Tisdale tasks Tamino

Atlantic Multidecadal Oscillation Timeseries w...

The AMO - Image via Wikipedia

Comments On Tamino’s AMO Post

by Bob Tisdale

Tamino’s AMO post is a response to my post Removing The Effects of Natural Variables – Multiple Linear Regression-Based or “Eyeballed” Scaling Factors (hereinafter referred to as the “Removing” post). Tamino took exception to my inclusion of the AMO as one of the datasets used to explain the rise in GISS Land-Ocean Temperature Index (60S-60N) during the satellite era. Please read Tamino’s AMO post before continuing.

My “Removing” post, as discussed in its opening paragraph, was the second in a series follow-ups to the earlier post Can Most Of The Rise In The Satellite-Era Surface Temperatures Be Explained Without Anthropogenic Greenhouse Gases? (hereinafter referred to as the “Can Most” post). The first follow-up was Notes On Polar Amplification.

And for those new to the Atlantic Multidecadal Oscillation (AMO) please refer to the post An Introduction To ENSO, AMO, and PDO — Part 2.

THE REAL CLIMATE DESCRIPTION OF THE AMO

Tamino wrote in his post,

“Bob Tisdale (and others) simply can’t wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly. Therefore global warming is the cause, not the effect, of much of the variation in the AMO.”

My AMO posts typically include the RealClimate description of the Atlantic Multidecadal Oscillation (“AMO”), but I failed to include it in “Removing” post. RealClimate states, “A multidecadal (50-80 year timescale) pattern of North Atlantic ocean-atmosphere variability whose existence has been argued for based on statistical analyses of observational and proxy climate data, and coupled Atmosphere-Ocean General Circulation Model (“AOGCM”) simulations. This pattern is believed to describe some of the observed early 20th century (1920s-1930s) high-latitude Northern Hemisphere warming and some, but not all, of the high-latitude warming observed in the late 20th century. The term was introduced in a summary by Kerr (2000) of a study by Delworth and Mann (2000).”

Tamino’s opinion contradicts the opinions of his associates at RealClimate, or at least the opinion of the author of the RealClimate AMO webpage. RealClimate describes the AMO as being responsible for some, but not all, of the warming, but Tamino states it’s the other way around, that the global warming signal is the cause of the AMO variability.

Tamino’s RealClimate associates must be among “the others” who “simply can’t wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly.”

A NOTE ABOUT THE SST DATASET USED IN THIS POST

GISS uses two SST anomaly datasets in its Land-Ocean Temperature (LOTI) product: HADISST from January 1880 to November 1981 and Reynolds OI.v2 from December 1981 to present. There is little difference between the HADISST and Reynolds OI.v2 data for the North Atlantic during the satellite era, as shown in Figure 1. So my use of HADISST data in the short-term will not influence the results of this post.

http://i52.tinypic.com/fxyvwp.jpg
Figure 1

However, there is a significant difference between the long-term Kaplan North Atlantic SST data used by the ESRL (and Tamino) and the HADISST data used by GISS. Refer to Figure 2. Keep in mind my use of the ESRL data was only for the AMO index in the short term, not the long-term SST data used by Tamino. (Note: I confirmed via email that the ESRL uses the coordinates of 0-70N and 80W-0 for its AMO data.)
http://i51.tinypic.com/28atkzb.jpg
Figure 2

And the difference does impact Tamino’s post. He uses the wrong North Atlantic SST anomaly dataset when he subtracts global temperatures from it. That is, assuming Tamino did not switch to the HADISST version of the North Atlantic, he biased the results in his last graph by the difference in the trends of the HADISST data (used by GISS) and the Kaplan data (used by ESRL) shown in Figure 2.

ON THE NONLINEARITY OF THE WARMING SIGNAL

The natural multidecadal variability of the North Atlantic SST anomalies is significantly greater than that of the Global (90S-90N) SST anomalies. This is very apparent if we compare detrended North Atlantic SST anomalies (AMO) to detrended Global SST data, Figure 3. The data have been smoothed with a 121-month running-average filter.
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Figure 3

Tamino opens his post with a discussion of the how the AMO is calculated by detrending North Atlantic SST anomalies, and he notes that the Wikipedia definition warns about the nonlinearity of the actual warming signal. The nonlinearity of the detrended global SST signal is shown clearly in my Figure 5 above. Based on his presentation, Tamino concludes, “Variations in the forced signal do leak into the AMO definition.”

Let’s compare the short-term linear trends of the North Atlantic SST anomalies to the trends of the other ocean basins. This is a general discussion of the AMO, so I’ve left in the Arctic and Southern Ocean data. Keep in mind that my “Removing” and “Can Most” posts only dealt with the period starting in 1982, which is the satellite era for SST data. As shown in the spaghetti graph, Figure 4, the SST anomaly linear trend of the North Atlantic is significantly higher than all other SST basins. The linear trend of the Arctic Ocean SST anomalies comes in second, in part because those two datasets overlap and due to the influence of the North Atlantic on the Arctic Ocean. Regardless, the North Atlantic linear trend is almost twice that of the Arctic Ocean. The North Atlantic trend is more than 3 times higher than the trends of the North Pacific and Indian Oceans and more than 5 times higher than the trends of the South Atlantic and South Pacific. And of course, the Southern Ocean linear trend is negative. (Note: The impact of the Southern Ocean cooling is so substantial that the trend is basically flat for all HADISST anomaly data south of 40S, or about 35% of the global oceans, since 1982.)
http://i56.tinypic.com/vo0ck0.jpg
Figure 4

This difference in linear trends can also be seen in the comparison of North Atlantic SST anomalies and the SST anomalies for the rest of the world. To determine the rest-of-the-world data (identified as “Global Without No Atlantic” in Figure 5), I approximated the North Atlantic surface area as a percentage of the global oceans. The Atlantic represents approximately 30% of the surface area of the global oceans. I assumed the North Atlantic made up half of that, or 15%, before scaling the North Atlantic data and subtracting it from the global data for Figure 5. The linear trend of the North Atlantic SST anomalies is more than 5 times greater than the average of the other ocean basins.
http://i53.tinypic.com/ml1jz9.jpg
Figure 5

In fact, the contribution of the North Atlantic is so great, without it, the global trend drops by 45%, Figure 6.
http://i56.tinypic.com/2zhei46.jpg
Figure 6

Tamino did not suggest how to account for the global warming signal in his AMO post, unless the last graph in which he subtracts global GISS LAND-Ocean Temperature Index data from North Atlantic SEA Surface Temperature data is his recommendation. But he did make a suggestion on his earlier How Fast is Earth Warming? thread. He wrote in response to a January 23, 2011 at 4:42 pm comment, “It might be interesting to correlate AMO to short-term global temperature fluctuations, if AMO is detrended nonlinearly, or if only the modern era (1975 to present) is detrended separately. But then: the denialists’ claim disappears.”

