Melting of the Arctic sea ice

Below is a guest blog by Jos Hagelaars who regularly posts on Bart Verheggens Dutch-English climate blog. Jos has been a hot streak lately, looking back at how the Klotzbach 2009 Hot Spot paper is holding up, producing a new iconic graph called the Wheelchair (TM: Rabett inc.) and with his latest blog post discusses the result of the first Climate Dialogue that had Arctic sea ice as its first subject.

I wrote about this Dutch initiative when it was first presented, and even though I thought there wasn't enough talk about potential consequences/risks that disappearing Arctic sea ice poses, I found it actually exciting to have the representative of (fake) skeptics admit that the decrease is largely caused by Anthropogenic, or human-caused global warming. That ought to be a game changer. Some day. Hopefully soon.

Below is Jos Hagelaars' take on the discussion, starting with an excellent summary of everything regarding Arctic sea ice.

Melting of the Arctic sea ice

by Jos Hagelaars

This was the title of a discussion that was held on the recently launched website ClimateDialogue regarding the possible causes of the decline in Arctic sea ice over the past decades. Three experts participated in this discussion: Walt Meier, Research Scientist at the NSIDC, Judith Curry, professor at Georgia Institute of Technology and Ron Lindsay, Senior Principal Physicist at the Polar Science Center of the University of Washington.

In this blog post I will start off with a description of the observations of the Arctic region, followed by a short overview of the potential causes of the decline in Arctic sea ice, incorporating the views of the three experts as they were expressed on ClimateDialogue. The final parts concern the uniqueness of this decline in a historical perspective and the possibility of having an ice-free Arctic in the summer in the not too distant future.

Observations of the Arctic region since 1979

Since 1979 the Arctic region has been extensively monitored by satellites. They detect e.g. the ice surface area, the extent of the area covered with ice and also the total amount or volume of ice. The results of these observations are startling. For example, sea ice area and the amount of perennial (multi-year) ice has decreased dramatically over the past 3 decades, as is visualized by the images in figure 1 and 2, generated by NASA (see here and here).

Fig. 1. Minimum ice extent.
The yellow line indicates the average minimum ice extent of the past 30 years
compared to the minimum ice extent on September 16th 2012.

Fig. 2. Perennial ice.
The bright white central mass shows the perennial sea ice. The larger light blue area shows the full extent of the winter sea ice including the average annual sea ice during the months of November, December and January.

Read the rest over at Our Changing Climate.

Comments

[Robert Fanney]

Good analysis. For my part, I think the notion that variability accounts for 50% of ice melt is pretty out of bounds. We've seen a long enough trend and a rapid enough decline to rule out most natural variability features.

[Jim_pettit]

The post at Our Changing Climate is definitely an interesting one. It's disappointing--though entirely expected, of course--to see Judith Curry downplaying the role of greenhouse gases in the disappearance of ice, and practically going into contortions to do so. Though I suppose the fact that she's willing to admit a 50/50 split between natural variation and anthropogenic causes is a sign of progress where she's concerned. At any rate, I, too, tend to agree with Curry's colleague--NSIDC's Walt Meier--in his agreement with Day et al. 2012, who (as noted in the article) arrived at a 70-95% anthropogenic origin for ice loss based on the following:

1. The decline in sea ice correlates with the increase in global temperature.
2. The decline is outside the range of normal variability over the past several decades and probably over the past several centuries
3. The decline is pan-Arctic, with all regions experiencing declines throughout all or most of the year.
4. Climate model simulations cannot explain the decline without taking greenhouse gases into account.
5. There does not appear to be another mechanism to sufficiently explain the long-term decline.

[Carex]

Wouldn't it be reasonable to consider an anthropogenic origin of greater than 100% due to natural forcings being negative or cooling?

[Steve Bloom]

(Corrected comment from previous thread).

Well, one thought I have is that standards had to be severely bent to include Judy as a sea ice expert. Her limited publication record on the subject just doesn't support it. That much of what she said was wrong is thus no surprise. So, Jos, my major criticism of your article is that you carried forward that premise.

