Dear Alison,
1. I've looked into the elemental/black carbon issue briefly, and I agree that this is confusing. We have 22 names referring to elemental_carbon_dry_aerosol_particles and two referring to black_carbon_ambient_aerosol. It appears that "elemental carbon" can be used as a synonym for "black carbon", but it also has a more precise meaning referring to graphite (or a "graphitic substance".. though I don't understand the distinction). There is a 2013 paper (
https://www.atmos-chem-phys.net/13/8365/2013/acp-13-8365-2013.pdf) which sets out precise definitions and appears to be well used. They defined "black carbon" as a black carbonaceous material, and elemental carbon as a substance made up of pure carbon. My impression is that it would be beneficial to adopt this approach and I think the only logical interpretation of the names we have is as referring to a black carbonaceous material, as aerosol particles of pure elemental carbon will be rare in the atmosphere.
However, it may make sense to deal with that in a separate discussion and try to get some relevant experts involved.
9. I'm still a little uncomfortable with the idea of "ambient_aerosol" referring to the suspension of particles in air. The phrase "ambient_aerosol_particles" is used when we are referring to properties of the particles rather than the suspension, and these can be measured either as they occur in the suspension (i.e. "ambient") or in a "dry" or "dried" form. many measurements refer to the "dry" form because it is a side effect of the measurement process. On the other hand, when we talk about the suspension, i.e. the aerosol, is it not the case that we always talk about the suspension which is in the atmosphere? I can't think of a meaningful interpretation of a "dry aerosol" (I think dust_dry_aerosol is only used in the form dust_dry_aerosol_particles).
Well done for spotting the link to log10_size_interval_based_number_size_distribution_of_cloud_condensation_nuclei_at_stp_in_air.
It occurred to me that the more usual form (by 2 to 1) of expressing such a quantity is histogram_of_X_over_Y. In this case "X" would be "number_size_distribution_of_cloud_condensation_nuclei_at_stp_in_air" and "Y" would be "log10_electrical_mobility_diameter_of_ambient_aerosol_particles". It is probably best to leave it as it is rather than try to force it into the standard form. I agree with your proposed changes to the definition.
For "relative_humidity_for_aerosol_particle_size_selection", I recognise that this would be the only use of "particle" in the singular. There is some precedent in the use of "stem", "root" and "leaf" as prefixes for terms such as "leaf_area_index" and "stem_mass_content_of_carbon" while using "stems", "roots" and "leaves" in terms such as "net_primary_productivity_of_biomass_expressed_as_carbon_accumulated_in_leaves". As you say, "relative_humidity_for_aerosol_particle_size_selection" is an unusual term, so I think that the current formulation helps to make this clearer.
regards,
Martin
________________________________
From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of Alison Pamment - UKRI STFC <alison.pamment at stfc.ac.uk>
Sent: 01 May 2019 18:41
To: CF-metadata (cf-metadata at cgd.ucar.edu)
Subject: Re: [CF-metadata] Some standard name updates to improve consistency.
Dear Martin,
1. I agree we should create the alias mass_concentration_of_biomass_burning_dry_aerosol_in_air -> mass_concentration_of_biomass_burning_dry_aerosol_particles_in_air. This will be added to the standard name table in the May update.
The black_carbon names should indeed refer to "particles" but there is another issue relating to these which I think is why I left them out when the other aerosol names were updated in 2014. It would be useful if we can resolve both issues before deciding how to update the names.
There used to be 20 black_carbon names in the standard name table, only two of which (atmosphere_optical_thickness_due_to_black_carbon_ambient_aerosol and atmosphere_absorption_optical_thickness_due_to_black_carbon_ambient_aerosol) are still current. The other 18 were turned into aliases of elemental_carbon names. The aliases were requested at the same time as many new standard names were being added for gases and aerosols in various IPCC categories emission categories (marine transport, aviation, savannah and grassland fires, etc.) It was argued that a definition based on the chemical properties was most appropriate for the emission names and the following sentences were added to the definitions: 'Chemically, "elemental carbon" is the carbonaceous fraction of particulate matter that is thermally stable in an inert atmosphere to high temperatures near 4000K and can only be gasified by oxidation starting at temperatures above 340 C. It is assumed to be inert and non-volatile under atmospheric conditions and i
nsoluble in any solvent (Ogren and Charlson, 1983).'
I was cautious about updating the optical thickness names, because these relate to the radiative properties rather than the chemical properties of carbon. My understanding is that the terms 'black carbon' and 'elemental carbon' are often used interchangeably, but they are measured differently and there can be large discrepancies between the concentrations resulting from the different measurement methods. I don't claim any great expertise in this area, but my feeling is that we should probably retain the use of black_carbon in the optical names (and add 'particles'). However, I'd like to know if others agree with this approach.
If we do retain black_carbon, we also need to clarify the definition. At the moment it says 'Black carbon is composed of elemental carbon. It is strongly light absorbing.' I think this only serves to create confusion about why some names say elemental carbon and others say black carbon.
I agree that we shouldn't change "angstrom_exponent_of_ambient_aerosol_in_air or the "assuming_no_aerosol" names.
9. particle(s)
To take your last point first, I agree that it is simpler to drop 'particle(s)' altogether from the radiative effect names. Those google search statistics are pretty convincing! I'd prefer that we keep 'ambient' to avoid any confusion, as we do also have standard names for dust_dry_aerosol. We have already agreed to drop the 'net_downward', so the aliases would then be as follows:
*surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect -> surface_longwave_dust_ambient_aerosol_direct_radiative_effect
*surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky -> surface_longwave_dust_ambient_aerosol_direct_radiative_effect_assuming_clear_sky
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect -> surface_shortwave_dust_ambient_aerosol_direct_radiative_effect
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky -> surface_shortwave_dust_ambient_aerosol_direct_radiative_effect_assuming_clear_sky
* toa_longwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky -> toa_longwave_dust_ambient_aerosol_direct_radiative_effect_assuming_clear_sky
If you are happy with these I think they can be accepted for inclusion in the standard name table.
Regarding the other four names:
. aerodynamic_particle_diameter -> aerodynamic_diameter_of_(aerosol)_particles
I agree that this name probably does refer to aerosols, as does the aerodynamic_resistance name. I also agree that some further research/consultation is needed before updating either name.
. ambient_aerosol_particle_diameter -> diameter_of_ambient_aerosol_particles
This one is now agreed - thank you. It will be added in the May standard name table update.
. electrical_mobility_particle_diameter -> electrical_mobility_diameter_of_ambient_aerosol_particles
It appears that electrical_mobility_particle_diameter is used as a coordinate variable for a data variable with the standard name log10_size_interval_based_number_size_distribution_of_cloud_condensation_nuclei_at_stp_in_air. Certainly I don't think these are 'dry' or 'dried' aerosol. The name relative_humidity_for_aerosol_particle_size_selection is also used as a coordinate variable for the same quantity. Presumably ambient conditions in this case refer to stp and the specified relative humidity, so it would be correct to say 'ambient' in the electrical mobility name.
This alias is accepted and will be added in the May update. The definition of log10_size_interval_based_number_size_distribution_of_cloud_condensation_nuclei_at_stp_in_air will also be updated to reflect the change.
. relative_humidity_for_aerosol_particle_size_selection -> relative_humidity_for_size_selection_of_aerosol_particles
You say:
> I would prefer to stay with the existing relative_humidity_for_aerosol_particle_size_selection because this term refers to the relative humidity of
> the air, not to a property of the aerosol particles. "aerosol_particle_size_selection" is a procedure in itself. But I'll defer to your judgement if you
> consider the new form better.
I'm happy to leave this one as it is. It will now be the only name to use 'particle' in the singular, but I don't think that is a problem as it is a unique quantity and doesn't really follow a pattern used in other names.
Best wishes,
Alison
-----------------------------------------------------------------------------------------------------------
Alison Pamment Tel: +44 1235 778065
NCAS/Centre for Environmental Data Analysis Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Oxford, Didcot, OX11 0QX, U.K.
