From the Georgia Institute of Technology
‘Stadium waves’ could explain lull in global warming
One of the most controversial issues emerging from the recent Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) is the failure of global climate models to predict a hiatus in warming of global surface temperatures since 1998. Several ideas have been put forward to explain this hiatus, including what the IPCC refers to as ‘unpredictable climate variability’ that is associated with large-scale circulation regimes in the atmosphere and ocean. The most familiar of these regimes is El Niño/La Niña, which are parts of an oscillation in the ocean-atmosphere system. On longer multi-decadal time scales, there is a network of atmospheric and oceanic circulation regimes, including the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation.
A new paper published in the journal Climate Dynamics suggests that this ‘unpredictable climate variability’ behaves in a more predictable way than previously assumed.
The paper’s authors, Marcia Wyatt and Judith Curry, point to the so-called ‘stadium-wave’ signal that propagates like the cheer at sporting events whereby sections of sports fans seated in a stadium stand and sit as a ‘wave’ propagates through the audience. In like manner, the ‘stadium wave’ climate signal propagates across the Northern Hemisphere through a network of ocean, ice, and atmospheric circulation regimes that self-organize into a collective tempo.
The stadium wave hypothesis provides a plausible explanation for the hiatus in warming and helps explain why climate models did not predict this hiatus. Further, the new hypothesis suggests how long the hiatus might last.
Building upon Wyatt’s Ph.D. thesis at the University of Colorado, Wyatt and Curry identified two key ingredients to the propagation and maintenance of this stadium wave signal: the Atlantic Multidecadal Oscillation (AMO) and sea ice extent in the Eurasian Arctic shelf seas. The AMO sets the signal’s tempo, while the sea ice bridges communication between ocean and atmosphere. The oscillatory nature of the signal can be thought of in terms of ‘braking,’ in which positive and negative feedbacks interact to support reversals of the circulation regimes. As a result, climate regimes — multiple-decade intervals of warming or cooling — evolve in a spatially and temporally ordered manner. While not strictly periodic in occurrence, their repetition is regular — the order of quasi-oscillatory events remains consistent. Wyatt’s thesis found that the stadium wave signal has existed for at least 300 years.
The new study analyzed indices derived from atmospheric, oceanic and sea ice data since 1900. The linear trend was removed from all indices to focus only the multi-decadal component of natural variability. A multivariate statistical technique called Multi-channel Singular Spectrum Analysis (MSSA) was used to identify patterns of variability shared by all indices analyzed, which characterizes the ‘stadium wave.’ The removal of the long-term trend from the data effectively removes the response from long term climate forcing such as anthropogenic greenhouse gases.
The stadium wave periodically enhances or dampens the trend of long-term rising temperatures, which may explain the recent hiatus in rising global surface temperatures.
“The stadium wave signal predicts that the current pause in global warming could extend into the 2030s,” said Wyatt, an independent scientist after having earned her Ph.D. from the University of Colorado in 2012.
Curry added, “This prediction is in contrast to the recently released IPCC AR5 Report that projects an imminent resumption of the warming, likely to be in the range of a 0.3 to 0.7 degree Celsius rise in global mean surface temperature from 2016 to 2035.” Curry is the chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology.
Previous work done by Wyatt on the ‘wave’ shows the models fail to capture the stadium-wave signal. That this signal is not seen in climate model simulations may partially explain the models’ inability to simulate the current stagnation in global surface temperatures.
“Current climate models are overly damped and deterministic, focusing on the impacts of external forcing rather than simulating the natural internal variability associated with nonlinear interactions of the coupled atmosphere-ocean system,” Curry said.
The study also provides an explanation for seemingly incongruous climate trends, such as how sea ice can continue to decline during this period of stalled warming, and when the sea ice decline might reverse. After temperatures peaked in the late 1990s, hemispheric surface temperatures began to decrease, while the high latitudes of the North Atlantic Ocean continued to warm and Arctic sea ice extent continued to decline. According to the ‘stadium wave’ hypothesis, these trends mark a transition period whereby the future decades will see the North Atlantic Ocean begin to cool and sea ice in the Eurasian Arctic region begin to rebound.
Most interpretations of the recent decline in Arctic sea ice extent have focused on the role of anthropogenic greenhouse gas forcing, with some allowance for natural variability. Declining sea ice extent over the last decade is consistent with the stadium wave signal, and the wave’s continued evolution portends a reversal of this trend of declining sea ice.