[wayne]

Guessing about factors is a very weak way of understanding the matter. The effort should be in coming up with a working model as potent as Global temperature GCM's. The only thing good I read about this discussion was from Dr Meier "

"the multi-decadal decline in all seasons, and in virtually all regions cannot be explained without the long-term warming trend that has been attributed to anthropogenic greenhouse gas (GHG) emissions.”.

This means that a model without CO2 doesn't give the current melting. But these models even with CO2 fail by quite a large time factor in emulating current volume melts. It would be good if the sea ice models used are explained in modular details. Something is obviously a miss. Many of us can help in finding the faults with them. All we read is that they fail, without seeing how they function. It would be like Einstein guessing gravitational lensing without actually formulating it, the guess is interesting, the calculation is science.

[Erimaassa.blogspot.com]

http://nsidc.org/arcticseaicenews/ notes that of 10 lowest maximums of arctic sea ice, 10 have happened in the last 10 years.

[Jim Hunt]

Hi Wayne,

"Something is obviously a miss. Many of us can help in finding the faults with them. All we read is that they fail, without seeing how they function."

A nascent attempt to address that issue, over on the forum:

The Distributed Arctic Sea Ice Model

[Doomcomessoon]

Jim_pettit. I can't see why you and Walt Meier consider the anthropogenic origin for ice loss to be 70-95% instead of at least 70-100% (or as Carex suggests, 70% to greater than 100%, to make the point that we might be countering a negative trend). With solar activity falling and without the obvious presence of other natural forces that one would expect to heat the climate, shouldn't one expect that human influence is just as likely to counter a natural cooling that would be increasing the ice volume (and thus be responsible for 100% of the arctic melting), as it is to be strengthened by any natural variation that is causing the the ice pack to melt further?

[wayne]

Hi Jim, that is a very good idea, and deserves a work out.
But I am curious about the failed models. I suspect that they use something like an empirical formula, for instance Lebedev and
deal with albedo, aerosols, Greenhouse gases ,radiation budget and somehow fail to calculate something as simple as ice thickness over a season. So for instance currently first year ice thickness over much of the CAA is about 150 cm. Lebedev denies this measurement, it should be somewhere around 220 cm. Amount of snow on its surface should be at all time lows, so thickness should be close to the empirical formula. It isn't. But now I am guessing that they use something like Lebedev. Also under thick sea ice water temperature is -1.8 C or colder. I suggest likely a radiation budget miscalculation, whereas the sun has far greater impact in slowing growth of new ice than previously calculated.
Arctic Aerosols are so low and also there is actually no observable
impact of direct sun and thickness to data (although there is a method). I suggest the sun slows growth, along with low or mid level clouds. Snow cover as well. This means that there is very little time for new ice to actually expand, only during a clear night, how cloudy the long night was becomes crucial. When the sun appears the Maxima extent and volume diminishes shortly after. But I believe that there is something like what elevations of sun actually stop thickness expansion dead. Leaving the nights before the long day the only time for further growth. Hudson Bay is very interesting place to work out any new model formulation because it has sun most times of the year, along with very cold surface temperatures. As we all know its ice vanishes during summer. So as an experimental location, it is perhaps ideal to try out any new model.

[Robert Fanney]

@ Wayne

I wonder, and this is complete speculation on my part, if what the models are missing is one of these:

1. The amount of inertia in the ice (over-estimated due to not taking into account non-linear influences of heating such as changes in ice sub-states -- cracked, broken, mobile, etc, changes in albedo of ice and surrounding environment, and contact with heat vectors -- currents, winds, etc).

2. Sensitivity not just to temperature change, but to the rate of change.

3. Modeling how the ocean environment moves heat around as it warms.

4. Getting the feedbacks right in the models. And I guess that would involve taking a look at the underlying assumptions.

5. Looking at the way the atmosphere moves heat around and how this impacts energetic/disruptive systems such as storms, winds, and warm air invasions.

I also wonder if the final, official models are the more conservative ones and if more accurate models are available but not widely publicized? Again, total speculation, but a question worth asking.

Lastly, I guess we need to ask how much of the energy imbalance we've created is going to work melting ice. Early climate change models assumed that ice would be slow to respond. At least in the case of Arctic sea ice, the response has been quite rapid. And we are seeing Greenland and, to a lesser degree, West Antarctica begin to respond with increasing speed as well.

Complete speculation. But, I think, questions worth asking.

[Robert Fanney]

@ Jim

Great to see you back.

RE variability...

Yeah, at this stage, the 50% number would seem very tough to defend. And Meier does seem to make the more rational case.

But it's probably worth discussing where even the 30% or 5% of natural variability melting the ice comes from. We have a long-term natural cooling trend, we have short-term lower solar activity, and we have a short-term slightly higher level of volcanic aerosols.

Does that variability assumption come from natural yearly ups and downs? Well, we haven't seen much in the way of ups in recent years.

What, outside of AGW, is melting the ice? Is that specifically identified or is it assumed. Maybe something worth talking about in these discussions.

[NLPatents]

I thought there was a concensus that we had passed the climate optimum and were on the downward trend towards a new ice age? I guess not. Reminds me of a Robert Frost poem:

Fire and Ice
Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice.

[wayne]

Robert, all these assumptions are worth while testing. But not being able to put my teeth in any sea ice model is frustrating. For the time being , I know that Lebedev is not working well right now. And there has to be some way to calculate freezing time, when Lebedev can be applied, as opposed to applying it all the time, accumulate degree days only when there are no low clouds and no sun. I think that Lebedev would work better with these restrictions. Right now its off by a good 30 % or more. A huge discrepancy.

[Donald]

Over the last two days there has been a very noticeable breakup of ice in the Fram Strait.

Compare today, March 26 -- http://earthdata.nasa.gov/labs/worldview/?map=-493632,-1533056,-2112,-1241472&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-26T12:00:00&switch=arctic

With March 24 -- http://earthdata.nasa.gov/labs/worldview/?map=-493632,-1533056,-2112,-1241472&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-24T12:00:00&switch=arctic

[Robert Fanney]

@ Wayne

Ouch. 30%? That's pretty high.

Yeah. It would be good to get into the guts of one of these, change some of the assumptions, and see how much closer it comes to reality. Any good papers on models worth cracking open? Or are the ice modeler just circling the wagons until they can make sense of what's happening?

@ Donald

Ice motion in the Fram has been very fast on the navy models over the past couple of days. Thanks for the live shots. Good ones!

[Jim Hunt]

Wayne - I can't claim to have been through it in any detail, but the CICE manual briefly covers the theory of operation.

Robert - If you fancy getting into the guts of CICE you can even download the source code. The docs included in there cover more of the theories behind the model.

[NeilT]

Realclimate has links to data, raw and processed and also the code for reconstructions and some of the GCM's.

http://www.realclimate.org/index.php/data-sources/

I guess it's a place to start.

[Jim Hunt]

Thanks for that long list of resources Neil. Actually it should be even longer now, as I endeavour to explain over on the forum:

http://forum.arctic-sea-ice.net/index.php/topic,108.msg2493.html#msg2493

[Robert Fanney]

@ Jim @ NeilT

I've been lurking over at the forums and it looks like a great little project/experiment is evolving. It is good to look at the guts of this. Will probably need some modeler types to help us understand the mechanics.

These are usually run on supercomputers, right? Anyone ever try to crowd-source it? A long time ago, SETI did a crowd source for analysis of radio waves from other star systems. Wonder if you could run different tweaks of CICE or other models through a crowd/cloud?

[Jim Hunt]

Hi Robert - Take a look at Crandles remarks about climateprediction.net on the ASI forum:

https://forum.arctic-sea-ice.net/index.php/topic,108.msg1436.html#msg1436

CPDN = SETI 4 Climate!

As you say, these things are usually run on supercomputers. Hence the interest in a potential "crowd-sourced supercomputer"

[NeilT]

I posted on the forum about discrete gpu clusters rather than huge grid.

Nothing I can follow up for you but a thought anyway. Parallel GPU systems are acting much like supercomputers today.

