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
“There is something fascinating about science. One gets such wholesale returns of conjecture out uf such a trifling investment of fact.”
Mark Twain
About the 60 year cycle in the AMO, it is also reflected in the Ocean Heat Content of the North Atlantic. If it is reflected in the ocean temperatures all the way down, then there is certainly an ocean thermohaline circulation driver in it.
http://s15.postimg.org/cpoj3crwb/North_Atlantic_Ocean_Heat_Content_Q2_2013.png
Now if we compare the NODC OHC for the North Atlantic with the AMO Index going back, we can imagine that the OHC followed this pattern as well.
http://s21.postimg.org/5o4z4edhj/AMO_and_North_Atlantic_Ocean_Heat_Content_Q2_201.png
But does the Ocean Heat Content data going even farther back show this? Yes, it does in one of the only studies looking at North Atlantic OHC going back to 1900.
http://s14.postimg.org/dq96zg4b5/North_Atlantic_Temp_400m_01.jpg
As a LONG TERM AVERAGE it’s probably trending up…
=
depends on what you call long term…
…overall it’s been trending down
http://www.foresight.org/nanodot/wp-content/uploads/2009/12/histo3.png
kcrucible says:
October 10, 2013 at 11:54 am
Depends on what you mean by long-term average. Definitely from the depths of the LIA 300 years ago, the T trend has been up. But the longer term trend is still down, as it has been since at least the Minoan Warm Period, if not indeed the end of the Holocene Climatic Optimum.
The Modern Warm Period still probably has hundreds of years to run, so after the next 20-30-year cool phase, there will be another up trend, matching in slope those of the early 20th & late 19th centuries, recovering from the LIA. Given the pattern of the past 3000 to 5000 years, peak warmth of the Modern WP should be lower than that of the Medieval WP, which was lower than the Roman WP, which was lower than the Minoan WP. We may already have seen the peak however in the 1920s-40s or 1970s-90s, as the hottest parts of WPs seems to come early in the cycle. Same goes for interglacials themselves, as during the early Eemian & Holocene, for instance.
Nice. I liked the look of the stadium wave when I first saw it here a couple of years ago, and it’s good to see it not only back but thriving and with the support of someone of Judith Curry’s calibre. Shall watch with interest.
Greenhouses and stadiums. I get the feeling climatology got merged with an architecture school at some point. So are climatology’s leading lights going to have a press conference in 20 years?
Looking at the Hadcrut (eg.) temperature record, Blind Freddie can see that there’s a multi-decadal cycle of sorts in the data. Nicola Scafetta, who has commented in this thread has been pointing it out for eons (but has no mechanism). Years ago, it was pointed out that it related to the ocean cycles, eg: http://notrickszone.com/wp-content/uploads/2011/08/Bastardi-PDOAMO-correlation.gif.
Kudos to the authors (unlike the IPCC) for at least looking at the phenomenon, but I’m unconvinced that they have identified the mechanism. To convince me, they need verifiable, testable scientific evidence. That doesn’t mean waiting several decades to see if the pattern repeats, and in fact that would still not be sufficient as it does not address the underlying mechanism. They need to identify features – by-products of the supposed mechanism – that can be tested for, and which are incompatible with other possible causes. Until they can do that, as Stephen Wilde so correctly says, “the ‘stadium wave’ concept is just a fancy name for the net interaction between the various oceanic oscillations ”.
In spite of my sceptical view, I regard this paper by Curry and Wyatt very positively in one way – as Theo Goodwin says (October 10, 2013 at 11:17 am) “Dr. Curry and Dr. Wyatt are paradigm breakers”. Of course, it should not be that way, because the paradigm should have broken years ago.
Regardless, the mere existence of this ‘multi-decadal cycle’ is sufficient to remove the ‘C’ from CAGW, because, of course, its upward cycle explains much of the late 20thC warming for which CO2 has been credited. But then, the IPCC has been blind to the cycle all this time, and will no doubt continue to keep its eyes firmly shut. Judith Curry, one of the authors of this paper, has recently called for the IPCC to be put down. In that she is undoubtedly correct.
Since someone mentioned the pauses at the beginning and middle of the last century, ‘ve been waiting for this one. But is anyone checking where you should start to notice statistical resistance from previous historical highs, or for that matter, how soon we are due for another ice age decline? If the historical factors are strong and the CO2 factors are weak we should be expecting a turn, hopefully the upturn!.
Perhaps there will be some symmetry between tops and bottoms. I’ve toyed with the idea that the difference in slopes of the horizontal or declining pauses may be an indicator of any CO2 effect.
While technical analysis and charting doesn’t work too well for stocks, they seem to have some predictive use in climate data. I like trend lines, Bollinger Bands, channels, and support and resistance levels. I’ll leave to those who remember their statistics to write a proof or disproof, LOL.
“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.”
