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CRU Abandons Yamal Superstick

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Steve McIntyre, Climate Audit

Unreported by CRU is that they’ve resiled from the Yamal superstick of Briffa 2000 and Briffa et al 2008 and now advocate a Yamal chronology, the modern portion of which is remarkably similar to the calculations in my posts of September 2009 here and May 2012 here, both of which were reviled by Real Climate at the time.

 

In today’s post, I’ll demonstrate the degree to which the new Briffa version has departed from the superstick of Briffa 2000 and Briffa et al 2008 and the surprising degree to which it approaches versions shown at CA.

First here is a comparison from CA in Sep 2009 here of the Briffa 2008 superstick to a version that simply incorporated Schweingruber’s Khadyta River data, applying the method used by Briffa for Taimyr in Briffa et al 2008. Real Climate screeched in fury against this comparison.

yamal_chronology_compare-to-sept09
Figure 1. Comparison of Briffa et al 2008 version to green (sensitivity) chronology in CA post http://climateaudit.org/2009/09/27/yamal-a-divergence-problem/. Converted to z-scores.

In May 2012, I did a quick calculation incorporating more recent Hantemirov data, showing that the resulting modern portion was remarkably similar (TM-climate science) to the green chronology of my September 2009 and had an almost identical discrepancy to the Briffa et al superstick. For reasons that remain unclear, Hantemirov objected to the calculation (see comments within post) and, once again, Real Climatescreeched in fury. The figure below compares the Briffa superstick to the CA calculation of May 2012.

yamal_chronology_compare-to-hant
Figure 2. Comparison of Briffa et al 2008 superstick to CA sensitivity version of May 2012: http://climateaudit.org/2012/05/15/new-data-from-hantemirov/. Converted to z-scores.

Briffa et al 2013 report a new Yamal chronology (see SI here – look for yamal_trw). Below is a comparison of this new chronology to the Briffa et al 2008 superstick. Observant readers will note a remarkable similarity (TM-climate science) to the above comparisons to previous CA calculations.

yamal_chronology_compare-to-b13
Figure 3. Comparison of Briffa et al 2008 superstick to yamal_trw chronology of Briffa et al 2013. Both in z-scores.

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