Category Archives: Steig at al 2009

…-omatic Correlations

Update Mar 28: Here is Luboš version replacing my much less pretty monochrome version showing the spatial decorrelation of the “Comiso” version of the data recently archived a couple of days ago by Steig. Figure 1. Spatial Correlation for Sample of “Comiso 2009” Antarctic Gridcells Jeff Id has compared this to corresponding surface stations at […]

Antarctic Spatial Autocorrelation #1

“Noisy” covariance matrices have been discussed here on many occasions in a variety of contexts, largely because the underlying strategy of Mannian methods is to calculate the covariance of everything to everything else and then calculate verification stats using methods that ignore the data mining that effectively takes place with huge covariance matrices. Steig et […]

RegEM PTTLS Ported to R

I’ve now ported my emulation of Schneider’s RegEM PTTLS to R and benchmarked it against Jeff’s Matlab as shown below. I caution readers that this is just an algorithm. There are other ways of doing regressions and infills. The apparent convergence to three PCs noted by Roman is still pending as a highly interesting phenomenon. […]

Interaction of Infilling on Std Deviation

Standardization in Mannian algorithms is always a bit of an adventure. The bias towards bristlecones and HS-shaped series from the impact of Mann’s short segment standardization on his tree ring PCs has been widely publicized. Smerdon’s demonstration of defects in Rutherford et al 2005, Mann et al 2005 and Mann et al 2007 all relate […]

Dirty Harry 4: When Harry Met Gill

Yesterday, I noted that Steig had criticised previous developers of Antarctic gridded temperature data for not having “paid much attention” to West Antarctica (e.g. the NASA GISS trend map left the area blank due to lack of data meeting their quality standards) and reproached his predecessors (including, it seems, even Hansen) for “calculating with their […]