I think I need to read the actual scientific article to tell if the ‘grant trolling’ dbstealey suggested is going on is in the work itself or is the response of Curry and Wyatt to interview questions. Certainly tying one’s findings to recent events raises the profile of one’s work – and what a great feat, solving the problem of the ‘pause’. (What a loathsome, propagandistic, non-scientific term…) The interview quotes from Wyatt to the effect that “The stadium wave signal predicts that the current pause in global warming could extend into the 2030s,” and Curry’s response have sent the sine wave of my opinion regarding Judith Curry back on a downward course.
Dr. Curry’s article is about science, not the politics of the IPCC or Obama. Having actually read it and studied its figures, it makes a number of major contributions beyond its PR. Since the CMIP3 archive did not reproduce the stadium wave, (CMIP5 not yet tested, or at least test reported) means all the IPCC stuff misses this phenomenon. Falsifies the models right there. Means they have over predicted temperature rise and climate sensitivity. More important, if you study the graphics, the present status of this stadium wave says the pause will continue for perhaps another decade, and that sea ice is beginning a natural 30 year recovery to maximum extent from its present stadium wave minimum. Both things mean increasingly obvious falsification of IPCC AR5. She is making predictions which should have everyone here rejoicing, not grousing.
I agree with cwon14 above (as well as with those who have noted that “the pause” is a propaganda term, not an element of reality). The incompetent Curry even throws in “self-organizing”, to gain the quick sympathy of all who recognize and identify with it, since its invention and use in the never-ending struggle to defend the undirected-evolution paradigm, that provides the unquestioned (and for most, unquestionable) foundation for all of the life and earth sciences–which means that defending the consensus (and “damn the contrary evidence”), and beyond that, defending that reigning paradigm (which is as false as the climate science consensus), is her real central goal. She is, in essence, an academic “priest” with blatant political ambitions–she wants to be a climate ecclesiastic, having a strong influence on governmental (i.e., tyrannical) climate policy.
“Self-organizing” really means uncaused, something just happens because it “wants to”, because it has a “preferred state” that it is magically attracted to, over and over again. All of these model-driven “scientists” of today obviously really just want to believe that “you create your own reality”, so they can diddle with reality as just so many word associations they feel entirely free to make up at will. And the believers, alarmist and lukewarmers alike, fall for it every time.
Incompetent Skeptics IV: Dr. Judith Curry
Go Home says:
October 10, 2013 at 10:24 am
So are they saying that CO2 is warming the planet measurably, and the wave is currently cancelling these measurable CO2 effects predicted by the AGW crowd, but when the wave is not cancelling these CO2 effects, watch out? Or does this say CO2 has no measurable effect on climate?
Go home needs to look up “support” and “refute” in the dictionary. This paper does not deal with questions of what causes the stadium waves (such as the sun), nor does it deal with the AGW warming hypothesis beyond acknowledging its existence. It is very similar to an article published here a week ago, breaking up the temperature signals into two components–a wave that is similar to Wyatt/Curry’s and a long-term upward trend. That article pointed out that the conclusions depended on accepting HADCrut’s temperature record.
Since the HADCrut record does not match the Central England record, nor the radiosonde/RSS data, nor the satellite data, all of which agree with each other, it is unlikely that these two articles/papers are correct about the pause/long term trend, although they are correct about the cyclic behavior. Rather, the HADCrut data is out of line, and the real explanation for the pause is the real explanation for the discrepancy–fiddled data.
One part of the difference was found on a WUWT article showing the number of weather stations versus HADCrut temperature. The other part is found by following the money. For all the alarmist yowling about Skeptics well-funded campaigns supported by oil money, it is a running joke here that one has not received their Koch Brothers money yet (I have not received a penny of oil or fossil money either). The actual funding ratio is 1000 to 1 in favor of Alarmists. That includes oil money. Oil companies invested heavily in alternative fuels after the OPEC gas lines of the 1970’s, and they stand to make billions if the carbon tax is ever implemented.
Ah yes, the carbon tax. It is an effort by politicians to grub more money out of a tapped-out public. This won’t work, since trashing Fossil Fuels reduces energy availability and raises energy costs, which have the US government on the ropes and wide disasters in Europe’s economies as well. How do you raise more taxes out of the unemployed? The real solution for the tax-feeders is to fire a third of the government workers, mostly the most regulatory ones, the ones squashing enterprise and freedom. It has been proven over and over that more freedom releases the creativity of the people, and you get whole new industries, wealth for everyone, and that includes more taxes without resentment.
Most of us here are out to save the world–from “the environmentalists,” who are not merely devastating economically, but antagonistic to human life–and who trash the very basis of ALL life: carbon. If you really want to save the rainforests and the whales, the rare butterflies and the bees, then you need to handle the economics. Most of our enemies’ money comes from America’s National Science Foundation, which is heavily invested in warmist propaganda, and similar government funding in other countries. How do we replace this gravy train? By giving freedom back to the people, and by funding research in high schools as well as in colleges and universities, so that high school students would be taught by real researchers and also experience doing research. Gene sequencing, for example, is now so simple that high school students could easily be taught how to do it. The full research involves bacterial culture, and I do not think high school students should be doing that. This part could be done in local colleges and in grant-funded labs. This would provide more jobs for PHD’s and improve the Quality of Life for a lot of people. It would improve the dangerous science ignorance that we have now in the general population.
