Has Gavin posted on his IJOC paper? [SM – yes. At RC today.] I will head over tomorrow to have a look. Not today–it’s very sunny here and the ice rink beckons. I am not sure how replication plays into the issue, since I posted my data and code from the get-go.
I got a copy of Gavin’s paper (from Jos de Laat) 2 weeks ago, and Gavin sent me his data promptly in response to my request. I have been having a lot of fun with it. In his paper, Gavin shows that the coefficients weaken a bit when RSS is substituted for UAH. But he doesn’t report the joint F tests which form the basis of the conclusions about contamination. They are still strongly significant. He also points out that the coeff’s are significant when GISS data are swapped in, and claims this shows the effects are spurious. I am sure I am not the only person who has actually read the paper and noticed that to the extent they are significant the coefficients on GISS data take the opposite signs to those on the observational data. Far from showing the effects are spurious, it shows that the observations negate a significant pattern in the modeled data and make it significant in the other direction. That’s called an observable effect, not a spurious result. And since it’s a comparison of ‘clean’ GCM data versus observations it has as much causal interpretation as the 3-part ‘signal detection’ methodology in the IPCC reports. I.e. in this case it’s a “signal detection” result for non-climatic contamination of the surface data. Gavin doesn’t report a chi-squared test of parameter equivalence between coeff’s estimated on modeled and observed data (akin to the outlier test and hausman test shown in MM07), but that’s OK because he posted his data, so I have done it and parameter equivalence is strongly rejected.
The issue of spatial autocorrelation is a huge red herring. Over a year ago I responded to the RC posting on this by writing a paper showing that spatial AC is not significant and even if we control for it anyway the results all hold up. The JGR would not publish my response unless Rasmus submitted his comment. I challenged him to do so in December of 2007 and he said it might take a while since he was getting busy with work. That’s the last I heard from him on it. I also deal with the topic in a more recent paper under review elsewhere, which I have reason to believe Rasmus has read. But when I write up my response to Gavin’s paper I’ll be sure to give the spatial AC issue a thorough discussion.
Editorial note (SM): I have not worked through any of these papers and accordingly have no personal view or opinion on the details. Schmidt acknowledges that Ross’ due diligence package was complete. Schmidt sneers at the problems that others encounter in trying to get to the starting point (for e.g. Steig) that would have been provided by a proper due diligence package, such as the one that Ross provided, but, inconsistently, appears to have consulted Ross’ well-prepared due diligence package in his own paper.