From the AGU Journal Highlights, some news that NSIDC’s “death spiral” has zombie like characteristics, and that the ice may quickly return from the dead, even if the Arctic turned ice free during summer. Nature is more resilient it seems, than some people give it credit for.
No tipping point for Arctic Ocean ice, study says
Declines in the summer sea ice extent have led to concerns within the scientific community that the Arctic Ocean may be nearing a tipping point, beyond which the sea ice cap could not recover. In such a scenario, greenhouse gases in the atmosphere trap outgoing radiation, and as the Sun beats down 24 hours a day during the Arctic summer, temperatures rise and melt what remains of the polar sea ice cap. The Arctic Ocean, now less reflective, would absorb more of the Sun’s warmth, a feedback loop that would keep the ocean ice free.
However, new research by Tietsche et al. suggests that even if the Arctic Ocean sees an ice-free summer, it would not lead to catastrophic runaway ice melt.
The researchers, using a general circulation model of the global ocean and the atmosphere, find that Arctic sea ice recovers within 2 years of an imposed ice-free summer to the conditions dictated by general climate conditions during that time. Furthermore, they find that this quick recovery occurs whether the ice-free summer is triggered in 2000 or in 2060, when global temperatures are predicted to be 2 degrees Celsius (3.6 degrees Fahrenheit) warmer.
During the long polar winter the lack of an insulating ice sheet allows heat absorbed by the ocean during the summer to be released into the lower atmosphere. The authors find that increased atmospheric temperatures lead to more energy loss from the top of the atmosphere as well as a decrease in heat transport into the Arctic from lower latitudes. So the absence of summer sea ice, while leading to an increase in summer surface temperatures through the ice-albedo feedback loop, is also responsible for increased winter cooling. The result is a swift recovery of the Arctic summer sea ice cover from the imposed ice-free state.
Title:
“Recovery mechanisms of Arctic summer sea ice”
Authors:
- S. Tietsche, D. Notz, J. H. Jungclaus, and J. Marotzke
- Max Planck Institute for Meteorology, Hamburg, Germany
Source:
Geophysical Research Letters (GRL) paper 10.1029/2010GL045698, 2011
GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L02707, 4 PP., 2011
doi:10.1029/2010GL045698
Recovery mechanisms of Arctic summer sea ice
S. Tietsche, Max Planck Institute for Meteorology, Hamburg, Germany
D. Notz, Max Planck Institute for Meteorology, Hamburg, Germany
J. H. Jungclaus, Max Planck Institute for Meteorology, Hamburg, Germany
J. Marotzke, Max Planck Institute for Meteorology, Hamburg, Germany
We examine the recovery of Arctic sea ice from prescribed ice-free summer conditions in simulations of 21st century climate in an atmosphere–ocean general circulation model. We find that ice extent recovers typically within two years. The excess oceanic heat that had built up during the ice-free summer is rapidly returned to the atmosphere during the following autumn and winter, and then leaves the Arctic partly through increased longwave emission at the top of the atmosphere and partly through reduced atmospheric heat advection from lower latitudes. Oceanic heat transport does not contribute significantly to the loss of the excess heat. Our results suggest that anomalous loss of Arctic sea ice during a single summer is reversible, as the ice–albedo feedback is alleviated by large-scale recovery mechanisms. Hence, hysteretic threshold behavior (or a “tipping point”) is unlikely to occur during the decline of Arctic summer sea-ice cover in the 21st century.
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This lends credence to this related story previously on WUWT:
The full paper is here (PDF) backup location here Tietsche_GRL_2011
phoenix ice?
Joe Lalonde
February 9, 2011 at 2:00 pm
The Holocene Climatic Optimum (AKA Atlantic Period) was much warmer and more humid. The temps were from 3 to 6 degrees warmer then today, depending who you talk to, though the greenies are doing their best to make the science go away. This was a time of great advancement in human civilization. Seas were 5 to 9 meters higher also, which probably gives a good maximum sea height, given the closure of the tethis (Mediterranean) and the blockage caused by the ismeth of Panama, coupled with the thermal isolation of antarctica.
Urederra
February 9, 2011 at 3:13 pm
phoenix ice?