To account for the nonlinear signal, Trenberth and Shea (2006) proposed subtracting the global (60S-60N) SST data from the North Atlantic in “Atlantic hurricanes and natural variability in 2005”. But the North Atlantic represents a major portion (almost 50%) of the recent rise in global SST anomalies (90S-90N) since 1982, Figure 6. Therefore, Trenberth and Shea are suggesting the subtraction of a dataset with a strong North Atlantic signal from the North Atlantic SST data itself. Why not subtract the SST anomalies of the rest of the world from the North Atlantic? It’s the additional variability of the North Atlantic, above and beyond the rest of the world, that’s of interest, not a signal that’s been suppressed by itself.

The reason that method hasn’t been suggested becomes obvious when one compares that dataset to the AMO data based on detrended North Atlantic SST anomalies. Refer to Figure 7. (The “Rest of the World” data is calculated the same as the “Global Without North Atlantic” from Figures 5 & 6.) Note how the curves mimic one another from 1905 to the early 1980s. They diverge from time to time, but the curves are similar. But note how VERY similar the two curves are after 1982. That’s the period of the AMO data used in my “Removing” post.
http://i53.tinypic.com/2v1ukg5.jpg
Figure 7

Let’s look at the satellite-era portion (1982 to present) of those two datasets, Figure 8. The trends are basically the same, and the year-to-year variability of the two signals mimic one another with small divergences and lags. Based on Figure 10, the “Variations in the forced signal do leak into the AMO definition,” as Tamino notes, but they have had little impact on the results of my “Removing” post.
http://i54.tinypic.com/kdpe7c.jpg
Figure 8

THE DIFFERENCE BETWEEN THE KAPLAN AND HADISST NORTH ATLANTIC SST ANOMALIES

The Kaplan and HADISST versions of the North Atlantic SST anomalies were illustrated together in Figure 2. There was a significant difference in their linear trends. For Figure 9, I subtracted the HADISST version of the North Atlantic SST anomalies from the Kaplan SST anomalies used by ESRL (and Tamino for his last graph). Note the similarities between Figure 9 and Tamino’s final graph in his AMO post.
http://i53.tinypic.com/2806uqx.jpg
Figure 9

TAMINO’S FINAL COMPARISONS

Tamino’s post included a comparison graph of Global (90S-90N) GISS LOTI and the North Atlantic SST anomalies he created from the data on the ESRL AMO webpage. The last illustration was a graph of the difference. While I can’t find fault in his not knowing there was a shift in the Kaplan North Atlantic SST data, I can find fault in his using the wrong SST dataset. GISS does not use Kaplan SST.

There is little difference between the HADISST and Reynolds OI.v2 versions of the North Atlantic SST data, as shown in Figure 1. To assure the following comparisons were correct, for the following graphs I spliced those two North Atlantic SST anomaly datasets using the method described by GISS in Step 4 on their current analysis webpage. Had Tamino used the HADISST/Reynolds OI.v2-based GISS SST anomalies for the North Atlantic in his comparison, Figure 10, the difference between it and the Global GISS LOTI data would have maintained the appearance of the AMO.
http://i53.tinypic.com/2hofas0.jpg
Figure 10

And had Tamino detrended both datasets and smoothed them with 121-month filters, Figure 11, he would have noted that the multidecadal variability of the North Atlantic far exceeds that of the Global GISS LOFTI data—even with the additional land surface temperature variability in the LOTI data—even with the exaggeration of polar amplification in the LOTI data—even with the bias caused by GISS’s deletion of polar sea surface temperature data in the LOTI data.

http://i52.tinypic.com/3149sm9.jpg
Figure 11

I’ll respond to his comments about “eyeballing” in another post.

SOURCES

With the exception of the ESRL North Atlantic SST data (linked numerous times in the post), all data are available through the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

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73 thoughts on “Tisdale tasks Tamino

  1. Steve McIntyre had a lot of fun with Tamino’s “bilge” over at CA over the years.

    Tamino has deleted several threads putting him a bad light. Let’s see how long this one lasts before it comes up missing.

  2. Bob Tisdale:

    Thankyou for your clear explanation. However, I fail to understand why anybody responds to ‘Tamino’, ‘Eli Rabbett’ and similar minor academics who blog under false names.

    Some academics (e.g. Roy Spencer, Roger Pielke, snr., etc.) use a blog as a method to debate ideas with a wide audience prior to deciding whether or not to publish those ideas. Of course, they do that using their own names because otherwise they could not claim originality if they later choose to publish in formal literature.

    Tamino, Rabbett, etc. are academics so they benefit from each and every publication they make in the formal literature: each publication increases their publication index. And they must recognise that what they write cannot obtain such publication when they choose to post it on a blog under a false name.

    In other words, when the likes of ‘Tamino’ post something on their blogs they demonstrate that they consider what they post to be unworthy of publication and is such rubbish that they are not willing to put their own names to it.

    I and many others consider we have much better things to do than to plough through rubbish whose owners throw out.

    I respectfully suggest that you, too, have much better things to do than to deal with such rubbish.