From: Juckes, Martin (STFC,RAL,RALSP) <martin.juckes at stfc.ac.uk>
Sent: 26 April 2019 13:37
To: Pamment, Alison (STFC,RAL,RALSP) <alison.pamment at stfc.ac.uk>; CF-metadata (cf-metadata at cgd.ucar.edu) <cf-metadata at cgd.ucar.edu>
Subject: Re: Some standard name updates to improve consistency.
Dear Alison,
thank you for that very detailed analysis.
(1)
After reading your response I checked again and found an additional three aerosol names which omit "particles":
atmosphere_optical_thickness_due_to_black_carbon_ambient_aerosol
mass_concentration_of_biomass_burning_dry_aerosol_in_air
atmosphere_absorption_optical_thickness_due_to_black_carbon_ambient_aerosol
There is also the "angstrom_exponent_of_ambient_aerosol_in_air", but I believe it is appropriate to talk about the aerosol (i.e. gas + particles) in this term. There are also a number of terms with the construction "assuming_no_aerosol" and variants ..which can also be taken as referring to the gas + particles.
2-8: I agree with your interpretation and suggestions.
(9) cloud particle(s)
I hadn't spotted the other water droplet terms .. I agree with your suggestions.
You pointed out 4 additional terms to consider:
. aerodynamic_diameter_of_particles : I believe this should be ambient aerosol particles (it may be worth waiting for further consultation). It would be unique in several ways if it really applies to generic particles: there are no other generic particle terms, and all other cloud particle terms which refer to size use the radius rather than diameter.
. diameter_of_ambient_aerosol_particles : OK
. electrical_mobility_diameter_of_aerosol_particles : perhaps should be ".._ambient_aerosol_particles". In existing terms, aerosol_particles is preceded by "dry", "ambient" or "dried", except when the term refers to a number concentration (which is understandable).
. relative_humidity_for_size_selection_of_aerosol_particles : I would prefer to stay with the existing relative_humidity_for_aerosol_particle_size_selection because this term refers to the relative humidity of the air, not to a property of the aerosol particles. "aerosol_particle_size_selection" is a procedure in itself. But I'll defer to your judgement if you consider the new form better.
I also suggested dropping the "s" from "particles" in the following 5 terms, because "particle" is more natural as an adjective:
* surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect
* surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
* toa_longwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
You did not accept this, because of a preference for maintaining a standardised usage. I can understand that argument, but it made me wonder whether the explicit mention of particles is needed here. Could the terms be shortened to the following?
* surface_net_downward_longwave_dust_aerosol_direct_radiative_effect
* surface_net_downward_longwave_dust_aerosol_direct_radiative_effect_assuming_clear_sky
* surface_net_downward_shortwave_dust_aerosol_direct_radiative_effect
* surface_net_downward_shortwave_dust_aerosol_direct_radiative_effect_assuming_clear_sky
* toa_longwave_dust_aerosol_direct_radiative_effect_assuming_clear_sky
The direct radiative effect is the modification of the radiative forcing which is directly associated with the presence of aerosol. The presence of aerosol is equivalent to the presence of aerosol particles .. spelling out particles does not add anything here (as with the terms I mentioned above which use the construction "assuming_no_aerosol").
I ran a google survey: 24,900 results for "aerosol direct radiative effect" and 3 for "aerosol particles direct radiative effect" (all in the CMIP6 data request -- titles taken directly from the standard names) and none for "aerosol particle direct radiative effect". It appears to be common practice to consider this as a property of the aerosol rather than of the particles within the aerosol.
regards,
Martin
________________________________________
From: CF-metadata <mailto:cf-metadata-bounces at cgd.ucar.edu> on behalf of Alison Pamment - UKRI STFC <mailto:alison.pamment at stfc.ac.uk>
Sent: 25 April 2019 19:17
To: CF-metadata (mailto:cf-metadata at cgd.ucar.edu)
Subject: Re: [CF-metadata] Some standard name updates to improve consistency.
Dear Martin,
Thank you for this set of proposals. I am always in favour of improving consistency in standard names - it makes them easier both for users to find and for us to maintain.
