IPCC and the Dunde Variations

There’s not much in climate science that annoys me more than the sniveling acquiescence of government bureaucrats in Lonnie Thompson’s flouting of data archiving policies. To his credit, Thompson has collected unique data. To his shame, Thompson has failed to archive data collected as long as 20 years ago. This would be bad enough if the versions were consistent in all publications on Dunde. But Thompson seems to have tinkered with his results over the years so that there has been an accumulation of inconsistent versions, compromising any ability to properly use this unique data. Needless to say, mere compromising of the data hasn’t stopped climate scientists from using Thompson data.

From time to time, as an exercise, I experiment with the different versions of the data, rather like a manuscript scholar looking at variations in medieval copies of ancient manuscripts to try to reconstruct the original manuscript. Today I noticed something odd even for climate “science” data. I had originally picked up this file because I was interested in the impact of consecutive smoothing and scaling of Thompson data in one of the important contributors to the modern proxy canon, the Yang et al 2002 China reconstruction, illlustrated in IPCC AR4 Box 4 below and a component of virtually every reconstruction since Mann and Jones 2003(e.g. Moberg et al 2006, Osborn and Briffa 2006, Hegerl et al 2007, Juckes et al 2007). The IPCC illustration is shown below, with the Yang composite being the maroon series (E Asia) ending at just over 3 sd units.

IPCC AR4 Box 6.4 Figure 1

The Yang series was originally created as a composite of 9 heterogeneous Chines proxy series, two of which were Thompson ice core dO18 (Dunde, Guliya). There are a couple of Yang versions, somewhat differently weighted. While Loehle critics have been quick to (correctly) notice that many contributing series end in mid-20th century, the ending of half the Yang series in mid-century has not been given equal attention. Only 4 of 9 series continue to 1990, of which two are the two Thompson ice cores, which end up dominating the results by the close. The next figure plots the 9 Yang proxy series, together with the composite (also re-scaled), as a spaghetti graph of scaled series. One of the interesting aspects of the re-scaling of the composite (which was done in the IPCC graphic) is that none of the individual components are at 3 sd units at the close. The E China documentary series is only at about 0.5 sd units.


To show a little better detail, here is the 1850-2000 portion of the data blown up. Notice the very high closing value of the re-scaled Dunde series and the great smoothness of the Dunde data used here.


The smoothness of the Dunde data used here contrasts with the smoothness in other data sets – here’s a spaghetti graph that I’ve shown previously. Obviously it’s not that the underlying Dunde data is all that smooth; it’s that Yang et al 2002 has used a “grey” version available in 50 year intervals, the most recent values being …1840, 1890, 1940, 1990. The use of closing values of smoothed series has come up in other contexts – Loehle critics were quick on this issue. Have you noticed these critics being equally attentive to the Yang data? Didn’t think so. If this 50-year version were (absurdly) to be used, then presumably it should end in 1965 rather than 1990, which, by itself, would have a noticeable impact on the closing 1990 uptick of the Yang composite.

Yang’s use of this smoothed 50-year version shows once again the impact of Thompson’s abysmal archiving practices. Had Thompson properly archived his data, then Yang would presumably have used a sensible version of the data.

There are also some interesting statistical issues raised here. Look at what Yang is averaging. The Dunde data has been changed into 50-year averages; other series are at 10-year resolution. Yang converted the smoothed series back to 10-year series – without the original decadal resolution. The scaling process used by Yang (and typical of climate science) made no allowance for the prior smoothing in calculating the standard deviation. Thus the amplitude of the Yang Dunde version ended up being inflated, relative to the other series. The Yang Composite (with inflated contributions of smoothed series), in Briffa’s hands, is once again scaled to unit standard deviation. Again, this is a much smoother series than (say) the West Greenland series and ends up with low-frequency variation being inflated relative to the West Greenland series. Although the Yang Dunde version shown below (purple) looks like it has minimal variation relative to the other versions, this version ends up yielding a 3 sd unit contribution to the IPCC spaghetti graph. Hey, it’s climate “science”.

Figure 3. Dunde Versions.

As I was parsing through this, I thought that it would be interesting to plot the various Thompson versions from annual scale up i.e. first plot only those versions with annual detail, then gradually smooth each one comparing to smoothed versions on an apples-to-apples basis. This resulted in something very unexpected.

First here is a plot of three versions at 3-year smooth (using two annual versions here and one 3-year smooth.) One is a smooth of the grey Dunde version in the MBH98 archive; the other two are digitizations of figures from Yao et al 2006 (Figure 6, Figure 4). The most striking difference is obviously the date of peak 20th century dO!8 values – more on this in the next graph.