###
Hockey was very popular when I was a kid in the late 60’s early 70’s. I loved the Roadrunners 🙂
Some posters here have mocked the conclusion that and ice-free arctic should recover its icecap. But this is a step in the right direction.
One of the central planks of warmist theory is the assumption of unstable equilibrium. The smaller-icecap/lower-albedo argument has a grain of truth, and the claim that this leads to irreversible warming has not yet been debunked.
The loathesome expression “tipping point”, with its image of a capsizing ship, struck fear into many viewers of An Inconvenient Truth: Mister Gore has consummate propaganda skills (we should grudgingly admit) and the “tipping point” expression is dazzlingly effective. If this AGU paper helps demolish the “tipping point” fallacy, then great!
No GCM model is required to come to the conclusions of this paper.
Annually averaged solar insolation in the Arctic is about 2 kWhr/m^2/day, or about 83 W/m^2. Open water at 276 K has an IR emissivity of almost 1, and emits about 329 W/m^2. A clear sky radiates back an empirically measured amount of about P = 8.8E-13*T^5.85 = 167 W/m^2. The net IR emission from open water is 329 – 167 = 162 W/m^2.
Therefore, open ocean will emit, on average, about 79 W/m^2 more energy than it will absorb from solar insolation. This is a low estimate, since all of the solar insolation is assumed to be absorbed, but this is not true because of the low angle of the sun above the horizon even at peak summer insolation.
Salute!
Can’t find the reference, but seems like in the 70’s or late 60’s someone ( might have been in Scientific American) postulated that the great continental glaciers came about because the Arctic had less ice and more water to form snowstorms further south year after year. Sorta like we’ve seen in Great Britain and to some extent in North America these past few years.
The persistent snow cover reflected more sunlight and global cooling became strong enough for those giant glaciers to form.
Anybody else remember this?
Pat sends…
Ugh GCMs.
Can’t we ge a study that uses empirical measurements as proof? Why is hard data so out of fashion? I guess it’s easier to sit at a desk with your C++ book and color graphs that actually picking up a thermometer.
Brent Hargreaves says:
February 9, 2011 at 3:52 pm
“Some posters here have mocked the conclusion that and ice-free arctic should recover its icecap. But this is a step in the right direction………..
If this AGU paper helps demolish the “tipping point” fallacy, then great!”
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Yes, of course, you are correct, but its a bit frustrating for some. Many of the comments here illustrate how far ahead of the curve skeptics are in this matter. There never was a tipping point to be considered. The albedo of the arctic has always been overstated. Nature has in place self regulating mechanisms. And water will turn to ice in freezing temperatures. I’ve been stating for quite some time that the arctic isn’t very relevant to the GW discussion, of course, others will probably disagree, but this paper would buttress my point of view. Ice comes and goes from that region by many causations. But if the ice were to totally disappear, nothing would happen and likely in short order, the ice would reappear. Man would forget and we’d drill ice cores again and pretend they hold some sequential information. “Oh look! Here’s some 3000 y/o CO2!!! This must mean…….”…..sigh
This is a very interesting model run, but given how AGW skeptics put little credibility in IPCC AR-4 model, I can hardly see how they would think much of the outcome of this model simulation.
Also of course, given how no true “tipping point” can ever be accurately predicted or modelled before it occurs, it is not surprizing that this simulation finds no tipping point in Arctic Sea ice.
Two additional interesting points– this model run is based on the assumption of AGW, and so of course must be rejected out of hand by AGW skeptics. And secondly, the run of this model assumes that the heat loss from the open water will simply go right out the TOA, without any consideration of other effects from the extra fall and winter heat in the Arctic. Others studies have shown substantial effects from that heat being released in the autumn and winter that most significantly include changes in atmospheric circulation patterns in the entire N. Hemisphere and hence a change in the climate of the Arctic, which this study ignores. See for example:
http://www.arctic.noaa.gov/future/docs/ArcticAND_Globe.pdf
http://www.arctic.noaa.gov/future/heat.html
http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0870.2009.00421.x/full
http://www.jamstec.go.jp/frsgc/research/d2/masayo.ogi/09056-galley-proof.pdf
So, while these model runs, might or might not be accurate to what might happen to the arctic sea ice under assumed AGW, why should AGW skeptics care as they either don’t think AGW is happening, or certainly don’t trust the IPCC AR-4 model this study was based on. Either way, it is based on the assumption in this study that you could have that much heat being released from open water in the Arctic during the fall and winter without significantly affecting global circulation patterns (as indicated in other studies). And most importantly, since “tipping points” are by definition, not predictable by any model, the fact that this model run didn’t find any, isn’t too terribly surprizing.