1. You are right that the aerosol names should say "particles".
There was a lot of discussion of aerosol names in 2014 and Markus Fiebig pointed out that the text book definition of "aerosol" means both aerosol particles and the gas that carries them. Standard names are usually concerned with the particulate component so it was agreed that both new and existing names should say "aerosol_particles" rather than simply "aerosol". Aliases were made for about 200 existing names, but it looks like a few were missed.
The following 3 aliases are accepted and will be added in the May update of the standard name table.
tendency_of_atmosphere_mass_content_of_sulfate_dry_aerosol_expressed_as_sulfur_due_to_wet_deposition -> tendency_of_atmosphere_mass_content_of_sulfate_dry_aerosol_particles_expressed_as_sulfur_due_to_wet_deposition
mass_fraction_of_mercury_dry_aerosol_in_air -> mass_fraction_of_mercury_dry_aerosol_particles_in_air
tendency_of_atmosphere_mass_content_of_mercury_dry_aerosol_due_to_emission -> tendency_of_atmosphere_mass_content_of_mercury_dry_aerosol_particles_due_to_emission
2. Primary production vs. primary productivity
Roy's interpretation is correct: in standard names "productivity" is defined as "production per unit area". The land names say "productivity" because they are all quantifying the production of biomass in the horizontal area of a grid cell, whereas the ocean names are referring to production in a volume element. The ocean name definitions all say 'In the oceans, carbon production per unit volume is often found at a number of depths at a given horizontal location. That quantity can then be integrated to calculate production per unit area at the location. Standard names for production per unit area use the term "productivity."
I think our existing names are using the appropriate term and units consistently throughout.
3. aerodynamic_resistance
This name again dates back to our aerosol discussions of 2014. It was originally proposed by Brigitte Koffi-Lefeivre for the HTAP2 project. Many names were discussed over a protracted period, but the aerodynamic_resistance discussion starts here:
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2014/017813.html (it appears as item 7 in some of the longer emails). At the time, I suggested names such as aerodynamic_drag_on_turbulent_deposition_of_aerosol_particles or aerodynamic_resistance_to_turbulent_deposition but it was argued (
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2014/017841.html) that simply "aerodynamic_resistance" was the term most generally used.
I agree that the name seems more specialized than the generic definition in the AMS glossary and your proposal of aerodynamic_resistance_of_planetary_boundary_layer is consistent with the standard name definition which emerged from the original discussion. My gut feeling is that it would be useful to do a bit more research into this one - I will get hold of a copy of the paper referenced in the definition. If any aerosol experts can help, that would also be much appreciated!
4. Litter and soil
Agreed - and thanks for spotting this! We should definitely have a standard order for listing the terms.
The following alias is accepted and will be added in the May update of the standard name table.
carbon_mass_flux_into_soil_and_litter_due_to_anthropogenic_land_use_or_land_cover_change -> carbon_mass_flux_into_litter_and_soil_due_to_anthropogenic_land_use_or_land_cover_change
5. Products
Agreed - and thanks again.
The duplicate terms shouldn't simply disappear, so I will make aliases as follows:
1 and 2. product_of_specific_humidity_and_omega -> product_of_specific_humidity_and_lagrangian_tendency_of_air_pressure AND product_of_omega_and_specific_humidity -> product_of_specific_humidity_and_lagrangian_tendency_of_air_pressure
3. product_of_eastward_wind_and_omega -> product_of_eastward_wind_and_lagrangian_tendency_of_air_pressure
4. product_of_northward_wind_and_omega -> product_of_northward_wind_and_lagrangian_tendency_of_air_pressure
5 and 6. product_of_air_temperature_and_omega -> product_of_air_temperature_and_lagrangian_tendency_of_air_pressure AND product_of_omega_and_air_temperature -> product_of_air_temperature_and_lagrangian_tendency_of_air_pressure
7. product_of_geopotential_height_and_omega -> product_of_geopotential_height_and_lagrangian_tendency_of_air_pressure
These changes are accepted and will be added in the May update of the standard name table.
6. Use of "net_downward" in aerosol indirect radiative effect terms.
I agree that radiative forcing and radiative effect names should be treated consistently, and that aerosol radiative effect should be treated consistently with cloud radiative effect. I agree also with your statement that "the sign convention is assumed to be that positive forcing/radiative effect is equivalent to a downward radiative flux" . This is certainly consistent with general usage in the literature.
