Hi Alison, If a community uses the term 'diameter' then I would stick with that and in our experience with both sediment grain-size and aerosol size spectra 'diameter' is the word exclusively used.
Cheers, Roy. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: 24 November 2010 13:47 To: [email protected] Subject: Re: [CF-metadata] Correct name for aerosol size distributionexpressedin numbers ? Dear Jonathan and Bruno, I agree with Jonathan's point that the particle size is a geophysical parameter, so we should not refer to 'bins' in the standard name. I think 'size' is too ambiguous a term so I vote for aerosol_particle_radius or aerosol_particle_diameter. Jonathan is correct that we do have existing standard names that refer to the effective radius of cloud particles. However, we also have aerosol name explanations that refer to the particle diameters, e.g., the explanation of atmosphere_optical_thickness_due_to_pm1_ambient_aerosol says "Pm1 aerosol" is an air pollutant with an aerodynamic diameter of less than or equal to 1 micrometer." Personally, I don't mind whether we refer to radius or diameter, but if diameter is the most commonly used measure of aerosols then it makes sense to use it in the name. Best wishes, Alison ------ Alison Pamment Tel: +44 1235 778065 NCAS/British Atmospheric Data Centre Fax: +44 1235 446314 Rutherford Appleton Laboratory Email: [email protected] Chilton, Didcot, OX11 0QX, U.K. > -----Original Message----- > From: [email protected] [mailto:cf-metadata- > [email protected]] On Behalf Of Jonathan Gregory > Sent: 24 November 2010 12:30 > To: [email protected] > Subject: [CF-metadata] Correct name for aerosol size > distributionexpressedin numbers ? > > Dear Bruno > > > I love simple solutions. > As physicists, we always think simplicity and elegance imply > correctness! > > > As for the name of the coordinate variable, I would prefer diameter > > over size. > What about radius? There are existing names for radii of cloud > particles, > and these are analogous. > > > It is usual to call the size classe "bins", so we might come to > > particle_bins_mid_diameter. > But here we are discussing the name of a geophysical quantity, which > you happen > to be using as an independent coordinate variable. So I think it's > better to > call it the aerosol particle size/radius/diameter in the standard name. > The > fact that you are using it in bins is evident from the structure of the > data: > > dimensions: > aerosol_particle_bins=30; > two=2; > variables: > int size30(aerosol_particle_bins); > size30:long_name = "index values from 1 up to 30" ; > float mic_conctab_SPP200_sync_1(time, aerosol_particle_bins); > mic_conctab_SPP200_sync_1:units = "count/cm3" ; > mic_conctab_SPP200_sync_1:coordinates = "size30"; > mic_conctab_SPP200_sync_1:standard_name = > "number_concentration_of_ambient_aerosol_in_air" ; > float aerosol_particle_bins(aerosol_particle_bins); > aerosol_particle_bins:long_name="median diameter of size class"; > aerosol_particle_bins:units="SOMETHING"; > aerosol_particle_bins:standard_name="aerosol_particle_radius"; > aerosol_particle_bins:bounds="aerosol_particle_bin_bounds"; > float aerosol_particle_bin_bounds(aerosol_particle_bins,two); > > where the last variable specifies the range of size/diameter/radius for > each > bin. > > Best wishes > > Jonathan > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- Scanned by iCritical. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- This message (and any attachments) is for the recipient only NERC is subject to the Freedom of Information Act 2000 and the contents of this email and any reply you make may be disclosed by NERC unless it is exempt from release under the Act. Any material supplied to NERC may be stored in an electronic records management system. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
