I have always had a problem with the ambiguity of units like ppm. An oxygen measurement in the atmosphere in ppm could have two different values, one in mass/mass and the other in volume/volume. Consequently, the use of ppmv by some but my preference has always been to be semantically explicit with units such as microlitres/litre or mg/kg. Consequently, I was disappointed when ppm was added to UDUNITS. @JonathanGregory 's suggested change of words is an improvement in my view, but I would like to see it accompanied by a suggestion to use unambiguous, semantically implicit units.
To @dopplershift I would say that UDUNITS was incorporated into the initial CF standard because it was a part of the NetCDF community standard upon which the CF community standard was based. Replacing UDUNITS by a units vocabulary under CF governance is something that has been discussed by the CF community several times - usually during discussions of the units to be used for salinity in oceanography - but it was and isn't a feasible proposition within available resources and so solutions such as "1e-3" and "1e-6" were written into the conventions. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/cf-convention/cf-conventions/issues/260#issuecomment-618264885 This list forwards relevant notifications from Github. It is distinct from [email protected], although if you do nothing, a subscription to the UCAR list will result in a subscription to this list. To unsubscribe from this list only, send a message to [email protected].
