It’ll take several posts to explore the subject of PCA (principal components analysis) sufficiently to get a good idea of how it relates to some of the climate science that’s often under discussion (i.e., hockey sticks and all that). So here’s part 1, an introduction to PCA.
Some time ago I came across data for ice-out day (the day of the year on which the lake ice breaks up) for a number of the New England lakes. Here’s the data for two of them, lakes Auburn and Moosehead:
