Collation of Moberg Data

I’ve written a script in R to collate Moberg data from original sources (plus 3 collations of tree ring site chronologies which I’d done previously and 1 digitized version sent to me). This is a working document and subject to change as more information becomes available, but is posted here in case other people are interested in Moberg data (and to save them time). I don’t know why multiproxy authors don’t do these things. I comment here on data access issues that I’ve noticed so far.

Unusually for a multiproxy study, there are data citations for the 9 of the 11 low-frequency series. By data citation, I mean an actual archived digital reference, rather than a print publication reference (which may or may not correspond to the digital citation). For some data citations, there are more than one series in the digital link and it would be helpful in SIs if people would specify how many lines down to look if there are similar sorts of data. Series 7 and 8 do not have digital references. Series 11 is a "combination" of two records, but the form of combination is not stated. I averaged the two series during the period of overlap for now, but perhaps some other method is used.

The tree ring data is described in the SI as "temperature reconstructions" – the original data is actually ring width "chronologies". The "temperature reconstructions" appear to be linear transformations of these chronologies with parameters determined by regression against temperature. Since everything gets standardized at a later stage, I’m not sure exactly what is accomplished by these linear transformations and it would be nice to have the parameters in the SI.

As for the the three non-bristlecone tree ring series, the versions used by Moberg et al. [2005] sure appear to me to be similar to the RCS versions archived at Briffa’s website. See Tree Ring Versions. In the case of Yamal, the Moberg version has a distinctly different look than the apparently corresponding figure in Hantemirov et al [2003], which was cited and has a distinctly similar look to a plot of the Briffa version. The absence of a digital citation always makes these matters frustrating.

I have been unable so far to locate a digital version of the Indigirka, Yakutia series. I’ve temporarily used the shorter version of this series archived at Briffa (starting in 1400).

In my opinion, no policy agency should use any study which does not have a complete archival record. Right now, there are several holes in the Moberg archival record. If an author wants to use unpublished data, then he should get permission from the originating author to archive the data or not use it. A few missing series can easily frustrate replication efforts, and, in the paleoclimate world, archiving sometimes proceeds at a geological pace (e.g. Thompson’s continued failure to archive Dunde and other ice core series.)


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