Dear Alison et al. I wrote
> I think we could include both of these: > > > >'water_vapour_mixing_ratio' > > >'mass_fraction_of_water_vapour_in_dry_air' > > They are different quantities, and people should use the one which describes > their data. That was wrong, sorry, I wasn't thinking. Shouldn't the second option be mass_fraction_of_water_vapour_in_moist_air or just mass_fraction_of_water_vapour_in_air assuming that "air" means just as it comes i.e. not dry? The mass fraction of water vapour in dry air is zero. I think mass_fraction_of_water_vapour_in_[moist_]air water_vapour_mixing_ratio are two different quantities, which should have different standard names. If A is the mass of water vapour and B is the mass of dry air, the mixing ratio is A/B and the mass fraction is A/(A+B), I believe. I think the mass fraction is what we use for other chemical constituents. If C is the mass of some other species, the mass fraction of C in air is C/(A+B), because "air" would be assumed to be ambient, including whatever moisture A it has. Best wishes Jonathan _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
