Dear Martin If the new terms are calculated by extra radiation calls, could they be phrased with "assuming", like the clear-sky ones?
Cheers Jonathan ----- Forwarded message from Martin Juckes - UKRI STFC <[email protected]> ----- > Date: Mon, 21 May 2018 11:18:05 +0000 > From: Martin Juckes - UKRI STFC <[email protected]> > To: Karl Taylor <[email protected]>, Jonathan Gregory > <[email protected]>, "[email protected]" > <[email protected]> > CC: "[email protected]" <[email protected]> > Subject: Re: [CF-metadata] PMIP: standard names for the CMIP6 data request: > tws, lighning flashes, wetland emissions, etc > > Dear Karl, > > > I wasn't aware of the rule (2) you refer to .. there may be a number of other > terms that need to be reconsidered if we intend to impose this. > > > There is a disagreement between Jonathan and yourself about he nature of the > clear sky radiative fluxes: Jonathan has expressed the opinion that the clear > sky fluxes are, like the proposed "due_to_ambient_aerosol_.." terms, > calculated by running the radiative transfer module in a diagnostic model. > This view is supported by the Ghan 2013 paper > (https://www.atmos-chem-phys.net/13/9971/2013/acp-13-9971-2013.pdf ) which > describes the relationship between the clear sky fluxes and a new set of > "clean-clear-sky" diagnostics. New standard names for these "clean-clear-sky" > fluxes have been in the CF Editor for some time (e.g. > downwelling_shortwave_flux_in_air_assuming_clean_clear_sky -- > http://cfeditor.ceda.ac.uk/proposal/1488 ). > > > If Jonathan is correct, then the proposed new terms are consistent with the > approach used for clear sky fluxes, > > > regards, > > Martin > > > > > ________________________________ > From: Karl Taylor <[email protected]> > Sent: 18 May 2018 17:18 > To: Juckes, Martin (STFC,RAL,RALSP) > Subject: Re: [CF-metadata] PMIP: standard names for the CMIP6 data request: > tws, lighning flashes, wetland emissions, etc > > Hi Martin and Jonathan, > > That is my understanding too, it is a extra calculation done at run time > purely for diagnostic purposes; it may not be required in performing a > simulation. So this puts it in a category between: > > 1) A simple change in a variable from one simulation of a coupled model to > another (e.g., the difference in temperature between a "historical" run and a > control run). We generally do not assign a new standard_name for such > differences. > > and > > 2) Prognostic and diagnostic variables calculated during run time and > needed in order to run the model or to compare the model with observations. > We generally do assign specific standard_names to each of these quantities. > > The proposal is to relax rule 2) to include additional diagnostic quantities. > If we want to consider a difference between two calculations performed by > a model (in this case a radiation code), does it warrant a new standard_name? > > In the CMIP6 archive we must surely assign it a different variable name (for > uniqueness), and I would think we would give it a nice descriptive long name > indicating the information about what it is (e.g., "due to"), but there is no > fundamental reason to assign it a unique standard_name, and I wonder if we > should draw the line as described in 2) above. > > There is precedence for *not* assigning a new standard name for a diagnostic > quantity not needed to run the model. In the CMIP6 request, we ask for > > variable name standard_name > long_name > ------------------- ------------------------- > -------------------------- > clt cloud_area_fraction Total Cloud > Cover Percentage > cltcalipso cloud_area_fraction CALIPSO Total > Cloud Cover Percentage > > best regards, > Karl > > > On 5/18/18 7:38 AM, Martin Juckes - UKRI STFC wrote: > > Dear Jonathan, > > > I believe that they are repeat calculations in the model, as you suggest. > They have been requested for PMIP by Yves Balkanski, so Yves may be able to > comment more on this point (the question refers to swsrfasdust and related > variables), > > > regards, > > Martin > > > ________________________________ > From: CF-metadata > <[email protected]><mailto:[email protected]> > on behalf of Jonathan Gregory > <[email protected]><mailto:[email protected]> > Sent: 18 May 2018 13:31 > To: [email protected]<mailto:[email protected]> > Subject: [CF-metadata] PMIP: standard names for the CMIP6 data request: tws, > lighning flashes, wetland emissions, etc > > Dear Martin and Karl > > > > In