A commenter observed that the forthcoming PAGES2K received over 50 pages of review comments from one reviewer. One wonders what he had to say about the PAGES2K South American network which has some very odd characteristics.
Here is a list of proxies with a couple of interesting features highlighted.
First, note that the “proxy” network includes four instrumental records, which seems to be peeking at the answer if the “skill” of the early portion of the reconstruction is in any way assessed on the ability of the network (including instrumental) to estimate instrumental temperature.
Second, one-third of the tree ring series are inverted. Is this an ex ante relationship or mere ex post correlation? We’ll find out eventually, I guess.
Finally, the two longest series are from Quelccaya, a site that we’ve regularly discussed. In the PAGES reconstruction, the d18O values are said to have been inverted. If this is how they actually used the data, as opposed to an error in the SI, it will be a surprise. A quick reverse engineering check indicates that the d18O orientation is inverted (A multiple correlation of recon against proxies in the 857-963 period.)
The PAGES2K Quelccaya version is different from any other Thompson version (as usual.) The graphic below compares the PAGES version (ending in 1995) with the PNAS version (archived in 2006) and the most recent (2013) version. The PAGES version has a sharp downtick in the late 1980s that was not reported in the PNAS version (ending in 1997) or in the 2013 version, though earlier aspects of the graphic cohere. Where did the new version come from? With Thompson, these inconsistencies are the rule, rather than the exception. If Thompson’s data is to be used by IPCC, every damn sample and measurement should be archived so that there is an audit trail.