Category Archives: Esper et al 2002

RCS Homogeneity- Esper in Jaemtland

Starting with the first of my recent posts on Yamal, I raised the issue of whether the CRU 12 actually came from a homogeneous population to the subfossil population. This issue was related to the surprisingly small sample size of the supposedly “highly replicated” Yamal chronology, but is distinct. In his online response to Yamal […]

Esper et al 2009 on West Siberia

Esper et al (Global Change Biology, in press) “Trends and uncertainties in Siberian indicators of 20th century warming” is relevant to our present consideration of Briffa’s Yamal, which I will get to shortly. The cutline in their abstract declares in effect that the divergence problem is not as “bad as we thought”: Despite these large […]

Mann's PC1 in Esper and Frank 2008

On previous occasions, we’ve noticed some strange appearances of the Mann hockey stick under different disguises. In Inconvenient Truth, a splice of Mann’s hockey stick and CRU instrumental data is described as “Dr Thompson’s thermometer”. Today, I noticed another peculiar incident, where Esper and Frank (Clim Chg 2008), who one would think would know better, […]

Strip Bark at Upper Wright Lakes Foxtails

As a sort of Methadone replacement for Mann’s bristlecone PC1 (which uses Graybill’s strip bark chronologies), two Esper foxtail chronologies (Upper Wright Lakes and Boreal Plateau) have come into use by the Team. These two chronologies were used separately in the small Esper network (two of only 7 or so medieval chronologies) making a very […]

IPCC AR4 and the Return of Chucky – He's Baaack!

Here’s something I meant to post up when AR4 came out. I was reminded of this when Rob Wilson posted recently: Lastly, lets not forget that TR based reconstructions of NH temperatures exist that do not use Bristlecone pine or Foxtail data. Rob’s point here is very disingenuous (to use Mann-speak) since millennial reconstructions are […]

An Esper Divergence Problem

The NAS Panel used Esper et al 2002 as a comfort series in their spaghetti graph, but did not perform any due diligence on it. As some of you may recall, I’ve had prolonged correspondence with Science, after being stonewalled by Esper, and, as a result of that, have obtained versions of the chronologies used […]

Jacoby in Mongolia

Trying to check even simple things like the correlation of individual Osborn and Briffa 2006 series to gridcell temperature always leads to complications. Today I’ll look at the situation with respect to Jacoby’s Sol Dav, Mongolia series, one of the 6-7 mainstays of Hockey Team reconstructions. Needless to say, nothing can be confirmed. Instead of […]

Briffa 2000 and Yamal

If you actually look at the medieval proxy index of the "other" studies (Briffa 2000, Crowley and Lowery 2000, Esper et al 2002, Moberg et al 2005), the medieval proxy index is usually just a razor’s edge less than modern proxy index – just enough that the study can proclaim with relief that the modern […]

Graumlich Archives Two Foxtail Series

The two “lost” Graumlich foxtail series used in Esper et al 2002 were archived today at WDCP. Only the specific series that I had requested were archived; other series in Bunn et al 2005 were not archived – see prior discussion here. UPDATE May 17: Graumlich also archived two chronologies (Boreal -ca636.crn; Upper Wright – […]

Esper Methodology

Getting methodological information from Esper is a bit like dealing with Mann, a lot like dealing with Mann. It really makes me wonder whether there might be some clunker like Mann’s PC methodology lurking in Esper’s closet. Like Mann, instead of providing a comprehensive methodological desscription ideally with code as in econometrics journals, Esper would […]


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