Dear Alison,
The two standard names: atmosphere_optical_thickness_due_to_ambient_aerosol_particles and atmosphere_absorption_optical_thickness_due_to_ambient_aerosol_particles Include the following in there descriptions: 'To specify the relative humidity and temperature at which the quantity described by the standard name applies, provide scalar coordinate variables with standard names of "relative_humidity" and "air_temperature".' I believe this should be interpreted as optional, is that correct? When they are used in CMIP6, the associated relative humidity and temperature will be provided in separate files, it would be awkward for everyone if they were required in the same file. Can we change "provide scalar ....." to "scalar ..... may be provided."? regards, Martin _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata