactly the sort of input/output/feedback relationships that I was suggesting, with pretty large error bars on every input and process step in the model, due to the data gaps. Although I'd love to, I don't really have the expertise to build a better model than those that are already out there :-)

zebra

Robert S,

I don't know how far back you followed the discussion.

Some contributors were calculating heats of fusion and energy absorption and so on over the Arctic area. I started out defending them and the idea that you don't need to have super-computer level models to draw valid (approximate) quantitative conclusions. When scientists and engineers start to solve problems-- I mean real problems, not plug-in school problems-- that's how we begin.

But, just because you are looking for numbers like orders of magnitude, or "is it going up or down", or relative rates of change, and so on, you don't get to ignore the rules.

That means clearly stating the boundaries of what you are trying to demonstrate, and justifying your quantities and conclusions.

The question at hand had to do with insolation, albedo, phase transitions, and the "ice-free" condition, and whether that condition represented a "tipping point".

So, clathrate bombs, for example, are irrelevant. Also ocean and atmospheric currents bringing energy in. Nor is the historical loss of volume useful. It's a simplified hypothetical case, not the whole shebang.

You have this big ocean with a big ice covered island, and part of the ocean has ice and part doesn't, depending on the time of year. Will there be a complete state change if the entire ocean is ice free for three days? Three weeks? Three months?

Will the island ice melt? Will the rate of change of planetary energy balance double? Will we all be doooomed?

Quickly playing with the numbers, I would say no, but I am willing to be corrected by a rigorous argument.

Rob Dekker

@zebra, yes, the term "albedo amplification" is kind of a misnomer.
After all, "albedo" is not amplified here. Better would be "albedo feedback" or even better (as Bill explained) "the component of Arctic Amplification caused by the +ve feedback introduced as a direct result of Albedo reduction".

What has captivated me over time is a way to quantify the strength of this albedo feedback, so that we may have an idea on when and how it could cause the first ice free summer in the Arctic.

In that regard, Tamino did a series of posts that are very interesting in quantifying the albedo feedback effect of sea ice in the Arctic :
https://tamino.wordpress.com/2012/10/01/sea-ice-insolation/
of land snow cover :
https://tamino.wordpress.com/2012/10/05/snow-2/
and of ice and snow cover combined :
https://tamino.wordpress.com/2012/10/08/snowice-by-request/

Note that he estimates that the albedo feedback effect of sea ice is 0.13 W/m^2 globally, but snow cover reduction is contributing more at 0.21 W/m^2 global climate forcing. The combined 0.34 W/m^2 (even 0.45 W/m^2 if you use a more realistic time filter) is quite substantially adding to global warming over the past few decades.

His goal was to estimate the global forcing of reduced ice and snow cover during the melting season, which is different from my goal to estimate the strength of albedo feedback on sea ice retreat.

What we really want to know is not the global climate forcing, but how strong the albedo feedback works locally. Like, if there is a hole in the ice in the Arctic in June, then how large will that hole become in September, based on albedo feedback alone.

For that, I'd like to present two methods. One is a calculation based on albedo and insolation (that graph I showed above), and one is based on observations.

1) To calculate how much more heat is absorbed by a hole (open water) than by ice, I use the insolation at Top Of Atmosphere (TOA) graph here as a starting point :
http://2.bp.blogspot.com/-k_S7N0VlMRg/UH4RNvJ3cjI/AAAAAAAAFjk/lqjQhGqLWOk/s1600/insolation_latitude.gif
Note that it peaks at about 500 W/m^2.
Now, I use the rule of the thumb that half of that makes it through the clouds, and the albedo different between ice covered and open-water is about 0.6-0.1=0.5, which means that overall TOA albedo should be about 0.25. Tamino in his post here
https://tamino.wordpress.com/2012/10/01/sea-ice-insolation/
uses 0.2, which is consistent with Hudson 2011.

Now, for a hole in the ice, with that 125 W/m^2 peak (or 100 W/m^2 if you go with Tamino), to estimate how much extra heat is absorbed from June to September, we need to integrate the insolation curve over June to September. That is a Cosine curve from 0 to 90 deg, the integral of which is a Sine of 90deg which is 1.
The total energy absorbed between June and September then becomes :
1 * 125 W/m^2 * 3600 * 24 * 91(days) / (2*pi (radians/year) = 156 MJ/m^2.
That is enough heat to melt 156 MJ/330,000 = 474 kg of ice.
For 1.5 meter thick FYI, that means the hole will get 32 % bigger between June and September.

Now, this suggests that the albedo feedback is quite strong, and it will advance the melting of FYI during the melting season, but it also means that there is no imminent danger of a "blue ocean event".

2) Some of you may have followed my estimates based on observation of how albedo feedback specifically about snow cover reduction and ice reduction affects the sea ice minimum in September, for ARCUS Sea Ice Prediction Network (SIPN). My latest assessment is here :
https://www.arcus.org/files/sio/25738/sio-2016-july_dekker.pdf
Based on these regressions, the best 'fit' (over the past 24 year) appears to be one where 'beta' is 0.368, which means that a 'hole' (extent-area) in the ice would expand (during an average summer) by 36.8 % between June and September.

That is quite consistent with the theoretical calculation in (1) above based on albedo and insolation alone.

Also note that the best fitting factor for snow reduction over the past 24 years is 0.434, which (with a beta of 0.368) suggests that every m^2 of land snow lost in June will result in 0.434*0.368=0.16 m^2 of sea ice loss. 160,000 km^2 sea ice lost in September for every 1 M km^2 of land snow lost in June.

Once again, these numbers (and Tamino's assessment) suggest that the albedo feedback is quite strong, and significantly contributes to global warming and sea ice retreat over the past decades, but it is not 'instable' in the sense that it does not cause a blue Arctic all by itself.

Rob Dekker

Let me also note that the calculations above suggest that if FYI becomes thinner (due to an excessively warm winter) that the albedo feedback in the next summer will be stronger.

AbbottisGone

Hans, some are predicting Trump will backflip on Climate Change out of pure necessity and that he can easily explain it to those who elected him on market principles,... whatever that means these days.

http://www.news.com.au/technology/environment/climate-change/trump-will-reverse-climate-change-position-former-republican-congressman-bob-inglis-says/news-story/209f63945a7a444d8373bea30e443e0c

I think we are seeing panic stations start to form, personally. These were the exact things the video was talking about. I got it from '5to10' on ASIF who posted a smaller excerpt and I just posted the larger version.

I think Trump always knew it was a problem that needed solving he just needed the votes and played the game accordingly. The media can't get him for hypocrisy and I think that was the simple game he played.

I always thought he would backflip on Climate Change: I still hope. It just can't go any other way can it?

AbbottisGone

http://www.livescience.com/32814-arctic-daylight-darkness-myth-equinox.html

This is a handy synopsis on the different types of 'twilight' in the Arctic.

wayne

Hi Rob

I did read Tamino's work and found it interesting. But it is not what I am looking for. Less sea ice and snow cover does affect global energy input That is nice to know.

What I am interested in is an acceptable-consensus w/m2 insolation value, For the entire Arctic Ocean sun year, 100 to 125 for 3 months is not enough because it is for 3 months. The long day is mostly 6 months long. I find this basic knowledge instructive and essential in order to better understand the geophysics at hand.
I wonder if any has come up with a basic insolation figure, similar to the US standard atmosphere?. Including 23% atmospheric absorption and 90% cloud + sea ice albedo. Would love to have a standard insolation number per season.

Jim Hunt

Following a request on the forum, here's the Canadian Ice Service's current "Stage of Development" map of the Beaufort Sea:

Click through for a larger version. It's almost all "Medium first year" sea ice.

Discuss!

Hans Gunnstaddar

"I always thought he would backflip on Climate Change: I still hope. It just can't go any other way can it?"

Trump is unpredictable so it's possible AG, and hope Bob Inglis is correct. One thing on the side of him changing his mind is the obviousness of the numbers making GW clearer for those in denial, such as three straight years of record breaking high temps, much higher CO2 increases and accelerated ice volume loss in the Arctic.

There's also Churchill's famous and humorous quote; "You can always count on Americans to do the right thing - after they've tried everything else." Hopefully everything else has been tried in regards to denial, however Trump just recently signed an executive order to allow coal mining companies to dump their waste material (such as overburden) into freshwater streams, so that's not a good sign. He's also cozied up to Steve Bannon who is a far right advocate that claimed in an interview yesterday that Trump plans to do everything he said he would do (which includes walking away from the Paris Accord).

I would say our best bet is to allow the process to unfold and see if he gets it and then acts to do something about it in a way that will make a difference. I was hoping for and voted for Hillary because she got the whole GW thing and wanted the US to invest a trillion dollars on a massive roll out of renewables along with modernizing the grid, which would have facilitated energy to be transmitted from wind farms in the mid-west to the East where demand is very high and from solar in Arizona and Nevada to California.

zebra

Rob Dekker,

I hope you take this in the spirit of constructive criticism; I don't want yet another person mad at me.

It seems to me that if you start with less(more) ice in June, you will inevitably end up with less(more) ice in September.

http://woodfortrees.org/plot/nsidc-seaice-n/from:1980.42/every:12/normalise/plot/nsidc-seaice-n/from:1980.67/every:12/normalise

I don't know how you would attribute this to albedo at all, except insofar as the January extent might be influenced by retained energy in the system. But that's a stretch.

zebra

Hans G,

You hit on one of my pet peeve topics there. We on the East Coast have plenty of our own wind offshore, and we just got the first US offshore project up and running.

We would have expected HRC to recognize our natural desire to put our under-utilized ports and boatmen to work rather than buying energy from the bigots who voted against her. More investment on the turbines, but perhaps less trouble and expense than routing HVDC lines over land.

What a difference a vote makes...sigh

Hans Gunnstaddar

Z, whatever renewable is available offshore will certainly help but I doubt even wind energy from the Midwest and offshore wind will meet the energy needs of the Eastern seaboard, so many different approaches will be needed if people are serious about transitioning to renewables.

Bill Fothergill

@ zebra "... It seems to me that if you start with less(more) ice in June, you will inevitably end up with less(more) ice in September ..."

Rob and I wrote a couple of posts a few years back which dealt with this subject.

Mine was basically a bit of simple number-crunching, but Rob's went deeper, and looked for a more causal relationship.

http://neven1.typepad.com/blog/2013/06/problematic-predictions.html

http://neven1.typepad.com/blog/2013/07/problematic-predictions-2.html

Rob Dekker

@wayne

What I am interested in is an acceptable-consensus w/m2 insolation value, For the entire Arctic Ocean sun year,

A good rule of the thumb is that 50% of TOA insolation makes it to the ground. So the insolation value you are looking for is half of the insolation value from this graph :
http://2.bp.blogspot.com/-k_S7N0VlMRg/UH4RNvJ3cjI/AAAAAAAAFjk/lqjQhGqLWOk/s1600/insolation_latitude.gif

@zebra, not sure what you want to show with that woodfortrees graph, but it is different from the feedback I calculates.
For starters, .42 and .67 year fractions do not correspond to June and September, and what is that 'normalize' function doing ? Is seems to flatten out the trends for both graphs.
Please clarify your point.

zebra

Rob,

I just skimmed your paper before commenting and I wasn't clear what you were trying to do. I now see that you are trying to improve the correlation beyond what we would expect just looking at the initial value as I do with the WFT graph.

OK, so let's try to get the communications clear.

First, we seem to agree that "albedo amplification" and "albedo feedback" can be confusing, but let's put that particular terminology aside for the moment.

Second, I think your hypothesis about land snow cover is a nice bit of reasoning, and I would like to see it developed further.

However, I've now read your paper over carefully, (as well as the post Bill referenced), and the particular terminology there has me puzzled.

What you are calling a "melt formula" seems to be what I would call a "melt factor", and I am assuming that what I would call the "melt formula" is the form (amount of melt) = alpha+beta*(melt factor).

Could you just demonstrate step-by-step how you calculated your prediction for the amount of melt for 2016, instead of describing it in words?

Rob Dekker

zebra,
Your request suggests that you don't yet fully understand what I did.
So I need some description with words, but I will follow it up with numbers.

In the regression formula :

september_extent - june_area = alpha + beta * (Melt_Formula)

I'm trying to determine the melt between June and September, based on a formula that contains 3 different factors that are available in June. After many regressions, this is the formula that gives the best result (smallest standard deviation) :
Melt_Formula = 0.434*june_snowcover - 1.0*(june_extent - june_area) + 0.65*june_area

Important to note is that this melt formula is really a 'feedback' factor.

If ice melt between June and September were always the same and thus "less(more) ice in June, you will inevitably end up with less(more) ice in September " as you suggest, then the 'beta' factor will be zero and the 'alpha' factor will be simply be the average june-to-september melt amount.

But reality is different : If you run linear regression over the 1992-2015 data to find the best fitting parameters, you will find 'alpha' is -5.8538 and 'beta' is 0.36827, an correlation factor R=0.9426 and a standard deviation of the residual of 0.9426.

What that means is that sea ice melt between June and September is not constant, but is mostly a result of the various feedback effects of snow cover, 'holes' in the ice, and plain old 'area'.

To obtain the prediction for 2016, simply fill in all the june 2016 data into the Melt_formula, multiply by 'beta' ( 0.36827 ) , add 'alpha' (-5.8538) and subtract the june 2016 'area' number from NSIDC.
Please do that, and see if you obtain the same number I obtained in the SIPN July report : 2016 September extent projected to be 4.12 M km^2.

Jim Hunt

The sun shining down on the sea ice in the heart of the Northwest Passage, live from O-Buoy 14's webcam (until the sun sets!)

Click the picture for a gallery of larger images.

zebra

Rob,

Of course I didn't understand what you were doing-- why would I keep asking these silly questions otherwise? :-)

I think the cause of my confusion all along may be that you are calling

delta (ice) = alpha - beta*(MF)

a "regression formula", and referring to "many regressions".

Again, could you just describe what you are actually doing there, with what data, without using the term regression? (Except maybe to say : "then I click on 'regress' in my spreadsheet.")


wayne

Hi Rob,

"A good rule of the thumb is that 50% of TOA insolation makes it to the ground. So the insolation value you are looking for is half of the insolation value from this graph :

http://2.bp.blogspot.com/k_S7N0VlMRg/UH4RNvJ3cjI/AAAAAAAAFjk/lqjQhGqLWOk/s1600/insolation_latitude.gif"

OK then a transect from March to September gives 260 W/m2 TOA. Which is close to my Equinox calculation 282 W/m2.

So I take 270 TOA

50% reaching the ground is too generous, summer time Arctic albedo was measured 80% by NASA. there is 23% atmospheric AbsorptionSo 20 % reaching the ground.
Now that is not finished, overall sea ice/snow cover/thin sea ice
for the entire summer should be 50% (I am ready to change this).
This gives melt potential of 90,969 km3 more than 4 times more than current inventory.

For entire Arctic Ocean area of 14 million km2
Latent heat of fusion: 3.04 E14 Kj/Km3

If roughly correct, top of ocean temperature plays a major role.

wayne

oops, I gave 6 times more energy than needed

W/m2 X 182.5 X 24 X 3600

This is better

Now the number makes better sense: 14,038 km3 is the melt potential with a lowered TOA to 250 W/m2.

This is what I was looking for. If you have 14,038 km3 at Maxima
all should be gone come minima.

Now change the cloud albedo say to 50% , then 35,096 km3 is the melt potential.

Let's see if I have someone else who agrees with this math.

Rob Dekker

Jim, thanks ! Obuoy 14 appears to have survived the winter ! That's awesome. Let's hope it survives a lot longer, since it is the only buoy in the Arctic with a web cam.

Rob Dekker

@zebra, I understand. Let's see if this helps.
Using this formula :

delta (ice) = alpha - beta*(MF)

Calculate "MF" for each June between 1992 and 2015.
Then calculate 'delta (ice' for each June between 1992 and 2015 as well.
That results in what we call a "scatter plot", with "MF" at the x-axis and 'delta (ice)' at the y-axis.
Something like this (from the Wiki page on regression analysis) :
https://upload.wikimedia.org/wikipedia/commons/3/3a/Linear_regression.svg
On that scatter plot we then run simple regression analysis which results in an offset (alpha) and a slope (beta).
Does that make sense ?

Rob Dekker

@wayne

OK then a transect from March to September gives 260 W/m2 TOA

This graph (the top one)
https://en.wikipedia.org/wiki/File:Insolation.png
suggests about 170 W/m^2 TOA insolation over 12 months, which would be average of about 340 W/m^2 TOA insolation over the 6 months March-September.
50% reaching the ground is too generous, summer time Arctic albedo was measured 80% by NASA.

Mmm. 80% albedo could be right even if 50% makes it to the ground.
Remember that TOA albedo depends on surface albedo, and if that is 50%, and 50% makes it to the ground, then TOA albedo will be 75%.
Now the number makes better sense: 14,038 km3 is the melt potential with a lowered TOA to 250 W/m2.

I'm sorry, you lost me. How did you get to that 14,083 km^3 number ?

Rob Dekker

wayne, take this graph again :
https://en.wikipedia.org/wiki/File:Insolation.png
The top map suggests that TOA insolation in the Arctic is some 170 W/m^2.
The bottom map suggest that insolation at the surface is some 90 W/m^2.
That means that on average, 90/170 = 53% of TOA insolation makes it to the surface in the Arctic.

wayne

Hi Rob

How interesting, and a bit exciting since we are calculating something long overdue. That insolation number is key,


OK I will factor 90 to surface which is big!

250 X .77 X .2 X .5 =19.25 w/m2 for the entire summer season

being 250 w/m2 X .77 atmospheric absorption X .2 cloud albedo X 0.5 sea ice albedo.

lets take 90 with .50 sea ice albedo

Time : 3600 s/hr X 24 hrs X182.5 days
area of arctic ocean 1.41e13 m2
admit 90 W/m2 reaches ice surface

simple 90 W/m2 X time X 1.41 E13 m2 = 2 e22 watts for entire Arctic ocean

with latent heat of fusion of sea ice = 3.04e17 w/km3

this gives a melt potential of 65,634 km3 of sea ice.

factor sea ice albedo spring/summer/fall being 50%'

32,817 km3 is the sea ice melt potential

That is not a bad number, not as simple as 14 K, but there are other factors to consider

Working on as precise melt potential as possible will help people making very good melt estimates.

