Climate Audit

You have to get up pretty early in the morning to surprise me with one of these millennial proxy series. But even I got a big surprise when I decided to investigate Juckes statement "Concerning the Indigirka data, the key phrase is “they are unpublished data”; and his challenge in 894#13:

But seriously, if you can stop posting extended discussion of your problems coming to grips with trivia long enough to say anything serious, do you have any authorative information about the Indigirka data in your possession which would justify its use as a proxy? If so I think it would be really useful if you could write it up and get it published."

Moberg et al 2005
I started with Moberg et al, where the Indigirka River chronology was one of 18 proxies said to be temperature proxies. (Whether its use was "justified" is a different question; that Moberg et al 2005 used it is beyond dispute. The Indigirka chronology was illustrated in Moberg et al 2005 Supplementary Figure 1 as shown below:

The reference for the proxy was given in their SI as follows:

The northern Eurasian records are obtained from conifer trees (Pinus silvestris from northern Sweden17 (D in Fig. 1), Larix siberica from the Yamal Peninsula [18] (E), Larix gmelinii from the Taimyr Peninsula [19] (F) and Larix cajanderi Mayr from the Indigirka River region in north-eastern Yakutia [20] (G)) growing close to the northern tree line limit where summer temperature is the major growth-limiting factor. …. (20. Sidorova O.V., & Naurzbaev, M. M. Reakzija na klimatitcheskie izmenemija listvennizi Kajandera na verchnei granitze lesa i v doline reki Indigirki (Response of Larix Kajanderi to climatic changes at the upper timberline and in the Indigirka River valley). Lesovedenie, 2, 73-75 (2002).)

The same reference is given in the Moberg et al Corrigendum, where they stated that, although the data is unarchived ("unpublished"), it could be obtained by emailing Moberg himself (who promptly provided me with the data when I requested it.)

Sidorova 2001
I don’t read Russian and haven’t consulted the original Lesovedenie article. However, Sidorova made a contemporary presentation in 2001 at the International Conference on the Future of Dendrochronology entitled "Climatic response of larch trees growing at the upper timber line and above flood-plain terrace of lower stream Indigirka River, which almost certainly covers the same ground as the Russian article. Sidorova said that the samples were taken from the tundra and forest tundra zones of the middle Indigirka lowland (70-70 40 N and 147-148 E). Sidorova reported that they used RCS standardization (so that there can be no complaint about their standardization method. ) They stated that: "the chronology is a reliable quantitative indicator of early summer temperature changes for the last 2,500 years." The chronology was illustrated in the conference as follows (which is recognisable as being closely related to the version used in Moberg et al 2005)

Sidorova et al 2006
Sidorova, Naurzbaev and Vaganov – all eminent Russian dendrochronologists – made a presentation on northern Asian long chronologies at Holivar 2006 entitled CLIMATIC CHANGES IN SUBARCTIC EURASIA BASED ON MILLENNIAL RING CHRONOLOGIES. Abstract Poster

Their Abstract stated (and I’ve bolded a point of interest):

We built 2000-year tree-ring chronologies based on the oldest alive trees, dead, and sub-fossil wood well preserved in the Eastern Taimyr [72°N – 102°E] (Naurzbaev et al. 2002), North-Eastern Yakutia [70°N – 148°E] (Hughes et al. 1999, Sidorova 2001) and used millennia chronologies, designed by our colleagues from the Yamal [67°N – 70°E] (Hantemirov and Shiyatov 2002), and Sweden [68°N – 20°E] (Grudd et al. 2002). For each chronology we calculated the response function and reconstructed temperature for the last 1000 years. We used data of closely located meteostations for each region. The correlation between temperature and tree ring indices is highly significant and increases after smoothing using a 5-year moving average for all regions (from 0.48-0.61 before smoothing and from 0.60-0.74 after smoothing).

