Dear Alison Ah, now I see. I found that confusing, though. If I read "fraction of A in B" I'd assume that A is a subset of B e.g. I assume that mass fraction of fat in cream means fat/cream, not fat/(cream-fat), and mole fraction of nitrogen in air means nitrogen/air. If I read "mass fraction of fat in fat-free yoghurt" I would be confused in the same way as I was about "mass fraction of water vapor in dry air".
I agree that your definition is exactly what humidity mixing ratio means. Here's a more explicit statement of what it means: mass_ratio_of_water_vapor_to_dry_air_in_air But would it be acceptable to stick with humidity_mixing_ratio and regard it as an exceptional name? It does seem like a good idea to avoid "mass mixing ratio" in general as it is not consistently used regarding the denominator. > We already have mole_fraction_of_water_vapor_in_air in the table and we > could certainly also introduce mass_fraction_of_water_vapor_in_air > which, using the same definitions of A and B as before, would mean > simply A/B. Yes. If we need that quantity, it would be the logical name. > If we use 'ambient air' instead of just 'air' in this case > then we ought really to change all the mass|mole_fraction_of_X_in_air > names to be consistent. That would mean creating 104 aliases. > Personally, I'm not convinced of the need for this. ... > So I would vote for continuing to use 'air' to mean moist/ambient air > and 'dry_air' to mean air excluding water vapor. OK. Best wishes Jonathan _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