A few specific numbers need be worked on:

1- total days or seconds of sun insolation for the entire Arctic Ocean, this is a rather big complex calculation since the Arctic Ocean is tot symmetrical with respect to the Pole.
2- surface albedo 0.5 may vary, ie melt ponds, thinner darker sea ice, snow cover, bare sea ice.

Once we get a rather closer more precise melt potential number, would like to work on sea water temperature impact.

Rob Dekker

wayne,
man, you are going way off.
We just determined from this map :
https://en.wikipedia.org/wiki/File:Insolation.png
that insolation on the surface is 90 W/m^2 if averaged over 12 months. Over the 6 months that the sun is shining, that is 180 W/m^2 from March till September.
Can you take it from there ?

wayne

180 sounds good Rob

I took your 90 directly, it did not have units.

But I think we are confusing TOA with surface? 250 * .77 =192.5
Close to 180 considering atmospheric Absorption factored in. With patience and help will get to a good approximate.

wayne

Rob

What is your state of the moment potential melt number estimate in Km3?

Rob Dekker

wayne, I think I went on record to suggest that the "melt potential" in the Arctic is some 9.5 meters of ice :
http://neven1.typepad.com/blog/2017/01/a-new-arctic-feedback-.html?cid=6a0133f03a1e37970b01b8d25ced44970c#comment-6a0133f03a1e37970b01b8d25ced44970c
That was based on 100 W/m^2 annual insolation. You can lower that by 10% if we go with the 90 W/m^2 annual insolation on the surface.

Rob Dekker

wayne said :

But I think we are confusing TOA with surface?

I don't think we are confusing at all. These two maps :
https://upload.wikimedia.org/wikipedia/commons/7/78/Insolation.png
show both TOA and surface insolation.

wayne

Rob

Nice maps with hardly a word explanation to them. Need more solid reference.

The other map you gave , the one with the colors, correctly calculated the Poles solar insolation at solstice, pure TOA from TSI.

" I think I went on record to suggest that the "melt potential" in the Arctic is some 9.5 meters of ice :"

"100x3600x24x365=3.1 GJoule/m^2/year."

Is ball park if 100 means everything factored in, including cloud/ice albedo atmospheric refraction. If you take the basic TSI graph presented you should be able to calculate that 100.

wayne

atmospheric absorption not refraction....

Rob Dekker

wayne said

Nice maps with hardly a word explanation to them. Need more solid reference.

You gotta be kidding me.
I'm sorry wayne.
We have gone through this two times now (first in the "a-new-arctic-feedback" thread, and now in this).
It's very clear that Arctic insolation at the surface is about 50% of TOA insolation.
If you have any better estimate, then please post it.

Rob Dekker

Sorry. An estimate is no longer enough.
If you have any better scientific reference than this one :
https://en.wikipedia.org/wiki/File:Insolation.png
then please let me know.
Until then, the rule of the thumb that 50% of TOA insolation makes it to the surface in the Arctic stands.

Can we please move on to my calculation and estimate of albedo feedback in the Arctic now ?

wayne

Rob

I posted it many times 2 Rob, I dont mind making sure about an important standard interpretations before accepting it.

"being 250 w/m2 X .77 atmospheric absorption X .2 cloud albedo X 0.5 sea ice albedo."

taking 200 W/m2 TOA does not make 100. from 23% atmospheric absorption , 80 % cloud albedo and a generous 50% sea ice albedo.

I think a simple map without inscriptions needs to be proof checked....

Rob Dekker

You just keep going at this, don't you ?

"being 250 w/m2 X .77 atmospheric absorption X .2 cloud albedo X 0.5 sea ice albedo."

No wayne, that expression is simply false.
For starters, the 250 W/m^2 is wrong (should be 340)
Next the 0.2 cloud albedo is wrong (.2 is TOA albedo, NOT cloud albedo).
taking 200 W/m2 TOA does not make 100. from 23% atmospheric absorption , 80 % cloud albedo and a generous 50% sea ice albedo.

Now you are just rambling.

Rob Dekker

wayne said :

I think a simple map without inscriptions needs to be proof checked....

