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JimD

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Li paper predicts cooler Northern Hemisphere temps
« on: October 18, 2013, 05:45:49 PM »
NAO implicated as a predictor of Northern Hemisphere mean temperature multidecadal variability

Thanks to idunno over on the blog for this info.  I thought it deserves its own topic as it is likely to trigger a number of comments.

Li is one of the lead authors of AR5 and his research indicates that the AMO leads the Northern Hemisphere detrended temperatures by 15-20 years.  Using this metric the authors predict NHT trends from the 1970's to the present to include 2012 and warming hiatus.  Most interestingly they predict that NHT temperatures will "cool" out to 2027.  This has interesting implications for fighting with the deniers and changing emission patterns.

Quote
Abstract
[1]The twentieth century Northern Hemisphere mean surface temperature (NHT) is
characterized by a multidecadal warming–cooling–warming pattern followed by a flat trend
since about 2000 (recent warming hiatus). Here we demonstrate that the North Atlantic
Oscillation (NAO) is implicated as a useful predictor of NHT multidecadal variability.
Observational analysis shows that the NAO leads both the detrended NHT and oceanic
Atlantic Multidecadal Oscillation (AMO) by 15–20 years. Theoretical analysis illuminates
that the NAO precedes NHT multidecadal variability through its delayed effect on the AMO
due to the large thermal inertia associated with slow oceanic processes. A NAO-based linear
model is therefore established to predict the NHT, which gives an excellent hindcast for NHT
in 1971–2011 with the recent flat trend well predicted. NHT in 2012–2027 is predicted to fall
slightly over the next decades, due to the recent NAO weakening that temporarily offsets the
anthropogenically induced warming.

http://onlinelibrary.wiley.com/doi/10.1002/2013GL057877/pdf
We do not err because truth is difficult to see. It is visible at a glance. We err because this is more comfortable. Alexander Solzhenitsyn

How is it conceivable that all our technological progress - our very civilization - is like the axe in the hand of the pathological criminal? Albert Einstein

werther

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #1 on: October 18, 2013, 10:10:26 PM »
Idunno (blog), JimD (Forum),

It is not the content that leads me to keep distance (not dismissal) from this type of research. It is the conclusive message that keeps being destilled that worries me. In the sense that Dr. Jianping Li is a contributor in the process guided by the IPCC to get AR5, it is completely OK to refer to his work.

It is very interesting to see how our natural world is being constantly surveyed. It helps to understand. In this case, NAO is studied as a predictor for Northern Hemisphere temperatures.
The described methodology leads to sentences like this: “The significance of the correlation between two auto-correlated time-series was accessed using the effective number of degrees of freedom…”. That completely wastes me.

Yesterday I read a deconstruction of the “stadium-wave” paper by William Connelly. After his ‘butchers’ work only PDO and AMO remained as significant and showed no serious case for a wave.
Please forgive me, I have no idea how data series are mathematically ‘normalized’ through MSSA, “Multi-channel Singular Spectrum Analysis”. I can imagine it to survey an oscillation that could make seemingly random series of data interpretable.
I just wish I could apply such an instrument on FI the repetitive Rossby-wave progress through the atmosphere. My cartographic work only gets me to an indication that, last winter, ridges had an incline to favour remaining through the Gulf of Alaska and the North Atlantic near Ireland and…



Mongolia, Hudson Bay as favoured hosts for troughs.

Jianping Li et al have published this paper without any reference to Curry-Wyatt. Nevertheless their correlation boils down to interaction between similar oscillations, in this case AMOC and NAO. I don’t know how they do it, but I would appreciate them to point out the difference in methodology compared to Curry-Wyatt.

But my aim here is to advice…not to raise this sort of study results to more than they represent. With all respect to the makers, to suggest that NAO is a predictor for NHT with a 15-16 year lag is, humbly, not very relevant. NAO is just a form applied by our limited perceptive means on nature. Nature “doesn’t give a damn”…

ggelsrinc

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #2 on: October 18, 2013, 11:13:42 PM »
It sounds like WUWT bull and I'm not even going to mention the part of that bull that it came from. WUWT has been on the toilet before it's foundation was planned and since the day it's founder was born, producing the same product.

Global warming is determined by heat flux and surface temperature are just an estimate or proxy of that change. The planet is more than it's skin.

One of the major problems is we can't just focus on one thing and need to see the whole picture. That sun during our Northern Hemisphere winter is warming southern oceans. We live in an ice age planet and oceans can suck up a lot of heat. Water and salinity are natural buffers to change, but that doesn't mean they can't be changed.

When ice stops melting, let me know!

Csnavywx

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #3 on: October 19, 2013, 12:43:54 AM »
The AMO is really just linearly detrended sea surface temperature anomaly data. Since AGW is neither linear nor spatially uniform, this by the very definition of the AMO, aliases AGW onto the index. This makes it difficult at best to determine the real AMO signal.

Therefore, I would take this sort of research with a big grain of salt. We don't even know how these modes of natural variability work in an "undisturbed" environment, much less how they will react to large external forcings.

JimD

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #4 on: October 19, 2013, 01:14:15 AM »
ggelsrinc,

I have to conclude from your statement that you did not read the paper and were reacting to my comment that the papers prediction that NHT is going to continue to decline out to circa 2027 will be used by the denier for advantage.

The paper in no way supports folks like WUWT or their arguments.  Li, in case you missed it, is one of the lead authors of AR5 so implying he is some sort of denier or facilitator is pretty off base in my opinion.  Just because a piece of research can be used improperly does not mean it is bad research.  Other experts will certainly look into this paper and provide comments.

Werther.  I would expect based upon the timing of the two papers (Li & Curry/Wyatt) that the papers passed each other in the ether on the way to being published.  Also, I think we can say that Li would be considered a serious researcher and might not be likely to be interested in anything Curry is involved in.

The paper describes an analysis which indicates that the AMO fluctuations lead the northern hemisphere temperature (NHT) by 15-20 years.  This is hardly surprising as the AMO is known to have impact and the paper is just bounding some of the effects.  It clearly states that the rise in temperatures associated with AGW continue unabated and this AMO induced fluctuation is part of the noise which is associated with climate/weather variations which ride on top of the base temperatures.

Quote
....It is well-known that the Earth's climate is warming, which has major global
implications for human well-being. Observations show that in contrast with the monotonic
increase in global annual mean concentration of atmospheric carbon dioxide (CO2) (Figure 1a,
black line), the oscillatory multidecadal variability in the twentieth century Northern
Hemisphere (NH) mean surface temperature (NHT) (Figure 1a, red line) is obvious
[Schlesinger and Ramankutty, 1994; Swanson et al., 2009], superimposed upon a long-term
warming trend.....

..... Meanwhile, after subtracting the AMO signal from the NHT,
the residual shows a nearly monotonic increase, which is very much like the linear trend in
the NHT (Supplementary Figure 4), and the multidecadal variability disappears.....

The kicker being, if the paper is correct, that we could expect the downswing in temperatures predicted to be coming at a really bad time.  Assuming of course that we are trying to change BAU behavior.  It might just make arguments with deniers and a dis-engaged public much harder to make.  Long-term this cycle makes no difference, but we don't have long-term to institute change.  It is a corollary to our persistent La Nina's and the missing El Nino which seem to be pumping the incoming energy into the deeps.   
We do not err because truth is difficult to see. It is visible at a glance. We err because this is more comfortable. Alexander Solzhenitsyn

How is it conceivable that all our technological progress - our very civilization - is like the axe in the hand of the pathological criminal? Albert Einstein

wili

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #5 on: October 19, 2013, 12:50:07 PM »
An up side though (again, if they are right) is that it might slow down (or reverse?) the melt of the Arctic sea ice and of the terrestrial permafrost and sea bed clathrates, giving us a bit more time before these feedbacks kick in with a vengeance.

No matter what is happening with data and with weather, denialists will always just keep on denying. That's what they're paid for. But the general public's opinions about GW does seem to be altered by heat waves that directly effect them and other extreme events. I expect extremes will continue, and things will keep getting weirder, weatherwise. It just means we have to work extra hard to point out the connections and the significant data points.

If the north does get cooler, will the south be warming up even faster? Or will all that heat just go into the deep oceans? And what happens when that heat starts coming back out?
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

idunno

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #6 on: October 19, 2013, 03:53:13 PM »
And what does it tell us about the Arctic Sea Ice melt?

As I understand it, Li is suggesting that there are two natural cycles involved, the AMO (not the AMOC, werther) and the North Atlantic Oscillation (NAO) ,which we ususally refer to as the Arctic Oscillation (AO).

Their combined effect has been to cool the Northern Hemisphere Temperature for the last 15 years or so ; since approximately 1998. Apparently his hindcast results match the 20th Century SAT record really tightly. He forecasts that this cooling influence will continue until approximately 2027.

If there is any reference to ASI in the paper, it passed me by. But it seems to me to be counterintuitive that the great decline of ASI should have happened during a cooling regime - after 1998.

In particular, I would be very interested in any and everybody's thoughts on whether this has any implications for Maslowski's forecast of an ice-free Arctic by 2016 +/- 3 years, based on the heat budget of the Arctic? My personal view being that, if Maslowski is basing his calculations on measurements taken in 2005, then as far as I can tell, that's also during the same cooling regime, so nothing much has changed.

Reading around the Wyatt + Curry paper, the press release says something about that paper "may help explain the pause" - this after Wyatt insisted that the first version of the press release was entirely rewritten, as it completely misrepresented their findings. Judith has form.

This Li paper, there's no "may help" about it - it does explain the pause, while leaving AGW theory entirely intact, and reinforced by a clear theoretical, modellable explanation for the recent aberration of the real-world data from the predicted trend. NH Temperatures are predicted to rise in steps of about thirty years, followed by a pause of thirty years. The proverbial really hits the fan from about 2027 onwards. At that point the natural cycles conspire to reinforce and enhance the anthropogenic forcings.

That this will be used by WUWT to mislead the gullible is a given. A fine site that updates exactly how WUWT is currently misleading the gullible is here:

http://blog.hotwhopper.com/

it updates in near real-time, and is clearly written. A hugely valuable resource for any of you dumb enough to leave these hallowed halls to take up weapons against the zombie apocalypse elsewhere. Tisdale is the WUWT go-to guy on ocean currents. The hotwhopper post of yesterday explains why.

The AMO, as I know I've written here before, is very sound climate science. If WUWT is going to march under that banner, they need to carefully ignore that a lot of the early work on  it was done by one of the main evil overlords of the whole AGW conspirizzy, Michael Mann. That they will manage to ignore this, I have little doubt. Ignorance is their strong suit.

Conversely, I haven't even sat Climate Science 101; and I certainly wouldn't claim to have the knowledge to mark it, but I am quite certain that you do not get an A+ grade for handing in a paper that reads 'It's all CO2, innit?" - that is simply a fiction, promulgated energetically by sites such as WUWT.

Climate is complicated. And as I prefer things slightly simpler, and CT is up and running, I am going to try to pay less attention to this and more to "those silly icebergs", as the long-suffering Mrs Neven is reported to call them.


bluesky

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #7 on: October 19, 2013, 04:57:03 PM »
Although it is quite a localised effect in the Northern Hemisphere, there are research papers on the impact of AMO on Alps glacier and snowfall (with a controversial answer for the paper on glaciers impact):
http://people.ee.ethz.ch/~vawweb/publications/glaziology_division_vaw/2010_2934.pdf
http://www.the-cryosphere-discuss.net/4/2475/2010/tcd-4-2475-2010.pdf
http://www.the-cryosphere-discuss.net/4/C1441/2011/tcd-4-C1441-2011.pdf

http://iopscience.iop.org/1748-9326/8/3/034026/article

bluesky

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #8 on: October 19, 2013, 05:07:04 PM »
Also a wider study on the NAO impact on European glaciers from Scandinavia to the Alps, the results varie from one location to another:
http://www.the-cryosphere-discuss.net/6/1/2012/tcd-6-1-2012.pdf

and one examining a 60 years data with regards to climate change and NAO on a French West Alpine glacier, correlation with NAO is not obvious:
http://www.the-cryosphere.net/7/47/2013/tc-7-47-2013.html


ggelsrinc

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #9 on: October 20, 2013, 02:58:38 AM »
ggelsrinc,

I have to conclude from your statement that you did not read the paper and were reacting to my comment that the papers prediction that NHT is going to continue to decline out to circa 2027 will be used by the denier for advantage.

