Dear Heinke,
Please find below my comments on the content and mass fraction names,
including the response from Jonathan (email 18/11).
>
> atmosphere_number_content_of_X (new physical parameter)
> ******************************
> atmosphere_number_content_of_cloud_droplet
> atmosphere_number_content_of_ice_crystal
> atmosphere_number_content_of_aerosol_particle
>
> This was Jonathan's proposal.
> Christiane talked about _in_air. But I think that does not fit.
> For example _in_cloud is not in_air. Is that right, Christiane?
I agree with the suggestions above, but have one small remark: if you
say number content of something, you would assume to have more than one
of the something. This would require the use of the plural, e.g. of
cloud_dropletS. The unit of these quantities should be m-2, as usually
for content quantities, which are in CF equivalent to what we usually
call column content, or burden. If you were referring to the total
number in the atmosphere, you would have to change to atmosphere_number_of_X
Jonathan wrote:
> I think in_cloud is in_air, and I suggested to Christiane using cell_methods
> to indicate the cloud portion of the grid box, if that is required. I think
> "atmosphere" indicates that the content is a property of the whole atmosphere,
> whereas in_air means a local property of the medium. I know this distinction
> is not strictly necessary; we have always made it like that because it is
> more like the terms that people normally use e.g. density of air, but
> energy content of atmosphere.
in_cloud is not in_air, the contrary. I have understood that these two
would be used to describe for example the concentration of a species in
the gas phase (in_air) and in the cloudwater (in_cloud). And I do not
agree that the cell method should be used here, as the quantities are
very different (e.g. so2->h2so2 when dissolved in water.) this topic is
however discussed under a different thread (medium 'atmosphere').
>
> atmosphere_mass_content_of
> ***************************
> atmosphere_mass_content_of_black_carbon_dry_aerosol
> atmosphere_mass_content_of_dust_dry_aerosol
> atmosphere_mass_content_of_particulate_organic_matter_dry_aerosol
> atmosphere_mass_content_of_seasalt_dry_aerosol
> atmosphere_mass_content_of_water_in_ambient_aerosol
agreed
> atmosphere_mass_content_of_sulfate_dry_aerosol_expressed_as_sulfur
this should be
atmosphere_mass_content_of_sulfate_expressed_as_sulfur_dry_aerosol
> _in_air
> *******
> mass_fraction_of_formaldehyde_in_air
> mass_fraction_of_methyl_hydroperoxide_in_air
> mass_fraction_of_carbon_monoxide_in_air
> mass_fraction_of_hydrogen_peroxide_in_air
> mass_fraction_of_sulfuric_acid_in_air
> mass_fraction_of_nitric_acid_in_air
> mass_fraction_of_hydroperoxyl_in_air
> mass_fraction_of_dinitrogen_pentoxide_in_air
> mass_fraction_of_nitrogen_monoxide_in_air
> mass_fraction_of_nitrogen_dioxide_in_air
> mass_fraction_of_hydroxide_in_air
>
agreed
>
> _in_air_of_atmosphere_layer
> ***************************
> mass_fraction_of_ozone_in_air_of_atmosphere_layer
> mass_fraction_of_nitrogen_dioxide_in_air_of_atmosphere_layer
> mass_fraction_of_nitrogen_monoxide_in_air_of_atmosphere_layer
> mass_fraction_of_carbon_monoxide_in_air_of_atmosphere_layer
> mass_fraction_of_sulfur_dioxide_in_air_of_atmosphere_layer
>
> mass_concentration_of_pm2p5_in_air_of_atmosphere_layer
> mass_concentration_of_pm1_in_air_of_atmosphere_layer
> mass_concentration_of_sulfate_dry_aerosol_of_atmosphere_layer
> mass_concentration_of_dust_dry_aerosol_of_atmosphere_layer
> mass_concentration_of_seasalt_dry_aerosol_of_atmosphere_layer
> mass_concentration_of_black_carbon_dry_aerosol_of_atmosphere_layer
> mass_concentration_of_particulate_organic_matter_dry_aerosol_of_atmosphere_layer
>
I still do not understand the meaning of these quantities. What would
this mean?
And why not in_atmosphere_layer to be consistent with the other
quantities e.g. in_air?
I am not sure, if the cell method would be applicable here, if the name
is referring to the concentration in a certain layer.
> Why do you change the unit from kg to ug?
> We changed the units to micrograms/m3 because these fields are hourly
> averaged values of PM and PM
> components which will be tipically compared to measurements which are
> normally expressed in micrograms/m3.
> In the same dataset there is anyway the variable rhoam1, which is air
> denisty [kg/m3] which can be
> used to convert back aerosol concentration to mass mixing ration
> [kg/kg]. If micrograms is not accepted
> we can use kg/m3, but we should correct the variables in the data set.
> I would like to discuss micrograms. I was not able to find it in
> http://www.unidata.ucar.edu/software/udunits/udunits-1/udunits.txt ?
> Is it in udunits-2. Is a link available? If micrograms is part of it we
> can use kg for the standard name list. If not
> we should discuss this.
>
Adressed under the thread 'physically equivalent units'. However, I
still find this very confusing and would advocate for a clear
explanation, not only in section 3.3 of the documentation, but also as a
link of the standard-names table's header. It would also be good to
include a link to the list of allowed units to the CF standard-name web
page. This page with the list of names is probably most often used and
important information should be foudn there.
Best regards,
Christiane
Received on Sun Nov 23 2008 - 10:15:28 GMT
