I showed a little while ago the impact of the Polar Urals update on the Briffa 2000 reconstruction – using it instead of the Yamal substitution resulted in an MWP index higher than the 20th century. Today I’ve done the same calculation for Jones et al 1998, this time substituting the Polar Urals update using […]
Rob Wilson wrote in today pointing out that D’Arrigo et al 2006 had obtained a correlation to gridcell temperature of 0.58 for the Jacoby Mongolia site chronology, working from original data and not relying on hand-me-down data from Mann and Jones. This is actually higher than the 0.25 reported by Mann and Jones for annual […]
Trying to check even simple things like the correlation of individual Osborn and Briffa 2006 series to gridcell temperature always leads to complications. Today I’ll look at the situation with respect to Jacoby’s Sol Dav, Mongolia series, one of the 6-7 mainstays of Hockey Team reconstructions. Needless to say, nothing can be confirmed. Instead of […]
The relationship of bristlecone/foxtails to gridcell temperature is something that I’ve discussed at length, but, surprisingly, I’ve never illustrated it at the blog. This is a type of relationship that, in some ways, is well suited to blogs. It’s simple to discuss; it’s important. It would be amply illustrated and discussed in business feasibility studies […]
I discussed Fisher’s Greenland dO!8 proxy yesterday and thought that it would be interesting to discuss its particular function in hockey stick manufacture in Jones et al 1998. Each hockey stick is, after all, made by a master craftsman. The Greenland dO18 is one of only 10 series in Jones et al 1998. Let’s see […]
Here’s an example of how one can wander off curious little by-ways in trying to replicate Hockey Team materials. I’m working on the seemingly simple task of testing the correlations to gridcell temperature in Osborn and Briffa 2006. One of the series – a "quiet" series – is Fisher’s "West Greenland dO18 Stack". Also with […]
Rutherford et al 2005 (the et al being half the Hockey Team: Mann, Bradley, Hughes, Briffa, Jones, Osborn) is a re-statement of the MBH98 network (flawed PCs and all) and the Briffa et al 2001 network using RegEM. I haven’t figured out exactly what the properties of the RegEM method are as compared to other […]
If you actually look at the medieval proxy index of the "other" studies (Briffa 2000, Crowley and Lowery 2000, Esper et al 2002, Moberg et al 2005), the medieval proxy index is usually just a razor’s edge less than modern proxy index – just enough that the study can proclaim with relief that the modern […]
There’s an interesting knock-on effect from the collapse of MBH98 Figure 7 (see here and here). See update from UC in May 2011 below in which he did a “bit-true” replication. We’ve spent a lot of time arguing about RE statistics versus r2 statistics. Now think about this dispute in the context of Figure 7. […]
Sometimes we hear that science is "self-correcting". To be "self-correcting", however, individual people have to step up to the plate now and then and actual do the work. To the extent that the term "science" includes the work of Mann et al., then analysis of MBH98 Figure 7 , which was actually the culmination of […]
Climate Audit 