In the next graph, I’ve increased the smooth to 5 years, adding in the PNAS version (already in 5-year intervals.) In a scribal sense, the Thompson’s PNAS 2006 version appears to be identical to 5-year averages of the grey data used in MBH98 (with the last few years not used) – confirming that the grey MBH98 version can be treated as the annual version of PNAS data. Unfortunately the Yao et al 2006 version has a different result (and yes, Thompson, is a coauthor of Yao et al 2006 as well.) One version has peak dO18 values in the 1950s and one in the 1930s. So here we have the remarkable spectacle of Thompson publishing different results in the same year (2006). And no one cares. Even though NAS requires data to be archived, Ralph Cicerone, who had personally reviewed Thompson’s article, did not require Thompson to archive the underlying data to reconcile the difference – even after a formal complaint. And climate “scientists” don’t care.


I’ve posted this sort of observation before. Here’s the new point. In the next plot, I went to 10-smoothing, adding in the Climatic Change 2003 version in its original form (10-year averages.) Once again, as you see, the smoothed MBH98 grey version and the PNAS versions track one another relatively closely with the Yao 2006 version being different. The Climatic Change 2003 version is different again – the differences around 1700 are especially noticeable.


You say- well, you’ve already observed that there are different versions, so what? Here’s what intrigued me. The Climatic Change 2003 version is intermediate in date between the similar MBH98 and PNAS 2006 versions. So it doesn’t appear that Thompson has consistently implemented some changes. The 2003 version (Clim Chg) implemented a lot of changes from the 1998 version (MBH grey version), but the 2006 PNAS version seems to have reverted back to the 1998 version, abandoning the 2003 changes. The Yao et al 2006 version looks like it might be related to the 2003 edition, but who can say with certainty?

No composite should be constructed using the 50-year Dunde version. The Yang et al 2002 China composite should not be used – indeed even Phil Jones avoided its use in Jones and Mann 2004. But the strong uptick in the Yang Composite has been too tempting a poison fruit for climate scientists, and has been willing consumed in Moberg et al 2005; Osborn and Briffa 2006; Hegerl et al 2007; Juckes et al 2007 and IPCC AR4.

YAO Tandong, Zexia LI, Lonnie G. THOMPSON, Ellen MOSLEY-THOMPSON, Youqing WANG, Lide TIAN, Ninglian WANG, Keqin DUAN, 2006. d18O records from Tibetan ice cores reveal differences in climatic changes, Annals of Glaciology 43 2006 1-7.


  1. Peter D. Tillman
    Posted Feb 3, 2008 at 1:07 PM | Permalink

    Once again, Steve, keep the pressure on. This is scandalous behavior by Thompson, and shameful that his colleagues swallow it without a peep of protest.

    I am an admirer of Thompson’s energetic and unprecedented ice-core research. He’s done some truly amazing fieldwork, and his biography THIN ICE is well-worth

    An item from Wikipedia (that I contributed): During a storm atop
    Huascaran, Peru’s highest peak (>6,000 m.), gale-force winds pushed
    Thompson’s tent (with him inside) towards a precipice. Thompson saved
    himself with a self-arrest, jamming his ice ax through the floor of
    his tent. (Source: Bowen, Thin Ice)

    What a pity he’s not a better scientist, and a scrooge with “his” data, too.

    Incidentally, no reply to my letter to Thompson of 1-16-08. What a surprise. Suppose I should Bump it, for politeness, then write OSU’s President directly. This is re “Dr. Thompson’s thermometer” in the Gore agitprop video.

    Best wishes, PT

  2. Bernie
    Posted Feb 3, 2008 at 3:36 PM | Permalink

    Besides the charting, is there a way to summarize the scope of the inconsistencies that you have laid out above – something akin to a Gini coefficient?
    I guess the bottom line here is how does one get Thompson’s funding agencies, particularly NSF I believe, to pay attention to these discrepancies and force a disclosure of the original data so that the inconsistencies can be hammered out. At a certain point it all begins to look like “Cold FUsion” experiments where nobody sees the lab data.

  3. John A
    Posted Feb 3, 2008 at 11:49 PM | Permalink


    To his credit, Thompson has collected unique data. To his shame, Thompson has failed to archive data collected as long as 20 years ago.

    Q: How do we know what Thompson has not simply made up data after going on these expensive trips? Or collected the samples and then took out data that he thought was bad in order to “improve the signal”?