“The stadium wave forecasts that sea ice will recover from its recent minimum, first in the West Eurasian Arctic, followed by recovery in the Siberian Arctic,” Wyatt said. “Hence, the sea ice minimum observed in 2012, followed by an increase of sea ice in 2013, is suggestive of consistency with the timing of evolution of the stadium-wave signal.”
The stadium wave holds promise in putting into perspective numerous observations of climate behavior, such as regional patterns of decadal variability in drought and hurricane activity, the researchers say, but a complete understanding of past climate variability and projections of future climate change requires integrating the stadium-wave signal with external climate forcing from the sun, volcanoes and anthropogenic forcing.
“How external forcing projects onto the stadium wave, and whether it influences signal tempo or affects timing or magnitude of regime shifts, is unknown and requires further investigation,” Wyatt said. “While the results of this study appear to have implications regarding the hiatus in warming, the stadium wave signal does not support or refute anthropogenic global warming. The stadium wave hypothesis seeks to explain the natural multi-decadal component of climate variability.”
Marcia Wyatt is an independent scientist. Judith Curry’s participation in this research was funded by a Department of Energy STTR grant under award number DE SC007554, awarded jointly to Georgia Tech and the Climate Forecast Applications Network. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: M.G. Wyatt, et al., “Role for Eurasian Arctic shelf sea ice in a secularly varying hemispheric climate signal during the 20th century,” (Climate Dynamics, 2013). http://link.springer.com/article/10.1007/s00382-013-1950-2#page-1
when I was a young boy back in the sixties we where told that the sun controlled the heating and cooling of earth . ? why the scientists will not mention the sun in any warming theory is beyond me . I think I have the answer you cannot tax the sun
Wowe !! I see Chasmod up there flexing his biceps in great style. Way to go Chas, I wondered why you have been so quiet of late.
George
More talk of the hiatus starting with 1998? 1998 was an extreme El Nino spike. When I look at a graph of global temperature anomaly, I find it obvious that the hiatus started in 2001.
Rud Istvan says:
October 10, 2013 at 5:05 pm
Worst of climate skepticism?
Correct but for all the wrong reasons Rud. The paper is a total distraction of what essentially wrong with the warming argument. Like the “Pause” it preserves and validates the core of the warming claim by moving into another side topic like “deep ocean heat” or now here “the wave”. It’s called moving the goal posts.
Higher co2, models and warming were where they hung their hats, a failure not a “Pause” and yes it was bad science what they claimed for their “cause” from the beginning. So we should talk about more ad hoc bad science as a patch explanation of the original bad science claims? What’s poor about skeptics is that they let the debate be controlled by activist players both obvious and/or ambiguous such as Dr. Curry. This paper is a smokescreen and empowering of the consensus as is the “Pause” meme. The idea that “Pause” needs to be explained and rationalized to validate skepticism is nonsense. AGW “science” failed and natural variability at the very least overcame co2 sensitivity if it even exists in a measurable way. So what we are reading are excuses about how the science is really sound “but” from the people who bet their reputations and lost bigtime already.
The worst of skepticism as that so many would buy this.
One reason Arctic sea ice continued its decline after the late 1990s is that global temperature, when averaged over as little as 3 years, did not peak then – but in 2005.
David Archibald says:
October 10, 2013 at 4:45 pm
“Well, according to MODTRAN, at the current concentration of 400 ppm each further 100 ppm is worth 0.1 degrees C.”
Can you direct me to any site you know of which discusses such MODTRAN results? I would like more info. It seems that ought to be a big deal, so I am wondering how it got swept under the rug.
milodonharlani said on October 10, 2013 at 12:06 pm that the Modern Warm Period is likely to peak at a cooler temperature than the Roman Warm Period did. I tried splicing HadCRUT3 onto Loehle’s corrected global temperature reconstruction (a non-tree-ring based one), and see we’re already slightly warmer than the peak of the Medieval Warm Period.
A lot of people here seem to want to cut off their noses to spite their faces. Yes, many people have noted the apparent 60-ish year oscillation in temperatures, which produced an upswing in global temperatures at just the time for the AGW brigades to catch a ride on it, claiming that completely natural process was indicative of CO2-induced warming. But, they weren’t taken seriously because they could not cite a physical mechanism for it.
Dr. Curry and Dr. Wyatt are providing such a mechanism. This should be a moment of jubilation, not of settling scores.
