Recently, after the posting of the Phil Trans B archive on Sept 8, 2009, I determined that the Yamal data set as used by Briffa is not more “highly replicated” than the Polar Urals data set and thus there is no basis for the preferential selection of the Yamal chronology over the Polar Urals chronology […]
Briffa 2000 is one of the canonical “independent” reconstructions in the IPCC AR4 spaghetti graph, the Wikipedia spaghetti graph and similars. I’ve discussed it in the past, but I’m going to revisit this in light of the new information on Tornetrask and I’m going to run Brown’s inconsistency statistic on it. Briffa used 7 series: […]
We keeping hearing the incantation from the Team that all the reconstructions on the Jesuit Index show a warmer modern than medieval period. I reported that I recently obtained a digital version of Grudd’s revised Tornetrask reconstruction and I’ve been anxious to test out its impact on the Jones et al 1998 reconstruction (together with […]
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 […]
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 […]
Naurzbaev et al [2004] is a terrific article by Naurzbaev, Hughes (yes, that Hughes) and Vaganov about deducing climate information from tree-ring growth curves in Siberia. (I find Naurzbaev’s work consistently interesting.) They studied 34 larch sites in a meridional transect from 55 to 72 N (at a longitude of about 90-100E) and 23 larch […]
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 […]
Just as an experiment, I plotted up all the ring widths for the Gaspé and Polar Urals sites, with each core displaced a little. What I was thinking of the type of graph that you see in seismic surveys. The look is interesting, given how much weight is placed downstream on these data sets in […]
