Dear Jon I am sure that the phrase "true longitude" in the standard name definition simply means "longitude", not "x-direction". If there were a need for standard names which had to distinguish different sort of longitude, that's another matter, which hasn't been raised before, presumably because "longitude" is usually accurate enough, certainly for GCMs and for many observational purposes as well. However it would be possible to have alternative more precise terms.
Best wishes Jonathan _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
