[CF-metadata] Clarifying standard names for 'mass_concentration_of_*_dry_aerosol_particles'

From: Jonathan Gregory <j.m.gregory>
Date: Wed, 21 Mar 2018 18:37:07 +0000

Dear Daniel

Thanks for your hard work on this and your careful description of what you
propose. I'm not an expert on this myself, so I don't have an insider's insight
and familiarity with these quantities. To me as a non-expert, what you propose
generally makes sense, seems logical and in many cases is appealing because
it is shorter.

> In the case of "atmosphere_mass_content_of_..." I added "_in_air" in
> the end, which was not there before.

Actually I don't think we should do this, because atmosphere_ and _in_air are
alternatives in standard names, similarly ocean_ and _in_sea_water. The former
denotes a property of the entire medium, the latter of the local fluid.

> (a) ..._dry_particulate_particulate_organic_matter...
> Thus, we had "particulate" twice. We could also call it
> (a) ..._dry_particulate_organic_matter...
>
> which would be less confusing to read. But it would break the rule.

I'm in favour of removing the duplication; particulate_particulate would look
like a mistake and cause confusion.

> the renaming convention in the beginning yields a name structure like
> "SIZE-CLASS_WHAT" with "SIZE-CLASS" in "particulate", "pm10",
> "pm2p5", ... and with "WHAT" in "nitrate", "ammonium", ... . In this
> situation, we don't have a "WHAT" because we mean "all compounds" or
> "total". Should we leave it like that or should we insert something
> for "WHAT"?

Do you mean e.g. mass_concentration_of_ambient_pm10_in_air? I think that
is fine. I understand pm10 to mean pm10 particles of any species.

> that "dry pm10" + "water in pm10" = "ambient pm10". This would be
> a consistent formulation.
> But it is not intuitive ... .

Do you mean e.g.
mass_fraction_of_ambient_pm10_in_air
mass_fraction_of_dry_pm10_in_air
mass_fraction_of_water_in_pm10_in_air
I'm not sure that I understand, but I don't think ambient = dry + water
in this case, because the last one appears to mean the mass fraction of
the ambient aerosol which is water. I have a vague recollection of discussing
before what this was intended to mean. Do you want to describe the mass
fraction of the air which is the water of the ambient aerosol?

> THE END
Good night and sleep well.

Best wishes

Jonathan
Received on Wed Mar 21 2018 - 12:37:07 GMT