OK. Once more, the full link is here :
https://en.wikipedia.org/wiki/File:Insolation.png
The graph at hand (for surface insolation) is from HadCM3.
Now, even if you don't like HadCM3, I would be very much interested in your reference to something better.
Also, wayne, what the heck is you problem ? Why is this graph/map so unacceptable to you ?

wayne

is clear calculations Rob

340 was my original post, but I explain

take 340 top of atmosphere, cloud albedo , from massive cloud presence in spring-summer-

340 * .77 (atmospheric absorption). 261.8
261.8 * .2 (cloud albedo) = 52.4
52.4 * .5 (sea ice albedo through all phases) = 26.18 watt/m2

.2 cloud albedo calculation of which 80% is reflected upwards.

Rob Dekker

wayne,
I posted such a nice and concise and important post explaining the strength of the albedo feedback in the Arctic.
why are you going over this with absurt arguments ?
For example, where do you get your "cloud albedo" factor .2 from ?

wayne

,2 , 20% gets through? Seems clear to me

the albedo factor is not the standard 30 or 40% you have down south.

So given a nice sunny day 350 watts, at 30% , 360 *.7 gets through...

Absurd? please correct.


Rob Dekker

wayne said

,2 , 20% gets through? Seems clear to me

Right. But you made that up all by yourself.
Once more, these two maps :
https://en.wikipedia.org/wiki/File:Insolation.png
show that 50% gets through on average.

wayne, I've always given you the benefit of the doubt, and at time stood up for your arguments. But at this point I've had enough.
Either you accept the maps above, or you can present better evidence.
There is not much in between.

wayne

Rob,

I would suggest reading up on Arctic cloud albedo, sorry you had enough, I was just getting started, You have to stretch out possibilities before being absolutely certain about any conclusion. Patience Rob is key. 80% was from NASA

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

I believe it so because I have observed summer Arctic sat pics way before there was an internet.

Patience Rob, will amount with something great.

Rob Dekker

wayne, as I said before : 80% albedo could be right even if 50% makes it to the ground.
Remember that TOA albedo depends on surface albedo, and if that is 50%, and 50% makes it to the ground, then TOA albedo will be 75%.

That still does not make your numbers right.
You want patience, fine. Let's start all over again : How much of TOA insolation makes it to the surface of the Arctic ocean, wayne ?

zebra

Rob Said:

@zebra, I understand. Let's see if this helps. Using this formula :

delta (ice) = alpha - beta*(MF)


Calculate "MF" for each June between 1992 and 2015.
Then calculate 'delta (ice' for each June between 1992 and 2015 as well.
That results in what we call a "scatter plot", with "MF" at the x-axis and 'delta (ice)' at the y-axis.
Something like this (from the Wiki page on regression analysis) :
https://upload.wikimedia.org/wikipedia/commons/3/3a/Linear_regression.svg
On that scatter plot we then run simple regression analysis which results in an offset (alpha) and a slope (beta).
Does that make sense ?

Rob, I think I could rewrite what you are saying here to make it clearer, but it is clear to me already that you have a very confused understanding of the math and the physics.

In case this is not obvious to others, I'm going to go through what I would consider the correct way to approach the question.

1. The question is: Does an initial condition in June (Land Snow Cover) have an effect on the sea ice minimum (in September)?

2. Let's look at the Charctic interactive graph for extent. We zoom in on June first to October first. We observe that June 1 through Sept 1 looks like it might be a straight line with some wiggles or "noise". (This is ice extent on the y axis and days on the x axis.)

3. We use the regression function to find the straight line that best fits the data for each year, June1 to Sept1.

This gives us the slope of the line, which is the rate at which the ice melts, for each year.

4. If June1 Land Snow Cover has an effect, that rate is what would be affected.

5. Now, we have a list of rates for each year.

5a. We can look for a trend by doing a regression again, with rate on the y axis and years on the x axis. Is the rate increasing?

5b. We can list the the rate for each year next to the June LSC for each year, and look for a correlation. Does the rate go up/down when the LSC goes down/up? You have that function on your spreadsheet as well.

So, to continue the theme that this all started on for me: Yes, it's great for people to look for quantitative information (first approximations) as part of understanding what's going on and countering the Denialists. However, we have to have the fundamental principles right and be disciplined in how we reason and how we communicate it.


wayne

well said Rob

I wrote from considering 340 TOA

340 * .77 (atmospheric absorption). 261.8

261.8 * .2 (cloud albedo) = 52.4 Watts/m2

Seems correct except need to polish TOA and other constants

Glenn Doty

Wayne,

You are calculating total insolation, but what is not factored in is the energy re-radiated from the surface. You have to have that in order to get the amplification/forcing.

I can accept Rob's model results without embellishment: climate models are estimating ~90 W/m2 average yearlong insolation is radiating the arctic surface.

