NCAR develops method to predict sea ice changes years in advance
From the NATIONAL CENTER FOR ATMOSPHERIC RESEARCH/UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH and the “we know so we’ll put that statement in a press release” department comes this interesting tidbit of modeling certainty.
BOULDER – Climate scientists at the National Center for Atmospheric Research (NCAR) present evidence in a new study that they can predict whether the Arctic sea ice that forms in the winter will grow, shrink, or hold its own over the next several years.
The team of scientists has found that changes in the North Atlantic ocean circulation could allow overall winter sea ice extent to remain steady in the near future, with continued loss in some regions balanced by possible growth in others, including in the Barents Sea.
“We know that over the long term, winter sea ice will continue to retreat,” said NCAR scientist Stephen Yeager, lead author of the study published online today in the journal Geophysical Research Letters. “But we are predicting that the rate will taper off for several years in the future before resuming. We are not implying some kind of recovery from the effects of human-caused global warming; it’s really just a slow down in winter sea ice loss.”
The research was funded largely by the National Science Foundation, NCAR’s sponsor, with additional support from the National Oceanic and Atmospheric Administration and the U.S. Department of Energy.
Yeager is among a growing number of scientists trying to predict how the climate may change over a few years to a few decades, instead of the more typical span of many decades or even centuries. This type of “decadal prediction” provides information over a timeframe that is useful for policy makers, regional stakeholders, and others.
Decadal prediction relies on the idea that some natural variations in the climate system, such as changes in the strength of ocean currents, unfold predictably over several years. At times, their impacts can overwhelm the general warming trend caused by greenhouse gases released into the atmosphere by humans.
Yeager’s past work in this area has focused on decadal prediction of sea surface temperatures. A number of recent studies linking changes in the North Atlantic ocean circulation to sea ice extent led Yeager to think that it would also be possible to make decadal predictions for Arctic winter sea ice cover using the NCAR-based Community Earth System Model.
Linking ocean circulation and sea ice
The key is accurately representing the Atlantic Meridional Overturning Circulation (AMOC) in the model. AMOC sweeps warm surface waters from the tropics toward the North Atlantic, where they cool and then sink before making a return south in deep ocean currents.
AMOC can vary in intensity. When it’s strong, more warm water is carried farther toward the North Atlantic and Arctic oceans, accelerating sea ice loss. When weak, the warm water largely stays farther south, and its effects on sea ice are reversed. The variations in AMOC’s vigor–from weak to strong or vice versa–occur over multiple years to decades, giving scientists some ability to predict in advance how it will affect winter sea ice, in particular.
AMOC now appears to be weakening. Yeager and his co-authors, NCAR scientists Alicia Karspeck and Gokhan Danabasoglu, found in their new study that this change in the ocean is likely to be enough to temporarily mask the impacts of human-caused climate change and stall the associated downward trend in winter sea ice extent in the Arctic, especially on the Atlantic side, where AMOC has the most influence.
The limits of a short satellite record
The amount of sea ice covering the Arctic typically grows to its maximum in late February after the long, dark winter. The sea ice minimum typically occurs at the end of the summer season, in late September. The new study addresses only winter sea ice, which is less vulnerable than summer ice to variations in weather activity that cannot be predicted years in advance, such as storms capable of breaking up the ice crust.
Despite their success incorporating AMOC conditions into winter sea ice “hindcasts,” the scientists are cautious about their predictions of future conditions. Because satellite images of sea ice extend only back to 1979, the scientists had a relatively short data record for verifying decadal-scale predictions against actual conditions. Additionally, AMOC itself has been measured directly only since 2004, though observations of other variables that are thought to change in tandem with AMOC–such as sea surface height and ocean density in the Labrador Sea, as well as sea surface temperature in the far North Atlantic–go back much farther.
“The sea ice record is so short that it’s difficult to use statistics alone to build confidence in our predictions,” Yeager said. “Much of our confidence stems from the fact that our model does well at predicting slow changes in ocean heat transport and sea surface temperature in the subpolar North Atlantic, and these appear to impact the rate of sea ice loss. So, we think that we understand the mechanisms underpinning our sea ice prediction skill.”
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About the article
Title: Predicted slow-down in the rate of Atlantic sea ice loss
Authors: Stephen G. Yeager, Alicia Karspeck, and Gokhan Danabasoglu
Publication: Geophysical Research Letters
The graphic in the post is misleading. It is labeled observed v. predicted. They predicted nothing. They tuned a new sea ice model to reasonably HINDCAST this result compared to observation. Hindcasts are not predictions. They are not even projections. And, as the pause has shown for CMIP5 climate models that were tuned to reasonably hindcast from 2005 back to 1975, they are not model validations, either. Validations still need to be out of sample.
