Tag Archives: PC1

ClimateBallers and the MM05 Simulations

ClimateBallers are extremely suspicious of the MM05 simulation methodology, to say the least.  A recurrent contention is that we should have removed the climate “signal” from the NOAMER tree ring network before calculating parameters for our red noise simulations, though it is not clear how you would do this when you not only don’t know the […]

t-Statistics and the “Hockey Stick Index”

In MM05,  we quantified the “hockeystick-ness” of a series as the difference between the 1902-1980 mean (the “short centering” period of Mannian principal components) and the overall mean (1400-1980), divided by the standard deviation – a measure that we termed its “Hockey Stick Index (HSI)”.  The histograms of its distribution for 10,000 simulated networks (shown in […]

What Nick Stokes Wouldn’t Show You

In MM05, we quantified the hockeystick-ness of simulated PC1s as the difference between the 1902-1980 mean (the “short centering” period of Mannian principal components) and the overall mean (1400-1980), divided by the standard deviation – a measure that we termed its “Hockey Stick Index (HSI)”.  In MM05 Figure 2, we showed histograms of the HSI […]

Moderate Low Weight

(This post is by Jean S.) A few days ago Steve discussed Raymond Bradley’s objection to use of the Yang Chinese composite reconstruction in the Mann et al Eos-response to Soon & Baliunas (2003). Bradley called the series “crap”, and demanded it to be removed from Figure 2 in the Eos article. It is not […]

Mann's PC1 in Esper and Frank 2008

On previous occasions, we’ve noticed some strange appearances of the Mann hockey stick under different disguises. In Inconvenient Truth, a splice of Mann’s hockey stick and CRU instrumental data is described as “Dr Thompson’s thermometer”. Today, I noticed another peculiar incident, where Esper and Frank (Clim Chg 2008), who one would think would know better, […]

"Mannian" PCA Revisited #1

One of Hansen’s pit bulls, Tamino, has re-visited Mannian principal components. Tamino is a bright person, whose remarks are all too often marred by the pit bull persona that he has unfortunately chosen to adopt. His choice of topic is a curious one, as he ends up re-opening a few old scabs, none of which […]

Juckes and the NOAMER PC1

Subsequent to MM05 (GRL), the issue of covariance and correlation PCs as applied to the North American tree ring network was considered in Huybers [2005], our Reply to Huybers [2005] and the NAS Panel. It was also discussed in the rejected Ammann and Wahl submission to GRL. Juckes did not even cite the discussion on […]

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