    Richard

  3. I’m not sure you’ll see him convinced that he is in error Bob, although I applaud your valiant effort.

    Not to get snarky, but his website is OpenMind, in utter contrast to the arrogant manner in which he addresses those who don’t agree with his point of view.

  4. Why is he so very rude? It was hard to follow his argument through all the abuse directed at you, WUWT, innocent bystanders who happened to question anything he said, etc.

  5. “The college idealists who fill the ranks of the environmental movement seem willing to do absolutely anything to save the biosphere, except take science courses and learn something about it.”

    — P.J. O’Rourke

    In Tamino’s case, I would suggest a class in Heat Transfer, as well as a prerequisitie class or two in Thermodynamics. Maybe then he might realize the absurdity of his cause/effect assertion.

  6. Tamino just wants us to “wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly.”

    In other words we should presuppose without evidence that his hypothesis is true. And we should ignore paleo and other evidence to the contrary because this time is different, for some unexplained reason, from all past time.

    Am I the only one who reads his statement that way?

  7. A minor grammar error (hate to be pedantic):

    While I can’t find fault is his not knowing there was a shift in the Kaplan North Atlantic SST data, I can find fault in his using the wrong SST dataset. GISS does not use Kaplan SST

    , makes the sentence harder to read than would otherwise be the case :p.

    REPLY:
    Fixed, thanks -A

  8. “RealClimate describes the AMO as being responsible for some, but not all, of the warming, but Tamino states it’s the other way around, that the global warming signal is the cause of the AMO variability.”

    Your quote from Tamino says this

    “Therefore global warming is the cause, not the effect, of much of the variation in the AMO.””

    How is this a contradiction?

  9. I propose that Tamino, the little rabbit, and others of their ilk should from here forward be referred to as “hotheads”.

  10. That’s amazing Tamino! The Global warming monster can change the AMO without raising the heat content of the oceans.

    That’s brilliant! /sarc

  11. tamino isn’t, AFAIK, an academic. Is he? Rabbett is, he’s a physicist, Halpern or something. tamino is well known to be Grant Foster and seems to do time series analysis in industry for a living. There is no real secret about who any of these people are, any more than there is about who Bishop Hill is. One can understand that they might want to keep using nicknames, if climate is not their day job and is as controversial as it is. Foster made no great efforts to preserve anonymity. Its more like a distancing of oneself from the persona which one uses for blogging. There can be no accusation of mixing business and hobby.

    Now, the rudeness and self righteousness of the tamino alter ego, that is a different matter. That is really not nice, and is in fact self defeating.

    [Correction: the bunny is a chemist. And Cook of Skeptical Science is a cartoonist.]

  12. Edit note:
    “Without No Atlantic” don’t make no sense nohow. But if you say “Without No. Atlantic”, it does.
    Punctuation is not pointless. Or period-less. Or SLT.
    ;)

  13. Sorry, but 0.X, and o.ox degrees of averaged out temp changes over a year ain’t changing much of anything.

  14. Therefore global warming is the cause, not the effect, of much of the variation in the AMO.

    If that’s the case, we owe Tamino a great debt of gratitude for pointing that out. It means:

    1) There is no trend signal in global warming
    2) Global warming is strictly a cyclical phenomenon, it will reverse whatever direction it’s currently on.
    3) No need for adaptation, mitigation or anything else for the cyclical nature of AGW.
    4) Climate Sensitivity to CO2 is negative AND positive, and quite variable, depending on where in the cycle we happen to be…
    5) WarmBlizzard and DroughtFlood really COULD be true!!!

  15. Tamio,

    Could it be that the global warming signal is significantly nonlinear? Here’s global temperature from GISS:

    How the hell can you compare anything with GISS?

  16. @Scott Cover

    “That’s amazing Tamino! The Global warming monster can change the AMO without raising the heat content of the oceans.

    That’s brilliant! /sarc”

    Taking your point as a given, can the AMO raise global temperatures without raising the heat content of the oceans?

  17. Wondering Aloud says:
    February 3, 2011 at 10:07 am
    “Tamino just wants us to “wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly.”

    In other words we should presuppose without evidence that his hypothesis is true. And we should ignore paleo and other evidence to the contrary because this time is different, for some unexplained reason, from all past time.

    Am I the only one who reads his statement that way?”

    No you’re not alone, it reads that way to me also.

  18. I’ve gotten the feeling for a long time that the guys at Real Climate privately talk to various bloggers and journalists and give them mistaken impressions of various climate-related things.

    Perhaps it is the “telephone” effect to some extent, but I also think guys like Gavin have no motivation to make them understand – they need their faith not their understanding.

  19. This exchange on the recent thread about the Lord Monckton documentary on Tamino (thread titled “Peer Pressure” Feb.1) made me smile…

    Contributor A: Did this show make any mention of that fact that he’s being investigated for involvement in human trafficking? I’m not making this up.

    Contributor B: I think I’d retract that.

    Contributor A: I was sure of myself, and now I can’t find my sources. Ouch. I ask tamino to pull all related posts on the subject, if that wouldn’t be dishonest.

    Contributor B: See, that’s what I love about real, proper, actual sceptics – a willingness to admit to a mistake.

  20. From the comments posted.

    Tom Curtis | January 30, 2011 at 3:57 am | Reply

    I notice your final graph has a significant negative trend. I suspect that is because land temperatures are rising faster than sea surface temperatures, so that GISS global temperature anomaly rises faster than sea surface temperatures in general, and those of the North Atlantic in particular. Can you show us a graph of the NA SST anomaly minus the global SST anomaly for comparison?

    Might this also indicate how GISS has been fudging the temperature data?

  21. I agree with most others here. Tamino is basically some anonymous blogger with no credentials. It don’t think it merits a whole article here dealing with any such noise on the net.

    One point:
    >>
    The Atlantic represents approximately 30% of the surface area of the global oceans. I assumed the North Atlantic made up half of that, or 15%, before scaling the North Atlantic data and subtracting it from the global data for Figure 5.
    >>

    I get a bit twitchy when I read things like this, “about” this , “I assume that”.. . Since you have detailed plots of the other ocean areas , why not plot their sum against N Atl. ? Then you would be based on data not guesstimates. It would eliminate that possibility that you over or under-weight the N.A. component when you subtract.