CMIP6, we want, for each experiment, surface net downward longwave flux > (rls) and the two aerosol sub-components, surface net downward longwave flux > due to the ambient aerosol direct effect and surface net downward longwave > flux due to dust in clear sky. I feel that this falls comfortably into the > existing usage for the "due_to" construction. > > > I agree that if these fluxes mean the part of the net downward flux LW flux > that is emitted by the ambient aerosol or by the dust you could say it was > "due to". How are they calculated? Are there repeated radiation calculations > in the model, like for the clear-sky fluxes? > > Best wishes > > Jonathan > > > > ________________________________ > From: Karl Taylor <[email protected]><mailto:[email protected]> > Sent: 17 May 2018 15:58 > To: Juckes, Martin (STFC,RAL,RALSP); Pamment, Alison (STFC,RAL,RALSP); > [email protected]<mailto:[email protected]>; > [email protected]<mailto:[email protected]> > Cc: Jean-Yves Peterschmitt > Subject: Re: [CF-metadata] PMIP: standard names for the CMIP6 data request: > tws, lighning flashes, wetland emissions, etc > > Dear Alison, Martin, and all > > On the last point commented on by Martin: > > "4.3-4.7 Perturbed radiation calculations" > > I wonder if it is wise to assign a new name every time experiment > conditions change. I would limit names to quantities that are > calculated independently by a physics model or that can be measured > more-or-less directly using instruments. A quantity that is obtained by > subtraction or by redoing a calculation with altered conditions could be > described as being "due to X" where X is whatever condition was changed, > but I'm afraid these names will multiply endlessly. > > I think it is fine that we include "clear-sky fluxes of radiation" > because they are both measured and must be calculated as part of a > normal radiation calculation. > > I would be unhappy with "temperature_change_due_to_greenhouse_gases" and > 'temperature_change_due_to_aerosols" and > "temperature_change_due_to_solar_variability", etc. Each of these can be > obtained by carefully designed experiments and they do contribute > individually to the total temperature change found in a historical run, > but it in all cases I think the standard_name (air_temperature, or > surface_air_temperature) should identify the quantity. > > Similarly, I would leave out "due to ..." in the definitions proposed. > [I realize this is a judgement call about where to draw the line.] > > best regards, > Karl > > > > On 5/17/18 2:54 AM, Martin Juckes - UKRI STFC wrote: > > > Dear Alison, > > > Thanks .. some answers and comments below. I've copied Yves Balkanski in to > comment on the dust deposition parameters (4.1-4.2) [Yves, this discussion is > trying clarify the definition of parameters depdust anf sedustCI, and to > define appropriate standard names for these variables]. > > > 1.1 I’m waiting for some feedback from LS3MIP to clarify intention regarding > land ice; > > > 1.2 Thanks, frequency_of_lightning_flashes_per_unit_area (m-2 s-1) and > propsoed definition are good; > > > 2.1 > surface_net_upward_mass_flux_of_methane_due_to_emission_from_wetland_biological_processes > (kg m-2 s-1) and proposed definition are good; > > > 3 Stratospheric depths: thanks. > > > 4.1-4.2 Dust deposition > > I’ve checked the initial request from PMIP and it now looks clear to me that > the dry aerosol mass flux is wanted for these variables. I’ve copied Yves > Balkanski in to this discussion, as he specified these parameters for PMIP > and may wish to comment. For mass budgets of aerosol amounts it makes more > sense to deal with dry aerosol fluxes, rather than ambient mass which depends > on local conditions. The definition of “dry aerosol” is, I believe, intended > to refer to aerosol propoerties applied to aerosol particles which have been > dehydrated, either physically or conceptually, in order to make the required > measurement, not to aerosols which are naturally free of moisture in the > atmosphere. I accept your other suggestions, hence > > 4.1: > tendency_of_atmosphere_mass_content_of_dust_dry_aerosol_particles_due_to_deposition > (kg m-2 s-1) [depdust] > > 4.2: > tendency_of_atmosphere_mass_content_of_insoluble_dust_dry_aerosol_particles_due_to_deposition > (kg m-2 s-1) [sedustCI] > > 4.3-4.7 Perturbed radiation calculations > > As I understand it, terms or the form radiative flux due to X refer to the > result of a perturbed