In today’s post, I’m going to critically examine another widely used tree ring chronology: the Icefields (Alberta) MXD RCS chronology of Luckman and Wilson (2005 pdf), used most recently in Wilson et al 2016. I’ll show that the RCS technique used in the LW2005 MXD chronology eliminated high medieval values as a tautology of their method, not […]
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 […]
Today’s post is complementary to MMH10, which, as readers obviously realize, is in Ross’ excellent style. There has been a kneejerk reaction from climate scientists that the article is “wrong” – typically assuming that we have neglected some trivial Santerism (which we haven’t). This post is NOT – repeat NOT – an explication of MMH10. […]
On December 8, 2009, I received one of my rare invitations to make a presentation to climate scientists – a keynote speech at the plenary session on June 16, 2010 of World Dendro 2010. At the time they had received almost 500 abstracts. It was proposed that I speak on a program chaired by Achim […]
Obviously I think that R is a great language. But one of the reasons that it’s great is because it’s open source and because of the incredible energy and ingenuity of the packages contributed by the R Community for the use of others. In a real sense (as opposed to a realsense), this sort of […]
De’ath et al (Science 2009) here SI received a considerable amount of press at the start of 2009. De’ath et al reported that the there was an “unprecedented” decline in Great Barrier Reef coral calcification: The data suggest that such a severe and sudden decline in calcification is unprecedented in at least the past 400 […]
I’ve discussed “mixed effects” methods from time to time in paleoclimate contexts, observing that this statistical method known off the Island can provide a context for some paleoclimate recipes, e.g. in making tree ring chronologies. This would make a pretty good article. Another interesting example of this technique, which would also make a pretty good […]
I’ve already received my first condescending comments from the dendro world about the mysteries of standardization. Just to pre-empt some further pontification presuming that I know nothing about these mysteries, I’m posting up some notes that I wrote in 2004 on standardization – which was what I would have been working on had people just […]
I’ve got some preliminary measurement data back on several trees with Graybill tags in digital form. The dendro lab is working on cross-dating this week. The measurement data for our Tree #31 (Graybill 84-56), which Pete Holzmann posted a picture of earlier today, is very interesting. This is a strip-bark tree – remember that the […]
Von Storch et al 2004 advocated using climate models to generate pseudoproxies to test the properties of proposed multivariate methods. Hardly unreasonable. I might argue that these are long-winded ways of generating proxy series with certain kinds of temporal and spatial covariance structures, but there’s much to be said for testing methods on some standard […]
By Stephen McIntyre
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Posted in Multivariate, RegEM
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Also tagged multivariate, nlme, overfitting, pseudoproxy, r2, random effects, ridge, stone, stone and brooks, storch, von storch, zorita
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Climate Audit 