The paper in no way supports folks like WUWT or their arguments.  Li, in case you missed it, is one of the lead authors of AR5 so implying he is some sort of denier or facilitator is pretty off base in my opinion.  Just because a piece of research can be used improperly does not mean it is bad research.  Other experts will certainly look into this paper and provide comments.

Werther.  I would expect based upon the timing of the two papers (Li & Curry/Wyatt) that the papers passed each other in the ether on the way to being published.  Also, I think we can say that Li would be considered a serious researcher and might not be likely to be interested in anything Curry is involved in.

The paper describes an analysis which indicates that the AMO fluctuations lead the northern hemisphere temperature (NHT) by 15-20 years.  This is hardly surprising as the AMO is known to have impact and the paper is just bounding some of the effects.  It clearly states that the rise in temperatures associated with AGW continue unabated and this AMO induced fluctuation is part of the noise which is associated with climate/weather variations which ride on top of the base temperatures.

Quote
....It is well-known that the Earth's climate is warming, which has major global
implications for human well-being. Observations show that in contrast with the monotonic
increase in global annual mean concentration of atmospheric carbon dioxide (CO2) (Figure 1a,
black line), the oscillatory multidecadal variability in the twentieth century Northern
Hemisphere (NH) mean surface temperature (NHT) (Figure 1a, red line) is obvious
[Schlesinger and Ramankutty, 1994; Swanson et al., 2009], superimposed upon a long-term
warming trend.....

..... Meanwhile, after subtracting the AMO signal from the NHT,
the residual shows a nearly monotonic increase, which is very much like the linear trend in
the NHT (Supplementary Figure 4), and the multidecadal variability disappears.....

The kicker being, if the paper is correct, that we could expect the downswing in temperatures predicted to be coming at a really bad time.  Assuming of course that we are trying to change BAU behavior.  It might just make arguments with deniers and a dis-engaged public much harder to make.  Long-term this cycle makes no difference, but we don't have long-term to institute change.  It is a corollary to our persistent La Nina's and the missing El Nino which seem to be pumping the incoming energy into the deeps.

Is there some reason many people on this site claim someone they don't even know hasn't read something?

I was making a statement about WUWT using any data on climate patterns and not a statement about the merits of the paper. Obviously, I wasn't clear enough to make my point.

If we couldn't recognize a climate pattern, it would never be mentioned or considered. Since scientists have found such climate patterns useful, they discount the effects of global warming on SSTs, hoping to continue the benefit of observing climate patterns. In doing so, they assume a climate pattern will continue to be useful as it once was, with the noise of global warming filtered out. I'm of the opinion that global warming can completely change climate patterns and looking at the Earth in ways that aren't truly as it exists can be very misleading. My opinion is based on an assessment of the past during the Eemian, so my model of Earth isn't a computer model. It's an Earth model with approximately a similar Earth having higher temperatures than today and what climates were at that time. Yes, adjustments have to be made for differences in solar insolation, which have direct effects on certain areas and the effects of greenhouse gas forcing are more universal.

Climate patterns are in a sense climate change and that's why I call it global warming and not climate change. Nutcases will seize on anything pertaining to climate patterns, which are adjusted discounting global warming, to further their agenda that increases in CO2 are meaningless to global warming and it's just a natural cycle. It doesn't make a difference if some global warming discounted climate pattern is predicting cooler Northern Hemisphere temps, because a bigger Gorilla is in the room. The future change in radiative forcing from clean air standards will totally overwhelm and then some any benefit from changes in climate patterns in the Northern Hemisphere.

AMO, AMOC and NAO are things Denialistas like to focus on. The Atlantic Ocean has been cooling for millions of years and I don't consider it significant in warming our planet. When we see changes in the Pacific Ocean predicting warming, like ENSO and PDO, look out! 1998 will become a thing of the past.

I apologies if my post was that misleading.   

werther

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Re: Li paper predicts cooler Northern Hemisphere temps
« Reply #10 on: October 20, 2013, 11:10:33 AM »
Thanks, Idunno,

I always superficially imagine the AMO is the North Atlantic part on the Meridional Overturning Circulation. But I agree there's also the SST mean over the whole North Atlantic Basin, which has a different meaning.