Anthony Watts has posted an article at WUWT about an ensemble of global temperature time series being shown by NASA. This has a twist, there is a new kid on the block it seems Anthony didn’t know about, neither did I.
Apparently they use their own GHCN/SST variant but switch from GHCN to CLIMAT data in recent years. I’ve mentioned CLIMAT to do with the UK surface stations project. Ask if you need to know more from me.
He adds at the bottom of the article
BTW if anyone wants to analyse the Japanese data, here is the source for it:
It is gridded, and I don’t have software handy at the moment to work with gridded data, but some other readers might.”
Been there, done that earlier today, one click update of a database version here, put into a common format for many datasets in sqlite. Internal name gst
Inside the gridded data looked similar to some UK Met Office files, at least in layout, if very different in other respects. As it turned out it was quite easy to use the hadcrut configuration and subroutine as a template. Figured the field width and to my surprise the years started scrolling as it built the database, then committed. Size looked sane. So I ran compute global and hemisphere means, worked first time. Only floor is I think, longitude is reversed, need to flip a flip flag. Check that later.
Means are computed from a linear grid as a cosine() weighted mean, with missing data handled straightforwardly. I do no fancy stats stuff, is a straight work used here for all gridded. In the case of RSS and UAH produces a clone.
Here is my compute of global mean and hemisphere means. On plot overlays the official annual well enough, slight increase on claimed straight line trend, 0.71 vs. 0.68, of no significance. Looks like their plot has recomputed the reference period, so zero doesn’t match, your problem.
Data runs from January 1891 through December 2011. Presumably they update rarely.
Tab delimited text file inside zip archive is here. This is unofficial version.
Post by Tim Channon