UC observed a couple of days ago that Hadley Center, authors of the pre-eminent temperature series, have suddenly identified an “error” in how they presented temperature data. For presentation of their smoothed temperature series in a part-year situation, their methodology calculated the average of months then available and used that to estimate the current year’s […]
A few days ago, I showed some plots showing distribution of weights arising from principal components carried out on data from a region arranged as a line segment (think Chile). Today I’ve done a similar analysis for a square shaped region again assuming spatial autocorrelation governed by distance. In this case, I made a regular […]
Tamino has recently re-iterated the climate science incantation that Mann’s results have been “verified”. He has done so in the face of the fact that one MBH98 claim after another has been shown to be false. In some cases, the claim has not only been shown to be false, but there is convincing evidence that […]
Minus Kim Basinger. http://wattsupwiththat.wordpress.com/2008/03/24/how-not-to-measure-temperature-part-54-los-angeles-the-city/ As a reader at Anthony’s blog notes, there’s an interesting history here. Note that the temperature graphic shown linked at Anthony’s site is the version used by NOAA, rather than the version used by NASA. The differences are shown in the two graphs below. The NASA adjusted version increases past L.A. […]
As I observed a couple of posts ago, the Stahle SWM network can be arranged so that its correlation matrix is closely approximated by a Toeplitz matrix i.e. there is a “natural” linear order. I also noted that results from matrix algebra proving that, under relevant conditions, all the coefficients in the PC1 were of […]
Yesterday’s results connecting eigenvector patterns in the Stahle SWM network to Toeplitz matrices and spatial autocorrelation were obviously pretty interesting. Needless to say, I was interested to test these ideas on out some other networks and see how they held up. There is a large literature on spatial autocorrelation and there appear to be well-known […]
One of the most ridiculous aspects and most misleading aspects of MBH (and efforts to rehabilitate it) is the assumption that principal components applied to geographically heterogeneous networks necessarily yield time series of climatic interest. Preisendorfer (and others) state explicitly that principal components should be used as an exploratory method – and disavowed any notion […]
Tamino, in his continuing effort to bring every one of Mann’s questionable practices back into the light of day, has stumbled into the treeline11.dat series, which he proclaims triumphally in his most recent post as having a hockey stick shape. This is none other than the notorious Gaspé cedar series, which was analyzed at length […]
Today’s post, which has a forbidding title, contains an interesting mathematical and statistical point which illuminates the controversy over how many PCs to retain. In my re-visiting the totally unknown corner of Mannian methodology – regression weights and their determination – I re-parsed the source code, finding something new and unexpected in Mannian methodology and […]
In order to illustrate a useful application of principal components, Tamino showed coordinate systems for the motion of a canoe. In the context of MBH, it would have been more instructive to show how principal components apply to tree ring networks than to canoes. In such a context,a non-Mannian centered PC1 will typically show some […]
Climate Audit 