Yesterday, we discussed the remarkable decomposition of the AVHRR reconstruction into 3 PCs, initially observed by Roman and discussed yesterday by Jeff Id. I thought that it would be interesting to see what happened with the PC3 in the AWS reconstruction (and in the process, do some comparisons of the RegEM emulation (file-compatible between Jeff […]
Bruce McCullough and Ross McKitrick today published an interesting article under the auspices of the Fraser Institute entitled Check the Numbers: The Case for Due Diligence in Policy Formation. Their abstract states: Empirical research in academic journals is often cited as the basis for public policy decisions, in part because people think that the journals […]
Roman Mureika perceptively observed about 10 days ago that the AWS reconstruction consisted of only 3 PCs. Jeff Id has extended this to observing that the AVHRR reconstruction consists of only 3 PCs. Jeff’s demonstration of this is correct, but a little awkward. I’ll show an alternate demonstration which shows a useful linear algebra property […]
I’ve now ported my emulation of Schneider’s RegEM PTTLS to R and benchmarked it against Jeff’s Matlab as shown below. I caution readers that this is just an algorithm. There are other ways of doing regressions and infills. The apparent convergence to three PCs noted by Roman is still pending as a highly interesting phenomenon. […]
I’ve transliterated relevant Tapio Schneider code into R (pttls.m) and parts of regem.m that seem relevant at present. Jeff Id has extracted a variety of intermediates from his Matlab run and I’ve fully reconciled through two steps with remaining differences appearing to be probably due to transmission rounding. My dXmis statistic at step one was […]
Standardization in Mannian algorithms is always a bit of an adventure. The bias towards bristlecones and HS-shaped series from the impact of Mann’s short segment standardization on his tree ring PCs has been widely publicized. Smerdon’s demonstration of defects in Rutherford et al 2005, Mann et al 2005 and Mann et al 2007 all relate […]
The two Jeffs ( C and Id) have interesting progress reports on emulating Steig using unadorned Tapio Schneider code here. Check it out. One of the first questions that occurred to third party readers was whether RegEM somehow increased the proportional weight of Peninsula stations to continental stations as compared to prior studies. Jeff C […]
Andrew Sullivan, a well-known writer, has been blogging since 2001 and won the 2008 Best Blog award (displayed at his site.) In November, prior to this competition, he published an excellent essay on blogging in the Atlantic Monthly, one that I read at the time and meant discuss. Give it a read. While his lessons […]
Smerdon et al 2008 is an interesting article on RegEM, continuing a series of exchanges between Smerdon and the Mann group that has been going on for a couple of years. We haven’t spent much time here on RegEM as we might have. I did a short note in Nov 2007 here. In July and […]
My squash club has wonderful squash doubles pro-am that runs over the first few weeks of February. The pro at our club, Eric Baldwin, does a great job organizing and it is well supported by the pros around Toronto, which is an very active squash community. Jonathon Power is now a member, as is Gary […]
Climate Audit 