    I’m not accusing Dr Thompson of doing these things, but still the question is how do we track the provenance of data if Thompson does not provide the source materials?

  4. henry
    Posted Feb 4, 2008 at 12:12 AM | Permalink

    What’s even worse, the whole university may wind up being tarnished by one “rogue” professor. Until the other OSU professors start to “peer review” their “peers”, the world will assume that ALL of the OSU (or Arizona) professors are bad.

    Any OSU or Arizona professors or alumni out there that can use internal pressure to get this data released? Or are we to believe that all of you accept his actions?

  5. Geoff Sherrington
    Posted Feb 4, 2008 at 1:49 AM | Permalink

    There must have been an agreement with say the Chinese Academy of Sciences to permit the Chinese work and perhaps it has clauses on data availability. Would a letter to the Academy help?

  6. Anonymous
    Posted Feb 4, 2008 at 6:10 AM | Permalink

    There must have been an agreement with say the Chinese Academy of Sciences to permit the Chinese work and perhaps it has clauses on data availability

    In Communist China, the data owns you.

  7. MarkW
    Posted Feb 4, 2008 at 7:20 AM | Permalink

    If such clauses exist Lonnie could clear the whole thing up by just producing those clauses.

  8. Gary
    Posted Feb 4, 2008 at 7:45 AM | Permalink

    One begins to wonder about the quality of the lab processing and recording of the data. Maybe it can’t be archived because it’s a mess. Has any critic ever been able to ask Dr. Thompson about all these issues in a minimally threatening setting, say, in his office or over beers instead of at public conferences where everybody is watching and hoping for a show? I can guess the answer, but just for the record.

  9. Posted Feb 4, 2008 at 8:18 AM | Permalink

    The first 3 figures are z-scores, which make them doubly futile comparisons, since they depend on the arbitrary normalization period as well as the time-aggregation choice.

    The figures with units like -10 are presumably dO18 numbers, so at least they begin to compare like values.

    More later.

  10. MikeinAppalachia
    Posted Feb 4, 2008 at 2:01 PM | Permalink

    I’m an OSU alum and have attended a few faculty (SO is Prof in tOSU’s MEdu program)receptions where Dr. Thompson (and wife) were present. He receives “rock star” attention from the administration, who are not going to do anything that would risk funding or reflect badly on the Polar Studies program. Have to admit, for a fellow hillbilly with Marshall undergrad degree, Lonnie’s “done good”.

  11. Follow the Money
    Posted Feb 4, 2008 at 2:18 PM | Permalink

    “…The bigger the money the more openly principles will be compromised.”

  12. Patrick M.
    Posted Feb 4, 2008 at 2:35 PM | Permalink

    An item from Wikipedia (that I contributed): During a storm atop
    Huascaran, Peru’s highest peak (>6,000 m.), gale-force winds pushed
    Thompson’s tent (with him inside) towards a precipice. Thompson saved
    himself with a self-arrest, jamming his ice ax through the floor of
    his tent. (Source: Bowen, Thin Ice)

    Why does this make me think of “The Grinch Who Stole Christmas”?

  13. henry
    Posted Feb 4, 2008 at 3:17 PM | Permalink

    MikeinAppalachia said (February 4th, 2008 at 2:01 pm)

    I’m an OSU alum and have attended a few faculty (SO is Prof in tOSU’s MEdu program) receptions where Dr. Thompson (and wife) were present. He receives “rock star” attention from the administration, who are not going to do anything that would risk funding or reflect badly on the Polar Studies program. Have to admit, for a fellow hillbilly with Marshall undergrad degree, Lonnie’s “done good”.

    If I was the Admin, I’d be afraid that the attention Thopmson recieves for lack of archiving will start to attach to all professors at OSU. As far as I know, ALL OSU profs have problems archiving their data. It’s up to the Admin to prove they don’t.

    And if they can prove that other profs archive, they’d have to explain why Thompson doesn’t (Catch-22 is alive at OSU).

  14. Lance in AZ
    Posted Feb 4, 2008 at 7:39 PM | Permalink

    As a U. of Arizona alum, I’m appalled at my Alma Mater’s callous disregard for enlightenment basics. I’ll write the administration, but doubt they’ll listen much to a J.D. on this issue.

  15. china
    Posted Feb 4, 2008 at 9:07 PM | Permalink

    Can anyone obtain data from Chinese Scientists? Try your best! Impossible is nothing. Hehe! Let’s wait till death.

