Yamal has been a longstanding issue at Climate Audit. The new article appears to be their long awaited response to criticism from Climate Audit (though this criticism is not referred to anywhere in the aticle.)
In resisting FOI requests for their withheld 2006 Yamal-Urals regional chronology, CRU said that it was incomplete, as they were continuing to work on its development. However, they did undertake to disclose the 2006 regional chronology as part of the present publication. On my first reading, instead of living up to their undertaking to develop a regional chronology, CRU has instead provided reasons against using a regional chronology and do not present one in the paper – instead focussing on a variation of the original Yamal chronology.
In resisting the FOI, CRU said that production of the 2006 regional chronology would damage the reputation of CRU scientists. The 2006 version appears to be the “Urals raw” chronology illustrated in SM9 as Greater Urals (shown below), though it is not identified as such in my first reading. Readers can judge for themselves whether their foreboding was justified.
Readers who are convinced by Briffa’s arguments against a regional chronology may well wonder whether, for example, the Avam-Taimyr regional chronology of Briffa et al 2008 would pass corresponding tests, since no similar analysis has ever appeared in Briffa articles in which he presented earlier regional chronologies. Or whether these tests only became of interest when the regional chronology went the wrong way.
CA readers will recall the original controversy in September 2009 over the Schweingruber Khadyta River series in Yamal, a controversy on which I’ll review in the present context on a subsequent occasion. Leaving nothing on the table, Briffa excluded the Khadyta River from the present reconstruction, pointing out that recent trees in this area had been growing poorly (thereby lowering the late 20th century uptick.) They state:
the site report (and statistical evidence) demonstrating the anomalous “signal” in the Khadytla data lead us to omit them from the new Yamal chronology constructed here (see SM5 for details)