Yang et al. (2004) extends the isotopic stratigraphy of Yang et al. (2002) by a couple of hundred years. It contains the following text, which implies that the Thompson and Yang are working independently on the same core.

In this paper, we extend the existing d18O and accumulation records backward by 300 years… With the extension, we used the same methodology, laboratory as the old d18O measurements. The reconstruction for the new 300 years was also based on counting visible annual dust layers. It is noteworthy that our reconstruction of net accumulation during the last 2000 years shows great agreement with the reconstruction of Thompson [1996]. The only differences between the two series lie in minor details of high-frequency variation, which could be a result of having adopted slightly different parameter values of the same flow model. This, however, does not influence the final results in this paper.

Thompson et al. (2006) includes a plot of decadal resolution data for the last 2000 years from Guliya. The last thousand of which matches the Climate Change paper data.

He et al (2004) Asynchronous Holocene climatic change across China. Quaternary Research 61, 52–63.
Thompson et al (2006) Holocene climate variability archived in the Puruogangri ice cap on the central Tibetan Plateau. Annals of Glaciology 43, 61-69.
Yang et al. (2004), Evidence for a late Holocene warm and humid climate period and environmental characteristics in the arid zones of northwest China during 2.2~1.8 kyr B.P. J. Geophys. Res., 109, D02105.

Thanks for the clarification. I think it makes the most sense to refer to the paper and data separately which may reduce confusion.

Some people may find it amusing that Dr. Thompson himself mis-cites the Climatic Change article reference in his PNAS article this year, giving the year as 2002 (which is when he wrote it, not the year it was published) as you can see here (ref. 16).

http://www1.ncdc.noaa.gov/pub/data/paleo/icecore/trop/guliya/guliya-d18o.txt

They have made the following suggestion:

SUGGESTED DATA CITATION: Thompson, L.G., et al.. 2004.
Guliya, China Ice Core Oxygen Isotope Data.
IGBP PAGES/World Data Center for Paleoclimatology
Data Contribution Series # 2004-057.
NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

The date of the paper (2003) and the data citation (2004) are different and hence the confusion.

Just to re-confirm (since there are a number of references to “Thompson et al 2004, Climatic Change”) I think this refers to

Thompson et. al., “Tropical Glacier and Ice Core Evidence of Climate Change on Annual to Millennial Time Scales’, Climatic Change, Volume 59, Numbers 1-2 / July, 2003

correct?

Gary, I quite agree that the stacked SPECMAP record is an exemplar of excellent time correlation between the benthic d18-O record of deep ocean cores. Of course here the correlation is of like with like. That is an ice volume driven change in the oxygen isotope composition of the oceans. One should bear in mind however that the accuracy of the correlation is compromised by sedimentation rates and sampling intervals such that inter core correlation may only be accurate to 2000 to 4000 years.

Of course the SPECMAP project was targeted at understanding the Pleistocene glacial-interglacial cycles which have a periodicity of ca. 110,000 years for the last 4 ice ages and possibly a shorter period of 41,000 years for ice ages before this. On this time scale an accuracy of 2-4000 years represents a few percent only. One should also bear in mind that SPECMAP intended to provide a tool for correlation rather than an absolute dating technique.

One should question the robustness of correlating other records with the deep sea record, particularly where these records have a lower resolution and where the time period of interest is different to that of the Pleistocene.

There is no substitute for independent dating. For the recent Holocene ice core record this includes counting annual layers.

…the SPECMAP deep sea d18-O record, itself a stacked foraminiferal record and slightly tuned to orbital parameters.

.
#4 – Stacked records, yes, but carefully stacked. Here’s the paper on the method. Wiggle-matching of additional records should be at least as careful.

http://www.ldeo.columbia.edu/res/div/ocp/pub/martinson/science.pdf

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I think that the Vostok record may have been matched to the SPECMAP deep sea d18-O record, itself a stacked foraminiferal record and slightly tuned to orbital parameters. Now we have Guliya matched to the methane record in Vostok.

This process imparts a conformity to the data and suppresses any differences that are likely to exist. It is also based on the assumption that there is an underlying causality between atmospheric CH4 levels and the d18-O in Guliya, namely temperature. However, we know that the TP record is likely to contain both temperature and more importantly a monsoon (precipitation) signal that is not apparent in the methane record.

Finally we have the situation where a high resolution record (Guliya) is tuned to a low resolution one (CH4).

One has to wonder will this whole house of cards begin to crumble if and when people start to invest time and money in high quality dating of these archives. I admit it is difficult for ice, but wiggle matching is a very poor substitute.