[R. Gates]

Robert Fanney,

One of most significant things that the sea ice models are missing is a full accounting of the advection of heat from lower latitudes into the Arctic via the oceans. This problem is of course related to Trenberth's "missing heat" problem in that there is overall a very poor measurement of the actual number of Joules of energy the oceans are storing each year. We can come down to a rough approximation that down to 2000 meters or so the oceans have be storing about 0.5 x 10^22 Joules per year over the past 40+ years. But what about deeper levels? And how much of this energy is actually being advected into the Arctic Ocean? If we knew the number of additional Joules of energy that were eating at the ice from underneath over the past few decades, the sea ice models could do a much better job at telling is when the ice will disappear in the summer.

[wayne]

Thanks Jim,

CICE document is a first for me, it will take time for me to study it, of interest are the model components. But seeing its results on a near live or daily basis would be really practical, because we can actually judge if the model is getting things right. For instance I can confirm Incoming and outgoing radiation from a given ice sheet on an instantaneous basis, it would be simply excellent if this model would calculate its results for verification purposes. The reason why Lebedev is off by more than 30% is likely because it is a gross simplification. This CICE model is vastly more complex, but like others has failed to calculate reality. From this stand point, a really logical step would be to have ice model results (not just thickness but all components) available like GRIB, and observe on a near live basis if the simulation matches reality. If allowed to do so, it would take really very little time to figure out what may be incorrect. I think they evaluate by remote sensing,
is good, but on site evaluations complete the task.

[Jim Hunt]

R. Gates - As luck would have it I currently find myself debating Kevin Trenberth's "missing heat" with a bunch of denialistas over at The Economist. According to The Economist:

"A study in Geophysical Research Letters by Kevin Trenberth of America’s National Centre for Atmospheric Research and others found that 30% of the ocean warming in the past decade has occurred in the deep ocean (below 700 metres). The study says a substantial amount of global warming is going into the oceans, and the deep oceans are heating up in an unprecedented way. If so, that would also help explain the temperature hiatus."

According to one Dr. Norman Page:

"I would suggest that the modellers and the establishment scientists recalculate their climate sensitivity to CO2 in light of the Trenberth presentation at http://www.cpc.ncep.noaa.gov/products/outreach/proceedings/cdw31_proceedings/S6_05_Kevin_Trenberth_NCAR.ppt

This paper shows a strong natural negative feedback which has not been included in the IPCC - Met Office models and which independently of all the other evidence would necessarily substantially reduce model warming predictions."

According to Skeptical Science:

"A new study of ocean warming has just been published in Geophysical Research Letters by Balmaseda, Trenberth, and Källén (2013). There are several important conclusions which can be drawn from this paper. Completely contrary to the popular contrarian myth, global warming has accelerated, with more overall global warming in the past 15 years than the prior 15 years. This is because about 90% of overall global warming goes into heating the oceans, and the oceans have been warming dramatically."

Who should one believe in these difficult and confusing times, and why is it that none of them are willing and/or able to provide me with a straight answer to a straight question?

[Kevin O'Neill]

Jim, first thing I find is that Dr Norman Page is a well-known denier an oil consultant with a PhD, in Geology at University of Illinois at Urbana-Champaign.

Second, heat going into the oceans is NOT a negative feedback - it's simply a matter of distribution. It may well be that the models have the distribution wrong between atmosphere and oceans, but last I checked the oceans are still part of the earth.

Unless Dr Page has some magical way of simply making the ocean heat disappear, the best that can be said is that we might be able to buy a little more time before that 'missing' heat comes back to haunt us.

[Jim Hunt]

Hi Kevin,

Thanks. I suspected as much, though I hadn't had time to do my own due diligence on oil consultants.

Jeff Masters is on the same case also:

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2374

[Shared Humanity]

Second, heat going into the oceans is NOT a negative feedback - it's simply a matter of distribution.

From a systems perspective, the oceans are acting as a giant buffer which serves to store the "stock" of heat that is being accumulated. Given the mass of the oceans vs. our atmosphere this storage of heat could last for thousands (????) of years, I would think. Is this uptake of heat a slow process? If not it could mask the worst effects of warming for a long time, playing into the hands of the denialists and causing a profound sense of complacency. Feedback mechanisms that have a long delay in systems can be very disruptive.

[Fairfax Climate Watch]

Here's a 2000 year record of the Arctic summer temperature: http://climatewatch.typepad.com/blog/2013/03/arctic-2k-year-trend-is-toast.html

[Steve Bloom]

Judah Cohen and colleague have a new open-access snow paper. There's an accompanying video, which is a nice added feature.

