One of my objectives in looking at both the Dulan tree ring data and Chinese station data is to take a fresh look at the Dunde ice core information, which is near Dulan and Delingha. twq says that he’s been analyzing low-frequency information from Dunde.
A caveat for twq: the Dunde archiving situation is a fiasco. There are multiple inconsistent versions of Dunde (and other Thompson ice cores such as Guliya). Last year we discussed three inconsistent Guliya versions used in peer-reviewed 2006 articles – Dunde is just as bad.
I just noticed that Yao et al 2006 introduces yet another inconsistent Thompson version. I’ve complained to Science, NSF, NAS and gotten nowhere. So twq, before you start using Dunde data, you should ponder which Dunde you’re using.
The figure below shows 5 inconsistent Thompson versions, two from Thompson articles in 2003 and 2006 and the others from grey versions archived or obtained from multiproxy authors. The most detailed information comes from the MBH98 archive (annual); the Thompson 2006 PNAS article (red) archived 5-year averages; the Thompson 2003 Clim Chg article (blue) archived 10 year averages (only after I caused a data policy to be implemented at Climatic Change and complained about Thompson); the low frequency curves are from Yang (email) and Crowley (email). I’ve done a re-scaling estimate for the Crowley version, as he had lost his original data and only had a rescaled and smoothed version.
IPCC SPM told us that “additional data in multiple indicators” is showing “coherent behavior”. We don’t even see “coherent behavior” in different Dunde versions. (Guliya is just as bad.)
Dunde Versions. Black – MBH98 (annual); red – PNAS 2006 (5-year averages); blue – Clim Chg 2003 (10-year averages); purple – Yang et al 2002 (values in 50 -year intervals); green – Crowley and Lowery 2000 (original in standardized format, re-fitted here for display by regression fit to MBH98).
Will the Real Slim Shady Please Stand Up?
To this unseemly brew, Yao et al Ann Glac 2006 (including Thompson) has added yet another inconsistent Dunde version (thus far not available digitally). Dunde (their Figure 4 top panel) has a peak in the 1930s which is not present in the earlier versions.
“Fig. 4. The 3 year running averaged d18O records for the four ice cores from the TP presented in the paper: (a) Dunde, (b) Guliya, (c) Puruogangri and (d) Dasuopu. The trend lines of Guliya, Puruogangri and Dasuopu show obvious warming since 1900, but the Dunde warming is less obvious because the record ends in 1985.”
Yao et al also have a detailed figure of annual data from 1967 on, shown below. For comparison, on the right, the annual data from the grey MBH98 version is also shown The 1987 values in the MBH98 version end at very low values, while the Yao et al 2006 version ends on high values.
Left – Version in Yao et al 2006 Figure 6c: thin annual; solid – 3 year rolling average ; right – corresponding data from MBH98 version in black; Yao et al digitization in red
Every Dunde sample datum should be archived immediately. Thompson should be asked to reconcile the various versions. In business, if a company presented rolling inconsistent versions of their financial statements, you know what the outcome would be.
The acquiescence of Science, NSF and Ralph Cicerone of NAS in these shenanigans is a disgrace.
PS: For those of you uninfluenced by teenagers, the title of the post is from Eminem.
Tandong YAO, 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 url