Dear Daniel, Thanks for (re)proposing your names.
First a couple of general points that are relevant to many of your sea salt names. In your original posting in March (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2017/059293.html) you pointed out that there are two existing names, mass_fraction_of_pm10_sea_salt_dry_aerosol_particles_in_air and mass_fraction_of_pm2p5_sea_salt_dry_aerosol_particles_in_air, which refer to 'sea_salt' while all other salt aerosol names say 'seasalt', i.e. no underscore. Your suggestion was to make these two names consistent with the rest by changing them to also say 'seasalt'. I completely agree that the names should be consistent. However, I think we should change all the names to say 'sea_salt'. This is a little more work because it requires making aliases for sixteen names instead of two but a quick internet search for the terms 'sea salt' and 'seasalt' leads me to think the first one is more widely used in a scientific context. IPCC reports seem to use two separate words, e.g, https://www.ipcc.ch/pdf/assessment.../WG1AR5_Index_FINAL.pdf and https://www.ipcc.ch/pdf/assessment.. ./ipcc_wg3_ar5_annex-i.pdf. The AMS glossary http://glossary.ametsoc.org uses variously 'sea salt' and 'sea-salt' but not 'seasalt'. Also, in CF standard names we refer to 'sea_water', not 'seawater', so in terms of achieving overall consistency I think 'sea_salt' is the better option and I propose we standardize on that. Unless there are any objections to this change I will create the sixteen aliases at the next update of the standard name table, planned for 26th June. In commenting on your individual proposals I have also taken the liberty of changing 'seasalt' to 'sea_salt' throughout - I hope that's okay. You also made the point that where we refer to aerosols of a particular size range, such as pm1, pm2p5 and pm10, the definitions currently describe them as 'air pollutants' but this is not always true, particularly in the case of sea salt which is a naturally occurring aerosol. You suggested that we change this to say, for example, ' "Pm2p5 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 2.5 micrometers.' I agree that this is an improved definition that can be applied to existing names as well as your proposals - thank you. I will modify the existing definitions in the June update and I agree we should use this wording for your proposals. Please see below for my comments on the individual proposals. 1. mass_concentration_of_pm10_sea_salt_dry_aerosol_particles_in_air (kg m-3) 'Mass concentration means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" is an air pollutant with an aerodynamic diameter of less than or equal to 10 micrometers.' The name, units and definition all look fine. If we can agree on 'sea_salt' this name can be accepted for publication in the standard name table. 2. mass_concentration_of_pm2p5_sea_salt_dry_aerosol_particles_in_air (kg m-3) 'Mass concentration means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm2p5 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 2.5 micrometers.' The name, units and definition all look fine. If we can agree on 'sea_salt' this name can be accepted for publication in the standard name table. 3. mass_concentration_of_sea_salt_cation_dry_aerosol_particles_in_air (kg m-3) 'Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "seasalt_cation" summarizes cationic sea salt componds. Depending on the model or the measurement, these are mainly sodium (Na+) but also potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Thank you for your detailed explanation of why it is important to have standard names for sea_salt_cation mass as well as simply sea_salt. In standard names we use the phrase 'expressed_as' when talking about the mass of a chemical constituent of a species, for example, atmosphere_mass_content_of_nox_expressed_as_nitrogen means the mass of the nitrogen contained in the nox. There are very many similar examples (over 100) currently in the standard name table. I think it would be consistent to take the same approach for your cation names. Your third proposal would then become: mass_concentration_of_sea_salt_dry_aerosol_particles_expressed_as_cations_in_air (kg m-3) Based on your definition and our usual wording for 'expressed_as' names, the definition for this name would then be: ''Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. The phrase "sea_salt_cation" is the term used in standard names to descri be collectively the group of cationic species that occur in sea salt. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Sea salt cations are mainly sodium (Na+), but also include potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Okay? We need to take the same approach with all the cation names, and indeed the chloride names, so if we can agree this one I think we can also go ahead and agree proposals 4 - 9. 4. mass_fraction_of_pm10_sea_salt_cation_dry_aerosol_particles_in_air (1) 'Mass fraction is used in the construction "mass_fraction_of_X_in_Y", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" is an air pollutant with an aerodynamic diameter of less than or equal to 10 micrometers. "seasalt_cation" summarizes cationic sea salt componds. Depending on the model or the measurement, these are mainly sodium (Na+) but also potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribu te. Following on from my comments in (3), I suggest that we write this name as follows: mass_fraction_of_pm10_sea_salt_dry_aerosol_particles_expressed_as_cations_in_air (1) 'Mass fraction is used in the construction "mass_fraction_of_X_in_Y", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The phrase "sea_salt_cation" is the term used in standard names to describe collectively the group of cationic species that occur in sea salt. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Sea salt cations are mainly sodium (Na+), but also include potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Okay? 5. mass_fraction_of_pm2p5_sea_salt_cation_dry_aerosol_particles_in_air (1) 'Mass fraction is used in the construction "mass_fraction_of_X_in_Y", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm2p5 aerosol" is an air pollutant with an aerodynamic diameter of less than or equal to 2.5 micrometers. "seasalt_cation" summarizes cationic sea salt componds. Depending on the model or the measurement, these are mainly sodium (Na+) but also potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attri bute.' Following on from my comments in (3), I suggest that we write this name as follows: mass_fraction_of_pm2p5_sea_salt_dry_aerosol_particles_expressed_as_cations_in_air (1) 'Mass fraction is used in the construction "mass_fraction_of_X_in_Y", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm2p5 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 2.5 micrometers. The phrase "sea_salt_cation" is the term used in standard names to describe collectively the group of cationic species that occur in sea salt. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Sea salt cations are mainly sodium (Na+), but also include potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Okay? 6. atmosphere_mass_content_of_sea_salt_cation_dry_aerosol_particles '"Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. The mass is the total mass of the particles. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particle" means aerosol particles without any water uptake. "seasalt_cations" summarizes cationic sea salt componds. Depending on the model or the measurement, these are mainly sodium (Na+) but also potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions re presented, for example, by using a comment attribute.' The units of the name should be kg m-2 as with all mass_content names. Following on from my comments in (3), I suggest that we write this name as follows: atmosphere_mass_content_of_sea_salt_dry_aerosol_particles_expressed_as_cations (kg m-2) '"Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. The mass is the total mass of the particles. The phrase "sea_salt_c ation" is the term used in standard names to describe collectively the group of cationic species that occur in sea salt. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Sea salt cations are mainly sodium (Na+), but also include potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Okay? 7. mass_fraction_of_sea_salt_cation_dry_aerosol_particles_in_air (1) 'Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "seasalt_cation" summarizes cationic sea salt componds. Depending on the model or the measurement, these are mainly sodium (Na+) but also potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Following on from my comments in (3), I suggest that we write this name as follows: mass_fraction_of_sea_salt_dry_aerosol_particles_expressed_as_cations_in_air (1) 'Mass fraction is used in the construction "mass_fraction_of_X_in_Y", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. The phrase "sea_salt_cation" is the term used in standard names to describe collectively the group of cationic species that occur in sea salt. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Sea salt cations are mainly sodium (Na+), but also include potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Okay? 8. mass_concentration_of_pm10_sea_salt_cation_dry_aerosol_particles_in_air (kg m-3) 'Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" denotes atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. "seasalt_cation" summarizes cationic sea salt componds. Depending on the model or the measurement, these are mainly sodium (Na+) but also potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Following on from my comments in (3), I suggest that we write this name as follows: mass_concentration_of_pm10_sea_salt_dry_aerosol_particles_expressed_as_cations_in_air (kg m-3) ' Mass concentration means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodyna mic diameter of less than or equal to 10 micrometers. The phrase "sea_salt_cation" is the term used in standard names to describe collectively the group of cationic species that occur in sea salt. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Sea salt cations are mainly sodium (Na+), but also include potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Okay? 9. mass_concentration_of_pm2p5_sea_salt_cation_dry_aerosol_particles_in_air (kg m-3) 'Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm2p5 aerosol" denotes atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 2.5 micrometers. "seasalt_cation" summarizes cationic sea salt componds. Depending on the model or the measurement, these are mainly sodium (Na+) but also potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Following on from my comments in (3), I suggest that we write this name as follows: mass_concentration_of_pm2p5_sea_salt_dry_aerosol_particles_expressed_as_cations_in_air (kg m-3) 'Mass concentration means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm2p5 aerosol" means atmospheric particulate compounds with an aerodyna mic diameter of less than or equal to 2.5 micrometers. The phrase "sea_salt_cation" is the term used in standard names to describe collectively the group of cationic species that occur in sea salt. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Sea salt cations are mainly sodium (Na+), but also include potassium (K+), magnesium (Mg2+), calcium (Ca2+) and rarer cations. Where possible, the data variable should be accompanied by a complete description of the ions represented, for example, by using a comment attribute.' Okay? 10. mass_concentration_of_chloride_dry_aerosol_particles_in_air (kg m-3) Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chloride is Cl-.' Following on from my comments in (3), I think we should use the 'expressed_as' syntax to indicate that the name refers to the mass of the chloride in the aerosol in the same way as I have suggested for the cation names. You say: > Reasons for (10) to (12): Currently, standard names only exist for some > [cation]-chloride ion-compounds but not for chloride individually. When > considering aged sea salt it might be interesting to have the chloride > concentrations available. The names you are suggesting seem to refer to all chloride aerosol in air, regardless of whether it originated as sea salt. Is that the correct interpretation? If, on the other hand, you are specifically interested in chloride aerosol that originated as sea salt we would need to somehow include that in the names. For the name as proposed, I suggest rewriting it as: mass_concentration_of_dry_aerosol_particles_expressed_as_chloride_in_air (kg m-3) 'Mass concentration means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. The chemical formula for chloride is Cl-.' Okay? 11. mass_fraction_of_chloride_dry_aerosol_particles_in_air (1) 'Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chloride is Cl-.' Following on from my comments in (10), I suggest that we write this name as follows: mass_fraction_of_dry_aerosol_particles_expressed_as_chloride_in_air (1) 'Mass fraction is used in the construction "mass_fraction_of_X_in_Y", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. The chemical formula for chloride is Cl-.' 12. mole_concentration_of_chloride_in_air (mol m-3) 'Mole concentration means number of moles per unit volume, also called "molarity", and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chloride is Cl-.' I assume the intention of this name is to refer to all chloride compounds in air, whether aerosol or gaseous. Is that correct? Does chloride occur on its own as a radical or ion in the atmosphere? If so, is it also included in this quantity? 13. tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_due_to_deposition (kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. "tendency_of_X" means derivative of X with respect to time. 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. "Deposition" is the sum of wet and dry deposition. Usually, particle bound and gaseous nitrogen compounds, such as nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)), are included. The list of in dividual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' Just to clarify - is this the mass of only the nitrogen contained in the various species, or is it the total mass of the species containing the nitrogen? The name and definition as they stand are ambiguous because they could mean either. If it is only the mass of the nitrogen I would once again suggest using 'expressed_as' syntax to make this really clear, so I'd write the name as something like: tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_compounds_expressed_as_nitrogen_due_to_deposition On the other hand, if it is the total mass of the species I would say: tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_compounds_due_to_deposition Obviously the precise wording of the definition would depend on which syntax we choose, but in either case I would include the following sentence : ' "Oxidized nitrogen compounds" means all chemical species containing nitrogen atoms with an oxidation state greater than zero' before listing the most common species. We recently added three nitrogen_deposition names that you proposed: tendency_of_atmosphere_mass_content_of_nitrogen_due_to_deposition tendency_of_atmosphere_mass_content_of_nitrogen_due_to_dry_deposition tendency_of_atmosphere_mass_content_of_nitrogen_due_to_wet_deposition in which the definitions say ' "Nitrogen" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrage (NO3-), peroxynitric acid (HNO4), ammoina (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' I realise now that these names (and definitions) suffer from the same ambiguity as the current proposal. Neither the names nor the definitions really make clear whether we are talking about the mass of the nitrogen in the compoun ds or the total mass of the compounds. Whatever the outcome of the current discussion, we should update the three existing names to be consistent. 14. tendency_of_atmosphere_mass_content_of_reduced_nitrogen_due_to_deposition (kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. "tendency_of_X" means derivative of X with respect to time. 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. "Deposition" is the sum of wet and dry deposition. "reduced_nitrogen" summarizes all chemical species containing reduced nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, primarily ammonium (NH4+) and ammoina (NH3), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the spec ies represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (13). Again, we could write this name as: tendency_of_atmosphere_mass_content_of_reduced_nitrogen_compounds_expressed_as_nitrogen_due_to_deposition or tendency_of_atmosphere_mass_content_of_reduced_nitrogen_compounds_due_to_deposition depending on which mass is intended. In either case I would include the following sentence in the definition: ' "Reduced nitrogen compounds" means all chemical species containing nitrogen atoms with an oxidation state less than zero.' 15. tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_due_to_dry_deposition (kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. "tendency_of_X" means derivative of X with respect to time. 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. "dry_deposition" is the sum of turbulent deposition and gravitational settling. "oxidized_nitrogen" summarizes all chemical species containing oxidized nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic n itrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (13). Again, we could write this name as: tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_compounds_expressed_as_nitrogen_due_to_dry_deposition or tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_compounds_due_to_dry_deposition depending on which mass is intended. 16. tendency_of_atmosphere_mass_content_of_reduced_nitrogen_due_to_dry_deposition (kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. "tendency_of_X" means derivative of X with respect to time. 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. "dry_deposition" is the sum of turbulent deposition and gravitational settling. "reduced_nitrogen" summarizes all chemical species containing reduced nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, primarily ammonium (NH4+) and ammoina (NH3), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a com plete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (13). Again, we could write this name as: tendency_of_atmosphere_mass_content_of_reduced_nitrogen_compounds_expressed_as_nitrogen_due_to_dry_deposition or tendency_of_atmosphere_mass_content_of_reduced_nitrogen_compounds_due_to_dry_deposition depending on which mass is intended. 17. tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_due_to_wet_deposition (kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. "tendency_of_X" means derivative of X with respect to time. 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. "wet deposition" means deposition by precipitation. "oxidized_nitrogen" summarizes all chemical species containing oxidized nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxy acetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (13). Again, we could write this name as: tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_compounds_expressed_as_nitrogen_due_to_wet_deposition or tendency_of_atmosphere_mass_content_of_oxidized_nitrogen_compounds_due_to_wet_deposition depending on which mass is intended. 18. tendency_of_atmosphere_mass_content_of_reduced_nitrogen_due_to_wet_deposition (kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. "tendency_of_X" means derivative of X with respect to time. The specification of a physical process by the phrase due_to_process means that the quantity named is asingle term in a sum of terms which together compose the general quantity named by omitting the phrase. "wet_deposition" means deposition by precipitation. "oxidized_nitrogen" summarizes all chemical species containing oxidized nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)), are included. The list of individual species that are included in this quan tity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (13). Again, we could write this name as: tendency_of_atmosphere_mass_content_of_reduced_nitrogen_compounds_expressed_as_nitrogen_due_to_wet_deposition or tendency_of_atmosphere_mass_content_of_reduced_nitrogen_compounds_due_to_wet_deposition depending on which mass is intended. 19. tendency_of_ocean_mole_content_of_reduced_nitrogen_due_to_deposition (mol m-2 s-1) ' "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. "tendency_of_X" means derivative of X with respect to time. 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. Deposition of nitrogen into the ocean is the sum of dry and wet deposition of the considered species onto the ocean surface from the atmosphere. "reduced_nitrogen" summarizes all chemical species containing reduced nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, primarily ammonium (NH4+) and ammoina (NH3), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' As with the atmosphere mass content names, my question is: does the name mean moles of nitrogen contained in the compounds, or moles of the compounds? (I appreciate that they might be the same number if each molecule of the compound contains one nitrogen atom, but that won't necessarily always be the case. For example, some of the oxidised nitrogen species contain more than one atom of N). We have many existing names that use 'expressed_as' with mole_fraction and mole_concentration names, so I think it can perfectly well be extended for use with mole_content names. Similar to the atmosphere names I would suggest either: tendency_of_ocean_mole_content_of_reduced_nitrogen_compounds_expressed_as_nitrogen_due_to_deposition or tendency_of_ocean_mole_content_of_reduced_nitrogen_compounds_due_to_deposition depending on which species we are counting. 