Wow! R. Gates has a bad hair day.
The science page of Deutschlandradio, one of the big German radio stations, also ran this paper http://www.dradio.de/dlf/sendungen/forschak/1382801/ .
When it comes to CAGW this site is total propaganda. No matter what research it is always “worse than we thought”.
Now this time they admit it might be not as worse as thought.
Did we reach a tipping point here?
R. Gates says:
February 9, 2011 at 4:31 pm
“So, while these model runs, might or might not be accurate to what might happen to the arctic sea ice under assumed AGW, why should AGW skeptics care as they either don’t think AGW is happening, or certainly don’t trust the IPCC AR-4 model this study was based on.”
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Because we know the IPCC AR-4 is an extreme model with extreme assumptions. So, this study suggests that even if extreme conditions existed, the self-corrective mechanisms would still prevail. We all knew this already, but many of us are glad to see some “scientists” suddenly realize this. Maybe they’ll catch up……..in a few decades.
Additionally, the way I read it, it wasn’t dependent upon AGW, or even GW. But simply assumed an ice free arctic as a starting point for the run.
Don’t they mean hysteric threshold behavior ?
Dave Springer says:
February 9, 2011 at 1:06 pm
Climate boffins never seem to think these things through…
Please define the pejorative term “climate boffins”.
It certainly doesn’t apply to S. Tietsche, D. Notz, J. H. Jungclaus, and J. Marotzke, who ran the climate models and came up with the result showing there is no “tipping point” for Arctic Ice, where loss of ice is unrecoverable. Without this result, there is no quantitative way to tell. The hypothesis of the existence of a tipping point on the part of some climate scientists was wrong, but that doesn’t prove they haven’t thought something through. It only shows that their judgement about the strength of summertime warming, versus wintertime cooling was wrong.
R GAtes says:
>>
This is a very interesting model run, but given how AGW skeptics put little credibility in IPCC AR-4 model, I can hardly see how they would think much of the outcome of this model simulation.
>>
Correct, most skeptics would reject the whole idea as unproven. The point is what it shows to those who “believe”.
>>
Also of course, given how no true “tipping point” can ever be accurately predicted or modelled before it occurs, it is not surprizing that this simulation finds no tipping point in Arctic Sea ice.
>>
Why can’t a simulation simulate a tipping point?
Or do you just mean no climate events can be predicted before they happen and no model will ever get anything right?
Mr. R Gates,
This heat you speak of that is being ‘released’ is coming from where?
This heat that was ‘released’ goes where?
Since the atmosphere does little to heat the oceans, in the scenario of released heat, the net heat content of the planet should go down due to the warmer air radiating heat into space.
Scott Covert says:
February 9, 2011 at 4:20 pm
Ugh GCMs.
Can’t we ge a study that uses empirical measurements as proof? Why is hard data so out of fashion? I guess it’s easier to sit at a desk with your C++ book and color graphs that actually picking up a thermometer.
===
Yes but almost anyone can read a thermometer. You need esoteric code and massively expensive hardware to generate a priesthood that holds all secret knowledge and can “explain” it simply to the surfs, in return for their surfdom and lots more money.
Credibility of AGU releasing such papers under a cloud – credibility gap widens.
