Nature's Style: "Naturally Orthogonal"?
Wilson and Luckman 2003 observe: The first PCs from the RW and MXD PCA are naturally orthogonal (r = —0.006) over the 1900—1991 period suggesting the in’?fluence of different forcing mechanisms upon...
View ArticleMore on "Naturally Orthogonal"
I realize that not all CA readers are interested in multivariate methods and that dendroclimatologists want to “forget the math”, but I find it interesting to try to relate dendro and paleoclimate...
View Articlevon Storch et al 2004 in IPCC AR4
It’s interesting to see what’s been changed between the Second Draft and AR4 as it went out the door, and compare that to comments. von Storch et al 2004 argued that the low-frequency variance of...
View ArticleMultivariate Calibration
In calibration problem we have accurately known data values (X) and a responses to those values (Y). Responses are scaled and contaminated by noise (E), but easier to obtain. Given the calibration data...
View ArticleRe-Visiting RegEM: Rutherford et al 2005
Mann et al 2007 is a new RegEM version, replacing the RegEM calculations of Rutherford et al 2005. The logic is not entirely self-contained and so I re-visited some of our previous comments on...
View ArticleBack from Georgia Tech
First, let me thank me thank Judy Curry for inviting me to make a presentation at their seminar series and for both spending so much time and energy showing me around the department and hosting me so...
View ArticleAn Example of MBH "Robustness"
In the MBH source code, they apply steps that purport to weight the temperature PCs in their regression calculations proportional to their eigenvalues. Comments on their code say: c set specified...
View ArticleBrown and Sundberg: "Confidence and conflict in multivariate calibration" #1
Introduction If one is to advance in the statistical analysis of temperature reconstructions, let alone climate reconstructions – and let’s take improving the quality of the data as the obvious...
View ArticleReconciling to Wahl and Ammann
When Wahl and Ammann’s script first came out, I was able to immediately reconcile our results to theirs – see here. As Wegman later said: when using the same proxies as and the same methodology as MM,...
View ArticleSmerdon et al 2008 on RegEM
Smerdon et al 2008 is an interesting article on RegEM, continuing a series of exchanges between Smerdon and the Mann group that has been going on for a couple of years. We haven’t spent much time here...
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