If you factor that for the arctic ocean, you would get ~11 EWh of total incoming radiant energy. It takes ~92 TWh to melt a km3 of ice... So the total radiant energy striking the arctic could - in a perfect blackbody, in a perfectly shielded experiment - melt ~119.565 km3 of ice.

Then we start playing games with albedo. If you assume 50% albedo, you halve that figure. If you assume 80%, it gets down towards the numbers you were stating... etc.

But what you are not taking into account is the energy that is radiating from the Earth/atmosphere. It's cold in the arctic, but it's not absolute zero. Some energy is being constantly radiated out in microwave and longer-wavelength infrared.

At 273 K, there would be roughly ~55 W/m energy flux radiated out from the arctic (minus atmospheric reflection). At 240 K that energy flux would be reduced to ~33 W/m.

So that reduces the top-line insolation in the same manner that albedo does, and it starts messing with the total amount of energy that the arctic actually absorbs.

I feel - therefore - it's easier to assume very little change in temperature (especially during the summer), and focus on the difference in insolation seen as the ice and snow melt. The system itself will shed most of the energy flux that it absorbs over the year from the normal frozen state that the arctic has seen over the past few million years.

Glenn Doty

The correct figures, of course, are ~315 W/m2 at 273 K and 188 W/m2 at 240 K. (I am quite distracted when I chime in here, and I probably should just continue to lurk).

But again, of course, this is what would be expected from an ideal black body. From water, a grey body which absorbs many spectra of microwave and infrared, the actual energy flux emitted would be far less. Though I don't know what the emission would be.

The easiest way to solve the problem would be to find a Top-of-atmosphere reading or calculation of outgoing energy flux at the arctic. Then we reduce the issue to just albedo change and surface area.

I don't suppose anyone has a handy map of TOA outgoing flux or energy flux balance? I like this one from NASA, but I can't change the color range, and to look at the arctic you'd need a tighter color range.
http://neo.sci.gsfc.nasa.gov/view.php?datasetId=CERES_NETFLUX_M&year=2016

Elisee Reclus

I know the extremely low Sea Ice Extent levels this winter are pretty dramatic, but didn't I read somewhere (like right here on this forum!) that "winter and summer ice extents are very poorly correlated"?

Hans Gunnstaddar

https://www.co2.earth/

I know this is only a one day CO2 PPM reading (and that's why they average over longer periods of time) but for Feb. 26th, the difference between this year and last is FIVE ppm! 403.58 in 2016 and 408.58 in 2017.

wayne

Hi Glenn

Please lurk more not less, a combined effort to come up with something pertinent might come about.

"perfect blackbody, in a perfectly shielded experiment - melt ~119.565 km3 of ice."

Consider that number, with respect to current sea ice maximum Volume 21,000 km3. It is definitely not happening so strong.

The net absorbed radiation by NASA's Earth Energy budget is .6 watts from incoming solar 340.3 watts/m2. Back Radiation gets cancelled by outgoing quite a bit.

" it's easier to assume very little change in temperature (especially during the summer), and focus on the difference in insolation seen as the ice and snow melt."

Very correct. "Playing" with albedo is not at hand, it is finding the correct albedos I think that there are 2 constants to consider, total potential insolation time for entire Arctic Ocean and TOA radiation for same area. These are fixed numbers. Then we are left with atmospheric absorption, a near constant, what is left is cloud and sea ice albedo. There is return of flux energy from cloud reflection as well, I don't think it is impossible to come up with something
reasonable. Consider albedo reduction which was the case for summer 2007, then your 110,000 Km3 potential melt number looms heavier. What I am looking for is all known factors giving a standard potential melt of sea ice figure.
Once that number is know, then we will estimate melts a bit better. Furthermore , the search for this number always has revealed something else. So it is quite fascinating.

The NASA energy budget link is great for the entire planet not the Arctic. The reflected by clouds number is very close to 30%. No way this happens in the Arctic, The absorbed by surface is nowhere near sea ice ratio etc.

Rob Dekker

@zebra, thank you for your post in how I have a " very confused understanding of the math and the physics" of my own work, and how I communicated it wrong, and I'm sure you "could rewrite what you are saying here to make it clearer".

All I can say, I did my best in my 2011 post
http://neven1.typepad.com/blog/2013/07/problematic-predictions-2.html
in the SIPN ARCUS post
https://www.arcus.org/files/sio/25738/sio-2016-july_dekker.pdf
and in my answers to your questions in this thread.

I'm glad that you now understand what I did.

Rob Dekker

@wayne,

What I am looking for is all known factors giving a standard potential melt of sea ice figure.