    What seems odd is that N.A. should be so much more sensitive

  22. DDM: over a long enough period, GISS trend – SST trend = UHI +/- manual adjustments and compilation errors. Interestingly Satellite trend is closer to SST.

  23. Tamino’s ill-thought out post is barely worth a blog comment, I agree with others that you are wasting WUWT space by dedicating a post his silliness.

    What is more interesting from your graphs is why N. Atl. is so much more sensitive to GW trend and oscillations than the rest of the oceans. This seems paradoxical.

    Since you have detailed data to plot for the other oceans why don’t you plot thier sum rather than a crude estimate of how big the Atlantic is and a guess that N.A. is 50%.

    That way you’d be based on data not guesstimates and you’d be on firmer ground.

  24. I must agree with another poster here, Richard S Courtney, that no one should play along with Tamino. I personally found his behaviour odd to say the least, when I commented one or two times. He pulled a post when I pointed out that he had made a mistake. I REALLY urge people not to post on his website – it’s pointless, really.

  25. Very interesting, that the North Atlantic warms have coincided with the globes warming. I wonder if someone can do a study with the PDO and AMO, since i think the 2 of them together can explain a lot of what has happened in temps since 1900 across the globe.
    Great Post, and I agree that Global warming doesn’t cause the AMO to warm, the AMO is seperate of AGW, they just happened to coincide right now

  26. North Atlantic goes up and down, showing no relation with CO2. Unless, you claim the 1975-2005 rise is unprecedented and caused by CO2. The previous part rising and falling, well, the flat line of hockey stick will do.
    See how it switched in 2005 back to cooling, despite recent warm peak. Those people are desperate.

  27. “Bob Tisdale (and others) simply can’t wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly. Therefore global warming is the cause, not the effect, of much of the variation in the AMO.”

    So… I’m confused… If Global Warming causes the rise in AMO during the late 20th Century, then how could there be an AMO before that? I mean, really, I’m eyeballing the wikigraph, and I clearly see a positive AMO between 1860 and 1900, and another between 1940 and 1960. If global warming provides the heat to “cause” the current one….Where did the heat to fuel the two previous come from?????

    He is right though. I can’t wrap my brain around that!

  28. DD More: You asked, “Might this also indicate how GISS has been fudging the temperature data?”

    Not really. Land surface temperatures exaggerate ocean variability.

  29. P. Solar says: “Since you have detailed data to plot for the other oceans why don’t you plot thier sum rather than a crude estimate of how big the Atlantic is and a guess that N.A. is 50%.”

    I assume you mean average them. Any method one choses requires weighting and estimates of surface areas.

  30. I don’t see either side of this discussion establishing their position.

    It seems odd that N.Atl. is so much more sensitive , but accepting that , I don’t see that that fact argues for or against it being the cause or effect of GW.

    However, if it is the cause, where is the heat coming from ? Just observing that there is an oscillation or a trend does not say where the heat comes from that would be the true cause of the warming.

    Roy Spencer and R. Lindzen suggest these oscillations are at least partially driven by cloud variation.

  31. I find it funny that Tamino’s blog has been reduced to try to debunk WUWT posts. I posted a similar comment there but for some reason it didn’t pass moderation LOL

  32. I’ve not visited the misnamed “Open Mind” for ages, the condesending tone (At best) of the little bunch of sycophants is just intolerable, let alone the blatant rudeness of Foster himself!
    Much the same at (Sur)RealClimate, anything that might deviate them from the path of warming righteousness is dismissed with a wave of the hand.

  33. Wondering Aloud says:
    February 3, 2011 at 10:07 am

    Tamino just wants us to “wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly.”

    In other words we should presuppose without evidence that his hypothesis is true. And we should ignore paleo and other evidence to the contrary because this time is different, for some unexplained reason, from all past time.

    Am I the only one who reads his statement that way?

    ########
    The case for Global warming being the cause of changes in a regional index is
    simple.
    1. The correlation
    2. The negative lag.

    Since correlation does not prove causation both Bob and Tamino have a problem
    Since the lag is negative, that’s a point in Tamino’s favor.

    Does not excuse him for being a nasty human. His name is Grant Foster.

  34. “Open Mind”… what an Orwellian name for that site.

    Almost as misleading as Cook’s “skepticalscience.” Or “RealClimate.”

    Oh well. It all makes sense in this era of warmcold.

  35. Bob Tisdale said
    The PDO data from JISAO is not sea surface temperature anomaly data. It is a statistical component of it. Refer to:

    http://bobtisdale.blogspot.com/2010/09/introduction-to-enso-amo-and-pdo-part-3.html

    in response to my previous post.
    So if I read it correctly, the AMO is a measure of actual ocean temperature in the North atlantic, while the PDO is a measure of a certain variability with where the Pacific is warm/cool than, but not the actual temperature of the North Pacific?
    If so I wonder what the impact of the PDO in it’s ‘warm phase’ would have on surrounding landmasses and the world, and what impact it has in it’s ‘cold phase’?

  36. I think Bob is correct in replying to Tamino. If he was to stay silent, Tamino and his flock get even more smug with a conceived win under their belt.

    Some of Taminos flock will surely read this reply and see that their ‘preacher’ has got it wrong, even if they won’t admit it.
    I’d suspect each time one of these posts like Bobs appears at WUWT or CA, Tamino loses some of his followers until only the rusted on gullible ones are left.

    I look forward to some of Taminos followers supporting him by posting some comments here showing us why Bob is wrong. C’mon guys, show some guts and courage, post a comment.
    If Tamino supporters don’t post a comment, it will say quite a lot not just about Taminos blog, but about Tamino himself and the type of people he has surrounded himself with.

    QUESTION: Would you go to war with Tamino denizens at your back?