radiation calculation, with other factors, such as > atmospheric and surface temperature and reflectivity held constant. Hence, > the upwelling longwave flux will be unchanged, as you suggest, but not the > upwelling shortwave flux: the upwelling flux will change when the downwelling > flux is modified by changing the radiation calculation. There is a slight > problem with the approach here, in that the "due_to_X" construction is > intended to be used to distinguish contributions from different processes > "X", but "ambient_aerosol" is not strictly a process: the process is ambient > aerosol contributions to the radiative transfer calculations. In proposing > these names I stayed with the compact form, which has been used previously, > rather than trying to expand to indicate the process itself explicitly in the > standard name. The questions raised here make me wonder whether we should be > more expansive. In the scientific literature the terms "direct effect" and > "indirect effect" are now well established, with "direct effect" referring to > the impact of aerosol on the radiative transfer calculation through > scattering and absorbtion. The indirect effect refers to other changes caused > by aerosol through processes such as cloud seeding. Hence, I suggest sticking > with the "net_downward" formulation (it is required for shortwave, and using > the same approach for longwave looks neater to me), and appending > "direct_effect": > 4.3 > surface_net_downward_longwave_flux_in_air_due_to_ambient_aerosol_direct_effect > (W m-2) > 4.4 > surface_net_downward_longwave_flux_in_air_due_to_dust_ambient_aerosol_direct_effect_assuming_clear_sky > (W m-2) > 4.6 > surface_net_downward_shortwave_flux_in_air_due_to_ambient_aerosol_direct_effect > (W m-2) > 4.7 > surface_net_downward_shortwave_flux_in_air_due_to_dust_ambient_aerosol_direct_effect_assuming_clear_sky > (W m-2) > Regards, > > Martin > > ________________________________ > From: Pamment, Alison (STFC,RAL,RALSP) > Sent: 14 May 2018 16:21 > To: Pamment, Alison (STFC,RAL,RALSP); Juckes, Martin (STFC,RAL,RALSP); > [email protected]<mailto:[email protected]> > Cc: Jean-Yves Peterschmitt > Subject: RE: PMIP: standard names for the CMIP6 data request: tws, lighning > flashes, wetland emissions, etc > > Dear Martin and Jonathan, > > While going through the VolMIP names I realised I had made a mistake in some > of my suggestions for this group of PMIP names. I suggested 4.3, 4.4, 4.6 and > 4.7 should not be surface_net_downward_fluxes but simply surface_downward > ones. If we agree on this approach they should actually say downwelling, not > downward, so they would be > 4.3 surface_downwelling_longwave_flux_in_air_due_to_ambient_aerosol (W m-2) > 4.4 > surface_downwelling_longwave_flux_in_air_due_to_dust_ambient_aerosol_assuming_clear_sky > (W m-2) > 4.6 surface_downwelling_shortwave_flux_in_air_due_to_ambient_aerosol (W m-2) > 4.7 > surface_downwelling_shortwave_flux_in_air_due_to_dust_ambient_aerosol_assuming_clear_sky > (W m-2) > and the definitions would need to be adjusted accordingly. > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/Centre for Environmental Data Archival Email: > [email protected]<mailto:[email protected]> > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > -----Original Message----- > From: CF-metadata > <[email protected]><mailto:[email protected]> > On Behalf Of Alison Pamment - UKRI STFC > Sent: 14 May 2018 08:47 > To: Juckes, Martin (STFC,RAL,RALSP) > <[email protected]><mailto:[email protected]>; > [email protected]<mailto:[email protected]> > Cc: Jean-Yves Peterschmitt > <[email protected]><mailto:[email protected]> > Subject: Re: [CF-metadata] PMIP: standard names for the CMIP6 data request: > tws, lighning flashes, wetland emissions, etc > > Dear Martin and Jonathan, > > Thank you for proposing this set of names and for the comments received so > far. The proposals look good - I have accepted a couple that seem straight > forward and I think we can agree the rest quite quickly. Please have a look > through my comments on the individual names and let me know what you think. > > > > (1.1) CMIP6 short name mrtws. Terrestrial Water Storage > land_based_water_amount (kg m-2) 'The quantity with standard name > land_based_water_amount, often known as "Terrestrial Water Storage", > includes surface water (water in rivers, wetlands, lakes, snow, vegetation > and reservoirs) and subsurface water (soil moisture, groundwater).' > > > Jonathan