[Steve Bloom]

SH, ocean circulation is hugely critical to climate. Dumping a bunch of heat into the oceans is going to have effects, potentially ones worse than if it was going into the atmosphere.

Melting ice is fun to watch and is certainly a visible canary in the coal mine, but the impact we care about most is shifting rainfall patterns affecting the crop-growing regions, noting that we're already seeing some of that.

[Jim Hunt]

"Apocalypse" perhaps a lot sooner that The Economist seems to think?

https://www.economist.com/comment/1949714#comment-1949714

[GreenOctopus]

As fascinating and terrifying as this all is with regards to the deep ocean heating--especially regarding Balmaseda et al. (2013)--I'm still unable to wrap my mind around the ramifications of it.

If I understand it correctly, part of the reason the deeper ocean is warming faster than the surface recently may have something to do with the persistence of a negative PDO and the dominance of La Niña over the past decade, such that the extra energy being poured into the Earth is being bottled up deep in its patient waters, whereas cold water is being exposed to the surface. But, once the Earth snaps out of this passive-aggressive La Niña and switches to a cathartic and very aggressive El Niño, the heat that's been accumulating will at least be partially released to the air. This would make sense intuitively, but it leaves me wary as to how the deepest ocean waters would come to play, since I am somewhat unsure (apart from the role of thermohaline circulation) how the deepest, warmest of waters could be brought to the surface.

It isn't as though the laws of physics have changed. The acceleration of carbon dioxide within a logarithmic radiative forcing calculation still implies a steady rise in CO2's climate forcing role. And the fact that the oceans have been taking up more heat doesn't negate that some of the extra energy from GHGs and feedbacks is still going to go into melting sea ice/glaciers and lifting surface temperatures. If it's natural variation that's changing the distribution of heat at the moment, that's even more upsetting, since the pendulum will eventually swing the other way, and on and on. To me, it reads as the ocean building a savings account for future warming that will be brought to the surface from time to time via El Niño discharges or other climatic oscillations.

I, too, share my lament of a lack of understanding of the deep ocean with Trenberth. Given our current understanding of what 3% or so of the world's deepest oceans we've explored, I don't take much solace in the idea of the ocean being our savior.

[Chris Reynolds]

Thanks Steve,

That's serendipitous, I've just been digging some more into the causation of the new Summer circulation pattern. I've been looking at a box area in Eurasia showing the greatest negative anomalies in Rutgers plots for May, and temperature in May. Here the implication is that lack of snow causes warmer temperatures.

I may well blog on it now as this paper's out.

[Shared Humanity]

Green Octopus...

I am not very informed about climate change and struggle to understand most of what is posted here. (I am getting better.) but I thought I would comment on your post, ignoring entirely the climate implications.

It isn't as though the laws of physics have changed.

Certainly not. I actually think the slow but relentless uptake of heat by the oceans is entirely consistent with physics. When any two materials touching each other have different temperatures, the effect is to have these materials transfer heat from the warmer to the colder. In a closed system, they would eventually arrive at equal temperatures. In electronics, this allows us to build complex processor chips which generate a lot of heat that would actually destroy the chip. Heat sinks (frequently aluminum because of their ability to absorb heat rapidly) are used to draw heat from the chip. Don't ask me to provide equations (I am not an engineer.) but the relative masses of the two materials and the speed of transfer are critical to the behavior of this heat transfer. I live in Chicago. In the spring the air begins to warm but the lake which has cooled throughout the winter will cause the temperatures in the city to be much cooler than the suburbs, often as much as 10F. This effect is diminished through the summer as the lake water temperatures rise. The ocean's mass is far greater than the atmosphere. This is also not a closed system as the atmosphere continues to capture more of the sun's heat due to increasing levels of CO2. (I do understand the ocean also captures this heat directly as ice melts.) Because of the ocean's mass, the transfer of this heat being captured will be one way. The warming atmosphere will continue to transfer heat to the oceans. Due to the differences in mass, the ocean's ability to absorb warmth from the atmosphere could appear, in the short term, endless. I have no idea (and I mean no idea) what impact on ocean currents, climate and weather would be as a result of this slow but relentless uptake of heat in the ocean.