Of course, this won’t mean that Lindzen & Choi will cease to be a part of the denialist canon, to be trotted out every now and again in lists of papers skeptical of ‘man-made’ global warming and used to confuse an unfamiliar public; but it will mean that the warmists can quickly point out that it’s not quite what it’s cracked up to be and shut us deniers up about it for a while. This is very unfortunate, and frankly it’s a bit of a blow to the denialist credentials of the American Geophysical Union, publishers of Geophysical Research Letters and Journal of Geophysical Research – Atmospheres, the journal that hosted a paper by our friends McLean, de Freitas & Carter that became another denialist touchstone and which, together with Lindzen & Choi, made AGU the publisher of fully two-thirds of the peer-reviewed denial of 2009. Sadly, the McLean et al. paper, too, has lately been shown to be bollocks. [As an aside – it’s interesting to consider the two papers together, because while McLean et al. purported to show that ENSO, a phenomenon of tropical origin, has been exporting heat to the rest of the planet so efficiently it’s been responsible for almost all global temperature change since 1958, Lindzen & Choi implicitly assumed that tropical heat hasn’t been exported anywhere except into space. And the Friends of Science claim that temperature change is all because of the sun. Can’t accuse us deniers of being inconsistent…]
http://friendsofginandtonic.org/files/b78f644320e6cc9c1d8e3e1ce2b17432-137.html
R. |Gates 4:31
It is precisely because they used IPCC’s model with its biases and exaggerations that the finding is so solid. They also used an increase of 2C when empirically from the past century and a half it has been 0.7C, ie 0.5C per century (don’t forget the high priests have admitted that there has been no statistical warming since 1995, over a sixth of a century, and many of the faithful have even granted that we might have a cooling for another couple of decades).
Skeptics who bemoan yet another use of a model should understand that the Max Planck Institute deliberately used an accepted model that had been used to show the death spiral. The researchers chose a powerful strategy in using this worn model. They may privately believe that the reality will be even more ice growth in the arctic.
Another point touched on by others: I can’t believe that real scientists would not take into consideration a) the low angle of incidence where, even if there was no large reflected component, and the filtratation of sunlight by the effectively greatly increased air thickness could be ignored, the incident radiant energy is sine 20 x radiant energy at the equator.
So, the summer ice melts and the sun heats the cold Arctic waters. 24 hours a day, sort of. For a few days. Then the sun, as seen from the Arctic, heads south, taking its warmth with it. And the Arctic Ocean, denuded of ice, is exposed to darkness and space and sort of thermodynamicky stuff. And the heat left in the water is lost to the atmosphere even tho CO2 does its best to keep it warm. But the CO2 can’t keep it warm because the ice is gone and is not there to provide insulation. And the water, instead of staying warm and making sure no ice ever forms again in the Arctic, freezes. And there is no feedback and warmistas face the spring with the task of reforging GIGO for their models. Reality bites.
@P.Solar You can’t explain anything to the “surfs” but the “serfs” can be made to understand. I know this because I are 1.
@psolar
A nice result. Debunking the notion of a `tipping point’ for arctic sea ice in the published literature is a very worthwhile thing to achieve.
“Dave Springer says:
February 9, 2011 at 3:08 pm
Increased warmth results in increased evaporation which convection carries upward along with a huge amount of what’s called latent heat of vaporization.”
This is very true. But is there not also an increased negative feedback if the precipitation falls as snow and then the liquid water cools off still more in melting the snow due to the latent heat of fusion?
P.S. “high reflectance at low angle of incidence” The angle of incidence is measured from the normal so it should be “high reflectance at high angle of incidence”
There is now 1 positve feedback (arctic ice albedo)
but 3 negative feedbacks:
– heat and radiation loss of the open water finally to outer space
– evaporation causing increased cloud coverage further south, thus increasing albedo (and at much more improtant latitudes)
– increased snow at lower latitudes, again increasing albedo.
It doesn’t matter in this context what caused the sea ice to decrease for some time.
What matters is the size of these feedbacks, and as the authors come to the conclusion that any ice free arctic may recover within as little as 2 years, their combined effect should be strongly negative.
That blows one of the main scares and last straws of AGW out of the water.
We have seen expanding areas of open water in the Arctic summer since at least 1990. Most of the potential extra open water is already exposed to the summer sun. Because of the consistent sinusoidal pattern of Arctic melting and refreezing any additional exposure will likely occur between late August and the end of September when the Sun is circulating barely above the horizon and any additional effect beyond what has already transpired is likely to be marginal. Can anyone point me to some empirical observations that indicate that the projected scenario has been transpiring in the last two decades? I’ve had some difficulty locating it for myself.
A good example of the resilience of Arctic ice was shown be the recovery of ice thickness after the low areal extent of 2007. The average ice thickness actually continued to decline until 2008 but has now recovered to its long-term value. See mu analysis t:
http://www.climatedata.info/Impacts/Impacts/seaice.html