has suggested land_water_amount for consistency with land_ice names. > I agree this is a good idea, especially if the term "land water" is already > in general use. Regarding the definition, it seems we should also include at > least some elements of land_ice within land_water, but there is a question as > to whether this would also include floating ice shelves and/or ice sheets. > > This name is still under discussion. > > > > (1.2) CMIP6 short name Flashrate. Lightning flash rate cf. > number_of_icebergs_per_unit_area; number_of_observations There are no > standard names for frequency of events, but we can adapt the "number_of_" > construction. > > Proposed name: > frequency_of_lightning_flash_per_unit_area (km-2 s-1) 'A lightning > flash is a compound event, usually consists of several discharges.' > > > Jonathan has suggested, and Martin has agreed to, > frequency_of_lightning_flashes_per_unit_area. I agree that name looks fine. I > think the canonical units should probably by m-2 s-1, and I've added a > sentence about frequency to the definition: > > frequency_of_lightning_flashes_per_unit_area (m-2 s-1) 'A lightning flash is > a compound event, usually consisting of several discharges. Frequency is the > number of oscillations of a wave, or the number of occurrences of an event, > per unit time.' > > Is this okay? This name is still under discussion. > > 2. Wetland parameters > =================== > > > > (2.1) wetlandCH4 Grid averaged methane emissions from wetlands > surface_upward_mass_flux_of_methane_due_to_emission_from_wetland_biolo > gical_production is recently approved. In other existing names we have > "biological_processes" to cover production and consumption. The CF > area type table now includes the area type "wetland". This term is > intended to be the sum of the production term described by > surface_upward_mass_flux_of_methane_due_to_emission_from_wetland_biological_production > and a consumption term > (surface_downward_mass_flux_of_methane_due_to_emission_from_wetland_biological_consumption). > Proposed name: > surface_upward_mass_flux_of_methane_due_to_emission_from_wetland_biolo > gical_processes (kg m-2 s-1) 'The emission from biological processes is the > net emission resulting from combined production and consumption.' > > > Usually for a net flux, we say that in the name, so this one should be: > surface_net_upward_mass_flux_of_methane_due_to_emission_from_wetland_biological_processes > (kg m-2 s-1) ' "Upward" indicates a vector component which is positive when > directed upward (negative downward). A net upward flux is the difference > between the flux from below (upward) and the flux from above (downward). In > accordance with common usage in geophysical disciplines, "flux" implies per > unit area, called "flux density" in physics. The chemical formula for methane > is CH4. Methane is a member of the group of hydrocarbons known as alkanes. > There are standard names for the alkane group as well as for some of the > individual species. 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. "Emission" means emission from a primary source located anywhere > within the atmosphere, including at the lower boundary (i.e. the surface of > the earth). "Emission" is a process entirely distinct from "re-emission" > which is used in some standard names. W etlands are areas where water covers > the soil, or is present either at or near the surface of the soil all year or > for varying periods of time during the year, including during the growing > season. The precise conditions under which wetlands produce and consume > methane can vary between models. The quantity with standard name > surface_net_upward_mass_flux_of_methane_due_to_emission_from_wetland_biological_processes > is the difference between the upward and downward surface fluxes of methane > which have standard names > surface_upward_mass_flux_of_methane_due_to_emission_from_wetland_biological_production > and > surface_downward_mass_flux_of_methane_due_to_wetland_biological_consumption, > respectively.' > > I have adapted the sentence we usually use to describe net radiation to > describe fluxes instead. We have existing standard names for both the > production and consumption terms so I have added cross-references to those. > The rest of the definition was constructed from existing text. > > Is this okay? This name is still under discussion. > > 3. Stratospheric optical depths > > > > Following existing name