Hi John, I touched on this issue when the sea floor temperature and practical salinity names were set up. My understanding is that it does have a meaning which is the portion of the water column influenced by the seabed, sometimes termed the 'benthic boundary layer'. Oceanographers I've worked with certainly of a conceptual understanding of this, but what it means in terms of a quantitative definition varies depending upon whether one is working in shelf sea, deep ocean or other environments.
I think I suggested adding 'benthic boundary layer' to the CF sea_floor Standard Name definitions, but I don't recall any reaction. Cheers, Roy. I have now retired but will continue to be active through an Emeritus Fellowship using this e-mail address. ________________________________ From: CF-metadata <cf-metadata-boun...@cgd.ucar.edu> on behalf of John Graybeal <jgrayb...@stanford.edu> Sent: 12 November 2019 23:07 To: Marcelo Andrioni <marceloandri...@gmail.com> Cc: CF Metadata List <cf-metadata@cgd.ucar.edu> Subject: Re: [CF-metadata] Suggestion for standard names for bottom current and due to tides and Stokes drift I have a question about the definitions of the *_at_sea_floor standard names, which state "… is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model." I understand what this means for ocean models (but suspect it has quite different implications for models featuring cells of smaller thickness nearer the boundary). Does it mean anything for observational data? (In which case, there should be a corresponding definition, yes?) Or by definition, are all of these variables not applicable to observational data? This question is general and should not affect this particular request, so conceivably it should be a new topic if the answer is not straightforward. John On Nov 12, 2019, at 11:59 AM, Marcelo Andrioni <marceloandri...@gmail.com<mailto:marceloandri...@gmail.com>> wrote: Dear Jonathan, my suggestion of sea_water_from_direction_at_sea_floor was based on the "basic" standard name: sea_water_from_direction The phrase "from_direction" is used in the construction X_from_direction and indicates the direction from which the velocity vector of X is coming. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. so that the only difference would be to add the suffix _at_sea_floor like it was done with: sea_water_potential_temperature sea_water_potential_temperature_at_sea_floor Thank you. Em ter., 12 de nov. de 2019 às 16:22, <cf-metadata-requ...@cgd.ucar.edu<mailto:cf-metadata-requ...@cgd.ucar.edu>> escreveu: Send CF-metadata mailing list submissions to cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu> To subscribe or unsubscribe via the World Wide Web, visit http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata or, via email, send a message with subject or body 'help' to cf-metadata-requ...@cgd.ucar.edu<mailto:cf-metadata-requ...@cgd.ucar.edu> You can reach the person managing the list at cf-metadata-ow...@cgd.ucar.edu<mailto:cf-metadata-ow...@cgd.ucar.edu> When replying, please edit your Subject line so it is more specific than "Re: Contents of CF-metadata digest..." Today's Topics: 1. Suggestion for standard names for bottom current and due to tides and Stokes drift (Jonathan Gregory) 2. Re: Suggestion for standard names for bottom current and due to tides and Stokes drift (Marcelo Andrioni) ---------------------------------------------------------------------- Message: 1 Date: Mon, 11 Nov 2019 18:00:27 +0000 From: Jonathan Gregory <j.m.greg...@reading.ac.uk<mailto:j.m.greg...@reading.ac.uk>> To: "cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>" <cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>> Subject: [CF-metadata] Suggestion for standard names for bottom current and due to tides and Stokes drift Message-ID: <20191111180025.ga8...@met.reading.ac.uk<mailto:20191111180025.ga8...@met.reading.ac.uk>> Content-Type: text/plain; charset="us-ascii" Dear Francesca and Marcelo I think that "velocity" ought to appear in this one: sea_water_to_direction_at_sea_floor It's the velocity which has a direction. Best wishes Jonathan ----- Forwarded message from Francesca Eggleton - UKRI STFC <francesca.eggle...@stfc.ac.uk<mailto:francesca.eggle...@stfc.ac.uk>> ----- Date: Mon, 11 Nov 2019 17:29:31 +0000 From: Francesca Eggleton - UKRI STFC <francesca.eggle...@stfc.ac.uk<mailto:francesca.eggle...@stfc.ac.uk>> To: "cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>" <cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>> Subject: [CF-metadata] Suggestion for standard names for bottom current and due to tides and Stokes drift Dear Marcelo, Thank you for your proposals and apologies for the delay in responding. As you may have seen in Alison's last email, I will be helping out with the maintenance of the standard names. Thank you to Jonathan for comments on these proposals. They all look good and seem to match what already exists. The two phrases which were suggested as aliases, I believe to be new terms and have suggested a reason why so please comment if you agree/disagree. The following text will list each of the proposals, their units and descriptions (constructed from similar terms to be in line with standard name descriptions). Please let me know if there are any comments or further changes to be made. If no comments are made in the next 7 days, these are likely to be accepted in the next update. eastward_sea_water_velocity_at_sea_floor ms-1 A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). The velocity at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. northward_sea_water_velocity_at_sea_floor ms-1 A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward). The velocity at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. sea_water_to_direction_at_sea_floor degree The phrase "to_direction" is used in the construction X_to_direction and indicates the direction towards which the velocity vector of X is headed. