Wilson et al 2016, like D’Arrigo et al 2006, includes a ‘Polar Urals’ chronology as one of its components. Tree ring chronologies from Polar Urals and Yamal have long been a contentious issue at Climate Audit, dating back to the earliest days (see tags Yamal, Polar Urals). Whereas the D’Arrigo et al 2006 version had one […]
Nearly all readers agreed with the proposal (of my most recent post) for a comprehensive mapping and crossdating of all dead and living trees within one or more altitudinal transects in the Polar Urals, with the objective of achieving a crossdated dataset of at least 1000 subfossil trees and 500 living trees, each with accurately […]
Addiction of paleoclimate reconstructions to particular proxies has been a longstanding concern at Climate Audit. One of the battleground issues has been the addiction to Briffa’s Yamal tree ring series, while the nearby update of Polar Urals (with a pronounced MWP) was disappeared. (See CA category.) Just before Climategate, we raised questions about the Yamal […]
Now that we know the abysmally low replication of the modern portion of Briffa’s Yamal chronology (something previously unknown to specialists), I’ve been backtracking through some earlier documents to see how this may have impacted past studies. We’ve talked previously about how Briffa refused to provide measurement data to D’Arrigo et al 2006, resulting in […]
I showed a little while ago the impact of the Polar Urals update on the Briffa 2000 reconstruction – using it instead of the Yamal substitution resulted in an MWP index higher than the 20th century. Today I’ve done the same calculation for Jones et al 1998, this time substituting the Polar Urals update using […]
I’ve got to get back to the NAS presentation and this will be my last post on Polar Urals and Yamal for a while, but it is all quite delicious. Anyway, here is a spaghetti graph of 3 Polar Urals results – including the results from Esper et al [2002] just disclosed by Science, all […]
It’s interesting that the Hockey Team seems to be able to make spaghetti graphs of world temperature history when they can’t even arrive at a spaghetti graph for the Polar Urals. I posted up the difference between Briffa’s Yamal substitution and the updated Polar Urals ring widths. But before either one, there was Briffa’s Polar […]
By Stephen McIntyre
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Posted in Briffa, Esper et al 2002, Jones et al 1998, Multiproxy Studies, Yamal and Urals
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Tagged briffa, briffa_1995, briffa_2000, Esper, esper_2002, urals, Yamal
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Here’s another look at Polar Urals using a “grass plot” showing cumulative ring width for individual trees against time. The trees plotted in black are from the original archive (russ021) and the ones plotted in red are form the 1998 update (russ176). This gives a little different viewpoint on variance stabilization issues. First, one of […]
I’m finally trying to finalize my presentation on Jones et al [1998] for the US GCRP workshop in November, which is necessarily mostly about the Polar Urals and Tornetrask reconstructions. Bot MXD chronologies and RW chronologies are supposed to correlate to temperature. So an obvious quesiton is how do they correlate to eachother. I’ve plotted […]
I have obviously been very critical of the 11th century portion of the Polar Urals dataset used in Briffa et al. [1995], without which Jones et al [1998] does not have a cold 11th century (and which is a staple of other studies). It turns out that Schweingruber collected new subfossil samples for this site […]
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