  37. Robert asked, “If so I wonder what the impact of the PDO in it’s ‘warm phase’ would have on surrounding landmasses and the world, and what impact it has in it’s ‘cold phase’?”

    As the PDO rises, the Eastern North Pacific rises but that is countered by a drop in the the central and western North Pacific. Since the area of the central and western North Pacific is greater than the east, the net is typically a drop in North Pacific SST as the PDO rises.

    Land surface temperatures for Northwest North America correlate well with the rise and falls of the eastern North Pacific, and the land surface temperatures of Eastern Asia correlate well with the western North Pacific.

  38. L says:
    February 3, 2011 at 3:14 pm

    I thought Grant Foster made glass suns…
    ——-

    Also glass eyes… might explain a few things, like the state I was reduced to when I attempted to make sense of his posts several years ago, before giving up on him.

  39. Good Post Bob.

    I’m sure Tamino will find many ways to distort what you have presented as he always does.

    There are many paper about the North Atlantic and the AMO as a natural climate cycle. These go back a 1000 years in some cases.

    The problem is the AMO has a large trend from 1910 to the fall of 2010. It doesn’t from 1760 to today but we are obligated to detrend it so as not to confuse any global warming signal which might be present in it. It still has a 60 year cycle in the recent data but we must remove the upward trend.

    I’ve started using the Gulf Stream instead. Almost all of the upward trend in the AMO is from the 0n to 30N component not actually from the North Atlantic.

    Here is the Gulf Stream back to 1850 (using ERSSTv3b with HadSST2 appended to it so we can go way back to see if there is a trend. A very small one).

    The idea from this is that there are 7 or 8 major ocean currents which are the most responsible for moving energy around the planet and exchanging energy with the atmosphere.

    These are the Pacific ENSO, the Kuroshio, the Gulf Stream, the Atlantic Equatorial, the Brazil-Malvinas Confluence, the Agulhas and the Antarctic Circumpolar Current.

    You can see this in this animation from the US Navy.

    I’m having a little better luck modeling Hadcrut3 back to 1871 using this method. Still some bugs to work out when I can get the time.

  40. Bob,

    I have a question that may just be a variation of what

    P. Solar says:
    February 3, 2011 at 1:15 pm

    In Fig7&8 you subtract the global minus N. Atlantic from the N. Atlantic. You seem to suggest that in doing this you have removed the AGW trend from this data to reveal the natural variation. It’s strikes me all you have revealed is the difference in the trend between the N. Atlantic and the global, it seems like a leap to try to attribute this to any one cause. There’s no reason to assume that the N. Atlantic region should behave like the the global average to CO2 forcing. Having said that the shape of it is not to conducive to a linear forcing.

    I thought Fig3 was interesting. The comparison of detrended global and N. Atlantic looks how arctic polar amplification graphs would look. I did my own graphing using KNMI Climate Explorer trying to avoid an overlap between the Arctic and N.Atlantic data (0N-60N for the atlantic). You get pretty much the same effect as your Fig3. I don’t think it’s just the overlap It would be interesting to know how the amplification effect extends into regions of no ice when sea ice loss is meant to be the driver of this process.

    It looks like you’re leading this one on points ATM. I’d still love to see a KO blow.

    And if Tamino is reading this. Honestly sneering might get howls from the gallery but it does nothing for those of us who wish to be challenged.

  41. I tried to have a discussion over at Tamino’s “Open Mind” (which turns out to be a very inaccurate description.) Tamino accepted my first post but then deleted others. In support of how all oscillations can cause warming, I replied with the following, but Tamino couldn’t debate it scientifically, so he once again reverted to ad hominems, and deleting post, always a sign that someone is out of real ammunition. Who is Tamino? a real scientist?

    So although this is not specifically about the AMO it is applicable

    “There are several researchers who show that warming trends can be associated with oscillations. It is more than just sloshing heat around but also the resultant changes in wind patterns and thus heat transport. Asymmetries can create an illusion of average warming. Hurrell has shown that the NAO can explain most of the late 20th century European warming. Rigor and others have shown changing winds associated with the PDO has forced more ice out of the Arctic taking the “ice lid” off of the 2 degree Arctic ocean when air temps are -20 or lower.

    Other studies have clearly shown Alaska warmed with the changing winds of the PDO. The changing regime of winds have been associated with increased El Ninos. The 1998 El Nino caused a 0.8 jump in temperatures and then La Nina brought it back down again. That is a temperature change equivalent to the CO2 attribution, without any additional heat but by spreading it around to be measured over a greater spatial scale. So we look at trends but an asymmetry in El Ninos along with the change in winds, and ice and heat transport, can easily cause a warming trend that lasts for the 30-40 year PDO cycle, similar to what Wigley and others have modeled. Most of the fisheries data show global teleconnections with these oscillations with a few years lag times. So in general all these oscillations have been on an upswing.
    There is also a solar trend since 1900, and although that may only account for 25 % of the century warming, add that to the PDO oscillation induced increases, the NAO induced oscillations, etc and then there is only a minor amount that I would attribute to CO2.

    You stated “Therefore global warming is the cause, not the effect, of much of the variation in the AMO” and that sounds like your attributing the oscillation to AGW, or at least the major amplitude to AGW. If your use of global warming included the solar trend, we can now include that. But what I and and others including Tisdale are arguing is that the oscillations are causing asymmetries in heat distributions that cause warming trends.

    Sure the eyeball quote is a good hit point in an adversarial debate, but the focus should be on how oscillations can or can not contribute to trends, which has been the substance of what Tisdale has been arguing. I simply find focusing on the eyeball quote as uninformative and as unprofessional.

  42. Bob Tisdale wrote:

    RealClimate states,”….
    This pattern is believed to describe some of the observed early 20th century (1920s-1930s) high-latitude Northern Hemisphere warming and some, but not all, of the high-latitude warming observed in the late 20th century. The term was introduced in a summary by Kerr (2000) of a study by Delworth and Mann (2000).”