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. The direction at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. sea_water_speed_at_sea_floor ms-1 Speed is the magnitude of velocity. The speed at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. eastward_sea_water_velocity_due_to_tides ms-1 A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. northward_sea_water_velocity_due_to_tides ms-1 A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward). 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. sea_water_to_direction_due_to_tides degree The phrase "to_direction" is used in the construction X_to_direction and indicates the direction towards which the velocity vector of X is headed. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. sea_water_speed_due_to_tides ms-1 Speed is the magnitude of velocity. 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. The following should not be aliases of sea_surface_wave_stokes_drift_x_velocity and sea_surface_wave_stokes_drift_y_velocity, they should be proposed as new terms. The definition states '"x" indicates a vector component along the grid x-axis, positive with increasing x.', this has been done on purpose to allow this term to be used with any type of grid and not limiting it to a lat-lon grid. The term eastward is defined as '"Eastward" indicates a vector component which is positive when directed eastward (negative westward)' which limits this term to being 'zonal' (along a latitudinal circle). sea_surface_wave_stokes_drift_eastward_velocity ms-1 A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. sea_surface_wave_stokes_drift_northward_velocity ms-1 A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward). The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. sea_surface_wave_stokes_drift_to_direction degrees The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. The phrase "to_direction" is used in the construction X_to_direction and indicates the direction towards which the velocity vector of X is headed. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. sea_surface_wave_stokes_drift_speed ms-1 The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. Speed is the magnitude of velocity. Thank you, Francesca Eggleton Graduate Environmental Data Scientist Normal Working Hours (Mon-Thurs): 9am-5pm (Fri 4:30pm) RAL Space | R25 | Ext: 6710 Centre for Environmental Data Analysis (CEDA) Science and Technology Facilities Council (STFC) Rutherford Appleton Laboratory | Harwell Campus Didcot | OX11 0QX www.ceda.ac.uk<http://www.ceda.ac.uk><http://www.ceda.ac.uk/> [cid:image001.jpg@01D4F05B.30A11420][cid:image001.png@01D590AB.EC504AB0] P Please consider the environment before printing this e-mail Dear Marcelo These look fine to me, thanks. Just to be clear - you're *not* proposing at_bottom, are you? I agree with you that at_sea_floor would be the right phrase to use. Best wishes Jonathan Hello, I would like to suggest the inclusion of standard names for u, v, speed and direction for bottom current and due to tides and Stokes drift: An example of model output with bottom velocity is the HYCOM NCODA forecast: https://tds.hycom.org/thredds/catalog/GLBv0.08/expt_93.0/data/forecasts/runs/catalog.html?dataset=GLBv0.08/expt_93.0/data/forecasts/runs/FMRC_RUN_2019-10-13T12:00:00Z water_u_bottom (m/s) = Eastward Water Velocity = eastward_sea_water_velocity_at_bottom water_v_bottom (m/s) = Northward Water Velocity = northward_sea_water_velocity_at_bottom based on existing variables: sea_water_potential_temperature_at_sea_floor sea_water_temperature_at_sea_floor sea_water_salinity_at_sea_floor sea_water_pressure_at_sea_floor my suggestion would be: eastward_sea_water_velocity_at_sea_floor northward_sea_water_velocity_at_sea_floor sea_water_to_direction_at_sea_floor sea_water_speed_at_sea_floor An example of model output with currents due to tides and Stokes drift is the Mercator Forecast: http://marine.copernicus.eu/services-portfolio/access-to-products/?option=com_csw&view=details&product_id=GLOBAL_ANALYSIS_FORECAST_PHY_001_024 based on existing variables: eastward_sea_water_velocity_assuming_no_tide northward_sea_water_velocity_assuming_no_tide ocean_vertical_momentum_diffusivity_due_to_tides ocean_vertical_tracer_diffusivity_due_to_tides my suggestion would be: eastward_sea_water_velocity_due_to_tides northward_sea_water_velocity_due_to_tides sea_water_to_direction_due_to_tides sea_water_speed_due_to_tides Stokes drift is present in the current CF table with: sea_surface_wave_stokes_drift_x_velocity sea_surface_wave_stokes_drift_y_velocity I think it could help to add sea_surface_wave_stokes_drift_eastward_velocity sea_surface_wave_stokes_drift_northward_velocity as aliases to make it clear it is zonal and meridional currents, and not just along the grid X and Y dimensions. Thank you very much. -- Marcelo Andrioni marceloandrioni at gmail.com<http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata> _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu<mailto:CF-metadata@cgd.ucar.edu> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- ------------------------------ Message: 2 Date: Tue, 12 Nov 2019 16:21:43 -0300 From: Marcelo Andrioni <marceloandri...@gmail.com<mailto:marceloandri...@gmail.com>> To: cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>, francesca.eggle...@stfc.ac.uk<mailto:francesca.eggle...@stfc.ac.uk> Subject: Re: [CF-metadata] Suggestion for standard names for bottom current and due to tides and Stokes drift Message-ID: <CAECDRdfO-7adUp8XpBWXXEZse49KMtvAFY=f8noi8thqa68...@mail.gmail.com<mailto:CAECDRdfO-7adUp8XpBWXXEZse49KMtvAFY=f8noi8thqa68...