I don't take much solace in the idea of the ocean being our savior.

I wouldn't either. In fact it could cause our long term doom depending on the speed of the transfer (in either direction) between the atmosphere and oceans. The enormous amount of heat store capacity of the oceans and the likely slow transfer between them and the atmosphere will, I believe, serve to make the AGW driven climate changes very persistent.

[R. Gates]

While it is true that the heat capacity of the ocean and its greater thermal inertia "buys some time" in terms of the effects of global warming for we land dwelling creatures, there still of course is no free ticket. As we've seen with the gross miscalulation by the GCM's of how fast we'd be losing the sea ice, the heat going into the ocean has real effects, i.e. melting the sea ice from the bottom. Also, the notion that there is some kind of "negative feedback" provided by the oceans taking up much of the heat provided by increasing greenhouse gases is quite absurd or simply a gross misunderstanding of what a true negative-feedback is. The "human volcano" that has been erupting CO2 in increasing amounts over the past several centuries represents such a signficant shock to the Earth system (as any ordinary volcano does as well) that virtually all negative natural feedback processes(such as the normal rock and carbon cycles) for CO2 balance are being vastly overwhelmed. In such cases, it is in fact positive feedbacks that come to dominate the dynamics. This is exactly the case we are seeing in the Arctic, whereby the oceans worldwide are taking up the extra heat being trapped in the Earth system, but that heat is being advected via currents to the Arctic (and deeper waters near Antarctica), with the result that sea ice is disappearing much faster than the models ever indicated and this creates more open water for longer periods of time and thus the oceans absorb more energy and the positive feedback brought about by the human CO2 volcano continues.

[me.yahoo.com/a/nSjChi4X3vr8X3DRw93GkY1.cerja.8nvWk-]

Hi guys, I just saw this on CNN and thought it may be of interest. Does anyone have any more details?

Phil.

http://www.cnn.com/2013/03/29/world/europe/latvia-ice-stranded/index.html?hpt=hp_t2

[Werther]

Hi Phil,
The ice floe rescue in the Gulf of Riga is one of these stories illustrating the impact of the blocking cold event we're witnessing.
I'm on the SW tail of this transport band, in the Netherlands.
Yesterday we had icebreakers (not the Healy kind, mind you) cracking one to two inch ice on lakes to make spring boat trips possible in the Easter-weekend. That's very unusual here.
The extraordinary blocking is predicted by ECMWF to continue and even strengthen end of next week.

[Robert Fanney]

Don't find heat uptake by deep oceans all too comforting. Perhaps that's why we've seen less stable methane hydrates lately?

More rapid transfer to the deep ocean is a kind of two edged sword. One, it means more rapid sea level rise (thermal expansion). And, two, it means the heat gets dumped into the atmosphere later after a period of delay.

I don't know what it means RE water vapor. But a warmer ocean generally means more of it.

As for how the heat got into the deep ocean, it seems that La Nina probably played a role. Wonder about other mechanisms, though.

Lastly, according to Skeptical Science, the Economist got its sensitivity argument mostly wrong. According to Hansen, we have increased SO2 levels masking warming that would otherwise happen (his Faustian bargain warning again). And, according to Skeptical Science and Jeff Masters the pace of warming hasn't declined once you factor in the ENSO cycle and other natural variability.

Of course Trenberth is still on the hunt for the rest of the 'missing heat.' So I wonder, did some of it go into melting ice instead?

[Erimaassa.blogspot.com]

RE: Gulf of Riga.

This happens quite regularly in the Baltic. -gulf of riga, gulf of finland and the southern part of gulf of bothnia have these ice breakup events no one is able to predict well and anyway people want fish on their tables. northern part of gulf of bothnia still has quite predictable ice (i've heard) otoh, this was like the 10th time in the past 15 years. but anyway, this was one of the largest amounts of people on the floes that i remember.

[Erimaassa.blogspot.com]

see f.e. http://articles.chicagotribune.com/2000-04-18/news/0004180222_1_russian-fishermen-fishing-experience-fishing-hole