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.
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 Climate screeched in fury. [Note July 2- the screeching at RC in response to my Hantemirov post occurred in comments (see page 4 on) to their Yamal post of May 11, which chronologically was screeching in fury at my post of May 6 about regional reconstructions.) The figure below compares the Briffa superstick to the CA calculation of May 2012.
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.
For further reassurance to readers of the similarity of the three versions, the next graphic shows the two CA calculations that had been so reviled by CRU and Real Climate (the green chronology of Sept 2009 and the May 2012 calculation with updated information from Hantemirov). I think that I’m entitled to observe that the B13 chronology is more similar to the two reviled CA calculations than it is to the Briffa et al 2008 superstick. Needless to say, this was not reported in CRU’s recent Real Climate article.
Update (June 29): For comparison, here is an excerpt from RC Figure 2a on which I’ve plotted the versions used in the above post. In my comparisons above, I compared the most recent Yamal reconstruction (Briffa et al 2008) to the new version. The 2008 version is shown in red: it is somewhat more supersticked than the 2000 version, which CRU and Realclimate showed in their comparison (overplotted in yellow) and which has less difference to the 2013 version.
Below is an annotation of their Figure 2b, where, as too often, one has to watch the pea. They describe this figure as follows:
Figure 2b compares the new Yamalia chronology with two alternative chronologies heavily promoted by McIntyre and others – the so-called Polar Urals “update” chronology and a Yamal chronology using modern samples from the Khadyta River site.
On their Figure 2b, I’ve also overlaid the Briffa 2008 chronology (red) and the green chronology of my original post in September 2009 (also shown in the first figure above.) In my original post, I also showed a variation using Schweingruber’s Khadyta River without the YAD-12. In their Figure 2b, CRU selected the latter variation and made the fabricated assertion that I had “heavily promoted” this latter variation – conspicuously providing no reference to any such “heavy promotion” on my part. I am unaware of any “heavy promotion” on my part of the variation illustrated in Real Climate Figure 2b. To my recollection, I showed this variation only in one Climate Audit post in September 2009. I did not cite it in submissions to the Muir Russell panel. Nor did I cite in my May 2012 revisiting of the topic, where I showed the green chronology of my Sept 2009 post.
Figure 6. ANnotation of Real Climate Figure 2b, in which I’ve overlaid Briffa 2008 (red) – not shown by CRU in this figure, and the green sensitivity of my September 2009 blogpost – also not shown by CRU in this figure.