Radiation & carbon fluxes: standard names

[martinjuckes]

(1) Outgoing radiation assuming no aerosol rlutaf, rlutcsaf, rsutaf: need a standard names. Current names do not include aerosol free component.

• rlut, rlutaf: toa_outgoing_longwave_flux
• rlutcs, rlutcsaf: toa_outgoing_longwave_flux_assuming_clear_sky
• rsut, rsutaf: toa_outgoing_shortwave_flux

(2) Use of "forcing" and "direct_radiative_effect" The direct radiative effect appears to be synonymous with instantaneous forcing. Compare "Instantaneous forcing is the radiative flux change caused instantaneously by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.)." with "X_direct_radiative_effect" refers to the instantaneous radiative impact of X on the Earth's energy balance, excluding secondary effects such as changes in cloud cover which may be caused by X."

There is a subtle difference from _due_to_: "The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase.": i.e. _due_to assumes that a set of terms can be added to get the total, whereas "forcing" and "direct effect" refer to perturbations.

(3) Top of Atmosphere "forcing" Following variables don't have appropriate dust/aerosol information:

• lwtoaasdust, lwtoacsaer: toa_instantaneous_longwave_forcing
• swtoaasdust, swtoacsdust: toa_instantaneous_shortwave_forcing

(4) Ground level. downward_heat_flux_at_ground_level_in_snow: What does this mean on an ice sheet? Can it be used on an ice sheet?

(5) Melt heat flux: interpretation. surface_snow_and_ice_melt_heat_flux: is this a flux into the atmosphere?

(6) Assuming enhanced CO2. Several terms are for an artificially enhanced co2, e.g. rld4co2: Downwelling Longwave Radiation 4XCO2 Atmosphere, downwelling_longwave_flux_in_air.

(7) Use of "net" in carbon flux terms Some carbon fluxes have a spurious "net" in the term: e.g. surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_13C_due_to_all_land_processes The net downward flux of carbon, or other constituents, is generally expresed simply as a "downward flux" as in surface_downward_mole_flux_of_carbon_dioxide.

[martinjuckes]

Initial CF list query launched, for 4,5,7.

[martinjuckes]

https://github.com/cf-convention/vocabularies/issues/9 for issue 4.