This looks like a way to soften the coming warmunist Arctic ice meme blow, as Artic ice sure looks to be well into a roughly 30-35 year recovery from a nadir in 2007 (excepting the 2012 cyclone) as part of a natural roughly 70 year cycle. Satellite ice coverage coincidentally began in 1979, roughly around the natural sea ice peak based on DMI and Russian summer ice observations going back to the 1920’s.
I will have to review the paper to see:
Does their model accurately “predict” the 2011-2012 dip, and the subsequent recovery after 2012?
If so, can they parse whether that dip was due to their variables representing man-made global warming, or to this multiyear periodic oscillation? Or both?
If they say that the dip was largely due to ocean currents, then they are saying something heretical to all of their fellow warmista-cult-members – that the dip was a sure sign that the arctic sea ice would be gone in a matter of a couple or a few years.
I, and anyone else who felt that the dip was in the normal range of variation were oil-industry-shill deniers.
Now, are we vindicated by this paper? Can we expect an apology?
[BTW: Mann finished his dissertation on a DOE post-doc.]
Now we can safely bet that Arctic sea ice will expand quite a bit.
“We know that over the long term, winter sea ice will continue to retreat,”
We? How do we know this, exactly?
He means “we” in the majesterial sense. It is from on high. Not to be questioned, without fear of losing your head anyway.
Here’s a prediction: 20 years from now, after an extended period of global cooling, the left will take credit for this cooling, despite the fact that CO2 emissions continued to increase unabated. They will claim that the cooling was the result of their genuine concern for the planet. They will also ignore the increased misery that the cooler weather is causing around the world, blaming the misery on Bush.
This prediction is not from a computer model, but from pattern recognition, which is the only type of long-range prediction shown to have any kind of success with chaotic, non-linear systems.
“We know that over the long term, winter sea ice will continue to retreat,” Really? You mean winter ice will retreat in summer? Gotta be a Nobel Prize in that chunk of science!
These people say the warming contiues but the data from satellites and balloons say it isnt. I get very confused. If they are wrong about the warming they will also be wrong with their predictions will they not?
It looks like they have crawled out of one hole, only to fall back into another one. The inconvenient temperature pause was adjusted away, only to find that sea ice also paused. If you dig any deeper, you might not like what you find.
Whilst 2015 was somewhere in the middle for summer sea ice minimum extent, over the last 10 years, the recovery has been stark.
So far 2015 is suggesting above ‘normal’ winter sea ice maximum extent. This no doubt will lead to an increase in multi year sea ice.
See, generally:
http://ocean.dmi.dk/arctic/plots/icecover/icecover_current.png
I did not express myself well, but a picture is worth a 1000 words.
You can see from the above plot that 2015 (black line) in September was somewhere in the middle of the sea ice extent, whereas now in December it is tracking (slightly) above the maximum for any of the last 10 years.
Of course, it is difficult to say how things will shape up through to February/March 2016, and only time will tell. Nonetheless the recovery over the last 3 months has been stark suggesting that it is cold up there.
It will be interesting to see what it is like in Canada, and the Great Lakes.
Richard, I think we get played on the sea ice extent too. If it were measuring anything else, you would never measure the extremes…..you would measure around May and Jan when it’s tightly bunched together….where it’s been practically the same every year
But the graphs on “Cryosphere Today” show this year’s Arctic ice well below last year’s and about 4th lowest in their whole 36-year record.
Does this graph come from a different source?
DMI says this plot is bogus. http://ocean.dmi.dk/arctic/icecover.uk.php says:
The proper plot matches the WUWT Sea Ice page:
http://ocean.dmi.dk/arctic/plots/icecover/icecover_current_new.png
Nothing to get excited about….
Also that first graph uses a threshold of 30% coverage whereas their current graph uses the 15% threshold (like the other sites).
An important consideration when discussing “Arctic” ice is that the Sea of Okhotsk is usually included as part of the Arctic calculations. This artificially reduces recent year estimates since the Sea of Okhotsk accounts for a significant percentage of total ice loss.
opluso December 11, 2015 at 7:12 am
An important consideration when discussing “Arctic” ice is that the Sea of Okhotsk is usually included as part of the Arctic calculations. This artificially reduces recent year estimates since the Sea of Okhotsk accounts for a significant percentage of total ice loss.