    Tamino’s opinion contradicts the opinions of his associates at RealClimate, or at least the opinion of the author of the RealClimate AMO webpage. RealClimate describes the AMO as being responsible for some, but not all, of the warming, but Tamino states it’s the other way around, that the global warming signal is the cause of the AMO variability.

    Tamino’s RealClimate associates must be among “the others” who “simply can’t wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly.”

    There is a difference between saying the AMO is responsible for the warming, and saying it is the cause of the warming.

    It is clear that the North Atlantic is the portion of the ocean that has seen the most warming over the past 40 years. That is what is meant by the words “is responsible for the warming of the globe. It doesn’t rule out the possibility that some other force is driving the warming of the North Atlantic.

    The NAO has not been a strictly periodic or predictable ocean oscillation. It is not that well understood, and was only discovered recently. There is good evidence that the ocean has undergone a warming trend due the GHG induced warming over the past 40 years. If the oceans have been gaining heat, and the surface of the North Atlantic has been getting warmer, it doesn’t make sense to rule out global warming resulting from GHG’s as the ultimate cause.

  43. Even “realclimate” admits Tamino has it backwards, and that it’s ocean temps that drive air temps.

    http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/

    According to the September 5, 2006 posting,

    “The slope of the relationship is 0.002K (W/m2)-1. Of course the
    range of net infrared forcing caused by changing cloud conditions
    (~100W/m2) is much greater than that caused by increasing levels of
    greenhouse gases (e.g. doubling pre-industrial CO2 levels will
    increase the net forcing by ~4W/m2), but the objective of this
    exercise was to demonstrate a relationship.”

    Note that CO2 hasn’t yet doubled from the 280ppm at the beginning of
    the 20th century to now, but when it does, the net effect will be a
    warming of the oceans of 4*0.002= a whopping 0.008 C.

    Obviously any MEASURABLE changes in ocean warming must be due to
    factors other than CO2- most likely cloud cover- A. McIntire

  44. Bob,

    I think that you are missing the central point of Tamino’s post: that the current definition of the AMO does not adequately remove the global warming signal. He demonstrates this quite adequately. If you look at the AMO the uptrends and downtrends follow the periods of 20th century warming where that warming was faster than the linear trend. So you see an increase in the AMO from about 1910 to 1950 (or so) and again from 1970 (or so) to present. The GW signal leaks into the AMO signal.

    This combined with the fact that AMO shows a two month lag (AMO changes about two months after global temp.) makes it highly unlikely that AMO is driving anything.

  45. Bill Illis,

    How does the Kuroshio Current correlate with the oscillations in the Gulf Stream?

    Fisheries data suggest teleconnections that would also suggest there would be a similarity for the Kuroshio but lead the Gulf stream by several years. Have you plotted the Kuroshio as well?

  46. I think there is a hidden assumption, or at least usually unstated assumption that makes ‘warmists’ sceptical of claims cyclic processes like AMO, PDO, ENSO can be the cause of a trend.

    Cyclic processes with a long history are (in money terms) like savings accounts, you pay in for a while and then use them to spend more later. They change the timing of expenditure, but not the overall income. If cyclic processes COULD change the ‘income’ the amount of energy available to warm the globe then they would have been the cause of trends in the past.

    Therefore any trend in a cyclic process, longer periods or higher temperatures during peaks must be a response to an external source of extra energy because they cannot change the amount of energy that is input to the system themselves.

  47. Bob Tisdale says:
    February 3, 2011 at 2:28 pm

    steven mosher says: “Since the lag is negative, that’s a point in Tamino’s favor.”

    Care to expand on your statement?

    #####
    see ratuss’ comment.

  48. Woo woo another righteous chance to display a now quite old grudge I have with Dr. Foster, namely how lil’ alarmist kiddies prior to Climategate bashed my Central England Don’t Panic chart that plotted the world’s oldest actual thermometer record (that shows that recent warming is a boring continuation of a 350 year old linear trend)….based on his still standing blog post that is a classic example of lying with statistics. This is simple enough for anybody to understand and is a similar to what Dr. Mann clings to as well: bad maths.

    He moderated out my post containing this information. I post it here for posterity. Eventually I added a bunch of other single site very long running thermometer records to my original simple chart of Central England: http://oi49.tinypic.com/rc93fa.jpg

    Relevant to this wildly complicated thread is the simple observation that Dr. Foster has a history of data terrorism.

  49. I have found dissent is not tolerated at Tamino’s. They speak of intangibles affecting highly questionable probabilities that always tend to gloom and disaster.
    Simple questions that question the answers to their orthodoxy are deleted.
    Very head in the clouds pretend science, but very precise.

  50. eadler says:
    February 3, 2011 at 8:46 pm
    Bob Tisdale wrote:

    ” If the oceans have been gaining heat, and the surface of the North Atlantic has been getting warmer, it doesn’t make sense to rule out global warming resulting from GHG’s as the ultimate cause.”

    True, but it does not make sense to rule CO2 IN as primarily responsible. Until you can QUANTIFY the ocean warming effect of a given W/2m increase in SWR, COMPARED to the ocean warming effect of an equivalant W/2m increase in DWLR, then I see no reason that a multi decadal change in SWR due to increased solar flux at the surface driven by changes in TSI or cloud cover could not be seen as the primary driver of any ocean warming.

  51. Rattus Norvegicus says: “I think that you are missing the central point of Tamino’s post: that the current definition of the AMO does not adequately remove the global warming signal. He demonstrates this quite adequately.”

    Based on this portion of your reply, it appears you didn’t bother to read my post, Rattus.

    I didn’t miss the point Tamino tried (but failed) to make. Tamino used the wrong North Atlantic SST data in his post to attempt to make that point. If he had used HADISST/Reynolds SST anomalies, the North Atlantic SST data dominates the multidecadal variability. See my last two illustrations.

    Also refer to my discussion on nonlinearity of the warming signal that starts with Figure 3 and ends at Figure 8. That’s most of the post, and it’s tough to miss, Rattus. In it I concluded, if the AMO is represented as the difference between the North Atlantic SST anomalies and the SST anomalies of the rest of the world (to account for the additional variability of the North Atlantic), then there is little difference in the short-term trends and variability of the (detrended and ROW SST-adjusted) AMO datasets.