  16. Gary
    Posted Feb 5, 2008 at 10:56 AM | Permalink

    Although the data used in theses may not be archived online, it could very well exist in appendices of the bound copies deposited in the institution’s library. Nothing is stopping interested parties from taking a look other than getting to the library. Any alums close enough?

  17. Posted Feb 6, 2008 at 2:17 PM | Permalink

    Not only are the figures for Dunde (and Guliya) inconsistent between different Thompson et al articles, but the data for his 2006 PNAS article are actually internally inconsistent.

    Figure 5a of the PNAS article shows 5-year averages of dO18 ratios for 7 ice cores, including 4 Himalayan and 3 Andean sites, for 1600-1985 or later. Figure 6 shows composite dO18 z-scores for the cores in the two regions, along with a “tropical” composite series, decadally from year 0 to 2000. Data for the two figures are in Data Sets 2 and 3 on the PNAS website. (The archived data are inconveniently in non-machine-readable PDF format, but Steve has punched in Data Set 2 and I punched in the requisite part of Data set 3.)

    If the Himalayan composite were any fixed linear combination of the underlying four series, with equal or unequal weights before or after taking z-scores, a regression of the composite series on a constant plus decadal averages of its four component series should be an exact fit to within the .005 rounding error in the two-digit composite series. This should be true for the 37 decades for which complete data are available, as well as for any subperiod of 5 or more periods. (5 are required in order to identify the constant and 4 slope coefficients.)

    However, when the full sample is used, the standard error of the regression is 0.29, i.e. 58 times higher than the permissible value of .005. Guliya and Dunde are insignificantly different from 0 (t = 0.41, 1.14), so that only Puruogangri and Dasuopu are making any significant contribution. When the full sample is divided into 4 subperiods of 10, 9, 9, and 9 decades, even Puruogangri is only significant in the last subperiod. In the third subperiod (1800-1889), none of the coefficients is significant, and an F test cannot reject the hypothesis that all are zero (F(4,4) = 1.313; p = .399).

    It is therefore safe to say that the Himalayan “composite” series is inconsistent with the any linear composition of the four supposed component series. Some kind of non-linear aggregation might give an inexact fit, but nothing this bad. Thompson et al give no indication of how the aggregation was performed, but given the simplicity (and naivete) of the composition of the two regional indices into the summary “tropical” series, one would assume that an arithmetic average was taken.

    The Andean composite fares somewhat better, with a full sample standard error of 0.10, which is only 20 times the permissible rounding error. Despite the impermissibly large residuals, the coefficients are well defined and highly significant. (Quelccaya and Huascaran get approximately equal weights, while Sajama gets about half that value.) The four subperiods have higher coefficient standard errors, as is to be expected, but exhibit the same basic pattern for the three coefficients. There is some inconsistency here that ought not to be present, but the problem is not as egregious as with the Himalayan numbers.

    I’ve e-mailed Thompson and such of his PNAS co-authors as I have been able to locate about this, but with no response so far, either confirming or refuting my calculations. I’ll write PNAS with the specifics if I don’t hear from them soon. In my view, PNAS should demand a correction of one or both of the figures and corresponding data set or, if no such correction is forthcoming, simply retract the article and refer it to the JIR (the Journal of Irreproducible Results, a venerable science humor magazine).

  18. Peter D. Tillman
    Posted Feb 18, 2008 at 1:10 PM | Permalink

    Re #17, Hu McC

    Good work, Hu — thanks!

    Thompson seems to be in the “ignore critics & hope they go away” camp. Which reminds me, I should bump my letter re the Gore video again.

    These things take time & patience, but science is (in the long term) self-correcting. Then again, in the long term, we’ll all be dead 🙂

    Cheers — Pete Tillman

3 Trackbacks

  1. […] for Dasupo, Dunde, and Gulaya, is detailed (inter alia) here, here, here, here, here, here, and […]

  2. By Thompson Gets New NSF Grant « Climate Audit on Apr 21, 2012 at 9:59 AM

    […] notoriously lax about providing definitive archived versions of his measurements. See, for example, IPCC and the Dunde Variations, Juckes, Yang, Thompson and PNAS: Guliya, Gleanings on Bona Churchill, and Mann on Irreproducible […]

  3. By Lonnie Thompson’s Legacy « Climate Audit on Jul 8, 2012 at 12:44 PM

    […] the term used by dendros). As discussed at CA on numerous occasions – see, for example, here, Thompson has published or distributed inconsistent chronologies (see the figure below.) Some of […]

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