This is Wyatt / Curry's Stadium Wave (Marcia Glaze Wyatt, Judith A. Curry, Clim. Dyn., Sept. 2013; henceforth W+C), but you don't get a title like that past a staid journal like Climate Dynamics.
Note: the copy of W+C I started writing this from which I found at Curry's site offers graphics of truely outstanding industrial-strength awfulness. Really: if you don't believe me, go look. Most of them are completely unreadable (you need to go about half way down the comments at Curry's before you find anyone who notices this, strongly suggesting what the comments there also suggest: that few have troubled themselves with reading the paper). I subsequently found a better version elsewhere, so I can't claim ignorance as I was planning to.
Note: what this most reminds me of, off the bat, is the "Antarctic Circumpolar Wave" (White and Peterson 1996. I even made a small contribution to the literature). Its not the same - the ACW has a clearish mechanism and dynamics, and a very different though still "slow" period. But if I were W+C I'd definitely have mentioned it. Odd that they don't.
Behavior of numerous and diverse geophysical indices – from fish populations to cosmic nuclides – fluctuate at a quasi-periodic 50-to-80 year tempo (e.g. Ogurtsov et al. 2002; Patterson et al. 2004; Klyashtorin and Lyubushin 2007).
But Ogurtsov et al. say "It is seen from Figure 2 that two signiﬁcant century-scale oscillations really are in the spectrum of sunspot variability, a 90–100-year cycle (since the second part of the 18th century) and 50–60-year cycle (until the ﬁrst part of the 19th century)" (my bold). The bolded bit is important: it means the 50-60 years stuff has gone by 1900. So its useless to W+C. Interestingly, O et al. only say this in the body, not the abstract - perhaps some carelessness or confirmation bias from W+C there.
Patterson et al. covers ~1440–4485 years before present, so isn't much use, especially if you actually believe Ogurtsov et al. which tells you that the periodicity comes and goes; and Patterson et al. also say the periodicity comes and goes (and the 50-to-80 stuff isn't terribly convincing in their spectral plots either).
K+L doesn't look terribly valuable; bizarrely, it was posted by J Marohasy in 2008 but without comment. And note that the copy I've pointed you at is hosted by "klimarealistene.com/" who are An organization for those who do not agree with the UN climate panel, the IPCC.
None of this matters a great deal. People often lard their papers with some boilerplate. But its odd that W+C can't find better refs to support their desire to see a 60 year cycle.
WKT invoked numerous observational and model-based studies to support suggested physical dynamics potentially conveying connectivity within the stadium-wave network. Candidate mechanisms include...
This very definitely reminds me of numerous poor met/climate papers I've read that string together chains of "possible mechanisms" but end up offering nothing solid.
...This paper extends WKT by investigating the underlying physical mechanisms associated with the stadium wave through analysis of an expanded network of geophysical indices... The expanded index collection provides insight and perspective on attribution and potential predictive capacity of the stadium wave...
Um, so, still no fundamental dynamics then? Just more looking at indices? While I'm here, I'll also note that
WP hypothesized that failure to find the signal in any of the CMIP-model simulations might reflect the absence or poor representation of network dynamics fundamental to signal propagation
feels like the kind of model-bashing you'll see as a staple at WUWT.
Prior to analysis, all raw indices were linearly detrended (least squares method)... The cornerstone of our analysis is the Multichannel Singular Spectrum Analysis (M-SSA...). M-SSA is used to extract and characterize dominant spatio-temporal patterns of variability shared by indices within a network. The technique is particularly skillful...
This may be a sign of trouble ahead, because it reads very much like "we took a pile of data and stuffed it into a stats package we found but didn't understand"; Curry has form in this area.