I don’t care who gets the credit or recognition. I just want this long nightmare of throwback superstition and primitive nature worship trumping real science to end.
The (neutral) term I suggest we use is PLATEAU.
If “unpredictable climate variability” can create such a divergence from expected results, then how can we rely on the temperature data to model the impact of CO2 with any accuracy? Didn’t our data requirements just substantially increase? If natural variability can mess up the temperature trend for the last couple of decades to such a dramatic extent, how do we know it didn’t also mess up the data we’re using to build the predictive models?
There are a lot of variables. If some of them drive an acceleration of warming trends, while others are naturally mitigating, how can we ever hope to build a useful model? What if the effects of certain variables have a greater or lesser impact depending on the temperature range? How would we know how to reflect that in the model?
How do we know we shouldn’t be pumping as much CO2 into the atmosphere as we can in order to forestall and mitigate the inevitable cooling phase of the climate cycle?
Maybe there is no such thing as a natural climate cycle. Perhaps given enough time the temperature will naturally settle in at a temperature that is a bit warmer than today, and the climate cycles are merely the result of the earth getting whacked with a large asteroid — ringing the earth like a bell, and causing havoc. In this case, if we can avoid getting clobbered, the temperature cycles will gradually become less extreme until we reach stability again.
Just how do we know, based on a partial temperature history? We just don’t.
But maybe to be on the safe side we ought to raise taxes, increase the power of government to regulate industry, and transfer some wealth around.
harrydhuffman (@harrydhuffman) says:
October 10, 2013 at 12:26 pm
I liked your link but it isn’t a question of “competence” it’s a question of politics. Dr. Curry is a top-down statist with Obama donations recorded. Her function in the climate debate for skeptics is similar to the “Trust Operation” where the Soviets solicited foreign national counter revolutionary funding to overthrow the Soviet but instead were directly supporting it instead;
http://en.wikipedia.org/wiki/Trust_Operation
Dr. Curry is a wasted skeptic asset for the most part if at all.
Dr. Curry isn’t a skeptic or a reformer, she’s a tool of the consensus. This is as far as the consensus will go in dealing with dissent. The Emmanuel Goldstein purpose of defining what they debate on their own terms of discussion. The fantasy term “The Pause” is a perfect example. So much better then “Total AGW hypothesis failure” in the print sections. We live in a society where one special interest political culture seizes the dictionary and decides what the words mean for a politically desired goal. They pick who are acceptable as dissent also and Dr. Curry serves the purpose. Inferring climate sensitivity is so much more effective than having to prove it empirically and the paper does exactly that. Function served.
She reflects the weak mindedness of skeptics and why they are on the losing side, hanging by a thread to date. Needless to say I’m sick of imagined skeptics fawning over her statements without a clue or any critical thinking at all as to her positions. The timing of this paper, within a week of the IPCC release and calling for the IPCC to be “put down” but for completely nebulous reasons that have little to do with the political drivers of the AGW and IPCC meme?;
http://judithcurry.com/2013/09/28/ipcc-diagnosis-permanent-paradigm-paralysis/
“I tried splicing HadCRUT3 onto Loehle’s corrected global temperature reconstruction (a non-tree-ring based one), and see we’re already slightly warmer than the peak of the Medieval Warm Period.”
What is slightly?
0.1 C ?
Assuming that the (Homogenized, adjusted and corrected) HadCRUT3 dataset is an accurate presentation of the real Average Global Temperature and that we can accurately measure the Average Global Temperature of the Medieval Warm Period.
Yeah, right….
I am just curious as to how many of the commentors above have actually read the entire paper?
Did you?
http://link.springer.com/article/10.1007/s00382-013-1950-2#page-1
[snip – lose the personal attack and resubmit – Anthony]
In terms of scientific methodology, Curry and Wyatt have accomplished in their article exactly what Willis has been working toward with his Thermostatic Hypothesis. They have identified a long-term natural process that partially determines temperatures in the Northern Hemisphere and this natural process’s behavior is entirely independent of CO2.
So, they have broken free of the modeler’s assumptions and they have broken free of claims about “global average temperature.” The Sun is rising.
So Mexican Waves stop Global Warming! And I always thought that football was pointless!
(That’s Soccer for Americans and Australians.)
