Tag Archives: wahl

Caspar Ammann, Texas Sharpshooter

The Texas Sharpshooter fallacy is a logical fallacy where a man shoots a barn thirty times then circles the bullet holes nearest each other after the fact calling that his target. It’s of particular concern in epidemiology. Folks, you are never going to see a better example of the Texas Sharpshooter work itself out in […]

Fortress Met Office continued

More obstruction from the Met Office, in which they have changed their obstruction strategy. Previously they said that Mitchell had destroyed all of this email correspondence. This prompted David Holland to ask for information on the date of the destruction and on records management policy at the Met Office. Rather than answer the unanswerable, the […]

Fortress CRU #2: Confidential Agent Ammann

On March 31, 2008, David Holland sent a letter to Keith Briffa asking about several IPCC issues. In correspondence released from the Hadley Center, Briffa indicated his intention of being unresponsive. On May 15, Briffa sent an unresponsive reply to Holland, following which Holland initiated a FOI request on May 27, 2008 leading to an […]

Fortress CRU

As noted in other posts, IPCC policies state: All written expert, and government review comments will be made available to reviewers on request during the review process and will be retained in an open archive in a location determined by the IPCC Secretariat on completion of the Report for a period of at least five […]

Wahl and Ammann 2007 and IPCC Deadlines

In a previous post, I’ve observed some oddities in connection with the dating of Wahl and Ammann 2007 and with Schneider’s obfuscation when asked to explain how an article supposedly accepted on March 1, 2006 could cite an article that had not even been submitted until August 2006. (BTW, I note that Journal of Climate […]

The Dog That Didn't Bark

This is the title of a famous Sherlock Holmes story and not intended as a slight to any individual. Take a look at the Review Comments for AR4 Second Draft Chapter 6 online here. While I was reviewing these comments, I noticed that there are no reported comments on chapter 6 from Caspar Ammann, one […]

When Was Wahl and Ammann 2007 "Accepted"?

Last summer, on Aug 28, 2007, I wrote a post observing that Wahl and Ammann 2007, although being cited in IPCC AR4, had still not appeared in print. I think that it was then the only article cited in IPCC AR4 chapter 6 in that situation. In that post, I observed that it seemed anomalous […]

The RE Benchmark of 0

In MM2005a,b,c, we observed that the RE statistic had no theoretical distribution. We noted that MBH had purported to establish a benchmark by simulations using AR1 red noise series with AR1=0.2, yielding a RE benchmark of 0. We originally observed that high RE statistics could be obtained from PC operations on red noise in MM2005a […]

The MBH AD1450 Network

Most of my previous discussion of MBH pertained to the AD1400 network. In recent discussion over at Tamino, some of the posters have stated that BCPs only matter for the AD1400 network and that everything is fine for the AD1450 and later networks, relying here on statements in Wahl and Ammann 2007. (I don’t suppose […]

Overfitting by Inverse Regression

Wahl and Ammann 2006 reported that they could “get” something that was sort of HS-ish without principal component analysis. It wasn’t through a simple mean or CVM; it was through Mannian inverse regression. Juckes et al shows many reconstructions using “inverse regression”, mentioning in his conclusions that inverse regression caused over-concentration on a few proxies. […]

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