Other evidence that the stats are dodgy: in methods, W+C say:
One-hundred-year time series for each index were auto-correlated. The auto-correlation plots showed that the maximum autocorrelation after one year among the eight indices was r~0.65. Using this auto-correlation value in the Bretherton formula (Bretherton et al. 1999), the effective number of degrees of freedom was estimated to be 40. From this, the projected decorrelation time is N/N* = 100/40 = 2.5 years
which is plausible. However in the caption to figure 3 they say Error bars are based on North et al. (1982) criterion, with the number of degrees-of-freedom set to 40, based on decorrelation time of ~2.5 years which has reversed the causality between d.o.f. and decorrelation time. By itself its a small point; but it doesn't inspire confidence in their stats.
Curry's PR is pushing this paper as "‘Stadium Waves’ Could Explain Lull In Global Warming". But you should never trust PR. The denialists are all over this, in a rather short-sighted way: they love the "lull" or "hiatus" in the PR, because in their odd minds that means "global warming has stopped / was always a fake". But the only possible interpretation of this paper, were it correct, would be that GW is valid and this is merely "variability". However, very few people are actually reading the paper, which Curry is relying on.
Because the claims of explanatory power, and even more the claims of predictive power, that Curry's PR is pushing just aren't backed up by the paper:
We suggest that the stadium-wave hypothesis holds promise in putting in perspective the numerous observations of climate behavior; offers potential attribution and predictive capacity; and that through use of its associated proxies, may facilitate investigation of past behavior that may better inform our view of future behavior.
And the future? Again, we've got people sounding off:
“The stadium wave signal predicts that the current pause in global warming could extend into the 2030s,” Wyatt said, the paper’s lead author
but those are Wyatt's words, not those of the paper. The paper itself offers little in the way of prediction: While evidence strongly supports our hypothesis of a secularly varying climate signal propagating through a hemispheric network of synchronized ocean, atmosphere, and ice indices during the 20th century, we cannot know if this variability, tempo, and sequential chronology will continue into the future is about it.
Rebound in WIE, followed by ArcSib should occur after the estimated 2006 minimum of WIE and maximum of AMO...
An odd sort of prediction, you might say, because 2006 is well in the past. But their figure 3 (which I take to be an important figure; its one of the few that can actually be read) only runs up to 2000. I'm rather unclear what period their study covers; I'm going with the labelling on their figures, because I can at least see that; the "data" section is tolerably vague about time periods; at one point it says " These indices include 20th-century instrumental values of well-known indices" which is at least consistent with stopping in 2000. Its an odd end-point though; you're throwing a way a decade and more of good-quality data.
Its also an odd sort of "prediction", because as we all know Arctic sea ice has been on a steep decline over the last few decades, and doesn't seem to have shown any signs of recovery post 2006. The quote is from the summary+discussion section, and you'd have expected an alert referee to pick up on this. WIE includes, according to W+C, Greenland, Barents and Kara. And a recovery or "rebound" is not obvious.
To be continued
You'll notice that amongst all this, I haven't actually offered any critique of the paper's main thesis. Well spotted. That will have to wait until I have another spare evening. In the meantime, I'd be grateful for links to other people's analysis of the paper (and I mean a detailed analysis, not just an "oh, look, there's a badger" sort) either pro or con or neutral. I had a look, but didn't find any. I did trog through the endless comments on Curry's site, and found Wyatt saying we wanted to really understand dynamics propagating and sustaining the wave. That is the essence of the paper which sounds good, but does it live up to itssss promise, Baggins?
Possibly somewhat badger-spotting discussion here;
P.S. Wikipedia, citing Curry 2008, has the AMO peaking in 2020 or so, or 2000-2040.
[I know, we argued about that, but it does at least prefix that with Assuming that the AMO continues with its quasi-cycle of roughly 70 years.... As I say on the talk page, that makes it totally vapid -W]
Surprised to see this paper so specific about a peak in 2006. Do you know where that's from?
"Its also an odd sort of “prediction”, because as we all know Arctic sea ice has been on a steep decline over the last few decades, and doesn’t seem to have shown any signs of recovery post 2006."
I read this as a claim of recovery from the author:
"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."