And it would make it possible for the warmists to look at the actual science.
“So are they saying that CO2 is warming the planet measurably, and the wave is currently cancelling these measurable CO2 effects predicted by the AGW crowd, but when the wave is not cancelling these CO2 effects, watch out? Or does this say CO2 has no measurable effect on climate?”
The paper is absolutely neutral on the subject of Co2.
So, how much of the late 20th century warming was due to the ‘wave’, leaving what little remains to attribute to CO2?
Eyal Porat says:
October 10, 2013 at 10:09 am
But where is the sun?
================================
My immediate reaction as well. But then I am reading “The Neglected Sun”…
Mike Jonas says:
October 10, 2013 at 12:19 pm
Looking at the Hadcrut (eg.) temperature record, Blind Freddie can see that there’s a multi-decadal cycle of sorts in the data. Nicola Scafetta, who has commented in this thread has been pointing it out for eons (but has no mechanism).
*********
Actually my papers do propose mechanisms. There are specific solar models that predict the patters. The microscopic physical mechanism has to do with cloud modulation via electromagnetic interaction (cosmic ray etc) which are modulated by the astronomical cycles.
Rud Istvan says:
October 10, 2013 at 12:25 pm
Dr. Curry’s article is about science, not the politics of the IPCC or Obama. Having actually read it and studied its figures, it makes a number of major contributions beyond its PR. Since the CMIP3 archive did not reproduce the stadium wave, (CMIP5 not yet tested, or at least test reported).
****
Not correct. Both CMIP3 and CMIP5 models were extensively tested one by one. See may recent papers.
Latitude: “I don’t understand why this is “new”…”
I don’t disagree. But modern science, especially in some fields, is less studied inquiry than it is a Battle of the Bands. Curry might not be much of a rockstar, but she is one still. And she’s put her John Hancock down next to Wyatt on a paper that produces an affirmative claim. And like it or lump it, the fans don’t like it when you point out that Milli Vanillli is a fake band. Unless you give them a new band they can throw their underwear at.
This does not explain anything, and tries to tie the whole climatic system of the earth to the Atlanticc Multidecadel Oscillation and the sea ice extent in the Eurasian Arctic shelf seas. At the same time it does not address what is going on in the Southern Hemisphere which may be impacting the climate, and gives no attention to ENSO, VOLCANIC ACTIVITY, OR SOLAR.
This theory does nothing to explain the Little Ice Age, cold period, or the Medieval warm period, or past abrupt global climatic changes.
It is as bad as the AGW theory in that it tries to piegon hole one or two items that influence the climate and make it seem like these two items control the the whole climatic system of earth and can explain all the changes the climatic system of earth may take going forward.
It also lacks a reason to explain why the AMO may or may not shift into a different phase, it just says it does and when it does the whole climate system in response will change. It also gives an excuse to keep the AGW models valid. Not good enough Judith Curry.
The conclusions of the article (I’ve only read the above summary, as I don’t subscribe to the Journal) are somewhat like those of Warren Meyer in 2006 or 2007.
@cwon14
“Say something once. Why say it again?” (David Byrne, Talking Heads)
Mike Jonas says:
October 10, 2013 at 12:19 pm
“Judith Curry, one of the authors of this paper, has recently called for the IPCC to be put down. In that she is undoubtedly correct.”
Yes, but without listing the specifically the worst attributes of the IPCC and consensus in the process. Largely because the agenda failed. She’ll gladly support a renamed IPCC with the same failed agenda attached. She doubts the tactics but not the motivations of the AGW meme participants.
“Say something once. Why say it again?” (David Byrne, Talking Heads)
That would in eliminate 99% of climate related conversations in the past 30 years.
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.”
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A one year change is sea? That’s really going out on a limb when publishing about a 60 cycle.
Shame she didn’t have time to benefit from that article I submitted to Climate Etc last week.
http://climategrog.wordpress.com/2013/09/16/on-identifying-inter-decadal-variation-in-nh-sea-ice/
There is more that one year of change. It shows a slowing rather than a turnaround but this is a more credible reaction to the Pause than a one year glitch.
The lag it implies is more consistent with thier mexican wave analogy too.
Also it does nothing to addres why the climate may shift from one climate regime to another climate regime. This is the same problem Nicola Scafetta has by the way. They think every thing is cyclic,cyclic and more cyclic, when in fact this is not so . The climate is a non linear system which can shift from one climate regime to another climate regime, depending on the extent and location of certain forces, the degree of magnitude change of those forces, not to mention the beginning state of the climate.
Nicola’s work is great if the climate stays in the same climate regime but does NOTHING to explain abrupt climatic changes or climatic shifts from one climate regime to another one. Judith Curry also falls way short even more so then Nicola, in this area.
The upshot is they both don’t have the real answers as to why the climate changes.