[CF-metadata] New standard names for norm. direct radiation and atm. mass content of rain and snow + comments on existing descriptions

From: Jonathan Gregory <j.m.gregory>
Date: Thu, 5 Sep 2019 17:01:51 +0000

Dear Beate and Ronny

Thanks for your proposals.

> 1.
> Basing on surface_direct_downwelling_shortwave_flux_in_air we want to
> apply for the new standard name
> surface_normalized_direct_downwelling_shortwave_flux_in_air for use in
> renewable energy tasks.
> It is the surface_direct_downwelling_shortwave_flux_in_air on a plane,
> oriented perpendicular to the incoming beam.

I think there is a problem with "downwelling", which like "downward" refers in
standard names to a vertical component. Would it be reasonable to call this
quantity
  surface_direct_solar_irradiance_in_air
The existing definition of solar_irradiance says that it applies only outside
the atmosphere, but the concept is the same, meaning the radiative flux along
the direction of the beam. Alternatively, perhaps we could replace
"downwelling" with "along_beam" or something like that. I feel that
"normalized" isn't such a good word, since it could mean many possible things.

> 2.
> Analog to atmosphere_mass_content_of_cloud_liquid_water we want to apply
> for two new standard names: atmosphere_mass_content_of_rainwater and
> atmosphere_mass_content_of_snow.

I think atmosphere_mass_content_of_snow is OK, but I would propose
atmosphere_mass_content_of_rain for the other, since we already have e.g.
mass_fraction_of_rain_in_air.

> The standard name air_potential_temperature is misleading because the
> description refers to air and sea water.
> We recommend replacing the standard name by potential_temperature.

I disagree with that. When a similar property is measured in a different
medium, we have a distinct standard name for it, e.g. air_temperature vs
sea_ice_temperature, mole_concentration_of_dimethyl_sulfide_in_air vs
mole_concentration_of_dimethyl_sulfide_in_sea_water.

Best wishes

Jonathan
Received on Thu Sep 05 2019 - 11:01:51 BST