    You added, “This combined with the fact that AMO shows a two month lag (AMO changes about two months after global temp.) makes it highly unlikely that AMO is driving anything.”

    The trend of the recent AMO-related rise of the North Atlantic SST anomalies is more than five times higher than the trend of the SST anomalies for the rest of the world. See Figure 5 above. Your belief that it’s “unlikely that AMO is driving anything”, therefore, defies logic.

    And how are you determining this two month lag? Are you keying your observations off the responses of the AMO and global temperatures to ENSO events? Global temperatures include the primary ENSO signal in the central and eastern tropical Pacific. But the response of the North Atlantic to ENSO is through teleconnections, and it requires those teleconnections to slow the tropical North Atlantic trade winds, etc., in order to raise North Atlantic SST anomalies. The lag between the change in SST in the Eastern and Central Tropical Pacific and the response of the North Atlantic is approximately 2 months.

    If you’re not keying your 2-month lag off of ENSO responses, then please define how you are determining the lag.

  52. eadler: A reply to your February 3, 2011 at 8:46 pm comment: This is why we’re discussing the additional variability of the North Atlantic to show that that additional variability CAN account for a significant portion of the recent rise in global temperatures. Also, your reply assumes that the rise in the SST anomalies for the rest of the oceans can’t be explained as responses to natural variables, such as ENSO. But I have shown in a number of posts that it can.

    Also, the North Atlantic Oscillation (NAO) is a sea level pressure phenomenon, and it was discovered in the 1920s by Sir Gilbert Walker. It’s been studied for decades. Are you confusing the NAO for the AMO?

  53. HR says: “In Fig7&8 you subtract the global minus N. Atlantic from the N. Atlantic. You seem to suggest that in doing this you have removed the AGW trend from this data to reveal the natural variation. It’s strikes me all you have revealed is the difference in the trend between the N. Atlantic and the global, it seems like a leap to try to attribute this to any one cause.”

    I was attempting to show that it was better to subtract the ROW SST anomalies from the North Atlantic SST anomalies that to subtract global SST anomalies, because a major portion of the global variations are the result of the North Atlantic.

  54. “The AMO changes about two months after global temp.”

    The satellite UAH graph has a data point for each month. Is there an identical N.A. SST anomaly graph that could be overlaid” to see the two month lag? A separate chart of “NA only” SST with “NA only” air temperatures may help to see the lag which should not be surprising and has nothing to do with CO2.

    As my comment to Elder (David says: February 4, 2011 at 2:28 am) points out, SWR fluctuations are the primary driver of short term daily and monthly atmospheric temperature changes as well as the likely driver of some SST changes. Of course upwelling ocean warm pools (Long term lag SWR flux affects) and wind affects also change SST over short time scales. However CO2 can NOT be responsible for short term temperature flux in either the SSTs or atmosphere. CO2 can only affect the average atmospheric temperature and perhaps over much longer periods affect ocean temperature. The ability of LWR to affect the ocean appears to be poorly studied and quantified by experiments and observations.

    The point is that some things that control short term flux in both the atmosphere and SST, SWR / wind / cloud cover, obviously affect the atmosphere first, due to its much lower heat capacity. However the ocean, warming or cooling, drives the long term atmospheric average. A change or lag at the transition does not affect the average nearly as much as the average. The oceans may lag the atmosphere short term, but long term they drive it.

    This is seen on a hemispheric bases biannually, as the earth’s seasonal energy pulse can reveal on a hemispheric scale some of what happens with the ocean / atmosphere on a monthly daily and hourly basis. Sunlight, falling on the Earth when it’s about 3,000,000 miles closer to the sun in January, is about 7% more intense than in July. Because the Northern Hemisphere has more land which heats easier then water most people state that the Earth’s average temperature is about 4 degrees F higher in July than January, when in fact they should be stating that the stating that the ATMOSPHERE is 4 degrees higher in July. In January this extra SW energy is being pumped into the oceans where the “residence time” within the Earth’s ocean land and atmosphere is the longest. There are also other factors, such as the Northern hemispheres winter increase in albedo exceeds the southern hemisphere’s winter albedo due to the far larger northern hemisphere land mass. So at perihelion we have a permanent loss to space of ? W/2m SWR due to increased albedo and a temporary loss of SWR to the atmosphere, as at perihelion the SWR is falling on far more ocean, where it is absorbed into the oceans for far longer then if that SWR fell on land. Do these balance (unlikely) or is the earth gaining or losing energy during perihelion??? The TOA seasonal flux should tell us and climate models should accurately predict the observation. The point is CO2 cannot drive the changes, short term or long term compared to flux in SWR and its far greater ocean affect.

  55. Bob Tisdale says:
    February 4, 2011 at 3:38 am

    eadler: A reply to your February 3, 2011 at 8:46 pm comment: This is why we’re discussing the additional variability of the North Atlantic to show that that additional variability CAN account for a significant portion of the recent rise in global temperatures. Also, your reply assumes that the rise in the SST anomalies for the rest of the oceans can’t be explained as responses to natural variables, such as ENSO. But I have shown in a number of posts that it can.

    Also, the North Atlantic Oscillation (NAO) is a sea level pressure phenomenon, and it was discovered in the 1920s by Sir Gilbert Walker. It’s been studied for decades. Are you confusing the NAO for the AMO?