Well the winter maximum there is ~1million sq km out of a total of ~14million sq km, annual loss is about 10 million sq km.
So, strong AMOC = “climate change” and weak AMOC = natural variation.
Got it.
Strong AMOC = “climate change” and weak AMOC = “still climate change” but with natural variability.
Yeager missed his chance.
AMOC is turning negative and all of that warm water will stay south near the tropics. Sounds like hurricane generating conditions to me.
After so many years of a placid Atlantic, it will be interesting to return to hurricane conditions experienced in past decades; e.g. 1920s, 1930s, 1950s.
All of those Spanish galleons laden with gold were not sunk by conditions like the mild zephyrs of the last few decades.
spot on there a theok ,and of course all those storms use huge amounts of energy,leading to more cooling. we should really be asking what pulls us out of ice ages ,not worrying about what keeps us warm and well fed.
in saying that ,a nice ice age would bring some humility to the first world problem crowd that suffer delusions of grandeur due to never having to endure any form of hardship in their entire life. the second half of this uk winter may start focusing minds when the lights go out and the heating goes off .
“NCAR: winter sea ice could hold steady in the next several years”
Yep, and it could go through the roof! Who the hell knows?
And back to the surface stations (slightly off topic): their decreasing number and NOAA’s inclusion of only a fraction of them in its Climate Reference Network indicate that NASA and NOAA do not trust the surface stations themselves (despite the warmist claims to opposite).
So these alarmists are saying ice loss will slow down because the ocean temps are going down? But i thought their other alarmist friends proved the temps were going up? Boy am i confused
But, but, but… I thought the Arctic would be “ice free” by the summer of 2015????
Before that, an ice-free Arctic was predicted to occur in: 1980, 1990’s, 2000, 2008, 2013, 2015 and 2030…
https://stevengoddard.wordpress.com/ice-free-arctic-forecasts/
Arctic sea ice is sinusoidal in nature and follows closely the 30-year PDO and AMO warm/cool cycles…
A 30-year PDO cool cycle already started in 2008 and the Western Arctic sea ice is already close to the 1980~2012 average. The 30-year AMO cool cycle starts around 2020, so the Eastern Arctic sea ice will continue to slowly recover as it approaches 2020…
Arctic sea ice over the next 5~7 years will be VERY interesting to watch as we enter a La Nina cycle in 2016, the PDO cool cycle continues to cool, the AMO gets closer to starting its 30-year cool cycle in 2020, the sun enters the tail-end of its weakest cycle since 1906 and the next solar cycle starts around 2022, which is expected to be as weak as the Dalton Minimum, which started in 1790…
NCAR is just trying to get ahead of the curve as they realize they also FUBARed Arctic sea ice projections…
And so it goes…
I’m not as hard on these scientists as some have been. Clearly, they cannot just come right out and say the ice is a function of natural cycles and AGW never was a big player. They’d lose their jobs. So, they try to do the science as best they can and candy coat the narrative to please the bosses. Eventually, the science will win out.
Or as some else put it, “No problem? No funding”
That’s a straw man. There’s a middle ground, where they don’t have to say that, but neither support cAGW pseudoscience. But, that would mean having a modicum of moral scruples, gumption, and cajones, which I guess is too much to ask.
i would be much harder richard, much, much harder. big proclamations leading to huge amount of peoples earnings being spent on pipe dreams that in some cases led to premature deaths during winter should carry a large responsibility. these scientists have no sense of responsibility at all. the longer this goes on, the bigger the backlash will be, hopefully anyway.
the most unfortunate side effect will be science in general will tainted leading to problems for most disciplines ,not just the alarmist climate lot.
This seems just one more example of an organization that’s been consistently wrong in all of its predictions for decades coming up with the news that they’re revised their predictions and the new ones are right.
I don’t want to give the impression I don’t think research in the fields of climate and weather should stop, but someone needs to explain that these predictions shouldn’t be used to make economic or technological policy. Maybe someday they’ll know what they’re doing but they don’t now.
Oh never mind that double negative. I don’t want to give the impression I think research should stop.
“We know that over the long term, winter sea ice will continue to retreat…”
Yes, yes…we all “know” by now. You have recited the usual prayers and sacrificed the usual goats. Your ensuing text will be free of heresy, if a little unsettling. We are familiar with the code.
My God, how we are familiar with that code.