We considered the quality values of our reconstructed mean summer temperature results for each century of the last millennia for all four chronologies. The range of summer air temperature changes was about 2°C, the only exception being Yamal. For this region there was defined less temperature reduction. The current warming manifests more in the western part of Eurasia and less in the eastern part. The Medieval Warm Period (MWP) shows higher values of temperatures in the eastern part of Eurasia and approximately equal values in the western part in comparison with the current one. The difference in average temperature of current and MWP compared to Little Ice Age is not so large -1.5°C and is heterogeneous in space: higher in the eastern part and lower in the west.

In their conclusions, they stated:

Current warming started at the beginning of the XIX-th century and presently does not exceed the amplitude of the medieval warming. The tree ring chronologies do not indicate unusually abrupt temperature rise during the last century,
According to calculations based on climatic models, the strongest warming should be observed in the high latitudes of the Northern Hemisphere, with an increase of 3-4 C (Kelly et al. 1982; Budyko, Israel 1987). However, data obtained from analysis of the radial growth of trees from the sub-Arctic area of Eurasia, an area closely tied to the temperature changes, do not show such significant changes in climatic conditions (Briffa et al. 1998; Naurzbaev, Vaganov 2000; Sidorova et al. 2005 ). The rate and amplitude of the current warming testify about its uncommonness during the past centuries (Briffa et al. 1995; Mann et al. 1998). The Medieval Warm Period (A.D. 900-1300) is a recent, possible analog, although available data disagrees in many respects relative to its magnitude and duration (Bradley 1999). Other studies suggest similar temperature in the Northern Hemisphere during this period and the current warming (Dahl-Jensen et al. 1998; Naurzbaev, Vaganov 2000; Sidorova, Vaganov 2002; Esper et al. 2002, Sidorova et al. 2005).

Yakutia
Hello, Yakutia. Hello, Hughes et al 1999. When I re-read this poster, the mention of Hughes et al 1999 in connection with Yakutia stopped me. (There’s also a mention of Yakutia in the Moberg et al SI, but because Hughes wasn’t mentioned, I missed the connection.) We’ve met the Yakutia series before. It’s used in MBH98, the original SI of which contains the following information:

Yakutia Dendro ring widths air temp 62N 130E 1400 Hughes 1998"

Hughes 1998" in the original MBH98 SI is the following citation: Hughes, M.K., Vaganov, E.A., Shiyatov, S.A., Touchan, R. & Funkhouser, G., Twentieth-century summer warmth in northern Yakutia in a 600-year context (submitted). This was published as: Hughes, M.K., Vaganov, E.A., Shiyatov, S.A., Touchan, R. & Funkhouser, G., 1999, Twentieth-century summer warmth in northern Yakutia in a 600-year context Holocene 9, 629-634 – which is obviously the citation in the Sidorova et al 2006 poster (which doesn’t actually give the citation).

Now the geography in MBH98 is a little off. The correct location is 70N and 148E, over a thousand miles away. However, they got the right continent. But let there be no doubt: Yakutia of MBH98 and Indigirka River of Sidorova 2001 are the same site.

The earlier Hughes version of the series is even illustrated in the Briffa 2000 compendium that is the source of the Yamal reconstruction:

Excerpt from Briffa QSR 2000 Figure 1. Scale is from 0 – 2000. Caption: Northern & high-latitude temperature changes over the last 2000 years. The curves show selected reconstructions of summer (annual series and) temperatures or temperature-sensitive tree-ring chronologies: …. (b) Eastern Siberia (Hughes et al., 1999);

So in response to Juckes’ question:

But seriously, if you can stop posting extended discussion of your problems coming to grips with trivia long enough to say anything serious, do you have any authorative information about the Indigirka data in your possession which would justify its use as a proxy? If so I think it would be really useful if you could write it up and get it published."

the answer is really pretty simple. The Indigirka site is the same site as the Yakutia site, which was presented as a proxy by Hughes et al 1999 and used in MBH98 and Briffa 2000. Whether such use was justified in either case is a different question and one that I would have thought was well within Juckes’ terms of reference to "evaluate" these millennial reconstructions.
The only difference between the Indigirka long reconstruction and the other reconstructions is that it wasn’t done by Briffa.

Archiving of Yakutia Data
There’s an interesting backstory about archiving Yakutia data, as a considerable amount of Yakutia/Indigirka River measurement data has actually been archived – much more than for Yamal. Surprisingly (or perhaps unsurprisingly) I have a little history with the archiving of this data.

