Last fall, I discussed information sources on West Greenland ice core series, noting that the West Greenland version attributed by Juckes to Jones et al 1998 was a version that I’d not seen before. While I was looking at the proxy decisions in Juckes et al, I noticed the following intriguing rationalization:
The Greenland stack data used by MBH1999 is a composite of data analysed by Fisher et al. (1996), but the precise nature of the composite is not described by Fisher et al. (1996). … The Crete ice core series [of Jones et al 1998] is preferred to the stack series used by MBH1999 because it is better documented.
So one asks: exactly what is the “better documentation” preferred by Juckes and the Euro Team? Or is this “better documentation” a figment of their imaginations?
Jones et al 1998 and MBH98-99 both cite Fisher et al 1996 as a reference. As it happens, Fisher et al 1996 does not appear to describe either series (it only illustrates rather short versions, although it describes Fisher’s stacking methodology.) So any documentation advantage in this reference is a draw.
Fisher (2002) Table 1 reports the use of a version identified as DELNORM6.CWG (with that exact nomenclature) – “CWG” standing for Central West Greenland.: the file itself was ASCII. A couple of years ago, Fisher sent me a CD with a variety of series on it. Experimenting a little, I determined that the series DELNORM6.CWG, included on the CD, matched the MBH99 version 100%. The DELNORM6.CWG file listed its components for each step e.g. the following components in one of the steps. So any person who received the DELNORM6.CWG version from Fisher would have received a relatively adequate recipe for how it was constructed. In Mann’s MBH98 data archive, the email transmitting this series to Mann (from Frank Keimig of the University of Massachusetts) is preserved for some reason.
A CT85A-1Y.CRT 1983 AD 362 212 144
B CT84B-1Y.CRT 1982 267 211 50
D CT84D-1Y.CRT 1982 217 211 0
CRETE CT74-1YS.CRT 1973 922 202 714
MILCT MC73-1Y.MIL 1966 791 195 590
GISP2 GISP1YR.GSP 1985 718 214 498 DEUTERIUM
GRIP SIG#1YR1.GRIP 1979 917 208 703
GRIP SIG#2YR1.GRP 1979 917 208 703
GRIP SIG#3YR1.GRP 1979 917 208 703
I’ve attempted to locate the Jones et al version within the many variations in Fisher’s files, but so far have been unable to locate an exact reference. There are multiple series from Crete, including many of the series in the Fisher stack described above (Crete, A, B, C, D, H). The Jones version is not the same as any of the potential components. The Jones version goes from 1000 to 1983; the only version going back to 1000 (actually to 553) ends in 1973; there are a number of potential components ending in 1983, but all start after 1000. So the Jones version appears with a high degree of probability to also be a CWG stack – except in this case, unlike DELNORM6.CWG, we don’t know the precise components of the stack, although the Jones version is obviously closely related to these components.
So back to the question: is the “better documentation” of the Jones version a figment of the Euro Team’s imagination – the full team including Briffa, Osborn, Moberg, Allen, Hegerl, Weber, Esper. It sure seems that way to me. Perhaps Juckes can identify some such documentation, but he didn’t do so in the article itself. I guess Goosse and the referees didn’t ask him about it.
In addition, given Juckes’ professed concern about ensuring that all series versions have properly received permissions from their originators, it’s interesting to contemplate what permission (if any) Juckes has for archiving the Jones et al version of the Fisher data (or for that matter the MBH version.) I am unaware of any public archiving of either version by Fisher himself.
I presume that Frank Keimig got the DELNORM6.CWG version from Fisher either directly or indirectly. In the email at Mann’s FTP site, Keimig mentions re-formatting the series – in which process the documentation in the Fisher version was removed. Mann got this version from Keimig; Juckes presumably got it from Mann, either directly or from Mann’s archive. Did anyone in this chain ever get permission from Fisher to archive the data publicly? I doubt it. I don’t suppose that Fisher has any objections to people using his data provided they acknowledge him – why would he? But within Moberg’s definition, Fisher himself, to my knowledge, never publicly archived the version now disseminated by Juckes.
I believe that the Jones version is an earlier version of the DELNORM6.CWG series (or some close variation.) Jones may have got his version directly from Fisher who’s very cooperative (or he could have got it from Ed Cook or someone like that indirectly). Presumably Juckes got the Jones version from Briffa or Jones. (BTW Jones refused to provide the versions that he used to me when I requested.) Moberg expressed concern about the possibility of Sidorova issuing a new version and that he did not want to preempt any adjustments by Sidorova to her series. It seems inescapable that the DELNOM6.CWG version (which is used in Fisher 2002) is a version that Fisher prefers to the version used in Jones et al 1998. Yet Juckes seems to have no compunction about not only archiving the Fisher version used in Jones et al 1998 version – a version that never previously had been posted on the internet digitally – and in using a version seemingly not preferred by the originator of the data, all using the pretext of “better documentation”, though no evidence of such “better documentation” was provided anywhere.
David A. Fisher, 2002. High-resolution multiproxy climatic records from ice cores, tree-rings, corals and documentary sources using eigenvector techniques and maps: assessment of recovered signal and errors, The Holocene 12,4 (2002) pp. 401-419
Fisher, D. A., Koerner, R. M., Kuivinen, K., Clausen, H. B., Johnsen, S. J., Steffensen, J. P., Gundestrup, N., and Hammer, C. U.: Inter-comparison of ice core and precipitation records from sites in Canada and Greenland over the last 3500 years and over the last few centuries in detail using EOF techniques, NATO ASI Ser, Ser. I, vol. 41, edited by: Jones, P. D., Bradley, R. S., and Jouzel, J., pp. 297328, Springer-Verlag, New York, 1996.