As you point out, only the four ambient aerosol radiative effect names mention the sign convention. The other existing names make no mention of it and neither do their definitions. This strikes me as an omission. I'm fine with taking net_downward out of the aerosol names, but for absolute clarity I think we should add something to the definitions of all the radiative forcing and effect names. I suggest we add 'A positive radiative forcing or radiative effect is equivalent to a downward radiative flux and contributes to a warming of the earth system.' What do you think?
7. Use of "downwelling" in attenuation coefficients
I agree with Karl's comment about this one, and with Martin's response. In the absence of more detailed information about how this name is being used, I think we are agreed not to change it.
8. Specification of air vs. ocean
I agree that backscattering_ratio should become backscattering_ratio_in_air.
This alias is accepted and will be added in the May update of the standard name table.
We also have the name histogram_of_backscattering_ratio_over_height_above_reference_ellipsoid. Again it is clearly an "in_air" quantity, so perhaps for consistency we should also make the following alias:
histogram_of_backscattering_ratio_over_height_above_reference_ellipsoid -> histogram_of_backscattering_ratio_in_air_over_height_above_reference_ellipsoid.
On the other hand, the fact that it is above_reference_ellipsoid already implies that this is an air quantity rather than a sea water one. What do you think?
9. cloud liquid water particle vs. particles and aerosol particle vs. particles.
We try to write standard names that are grammatically correct in English, so we need to retain the flexibility to use singular and plural versions of nouns where strictly necessary, but I agree that we should be consistent in deciding which to use in a particular circumstance. In the case of particle/particles I think we can standardize on the plural, at least for existing names.
In the cloud names, certainly "particles" should be used in all the number concentrations. Up to now, we've used the singular in effective radius names although I'm not sure why! These apply to a size distribution of many particles, so I think it actually makes more sense to use the plural.
The following aliases are accepted and will be included in the May update of the standard name table.
effective_radius_of_cloud_liquid_water_particle -> effective_radius_of_cloud_liquid_water_particles
effective_radius_of_cloud_liquid_water_particle_at_liquid_water_cloud_top -> effective_radius_of_cloud_liquid_water_particles_at_liquid_water_cloud_top
effective_radius_of_convective_cloud_liquid_water_particle -> effective_radius_of_convective_cloud_liquid_water_particles
effective_radius_of_convective_cloud_liquid_water_particle_at_convective_liquid_water_cloud_top -> effective_radius_of_convective_cloud_liquid_water_particles_at_convective_liquid_water_cloud_top
effective_radius_of_stratiform_cloud_liquid_water_particle -> effective_radius_of_stratiform_cloud_liquid_water_particles
effective_radius_of_stratiform_cloud_liquid_water_particle_at_stratiform_liquid_water_cloud_top -> effective_radius_of_stratiform_cloud_liquid_water_particles_at_stratiform_liquid_water_cloud_top
number_concentration_of_convective_cloud_liquid_water_particle_at_convective_liquid_water_cloud_top -> number_concentration_of_convective_cloud_liquid_water_particles_at_convective_liquid_water_cloud_top
number_concentration_of_stratiform_cloud_liquid_water_particle_at_stratiform_liquid_water_cloud_top -> number_concentration_of_stratiform_cloud_liquid_water_particles_at_stratiform_liquid_water_cloud_top
There are a number of other cloud particle effective radius names, which should be changed at the same time:
effective_radius_of_convective_cloud_ice_particle -> effective_radius_of_convective_cloud_ice_particles
effective_radius_of_convective_cloud_rain_particle -> effective_radius_of_convective_cloud_rain_particles
effective_radius_of_convective_cloud_snow_particle -> effective_radius_of_convective_cloud_snow_particles
effective_radius_of_stratiform_cloud_graupel_particle -> effective_radius_of_stratiform_cloud_graupel_particles
effective_radius_of_stratiform_cloud_ice_particle -> effective_radius_of_stratiform_cloud_ice_particles
effective_radius_of_stratiform_cloud_rain_particle -> effective_radius_of_stratiform_cloud_rain_particles
effective_radius_of_stratiform_cloud_snow_particle -> effective_radius_of_stratiform_cloud_snow_particles
One could argue about the reference to ice, rain and snow "particles" which is probably not the most obvious terminology, but I suspect we chose to treat the names this way for consistency with the liquid water names. Unless anyone objects I will also add these aliases in the May update.