stratosphere_mole_content_of_nitrogen_dioxide > and > atmosphere_absorption_optical_thickness_due_to_dust_ambient_aerosol_pa > rticles and > atmosphere_optical_thickness_due_to_sulfate_ambient_aerosol_particles > > (3.1) CMIP6 short name: od550aerso Stratospheric Optical depth at 550 > nm (all aerosols) 2D-field (here we limit the computation of OD to the > stratosphere only) > > Proposed name: > stratosphere_optical_thickness_due_to_ambient_aerosol_particles (1) > > > 'The optical thickness is the integral along the path of radiation of a > volume scattering/absorption/attenuation coefficient. The radiative flux is > reduced by a factor exp(-"optical_thickness") on traversing the path. A > coordinate variable of radiation_wavelength or radiation_frequency can be > specified to indicate that the optical thickness applies at specific > wavelengths or frequencies. The stratosphere optical thickness applies to > radiation passing through the atmosphere layer between the tropopause and > stratopause. 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. > "Aerosol" means the system of suspended liquid or solid particles in air > (except cloud droplets) and their carrier gas, the air itself. > "Ambient_aerosol" means that the aerosol is measured or modelled at the > ambient state of pressure, temperature and relative hum idity that exists in > its immediate environment. "Ambient aerosol particles" are aerosol particles > that have taken up ambient water through hygroscopic growth. The extent of > hygroscopic growth depends on the relative humidity and the composition of > the particles. To specify the relative humidity and temperature at which the > quantity described by the standard name applies, provide scalar coordinate > variables with standard names of "relative_humidity" and "air_temperature".' > > The name and units look fine and I have constructed the definition from > existing text. This name is accepted for publication in the standard name > table and will be added in the May update. > > > > (3.2) CMIP6 short name od550so4so. Stratospheric Optical depth at 550 > nm (sulphate only) 2D-field (here we limit the computation of OD to > the stratosphere only) > > Proposed name: > stratosphere_optical_thickness_due_to_sulfate_ambient_aerosol_particle > s (1) > > > 'The optical thickness is the integral along the path of radiation of a > volume scattering/absorption/attenuation coefficient. The radiative flux is > reduced by a factor exp(-"optical_thickness") on traversing the path. A > coordinate variable of radiation_wavelength or radiation_frequency can be > specified to indicate that the optical thickness applies at specific > wavelengths or frequencies. The stratosphere optical thickness applies to > radiation passing through the atmosphere layer between the tropopause and > stratopause. 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. > "Aerosol" means the system of suspended liquid or solid particles in air > (except cloud droplets) and their carrier gas, the air itself. > "Ambient_aerosol" means that the aerosol is measured or modelled at the > ambient state of pressure, temperature and relative hum idity that exists in > its immediate environment. "Ambient aerosol particles" are aerosol particles > that have taken up ambient water through hygroscopic growth. The extent of > hygroscopic growth depends on the relative humidity and the composition of > the particles. To specify the relative humidity and temperature at which the > quantity described by the standard name applies, provide scalar coordinate > variables with standard names of "relative_humidity" and "air_temperature".' > > The name and units look fine and I have constructed the definition from > existing text. This name is accepted for publication in the standard name > table and will be added in the May update. > > 4. Dust > > > > Based on > atmosphere_absorption_optical_thickness_due_to_dust_ambient_aerosol_par > ticles > > (4.1) CMIP6 short name depdust. Total Deposition Rate of Dust > > Proposed name: > surface_downward_mass_flux_of_dust_ambient_aerosol_particles (kg m-2 > s-1) It might make more sense to ask for mass flux of dry aerosols here. > > > We have the following existing names: > tendency_of_atmosphere_mass_content_of_dust_dry_aerosol_particles_due_to_dry_deposition > tendency_of_atmosphere_mass_content_of_dust_dry_aerosol_particles_due_to_gravitational_settling > tendency_of_atmosphere_mass_content_of_dust_dry_aerosol_particles_due_to_turbulent_deposition > tendency_of_atmosphere_mass_content_of_dust_dry_aerosol_particles_due_to_wet_deposition. > Dry_deposition is defined as the sum of gravitational_settling and > turbulent_deposition. The sum of dry_deposition and wet_deposition is just > 'deposition' which we use in some existing nitrogen_compound names. The > quantity you are proposing looks to me like it should be the sum of all > deposition terms and for consistency with the existing names it should be > expressed as a tendency_of_atmosphere_mass_content. Putting all this > together, I think the name should be written as: > tendency_of_atmosphere_mass_content_of_dust_ambient_aerosol_particles_due_to_deposition > (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect > to time. "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. "Ambient_aerosol" means that the aerosol is > measured or modelled at the ambient state of pressure, temperature and > relative humidity that exists in its immediate environment. "Ambient aerosol > particles" are aerosol particles that have taken up ambient water through > hygroscopic growth. The extent of hygroscopic growth depends on the relative > humidity and the composition of the particles. To specify the relative > humidity and temperature at which the quan tity described by the standard > name applies, provide scalar coordinate variables with standard names of > "relative_humidity" and "air_temperature". 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.' > > The definition was constructed from existing text. > > I note your comment about whether this should be a 'dry' or 'ambient' aerosol > name - please see my comment on proposal 4.2 which leads me to think this one > should indeed be 'ambient'. > > > > (4.2) CMIP6 short name sedustCI. Sedimentation Flux of dust mode > coarse insoluble The adjective "coarse" has been left out of the standard > name because it appears to be implicit in the term "dust". > > Proposed name: > surface_downward_mass_flux_of_insoluble_dust_ambient_aerosol_particles > (kg m-2 s-1) > > > The fact that this one says 'insoluble' makes me think this is what we would > usually call 'dry_aerosol', i.e. it hasn't (or can't) take up water from the > atmosphere. That would then suggest that proposal 4.1 is referring to ambient > aerosol because it doesn't say 'insoluble'. Do others agree with that line of > reasoning? We have existing names for 'coarse_mode' aerosol particles, > defined as having a diameter greater than 1 micrometre, and 'nucleation_mode' > aerosol particles, defined as having a diameter of less than 3 micrometres. I > am not expert enough to advise on whether 'dust' would always be considered > 'coarse' so I don't know whether it's necessary to include that in the name. > Again we should write the name as a tendency_of_atmosphere_mass_content for > consistency with existing names. This would lead us to: > > tendency_of_atmosphere_mass_content_of_dust_dry_aerosol_particles_due_to_deposition > (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect > to time. "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. > "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 > 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.' > > The definition was constructed from existing text. > > Writing the name this way means we then have a pair of names, 4.1 and 4.2, > for deposition of ambient and dry dust aerosol particles, respectively. Are > these okay? > > > > (4.3) CMIP6 short name lwsrfasdust. All-sky Surface Longwave radiative > flux due to Dust > > Proposed name: > surface_net_downward_longwave_flux_due_to_dust_ambient_aerosol (W m-2) > > > If this is a surface flux due to dust, does it make sense to describe it as > net flux? A net downward flux would be the difference between the downwelling > flux and the upwelling flux at the surface. I assume that the models don't > calculate the upwelling flux due solely to dust lying on the ground(!) so I > think this name should be described simply as a surface_downward flux: > surface_downward_longwave_flux_due_to_ambient_aerosol (W m-2) 'The surface > called "surface" means the lower boundary of the atmosphere. "Downward" > indicates a vector component which is positive when directed downward > (negative upward). The term "longwave" means longwave radiation. In > accordance with common usage in geophysical disciplines, "flux" implies per > unit area, called "flux density" in physics. 