    I relied on a Wikipedia reference to the following paper as the first which identified the AMO:

    http://www.nature.com/nature/journal/v367/n6465/abs/367723a0.html

    Nature 367, 723 – 726 (24 February 1994); doi:10.1038/367723a0

    An oscillation in the global climate system of period 65–70 years

    Michael E. Schlesinger & Navin Ramankutty

    Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, 105 South Gregory Avenue, Urbana, Illinois 61801, USA

    IN addition to the well-known warming of approx 0.5 °C since the middle of the nineteenth century, global-mean surface temperature records1–4display substantial variability on timescales of a century or less. Accurate prediction of future temperature change requires an understanding of the causes of this variability; possibilities include external factors, such as increasing greenhouse-gas concentrations 5–7 and anthropogenic sulphate aerosols8–10, and internal factors, both predictable (such as El Niño11) and unpredictable (noise12,13). Here we apply singular spectrum analysis14–20 to four global-mean temperature records1–4, and identify a temperature oscillation with a period of 65–70 years. Singular spectrum analysis of the surface temperature records for 11 geographical regions shows that the 65–70-year oscillation is the statistical result of 50–88-year oscillations for the North Atlantic Ocean and its bounding Northern Hemisphere continents. These oscillations have obscured the greenhouse warming signal in the North Atlantic and North America. Comparison with previous observations and model simulations suggests that the oscillation arises from predictable internal variability of the ocean–atmosphere system.

    ——————

  56. Alan McIntire says:
    February 3, 2011 at 9:06 pm

    “Even “realclimate” admits Tamino has it backwards, and that it’s ocean temps that drive air temps.

    http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/

    According to the September 5, 2006 posting,

    “The slope of the relationship is 0.002K (W/m2)-1. Of course the
    range of net infrared forcing caused by changing cloud conditions
    (~100W/m2) is much greater than that caused by increasing levels of
    greenhouse gases (e.g. doubling pre-industrial CO2 levels will
    increase the net forcing by ~4W/m2), but the objective of this
    exercise was to demonstrate a relationship.”

    Note that CO2 hasn’t yet doubled from the 280ppm at the beginning of
    the 20th century to now, but when it does, the net effect will be a
    warming of the oceans of 4*0.002= a whopping 0.008 C.

    Obviously any MEASURABLE changes in ocean warming must be due to
    factors other than CO2- most likely cloud cover- A. McIntire

    The post of the experiment attempting to measure this effect directly, does not prove what you claim it does.

    This experiment was a first. Because of the small dimensions involved in the surface skin, it is not clear that the accuracy in placement of the equipment was sufficient to determine the quantitative effects accurately. It did detect a small effect, which was a first.

    The real underpinning of the theory that the downwelling radiation keeps the oceans warm, is the measurement of the fluxes from the atmosphere into and out of the ocean, and the principle of conservation of energy. When you add up the fluxes, it is found that downwelling radiation averaged over the surface of the earth is twice as large as the absorbed short wave solar radiation that strikes the earths surface.

    http://chriscolose.wordpress.com/2008/12/10/an-update-to-kiehl-and-trenberth-1997/

    The energy flow diagram, and the quantities involved, show that the claim that down-welling radiation, has a negligible effect on thermal energy flux into the ocean, is nonsense.

  57. Rattus Norvegicus says:

    Whatever you are calculating, it ain’t the AMO.

    Then you would agree that GISS does not contain the correct sst data in order to make comparisons with NOAA’s Kaplan based AMO calculation – as any difference artifacts between the data sources would not be accounted for?

  58. Rattus Norvegicus says: “Tamino is using the definition of the AMO to calculate it. He is using the correct dataset”

    Based in this reply also, it appears you did not read my post.

    The AMO is dervived from the North Atlantic SST anomalies. Since it’s detrended, there’s very little difference in the AMO if you use Kaplan or HADISST North Atlantic SST anomalies. The key word in that sentence is detrended.

    Tamino downloaded Kaplan North Atlantic SST data from the ESRL website and converted it to anomalies. The error he made was assuming that all SST datasets are the same. They are not. GISS uses HADISST data not Kaplan. He used the wrong SST dataset for his final two graphs. You can’t subtract an SST subset that’s not included in the global temperature dataset you’re referencing and expect to get the right results. You would have understood that if you had read my post.

  59. eadler says: “I relied on a Wikipedia reference to the following paper as the first which identified the AMO”

    Thank you for clarifying/confirming that you were discussing the AMO, and not the NAO.

  60. David says:
    February 4, 2011 at 2:28 am

    eadler says:
    February 3, 2011 at 8:46 pm
    Bob Tisdale wrote:

    ” If the oceans have been gaining heat, and the surface of the North Atlantic has been getting warmer, it doesn’t make sense to rule out global warming resulting from GHG’s as the ultimate cause.”

    True, but it does not make sense to rule CO2 IN as primarily responsible. Until you can QUANTIFY the ocean warming effect of a given W/2m increase in SWR, COMPARED to the ocean warming effect of an equivalant W/2m increase in DWLR, then I see no reason that a multi decadal change in SWR due to increased solar flux at the surface driven by changes in TSI or cloud cover could not be seen as the primary driver of any ocean warming.”

    If you don’t see a reason why these cannot be the drivers, it is because you are not looking. Solar radiation is not the driver of the warming we have seen in the past 40 years. We know this because measurments show that the solar irradience has been declining. Cloud cover is not a persistent process. Cloud formation and precipitation are processes that take place in a matter of hours. They are reactions or feedback processes rather than drivers.

  61. eadler: Why is my name in your February 4, 2011 at 8:00 pm comment? Nothing you included was written by me. It’s really difficult to follow what you’ve got there. In fact, it looks as though you are replying to one of your own comments.

  62. eadler, In fact, you presented this:
    XXXXXX
    Bob Tisdale wrote:

    ” If the oceans have been gaining heat, and the surface of the North Atlantic has been getting warmer, it doesn’t make sense to rule out global warming resulting from GHG’s as the ultimate cause.”
    XXXXXX
    But I did not write that. You did. Refer back to your February 3, 2011 at 8:46 pm comment.

    You have to change the way you reply to comments, because you’ve falsely attributed that statement to me, when it was you who wrote it.

    REPLY: Mr. Adler, you need to apologize to continue posting here – Anthony

  63. I was replying to a post by David,

    David says:
    February 4, 2011 at 2:28 am.

    which I copied and pasted as a reference. It was David who inserted your name into his post.

    I apologize for any confusion this caused.
    I am sorry about that.

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