Interestingly, there is one cloud effective radius name that already says "particles", effective_radius_of_cloud_condensed_water_particles_at_cloud_top, so that will no longer be the odd one out!
As you say, we already use "particles" in the vast majority of aerosol names. I can find only four that use the singular:
aerodynamic_particle_diameter
ambient_aerosol_particle_diameter
electrical_mobility_particle_diameter
relative_humidity_for_aerosol_particle_size_selection
It is natural to use "particle" if the names are written as above, but I think it can also be argued that the diameter names should be constructed following a similar pattern to the effective radius names, i.e. diameter_of_particles rather than "particle_diameter". If we take this approach, the names would become:
aerodynamic_diameter_of_particles
diameter_of_ambient_aerosol_particles
electrical_mobility_diameter_of_aerosol_particles
relative_humidity_for_size_selection_of_aerosol_particles.
(This also makes clear that the electrical mobility name refers to aerosol particles).
If we make these changes, then I think we shouldn't alter the radiative effect names to say "particle".
I'm putting this forward as a possible alternative, but would also be fine with your approach to the aerosol names. I'd be interested to know what you think.
Best wishes,
Alison
-----------------------------------------------------------------------------------------------------------
Alison Pamment Tel: +44 1235 778065
NCAS/Centre for Environmental Data Analysis Email: mailto:alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Oxford, Didcot, OX11 0QX, U.K.
-----Original Message-----
From: CF-metadata <mailto:cf-metadata-bounces at cgd.ucar.edu> On Behalf Of Martin Juckes - UKRI STFC
Sent: 24 April 2019 13:42
To: CF-metadata (mailto:cf-metadata at cgd.ucar.edu) <mailto:cf-metadata at cgd.ucar.edu>
Subject: [CF-metadata] Some standard name updates to improve consistency.
Hello All,
The standard name table has a high degree of internal consistency across thousands of variables, but there are a few anomalies. I'd like to suggest a few changes below. These are minor issues,
1. Change "aerosol" to "aerosol_particles".
The overwhelming majority of aerosol terms refer to "aerosol_particles". There are two anomalies:
* tendency_of_atmosphere_mass_content_of_sulfate_dry_aerosol_expressed_as_sulfur_due_to_wet_deposition
* mercury_dry_aerosol
Should these be changed to "aerosol_particles"?
2. Primary production vs. primary productivity
There are 6 terms for net_primary_productivity_of_biomass_expressed_as_carbon..., and one for net_primary_production_of_biomass_expressed_as_carbon_per_unit_volume_in_sea_water. In addition, there are 6 terms using primary_production in the construction "due_to_net_primary_production".
Production and productivity are often used interchangeably, but some people draw a distinction. E.g. using "productivity" for a rate and "production" for an amount. The usage in the standard names could be interpreted as using "primary_production" in oceanic contexts and "primary_productivity" in land contexts, but net_primary_productivity_of_biomass_expressed_as_carbon is not explicitly defined as applying only to land. Should it be?
Can we either change these terms to consistently use "productivity" (or "production"), or, if that is not appropriate, provide some explanation of the use of two different terms for the same quantity?
3. aerodynamic_resistance
The definition of this term implies that it refers to the aerodynamic resistance of the boundary layer, rather than the more general concept of aerodynamic resistance as defined, for example, by AMS:
http://glossary.ametsoc.org/wiki/Aerodynamic_resistance .
If the narrower term is intended, perhaps the name should be changed to aerodynamic_resistance_of_planetary_boundary_layer, so that it is clear that this is a boundary layer property.
4. Litter and Soil
To mean the combination of litter and soil, we have one use of "soil_and_litter", one of "litter_and_soil". There are multiple uses of "vegetation_litter_and_soil", so we can take this as the preferred order.