Rud Istvan, you talk of sceptics’ self destruction, because they are not buying into a paper which effectively puts down AR5. I find that rather insulting of the sceptical fraternity/sorority here. The fact that AR5 is lousy science doesn’t mean that any paper putting it down is good science. The fundamental principle, which has always applied, is: The wrong result is bad science. The right result for the wrong reason is still bad science.
If the paper – any paper – is dubious, then it is reasonable to challenge it, even if that indirectly protects AR5 a bit. cwon14 (October 10, 2013 at 5:55 pm) puts it well.
Donald L. Klipstein s(October 10, 2013 at 6:09 pm) “we’re already slightly warmer than the peak of the Medieval Warm Period”. I doubt that we can tell yet, because you have to compare like with like. The MWP temperatures are valid down to what period of time, and to what accuracy? And in any case, for how long a period would current temperatures need to be higher in order for the statement to be meaningful?
Steve Wilde
Several years ago you first planted the seed in my mind of the solar oceans atmosphere coupled system.
I want to thank you for that.
I hate to say it but Dr. Curry comes across in this paper as a closet – or not so closet – warmista. Inter alia, this wave theory offers no explanation for the hugely documented warming and cooling episodes of the past. Rather, this and her recent criticism of the alarmists comes across more as an effort to get them to present their message more effectively so that people will more readily buy into it. In short, it too obviously buys into the AGW argument that this is only a short-term pause in warming, not the beginning of a long-term cooling trend as many are now saying it is.
I used to post regularly on her blog but gave up on that finally after some of the things she said pointed towards the conclusion I’m drawing here. It might be said that she’s trying to reconcile skeptics and alarmists, but in the first place, that simply can’t be done as things stand – you can’t sit on the fence over an issue like this, it really is pretty close to black and white, not much gray there, and you pretty much have to take a stand, with whatever minor variations on details, but a stand nonetheless against the gross perversion of science – and second, I thought she was much too indulgent of some of the super-alarmists who posted there, never challenging them to back up their assertions.
The sad part is, I think she really does know that AGW is horse feces, but by reason of political sympathies or maybe even worry about her job, she hasn’t found the cojones to out with it and call AGW the horse feces that it is.
Steve Wilde
You should be given credit for your early understanding. There are many that know this.
Donald L. Klipstein says:
October 10, 2013 at 6:09 pm
The Modern Warm Period is still a long way from peak Medieval Warmth, as shown by proxy data from all over the world. In fact a number of decades in the Medieval WP were hotter than the last two warm cycles of the Modern, to say nothing of the first one in the late 19th century after the end of the LIA.
Here’s a survey of studies paper from just this year on this topic:
http://scienceandpublicpolicy.org/images/stories/papers/originals/mwp_china.pdf
Many other papers finding the same thing have been linked in comments & posts on this blog over the years.
If you have a study finding otherwise, please trot it out. Thanks.
Donald L. Klipstein says:
October 10, 2013 at 6:06 pm
Based upon what data set did global T peak in 2005? You are aware are you not that GISS & HadCRU have been shamelessly manipulated?
The warmth of c. 1977 to 1996 was nothing out of the ordinary, requiring no extra-natural explanation. Nor was the super El Nino of 1998. Nor has been the plateau of flatness to cooling since 1996.
If the average temperature of the lower troposphere was still warming that recently, then why has Antarctic sea & land ice been increasing?
The important observation is, no matter how long this important facet of the climate has been seen, it is now entering the realm of the mainstream academic science literature. Reality is inching closer.
Re: “cojones” mentioned several times above:
Ahem! Women do not NEED them to be strong. And we certainly do not want any, thank you very much. (flouncing out of the room, nose — in — the — air) #(:))
Okay, okay, wonderful men of WUWT — I get it. But, seriously, think about it.
As many of us know the cyclic ocean theories have been around for some time. They have been my candidates for the “best” explanation of the recent 100 years since it became obvious the global temps changed with the PDO around 2005. I haven’t read the paper yet but given various comments is appears to be attempting to link the various ocean cycles into a global phenomena. That would be what I would deem as new and interesting.
While this doesn’t change the fact that many skeptics have been pointing to the oceans for years, it could take the ideas another step forward. Let’s take some time and look at the details before taking positions based on incomplete information.
Personally, I have been pushing the global cooling until around 2035 claim due to the PDO. I have also been pushing future sea ice increases in the Arctic due to the AMO. Since both of these appears to be part of this global wave it fits right in with my own views.
Now, does anyone believe this will get any media attention?