Because of the puzzles in trying to replicate the NOAA graphic from archived data, I’ve also tried to replicate the HadCRU plots from archived data. Hu McCulloch has criticized the highly inappropriate use of Mercator projections by climate scientists and, as an exercise, I figured out a fairly simple method of plotting these results in Mollweide projection (which seems like a pretty reasonable method, also shown below).
First here is October CRUTEM, followed by my emulation from the data archived at http://hadobs.metoffice.com/crutem3/data/CRUTEM3.nc as of today. I spent a while trying to match the color coding and am close enough for practical purposes. The archived data appears to contain some stations not in the webpage graphic e.g. in Canada.
Here’s a Mollweide projection of the CRUTem3 data. I’ll post up a utility for doing this from gridded data, as Hu is 100% right that Mercator projections should not be used. They are a bit easier to do, but it didn’t take me that much time to figure out how to do color coded Mollweide plots and you’d think that CRU, Hadley Center and NOAA should be able to do as well.