Can we change carbon_mass_flux_into_soil_and_litter_due_to_anthropogenic_land_use_or_land_cover_change to carbon_mass_flux_into_litter_and_soil_due_to_anthropogenic_land_use_or_land_cover_change for consistency?
5. Products
There are 7 terms which use the old name "omega", which is now aliassed to "lagrangian_tendency_of_air_pressure". Two of these are redundant, because they are of the form "product_of_B_and_A" for terms already covered by "product_of_A_and_B".
1. product_of_specific_humidity_and_omega
2. product_of_omega_and_specific_humidity [redundant] 3. product_of_eastward_wind_and_omega
4. product_of_northward_wind_and_omega
5. product_of_air_temperature_and_omega
6. product_of_omega_and_air_temperature [redundant] 7. product_of_geopotential_height_and_omega
Can we remove the two redundant terms, and replace "omega" with "lagrangian_tendency_of_air_pressure"?
6. Use of "net_downward" in aerosol indirect radiative effect terms
There are 5 aerosol direct radiative effect terms. These are analogous to cloud radiative effect terms (3) and radiative forcing terms (12). For all the radiative forcing terms and the cloud radiative effect terms, the sign convention is assumed to be that positive forcing/radiative effect is equivalent to a downward radiative flux. This is also true for the TOA direct radiative effect term. For 4 terms describing the aerosol direct radiative effect at the surface, there is an additional inclusion of "net_downward" in the term. This looks redundant to me, and I think it should be removed for consistency with other radiative effect and forcing terms.
* surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect
* surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
7. Use of "downwelling" in attenuation coefficients
Attenuation of radiation is a measure of the reduction of strength of a radiation wave passing through a medium. It does not depend on the direction of travel of the radiation. One term includes redundant directional information:
* volume_attenuation_coefficient_of_downwelling_radiative_flux_in_sea_water
This term is intended have some relevance to downwelling fluxes in sea water. Possibly it is intended to be evaluated at frequencies representative of the downwelling radiative flux.
Can we remove "downwelling" from this term and/or clarify any assumptions about spectral range?
8. Specification of air vs. ocean
Scattering terms all specify whether they are in air or sea water, except one: backscattering_ratio. The definition makes it clear that this term is intended to refer to atmospheric backscattering. For consistency with other terms, it should be:
* backscattering_ratio_in_air
9. cloud liquid water particle vs. particles and aerosol particle vs. particles.
There are 2 terms referring to "cloud_liquid_water_particles" and 8 using the singular "cloud_liquid_water_particle". For aerosols, we have 236 referring to aerosol_particles and 2 referring to aerosol_particle.
One possible distinction is between adjectival use, as in "ambient_aerosol_particle_diameter", versus the more common substantive use, as in "asymmetry_factor_of_ambient_aerosol_particles". If this approach is adopted, there are 5 aerosol particle direct radiative effect terms which should be changed to the singular adjectival form:
* surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect
* surface_net_downward_longwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect
* surface_net_downward_shortwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
* toa_longwave_dust_ambient_aerosol_particles_direct_radiative_effect_assuming_clear_sky
The same argument would imply that all cloud liquid water particle terms should use the plural. There are two number concentration terms which already use the plural:
number_concentration_of_cloud_liquid_water_particles_in_air
number_concentration_of_cloud_liquid_water_particles_in_air_at_liquid_water_cloud_top
8 terms would need to be modified, 2 for number concentration and 6 for effective radius:
* effective_radius_of_cloud_liquid_water_particle
* effective_radius_of_cloud_liquid_water_particle_at_liquid_water_cloud_top
* effective_radius_of_convective_cloud_liquid_water_particle
* effective_radius_of_convective_cloud_liquid_water_particle_at_convective_liquid_water_cloud_top
* effective_radius_of_stratiform_cloud_liquid_water_particle
* effective_radius_of_stratiform_cloud_liquid_water_particle_at_stratiform_liquid_water_cloud_top
* number_concentration_of_convective_cloud_liquid_water_particle_at_convective_liquid_water_cloud_top
* number_concentration_of_stratiform_cloud_liquid_water_particle_at_stratiform_liquid_water_cloud_top
regards,
Martin
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Received on Thu May 02 2019 - 06:41:00 BST