In June 2004, I sent a complaint to NSF about various unarchived data sets, specifically mentioning Hughes’ Yakutia data. Needless to say, the NSF blew me off completely, sending me a letter on July 28, 2004 claiming that the various data sets had been archived, when obviously they hadn’t.

To address your specific concerns, the investigators you mention in your letter (i.e. Drs Thompson, Crowley, Jacoby, Hughes and Mann) have been responsive to the NSF policy on access to data. I understand that their data has been sent directly to you, in some instances, via electronic means. In other cases the data is archived in the publicly accessible World Data Center (WDC) that is managed by the National Oceanic and Atmospheric administration (NOAA) and from which you are free to download information of interest. This facility houses a wealth of paleoclimatic data that is organized by scientific subspecialty involving biological, sedimentological and chemical proxies from terrestrial and marine environments.

I then wrote to Bruce Bauer, the data manager of WDCP, with whom I’d had much cordial correspondence, and asked him to confirm that the various requested data sets were not at WDCP, contrary to the NSF statement. On August 11, 2004, he wrote to me as follows:

Two of the data sets in your list were added to the WDC Paleo archive in July 2004; otherwise I can confirm that the data listed are not archived here at WDC Paleo. The two data sets newly added to the WDC Paleo website are: Malcolm Hughes’ Yakutia, Russia tree ring data, currently posted in the ITRDB updates directory of our server at: ftp://ftp.ngdc.noaa.gov/paleo/treering/updates/

If you look back at Barton’s inquiry to Hughes about data archiving compliance discussed here, Hughes stated:

The U.S. National Science Foundation has stated that I have “complied with the policy guidelines set out by the US government, and the NSF in particular, regarding access to data from publicly funded research” [Email from Program Manager David Verardo 10 August 2004]

The timing is, to say the least, curious. Why would Verardo have written a letter to Hughes saying that he had "complied with the policy guidelines". Was he in compliance before the July 2004 archiving? Questions for another day.

In any event, the new Hughes sites are russ184 to russ191. They are all located in the Yakutia/Indigirka River. In fact, one of the sites (russ184) is even called Indigirka.

Conclusion
I think that I’ve shown conclusively that the Yakutia series is an alter ego for the Indigirka River series – a point that I was previously unaware. Juckes’ challenge to demonstrate the validity of the proxy indicates that he was unaware of the identity of the sites, especially since he was also unaware of the identity of the Tornetrask and Fennoscandia sites – which are easy to identify. Juckes’ challenge – that I publish and demonstrate the validity of the Yakutia/Indigirka River tree ring chronology – is ludicrous.

So is there any objective basis for Juckes’ de-selecting the Yakutia/Indigirka River chronology? No.

The measurement data used in the long chronology is not archived, but neither is the measurement data for Yamal, the Tornetrask update or Taymir – all of which are used repetitively. But there is a lot more archived measurement data from Indigirka than from Yamal. The long chronology is not archived at WDCP, but neither are the Briffa chronologies for Yamal, Tornetrask or Taymir. (The only Yamal chronology archived at WDCP is from Hantemirov and Shiyatov and it is much different from the Briffa version.) You can download the Briffa chronologies from his website, but you can get the long Yakutia/Indigirka chronology by emailing Moberg. Yakutia/Indigirka tree ring chronologies have been presented as proxies in published literature, not just by Sidorova et al, but even by Hughes and coauthors.

A relatively new long chronology, like the long version of the Yakutia/Indigirka chronology, should be like gold to paleoclimatologists. It’s an ideal opportunity to test their hypothesis about temperature history on out-of-sample data. But that’s not what we see here. We get the same old snooped series. Briffa’ Yamal version in; Yakutia/Indigirka out. Juckes’ exclusion pretext was flimsy in the first place and then totally tainted by his unawareness of the identity of the Yakutia and Indigirka River sites.

For reference, here is a clean plot of the Yakutia/Indigirka series from Moberg’s version. [Update OCt 7. 2007- graphic temporarily removed.]