Yet you don't even accept the first factor (0.5) from HadCM3, which is how much insolation makes it to the surface in the Arctic.

Not to mention that even if you would accept that number, the result is only one step towards calculating 'melting potential'. There is albedo, and then, as Glenn rightfully points out, there is the LW radiation budget, and beyond that there is heat input from lower latitudes. Even if you know the numbers for these, it is still a challenge to determine 'melt potential', especially since you did not even define what you meant with that.

What is much easier to do is to determine the "albedo feedback" potential of disappearing sea ice, because there you only have to look at the DIFFERENCE in albedo between ice cover and open ocean. Which is about 0.2 (not your absolute 0.2, but a difference).

But since I'm in danger of repeating myself, let me refer you to this post, which shows TWO ways in which the strength of the albedo feedback can be determined, and they both obtain approximately the same result :
http://neven1.typepad.com/blog/2017/02/piomas-february-2017.html?cid=6a0133f03a1e37970b01b7c8d9887a970b#comment-6a0133f03a1e37970b01b7c8d9887a970b

wayne

Hi Rob,'

Let's be clear about definitions,

"Yet you don't even accept the first factor (0.5) from HadCM3, which is how much insolation makes it to the surface in the Arctic."


What is this .5? everything? Atmospheric absorption, Sea ice albedo, clouds etc? How does one come up with 50 % when there is a 23, and 80 % reduction to sea ice. Not counting 50% sea ice albedo, I mayl accept that 50% when I understand what it involves.

I am not sure you understood my calculations, I look at everything,
and in particular about 9 meters potential melt is more than a bit too large. But correct if it precludes the factors I mentioned. There is a lot of energy not reaching the sea ice , would you agree? :) I think that number is very useful, it gives a nice idea about solar radiation and the potential foer total melts. But please define what it involves.

Rob Dekker

wayne said

What is this .5?

My point exactly : How can we move forward if you don't even accept the HadCM3 results ?
Why don't you start with a definition of what you call "melt potential" ?

wayne

now your cooking Rob!

How come you can't define this ratio?

For one thing

Next,

Arctic Sea ice Melt Potential: "Is a Volume in Km3 of potential sea ice calculated with the following geophysical factors: Total insolation of the Arctic Ocean, standard atmospheric absorption, standard (known average) total cloud and sea ice albedo during the entire melt season.

Feel free to add something else which may be useful, because there is no such definition that I know of in the literature.

Rob Dekker

Good luck wayne

wayne

Haa come on Rob!

It is not so hard to calculate, and in particular, I always wondered why Hadley model got 2007 wrong by 31 years. hmmmmm , that .5 number looks interesting.

Here is the latest state of the art, not complete , very tentative

Arctic sea ice melt potential:

Time 3600 seconds/hr X 24 hrs/day X 182.5 days per melt season
A constant (this needs be corrected with respect to Arctic Ocean duration exposure to solar insolation )

TOA Of Arctic Ocean melt season 250 watts/m2
A constant (needs be corrected or confirmed)

Arctic Ocean Area: 14 million km2

Atmospheric Absorption : 23%
source NASA (May be lower in the pristine Arctic Air)

Arctic Ocean Cloud albedo during the entire melt season : 80%
Source NASA

Sea ice albedo during entire melt season = 50%
Source NSIDC , Norwegian paper (Needs be confirmed, is a mix between thin sea ice albedo 0.2, bare sea ice .5 and sea ice with snow having albedo .9)

latent heat of fusion : 3.04E17 w/km3
a nice constant

And the result is : 14,038 km3

This number represents the melt potential given the current parameter factors.

A Note : if the Maxima reaches this estimate, and if the calculation is correct, it is highly likely that there will be very little sea ice left at minima. If tis summer's cloud Albedo changes to 70%, instead of 80, the minima would be very low ASIMP = 21,058 km3.


PJennen

Hi all,

A long time lurker-newbie here.
Isn't the 0.2 cloud albedo that Wayne is referring to actually a cloud cover? And actual cloud albedo varies massively, see e.g. https://en.wikipedia.org/wiki/Cloud_albedo.
This might explain the wild variance between the stances of Wayne and Rob.

Cheers, Paul

zebra

Rob,

If you want to be a "citizen scientist", then you have to be willing to undergo "peer review", and you should be willing to "defend your thesis".

It sounds like you are indeed very confused about the math and physics, and unwilling to take the opportunity to get a better understanding.

I gave you the correct way to do this. If you have all the data set up in your spreadsheet, why don't you give it a try-- it will take a couple of minutes at most. There is a lot of information that could be developed if you put aside your ego.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)