[Oh lordy, that is awful. "is suggestive of consistency with...", eugh. And min-2012, inc-2013 is (a) junk straight fro the depths of WUWT, and (b) drivel from Wyatt - her "wave" is a 60-year thing; it doesn't make year-to-year predictions like that -W]
I noticed this paper too and thought there was something familiar about it - I found out what: Marcia Wyatt is the lead author on the second of AnastasiosTsonis's climate 'waves' papers:
Atlantic multidecadal oscillation and Northern Hemisphere’s climate variability
MG Wyatt, S Kravtsov, AA Tsonis
Climate dynamics 38 (5-6), 929-949
The Tsonis papers seem to involve lots of maths and chaos theory but not all that much physics, however, I'm not a climate scientist so maybe there is something earth shattering buried in there. Tsonis certainly seems to think so.
I wonder if Tsonis was a reviewer for W+C?
"...junk straight fro the depths of WUWT."
Well yes, both are predicting Arctic recovery and decades of no warming. Is it a stadium wave?
By far the bast comment under Curry's modest blog post is this one by "Bart R":
["Bast"? - Freudian slip there -W]
They have gone full Landscheidt over there at Judy's. If something was originally farce, what does it repeat itself as???
A tour de farce.
The cumulative effect of many climastrological farcings.
Regarding the recovery expected in 2006 in the WIE, I have a suspicion that was an accidental copy/paste error from the thesis, since it also refers to the maximum of the AMO occurring then as well (which obviously hasn't happened either given additional peaks in 2010 and 2012).
I would say that the prediction better stated would be after AMO peaks, WIE will recover.
The Farce is strong with this one...
Thanks, people, for the many chuckles -- best in weeks!
Mother of God. I wonder if the sea-ice recoveries from 1990 to 1992, 1995 to 1996 and 2007 to 2008 are also 'suggestive of consistency' with their 'mechanism'.
> signs of recovery post 2006
'Off by one' error?
[Yes, 2006 rather than 2007 is a bit of an oddity, too -W]
You guys are such a tonic. Thanks, some common sense and sharp language about this idiocy are the medicine obfuscation needs at the moment.
"The denialists are all over this, in a rather short-sighted way: they love the “lull” or “hiatus” in the PR, because in their odd minds that means “global warming has stopped / was always a fake”."
My favourite quote from a recent FB comment: "So Fox news, which never accepted there was any warming, is now claiming the warming has slowed..." (from Geoffrey May)
I haven't actually bothered to engage with the paper, I'm afraid. I stopped when it seemed the argument appeared to be "effects propagate through space over time, therefore not global warming". Was the actual argument more sophisticated than that?
[Yes, 2006 rather than 2007 is a bit of an oddity, too -W]
The WIE indicator, which they define as Greenland+Barents+Kara might have had a lower August mean in 2006 than 2007. The NSIDC and HadISST1 records indicate as much though they're fairly indistinguishable. However, both also find the joint lowest August means in 2010 and 2012.
I believe the predictions come from the Stadium Wave Wheel of Fortune in Figure 13, which includes years followed by a question mark.
In terms of a recovery there's a bit of an issue in that the "WIE" August ice cover has been close to effectively zero for the past few years. If you were offered a bet for whether the trend would go up or down over the next couple of decades I would take up because negative ice is difficult to produce.
I’m new to this website, but I just wanted to say how much I’ve enjoyed reading this article, plus part 2 and all the comments. When I read something like Wyatt & Curry it really makes me wish I had the expertise to critique it properly.
My initial, probably unfair, opinion was that this paper is a cross between an NIPCC report and the works of Nicholas Curve-Fitter. After reading it 2 or 3 times I began to be struck by how little it is actually saying. I don’t think it’s really saying anything about how much of the recent temperature trend is explained by natural variability (which is what I thought it might be trying to address). I will nonetheless enjoy watching it misused as if it does address this question.
But wow look at the ice increase in the Antarctic, that dumps tremendous amounts of cold water under the oceans!