Monthly Archives: June 2006

Rational Decisions, Random Matrices and Spin Glasses

Interesting title, no? What if I added Principal Components to this odd concatenation of concepts? Galluccio et al 1998 published a paper with the above title here, which has led to a number of follow-ups, which you can locate by googling. I’ll try to summarize Galluccio’s basic idea and then tie it back into principal […]

Reconciling Zorita

One bit of housekeeping that I want to tidy up before more NAS postings: a couple of months ago, Eduardo Zorita kindly sent me comprehensive data from ECHO-G, on which, unfortunately, I’ve so far not been able to spend as much time on so far as I would have liked. So much to do, so […]

NAS Panel #2: Bristlecones

Readers of this site are familiar with our concern over the use of bristlecones/foxtails in MBH98-99 and other multiproxy studies. The NAS Panel found in one place that "strip-bark samples" (which Graybill sought out in his bristlecone collections) should "not be used". They also reported that the MBH results were "strongly dependent" on "Great Basin […]

NAS Panel Excerpts: #1 PCs

When you go through the NAS Panel report closely, it’s amazing how many of our views were adopted – on principal components, statistical skill, statistical methods, bristlecones. I started out trying to make a post showing our views side-by-side with those of of our opponents and those of the NAS Panel, but the post quickly […]

Bloomfield and the Mannian Average

In the NAS press conference, Bloomfield said that you could get a Hockey Stick from an average of the proxies. This was a pretty misleading comment. You CAN’T get a HS from averaging the MBH98 proxies. We showed this to the NAS panel on our presentation as follows: The simple mean of the Mann et […]

NAS 1995

Jean S has written me suggesting that I review the NAS panel claim that Mann was the “first systematic, statistically based synthesis of multiple climate proxies”. This claim is true only in the sense that Al Gore invented the Internet and I will discuss this in the next few days. While I was reviewing the […]

Letter to NAS

I want to convey one more time that, while I’m going to criticize the NAS report and in some cases I’m going to be pretty hard on it, I think that they are decent, intelligent and knowledgeable people, who’ve tried to do an honest job and who were civil and fair to Ross and I. […]

Some Ice Cores in NAS – Antarctic

Now that I’ve caught my breath a little, just for fun, I’m parsing through sections of the NAS report on areas not directly involving the MM-MBH battle. In the press conference, I recall Cuffey placing a lot of emphasis on the "regional" MWP, and that it wasn’t in the Antarctic ice core data (although it […]

Up-to-Date Proxies: Colorado

Another large batch of tree ring chronologies was archived on June 21, 2006, this time with records up to 2003. Are the results for the 1990s and 2000s off the chart?

NAS Ice Core – Dasuopu

If you look at Chapter 6 of NAS, you’ll see heavy reliance on Thompson’s tropical ice cores. There’s much to consider here and this is a very first look. Here’s an interesting statement: "A quantitative assessment of temperature change from north Tibetan cores [Dunde and Guliya], using typical [whatver that is in tropical ice cores] […]