At Climate Audit, Steve McIntyre has been frequently writing about Chladni patterns in connected with principal components of autocorrelated data. He developed it for the Steig paper, and was disappointed when J Climate wouldn't allow its inclusion in the response. And he's recently claimed an appearance in another paper.
Chladni patterns are modes of oscillation, originally of a vibrating plate. Now people more often think of a drum membrane, which is a slightly different wave equation, but the idea, and patterns, are similar.
I must admit that I hadn't heard of Chladni before Hans Erren drew attention to them in Steve's first post. Some interesting history there. But I am familiar with the modes in question.
Steve thinks that if a Chladni pattern emerges, that somehow means that the result is showing that rather than the information about the climate pattern being sought, so the information content is reduced. I don't agree - there are reasons why the patterns arise, and they are just as informative in PCA as they are in wave studies. I'll try to show why.
Warning - mathematics (and \(\LaTeX\)) after the jump.
Tuesday, May 17, 2011
I have implemented Latex (the MathJax version). It seems to work in comments too. You can just write normal Latex between these symbols(remove the _s)
- \_(...\_) for inline
- \_[...\_] or $_$...$_$ for display equations - note the doubled $'s
Posted by Nick Stokes at 7:35 PM
Last November, I was very pleased and flattered when ScienceofDoom chose Moyhu as the recipient of the Woody Guthrie award.
This award has an interesting history - it was initiated as a commendation of a "thinking blogger". The award was passed to SoD from Skeptical Science. I think both have been highly respected for their dedication to dispassionate analysis, and Moyhu has sought to live up to that.
I think Bart impressed all sides of the climate debate with his hosting of the very popular discussion on comparing temperature indices, which evolved into a debate about time series, unit roots and random walks. Strong views were expressed by well-informed commenters led by VS. Bart kept the discussion on track and constructive, with 2186 comments made. I think it is the best technical climate discussion I have seen.
But his blog isn't just technical - there is thoughtful, well-informed and inclusive discussion of policy as well. Bart always takes a broad view.
And there are brilliant cartoons as well.
I commend Bart's blog to readers, and I am very pleased to pass on the Award to him.
Here it is:
Posted by Nick Stokes at 10:02 AM