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. "Aerosol" means the system of suspended liquid > or solid particles in air (except cloud droplets) and their carrier gas, the > air itself. "Ambient_aerosol" means that the aerosol is measured or modelled > at the ambient state of pressure, temperature and relative humidity that > exists in its immediate environment. "Ambient aerosol particles" are aerosol > particles that have taken up ambient water through hygroscopic growth. The > extent of hygrosc opic growth depends on the relative humidity and the > composition of the particles. To specify the relative humidity and > temperature at which the quantity described by the standard name applies, > provide scalar coordinate variables with standard names of > "relative_humidity" and "air_temperature".' > > The definition was constructed from existing text. > > Okay? > > > > (4.4) CMIP6 short name lwsrfcsdust. Clear-sky Surface Longwave > radiative flux due to Dust > > Proposed name: > surface_net_downward_longwave_flux_due_to_dust_ambient_aerosol_assumin > g_clear_sky (W m-2) > > > As for proposal 4.3, I think this one should be a downward, rather than net > downward, flux: > surface_downward_longwave_flux_due_to_dust_ambient_aerosol_assuming_clear_sky > (W m-2) 'The surface called "surface" means the lower boundary of the > atmosphere. "Downward" indicates a vector component which is positive when > directed downward (negative upward). The term "longwave" means longwave > radiation. In accordance with common usage in geophysical disciplines, "flux" > implies per unit area, called "flux density" in physics. 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. "Aerosol" means the system of > suspended liquid or solid particles in air (except cloud droplets) and their > carrier gas, the air itself."Ambient_aerosol" means that the aerosol is > measured or modelled at the ambient state of pressure, temperature and > relative humidity that exists in its immediate environment. "Ambient aerosol > particles" are aerosol particles that have taken up ambient water through > hygroscopic growth. The extent of hygrosco pic growth depends on the > relative humidity and the composition of the particles. To specify the > relative humidity and temperature at which the quantity described by the > standard name applies, provide scalar coordinate variables with standard > names of "relative_humidity" and "air_temperature". A phrase > "assuming_condition" indicates that the named quantity is the value which > would obtain if all aspects of the system were unaltered except for the > assumption of the circumstances specified by the condition.' > > Okay? > > > > (4.5) CMIP6 short name lwtoacsdust. Clear Sky Longwave Radiative > Forcing due to Dust at TOA > > Proposed name: > toa_net_downward_longwave_flux_due_to_dust_ambient_aerosol_assuming_cl > ear_sky (W m-2) > > > The CMIP6 description says this one is a radiative forcing, rather than a > flux. Looking at existing names, I see that we have a three that include the > term 'cloud_radiative_effect', e.g. toa_longwave_cloud_radiative_effect, > defined as longwave cloud radiative forcing. I suggest we follow the pattern > of the existing names and write this one as: > toa_longwave_dust_ambient_aerosol_particles_radiative_effect (W m-2) ' "toa" > means top of atmosphere. The term "longwave" means longwave radiation. Dust > radiative effect is also commonly known as "dust radiative forcing". It is > the difference in radiative flux resulting from the presence of dust aerosol > particles, i.e. it is the difference between > toa_outgoing_longwave_flux_assuming_clear_sky and toa outgoing longwave flux > assuming a clear sky (i.e. no clouds) and no dust. "Aerosol" means the system > of suspended liquid or solid particles in air (except cloud droplets) and > their carrier gas, the air itself. "Ambient_aerosol" means that the aerosol > is measured or modelled at the ambient state of pressure, temperature and > relative humidity that exists in its immediate environment. "Ambient aerosol > particles" are aerosol particles that have taken up ambient water through > hygroscopic growth. The extent of hygroscopic growth depends on the relative > humidity and the composition of the particles. To specify the relative > humidity and temperature at which the q uantity described by the standard > name applies, provide scalar coordinate variables with standard names of > "relative_humidity" and "air_temperature". A phrase "assuming_condition" > indicates that the named quantity is the value which would obtain if all > aspects of the system were unaltered except for the assumption of the > circumstances specified by the condition.' > > Is this okay? > > > > (4.6) CMIP6 short name swsrfasdust. All-sky Surface Shortwave > radiative flux due to Dust > > As (4.3), but for shortwave. > > > To be consistent with 4.3, this one would be: > surface_downward_shortwave_flux_due_to_ambient_aerosol (W m-2) 'The surface > called "surface" means the lower boundary of the atmosphere. "Downward" > indicates a vector component which is positive when directed downward > (negative upward). The term "shortwave" means shortwave radiation. In > accordance with common usage in geophysical disciplines, "flux" implies per > unit area, called "flux density" in physics. 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. "Aerosol" means the system of suspended liquid > or solid particles in air (except cloud droplets) and their carrier gas, the > air itself. "Ambient_aerosol" means that the aerosol is measured or modelled > at the ambient state of pressure, temperature and relative humidity that > exists in its immediate environment. "Ambient aerosol particles" are aerosol > particles that have taken up ambient water through hygroscopic growth. The > extent of hygro scopic growth depends on the relative humidity and the > composition of the particles. To specify the relative humidity and > temperature at which the quantity described by the standard name applies, > provide scalar coordinate variables with standard names of > "relative_humidity" and "air_temperature".' > > Okay? > > > > (4.7) CMIP6 short name swsrfcsdust. Clear-sky Surface Shortwave > radiative flux due to Dust > > As (4.4), but for shortwave. > > > To be consistent with 4.4, this one would be: > surface_downward_shortwave_flux_due_to_dust_ambient_aerosol_assuming_clear_sky > (W m-2) ' The surface called "surface" means the lower boundary of the > atmosphere. "Downward" indicates a vector component which is positive when > directed downward (negative upward). The term "shortwave" means shortwave > radiation. In accordance with common usage in geophysical disciplines, "flux" > implies per unit area, called "flux density" in physics. 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. "Aerosol" means the system of > suspended liquid or solid particles in air (except cloud droplets) and their > carrier gas, the air itself. "Ambient_aerosol" means that the aerosol is > measured or modelled at the ambient state of pressure, temperature and > relative humidity that exists in its immediate environment. "Ambient aerosol > particles" are aerosol particles that have taken up ambient water through > hygroscopic growth. The extent of hygr oscopic growth depends on the > relative humidity and the composition of the particles. To specify the > relative humidity and temperature at which the quantity described by the > standard name applies, provide scalar coordinate variables with standard > names of "relative_humidity" and "air_temperature". A phrase > "assuming_condition" indicates that the named quantity is the value which > would obtain if all aspects of the system were unaltered except for the > assumption of the circumstances specified by the condition.' > > Okay? > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/Centre for Environmental Data Archival Email: > [email protected]<mailto:[email protected]> > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > _______________________________________________ > CF-metadata mailing list > [email protected]<mailto:[email protected]> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > _______________________________________________ > CF-metadata mailing list > [email protected]<mailto:[email protected]> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > _______________________________________________ > CF-metadata mailing list > [email protected]<mailto:[email protected]> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > ----- End forwarded message ----- > _______________________________________________ > CF-metadata mailing list > [email protected]<mailto:[email protected]> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > _______________________________________________ > CF-metadata mailing list > [email protected]<mailto:[email protected]> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