@mail.gmail.com>> Content-Type: text/plain; charset="UTF-8" Dear Francesca, the accompanying explanations of what the variables represent are perfect, I have nothing to contribute. I also agree with you that: sea_surface_wave_stokes_drift_eastward_velocity sea_surface_wave_stokes_drift_northward_velocity should *not* be aliases for sea_surface_wave_stokes_drift_x_velocity sea_surface_wave_stokes_drift_y_velocity I am glad the new names will be considered for the next update. I have some more suggestions for new standard names but I will be using the GitHub issues discussion from now on as instructed https://github.com/cf-convention/discuss/issues Thank you very much for your work in maintaining the list. -- Marcelo Andrioni marceloandri...@gmail.com From: Francesca Eggleton - UKRI STFC <francesca.eggle...@stfc.ac.uk> To: "cf-metadata@cgd.ucar.edu" <cf-metadata@cgd.ucar.edu> Subject: [CF-metadata] Suggestion for standard names for bottom current and due to tides and Stokes drift Message-ID: <b1ba4ab901f74a8fa48418a9a4c68...@stfc.ac.uk> Content-Type: text/plain; charset="us-ascii" Dear Marcelo, Thank you for your proposals and apologies for the delay in responding. As you may have seen in Alison's last email, I will be helping out with the maintenance of the standard names. Thank you to Jonathan for comments on these proposals. They all look good and seem to match what already exists. The two phrases which were suggested as aliases, I believe to be new terms and have suggested a reason why so please comment if you agree/disagree. The following text will list each of the proposals, their units and descriptions (constructed from similar terms to be in line with standard name descriptions). Please let me know if there are any comments or further changes to be made. If no comments are made in the next 7 days, these are likely to be accepted in the next update. eastward_sea_water_velocity_at_sea_floor ms-1 A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). The velocity at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. northward_sea_water_velocity_at_sea_floor ms-1 A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward). The velocity at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. sea_water_to_direction_at_sea_floor degree The phrase "to_direction" is used in the construction X_to_direction and indicates the direction towards which the velocity vector of X is headed. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. The direction at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. sea_water_speed_at_sea_floor ms-1 Speed is the magnitude of velocity. The speed at the sea floor is that adjacent to the ocean bottom, which would be the deepest grid cell in an ocean model. eastward_sea_water_velocity_due_to_tides ms-1 A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. northward_sea_water_velocity_due_to_tides ms-1 A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward). 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. sea_water_to_direction_due_to_tides degree The phrase "to_direction" is used in the construction X_to_direction and indicates the direction towards which the velocity vector of X is headed. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. sea_water_speed_due_to_tides ms-1 Speed is the magnitude of velocity. 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. "Due to tides" means due to all astronomical gravity changes which manifest as tides. No distinction is made between different tidal components. The following should not be aliases of sea_surface_wave_stokes_drift_x_velocity and sea_surface_wave_stokes_drift_y_velocity, they should be proposed as new terms. The definition states '"x" indicates a vector component along the grid x-axis, positive with increasing x.', this has been done on purpose to allow this term to be used with any type of grid and not limiting it to a lat-lon grid. The term eastward is defined as '"Eastward" indicates a vector component which is positive when directed eastward (negative westward)' which limits this term to being 'zonal' (along a latitudinal circle). sea_surface_wave_stokes_drift_eastward_velocity ms-1 A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward). The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. sea_surface_wave_stokes_drift_northward_velocity ms-1 A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward). The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. sea_surface_wave_stokes_drift_to_direction degrees The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. The phrase "to_direction" is used in the construction X_to_direction and indicates the direction towards which the velocity vector of X is headed. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. sea_surface_wave_stokes_drift_speed ms-1 The Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation. Speed is the magnitude of velocity. Thank you, Francesca Eggleton Graduate Environmental Data Scientist Normal Working Hours (Mon-Thurs): 9am-5pm (Fri 4:30pm) RAL Space | R25 | Ext: 6710 Centre for Environmental Data Analysis (CEDA) Science and Technology Facilities Council (STFC) Rutherford Appleton Laboratory | Harwell Campus Didcot | OX11 0QX www.ceda.ac.uk<http://www.ceda.ac.uk/> ------------------------------ Subject: Digest Footer _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ------------------------------ End of CF-metadata Digest, Vol 199, Issue 3 ******************************************* -- Marcelo Andrioni marceloandri...@gmail.com<mailto:marceloandri...@gmail.com> _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ======================== John Graybeal Technical Program Manager Center for Expanded Data Annotation and Retrieval /+/ NCBO BioPortal Stanford Center for Biomedical Informatics Research 650-736-1632 | ORCID 0000-0001-6875-5360 This email and any attachments are intended solely for the use of the named recipients. 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