20. tendency_of_ocean_mole_content_of_oxidized_nitrogen_due_to_deposition (mol m-2 s-1) ' "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. "tendency_of_X" means derivative of X with respect to time. 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. Deposition of nitrogen into the ocean is the sum of dry and wet deposition of the considered species onto the ocean surface from the atmosphere. "oxidized_nitrogen" summarizes all chemical species containing oxidized nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as P AN, (CH3COO2NO2)), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (19). Again, we could write this name as: tendency_of_ocean_mole_content_of_oxidized_nitrogen_compounds_expressed_as_nitrogen_due_to_deposition or tendency_of_ocean_mole_content_of_oxidized_nitrogen_compounds_due_to_deposition depending on which species we are counting. 21. tendency_of_ocean_mole_content_of_reduced_nitrogen_due_to_dry_deposition (mol m-2 s-1) ' "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. "tendency_of_X" means derivative of X with respect to time. The specification of a physical process by the phrase due_to_process means that the quantity named is asingle term in a sum of terms which together compose the general quantity named by omitting the phrase. "dry_deposition" is the sum of turbulent deposition and gravitational settling of the considered species onto the ocean surface from the atmosphere. "reduced_nitrogen" summarizes all chemical species containing reduced nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, primarily ammonium (NH4+) and ammoina (NH3), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (19). Again, we could write this name as: tendency_of_ocean_mole_content_of_reduced_nitrogen_compounds_expressed_as_nitrogen_due_to_dry_deposition or tendency_of_ocean_mole_content_of_reduced_nitrogen_compounds_due_to_dry_deposition depending on which species we are counting. 22. tendency_of_ocean_mole_content_of_oxidized_nitrogen_due_to_dry_deposition (mol m-2 s-1) ' "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. "tendency_of_X" means derivative of X with respect to time. The specification of a physical process by the phrase due_to_process means that the quantity named is asingle term in a sum of terms which together compose the general quantity named by omitting the phrase. "dry_deposition" is the sum of turbulent deposition and gravitational settling of the considered species onto the ocean surface from the atmosphere. "oxidized_nitrogen" summarizes all chemical species containing oxidized nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to a s PAN, (CH3COO2NO2)), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (19). Again, we could write this name as: tendency_of_ocean_mole_content_of_oxidized_nitrogen_compounds_expressed_as_nitrogen_due_to_dry_deposition or tendency_of_ocean_mole_content_of_oxidized_nitrogen_compounds_due_to_dry_deposition depending on which species we are counting. 23. tendency_of_ocean_mole_content_of_reduced_nitrogen_due_to_wet_deposition (mol m-2 s-1) ' "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. "tendency_of_X" means derivative of X with respect to time. The specification of a physical process by the phrase due_to_process means that the quantity named is asingle term in a sum of terms which together compose the general quantity named by omitting the phrase. "wet_deposition" means deposition by precipitation. "reduced_nitrogen" summarizes all chemical species containing reduced nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, primarily ammonium (NH4+) and ammoina (NH3), are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (19). Again, we could write this name as: tendency_of_ocean_mole_content_of_reduced_nitrogen_compounds_expressed_as_nitrogen_due_to_wet_deposition or tendency_of_ocean_mole_content_of_reduced_nitrogen_compounds_due_to_wet_deposition depending on which species we are counting. 24. tendency_of_ocean_mole_content_of_oxidized_nitrogen_due_to_wet_deposition (mol m-2 s-1) ' "Content" indicates a quantity per unit area. The "ocean content" of a quantity refers to the vertical integral from the surface to the bottom of the ocean. "tendency_of_X" means derivative of X with respect to time. The specification of a physical process by the phrase due_to_process means that the quantity named is asingle term in a sum of terms which together compose the general quantity named by omitting the phrase. "wet_deposition" means deposition by precipitation. "oxidized_nitrogen" summarizes all chemical species containing oxidized nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)), are included. The list of individual species that are included in this quan tity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' My comments about this name are very similar to proposal (19). Again, we could write this name as: tendency_of_ocean_mole_content_of_oxidized_nitrogen_compounds_expressed_as_nitrogen_due_to_wet_deposition or tendency_of_ocean_mole_content_of_oxidized_nitrogen_compounds_due_to_wet_deposition depending on which species we are counting. Best wishes, Alison ----- Alison Pamment Tel: +44 1235 778065 Centre for Environmental Data Analysis Email: [email protected] STFC Rutherford Appleton Laboratory R25, 2.22 Harwell Campus, Didcot, OX11 0QX, U.K. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
