Category Archives: Esper et al 2002

The Foxtails and the Hounds

There is something weird going with Esper’s delivery of data, where he delivered quite a lot of material – but left out some key data. Here ‘s the status on data – there are some puzzling methodological issues which I’l’l return to. Chronologies: Esper sent 13 of 14 chronologies in February. This was very interesting […]

Treydte, Moberg, Soon and Baliunas

Several people have written to me about today’s article in Nature by Treydte et al (including Esper) announcing that the 20th century is the wettest period in the millennium. Treydte et al state: Comparison with other long-term precipitation reconstructions indicates a large-scale intensification of the hydrological cycle coincident with the onset of industrialization and global […]

An Esper Spaghetti Graph

It’s obviously been pulling teeth to get data from Esper. After only two years of trying, I’ve recently obtained all but one site chronology and 10 of 14 measurement sets; and gobbledy-gook about methodology. It’s a very Mannian process. While I continue to try to get the rest of the information, I thought that it […]

Taimyr – Linear or Nonlinear?

While I’ve got Esper open, here’s some thoughts on the division of cores and sites between "linear" and "nonlinear" – where I’ve been seeking an operational definition for some time. Herr Esper told Science: The split into linear and non-linear ring width series is shown in a supplementary figure accompanying the Science paper. The methods […]

Taimyr in Esper and Osborn-Briffa

The chronologies for Taymir in Esper et al [2002] and Osborn and Briffa [2006] differ – not a whole lot but enough to be noticeable. Esper provided measurement data for Taymir, while Osborn and Briffa have refused. The letter from Science said: The other three series contain some non-identical tree-ring series derived from the same […]

Another Inch at Sciencemag

Update: Continued here I just heard back from Science on the continuing and frustrating effort to obtain data from Esper et al. [2002] and Osborn and Briffa [2006], last discussed here . I got interesting but incomplete information in February and March. The latest installment is very disappointing in comparison even though, in my opinion, […]

Alberta #3

In February 2006, Luckman and Wilson archived their STD chronology for the Athabasca Glacier, Alberta site (STD fits each tree individually; RCS fits trees in groups.) Rob Wilson wrote in criticizing an earlier post for, among other things, not showing their STD version and for how I implemented the RCS emulation for Esper et al […]

Alberta #2

There are 3 different versions of the Alberta site that have been applied in multiproxy reconstructions: 1) Luckman et al [1997] used in Jones et al [1998]; Crowley and Lowery [2000]; Briffa [2000]; 2) Esper et al. [2002] ; 3) the version used in Osborn and Briffa [2006], presumably from Luckman and Wilson [2005] and […]

The Alberta Site in Esper 2002

Here is some more analysis based on the Esper measurement data sent to me by Science on March 16, 2005 — this time on the “Athabasca” site, which refers to a location in the Rocky Mountains, Alberta near the Athabasca Glacier. This note is rather a status report, so that I keep track of what […]

More Correspondence with Science

Update: Next instalment here On March 16, Science sent me 10 (out of 14) measurement data sets used by Esper; one gridcell temperature series used by Osborn-Briffa and caused Briffa to archive annual data versions at WDCP in addition to the smoothed versions. The new information has been extremely helpful to me. However, the information […]