Richard M
December 10, 2015 at 9:03 pm
The LIA ended in the 19th century. The warming has already been going on for a couple hundred years. We may not be lucky enough to see much more. The 1000 years is kind of an average but if you look closer, the interval has been getting shorter each time and the amplitude lower as well.
It might. It might not. I’m too lazy to search for it at the moment but I’m pretty sure in was a guest post in Judith Curry’s blog, written by a fellow who has been “adding” to the front end of the Central England Temperature record through proxies and historical data. He pointed out various interesting things in the data.
Temperatures were all over the map as the decades went by. The LIA was far from an always cold time. One of the things he pointed out, and I’m pretty sure more than one of these periods was in the actually measured temperature data, people sometimes lived, to what in those days was the ripe old age of 65 (assuming some people did live that long during these particular stretches), where the temperatures increased, bit by bit, throughout their entire life.
Seems like “it isn’t likely to keep warming for quite some while yet”,
CO2 or not aside,
would be a hard proposition to falsify before at least another hundred years go by.
It shouldn’t need saying but. a “hindcast”, is not a prediction.
You can tune you models to perfectly replicate the past but that doesn’t mean they will be any good at forecasting the future.
From AndyG55: Periodical:
http://s19.postimg.org/4crolmgmr/amo_vs_NHice.jpg
“We know that over the long term, winter sea ice will continue to retreat,” said NCAR scientist Stephen Yeager, lead author of the study published online today in the journal Geophysical Research Letters. “But we are predicting that the rate will taper off for several years in the future before resuming. We are not implying some kind of recovery from the effects of human-caused global warming; it’s really just a slow down in winter sea ice loss.”
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I reject this prediction as unfounded in science.
I have a different prediction. I say that following the current El Nino, global cooling will resume by ~2020 or sooner, and so Arctic Sea Ice extent and thickness will increase with time.
Antarctic ice has already increased to record levels in the modern data-collection era.
As usual with my global cooling predictions, I hope to be wrong. A cooler world is a crueler world.
Now let’s wait and see who is correct. Ladies and germs, faites vos jeux!
Regards to all and Merry Christmas / Happy Holidays!
– Allan
.
We are not implying some kind of recovery from the effects of human-caused global warming; it’s really just a slow down in winter sea ice loss.”
FAIL
until that is proven beyond all doubt, anyone who keeps spouting this rhetoric has ZERO credibility.
It appears to me that climate science is desperately in need of an explanation for the Atlantic oscillation which has recently led to diminished arctic sea ice conditions. I don’t have the benefit of a super computer or massive government resources to create “data” to order, but I do have a brain with which I analyze and reason. Accordingly, I am prepared at this time to offer up a hypothesis ( also known as a theory to AGW proponents) that I feel is worth testing. Since the Southern and Northern Hemispheres of our little planet are quite distinct as far as seasonal warming is concerned, it seems to me that the Southern Hemisphere having more ocean area has a different heating trend. Because the equatorial winds tend to contain the heat generated in the Southern Hemisphere- it builds up heat which it periodically “dumps” Northward via ocean currents as evaporation causes the water to become more dense, sink, and be replaced by colder water from the North. This could be a very long cycle ( in human terms) with a massive amount of heat flow that exhausts itself and then stops, whereafter the arctic sea ice begins to increase and the Antarctic sea ice begins to diminish as the South starts to warm again. I base this on ship intake temperatures adjusted for the assumed length of their transit through the warm engine room and this hypothesis is offered only minimally in jest as I really do believe this is what we are seeing.
John, it is good that you are trying to unpuzzle the Arctic situation but you lack some basic information which the greenhouse warning gang does not disclose. You will find this information in my paper in E&E 22(8):269-283(2011). First, Arctic warming started at the turn if the twentieth century. Prior to that there was nothing there but two thousand years of slow, linear cooling. Its start was sudden but it was then interrupted by a mid-century cold wave which lasted thirty years. Warning resumed in 1970 and has been active ever since. There is no way to turn greenhouse warming on and off as happened three times during the twentieth century. It follows that the cause of warming must be a change in the North Atlantic current system which started to carry warm Gulf Stream water into the Arctic Ocean. It is the presence of this warm water that accounts for the differences between the north and south polar freezing history. It Its most visible effects are the opening up of the Northwest Passage and of the Eastern Passage from Russia to the Bering Strait area. In the overall picture it has probably reduced the North Polar ice cap by approximately a third of what it would have been without the Gulf Stream contribution. What worries me is the cold snap in the middle of the twentieth century. Should it return we can expect a blockage of Arctic transportation and development like we had before the Arctic warming started.