Artificial Correction

We now have the "artificial corrections" to tree-ring data, straight from the FOIA9009 archive. We plot the effect of these corrections in our new Climategate section here.

UPDATE: The Most Influential Tree in the World.

Is Our CRU/NCDC Data Corrupted?

It appears that CRU and NCDC discarded their raw data files at some point, as described here (thanks to Hugh for link). We downloaded our data from NCDC in early 2006. Is our data "adjusted" or otherwise "improved" or "value-added"? If so, in what way? Perhaps all they did was eliminated duplicate stations and correct some of the station names.

UPDATE: The answer appears to be yes. According to the Russian Institute of Economic Analysis, only 25% of the Russian stations were used, and these were the ones in cities. Over 40% of Russian territory was not included, and this 40% is the territory that showed no significant warming in the late twentieth century.

Climategate

On November 19th, the author of The Air Vent made a post entitled Leaked FOIA Files 62 mb of gold. The post opened with, "This is the biggest news ever broken here. The first thing I have to say is that I have no connection to the source of these files. It was left as a link on my blog while I was hunting for cloaked deers (fruitlessly) in the Upper Penninsula." Someone had posted a link to a zip archive in the comments of his site. The archive contained hundreds of e-mails and code obtained from a server at the Climate Research Unit in England. You will find plenty of heated discussion about the content and implications of these e-mails on the web. Over at The Air Vent, the verdict is that Climate Science is ruled by a cabal zealots who perverted the peer-review process to exclude dissent against the theory of man-made global warming. Over at Real Climate, the verdict is that skeptics of anthropomorphic global warming are making a big deal out of a few private e-mails. (We should mention, however, that Real Climate is run by the people who's e-mails were contained in the zip archive.) The Guardian newspaper's George Monbiot says that the some of the climate scientists involved should be sacked from their positions, but the revelations in no way undermine the case for man-made global warming. Over at Climate Audit the verdict is that prominent scientists colluded upon data manipulation to deceive the public. There is a lot of name-calling going on. Even the Wikipedia Entry has been "protected from editing until disputes have been resolved".

I have no interest in accusing anyone of foul play or fraud. I would, however, like to look at the code in the archive that makes corrections to tree-ring temperature estimates. There is a searchable database of the e-mails here and another here, but neither includes the code samples. Any help finding the original archive would be much appreciated. Also, I can't find any original papers by Briffa et al. on maximal density tree ring (MXD) studies. I'd appreciate a link to one of those papers, and some older data.

UPDATE: Found the zip archive here. List of all files containing the word "artificial" is here, and the piece of code that adds artificial corrections to the tree ring data is this one.

Post Corrections in Comments

Some of our readers have been kind enough to write to us with corrections to our humble document, Climate Analysis. We'd like to receive further corrections and answer further questions here at this blog. We invite you to send both to the comments instead of to my e-mail address. Instead of sending large files directly to me, please post links to the files into the comments section.