Dear Elodie,
Thank you for your post. This mailing list is the correct place to ask questions about all aspects of CF, including standard names, and to propose changes and additions.
Your post refers to names proposed by a number of other people who I hope will also comment on my suggestions below.
I see that Bruce has provided defintions for his proposed names although they haven't as yet been formally accepted for inclusion in the standard name table.
divergence_of_surface_downward_stress
' The divergence is a signed scalar that represents the magnitude of the 2D surface wind downward stress vector field's source (positive) or sink (negative) at a given point. The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a downward flux of momentum, which accelerates the lower medium along the vector and the upper medium against the vector. The surface downward stress is the wind stress on the surface.'
curl_of_surface_downward_stress
' The curl is a signed scalar that represents the magnitude of the 2D surface wind downward stress vector field's local anti-clock-wise rotation at a given point; clockwise rotation is thus given as negative curl. The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a downward flux of momentum, which accelerates the lower medium along the vector and the upper medium against the vector. The surface downward stress is the wind stress on the surface.'
The names themselves and defintions look generally OK to me. If these really are both scalar quantities that would imply a canonical unit of '1', i.e., dimensionless in both cases. Is that right? Also, isn't 'curl' usually a vector quantity?
The name proposed by Jonathan and Stephen hasn't received any discussion and I do still need to go through the whole set of names they proposed. However, to take this particular proposal just for now:
sea_water_potential_temperature_at_sea_floor (canonical units: Celsius)
' Potential temperature adjacent to the ocean bottom (at the deepest grid cell).'
The name itself looks fine and fits with existing syntax. I think the canonical units should be Kelvin which would still allow Celsius to be used in the data files because UDunits can convert between them. The definition needs to be expanded a bit to include the standard CF text for potential temperature:
' Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. The potential temperature at the sea floor is that of water adjacent to the ocean bottom, which would usually be the deepest grid cell in an ocean model.'
If Jonathan and Stephen are happy with my suggestions, then I think this name can be accepted for inclusion in the standard name table.
You have also proposed one new name:
mole_concentration_of_zooplankton_expressed_as_nitrogen_in_sea_water (canonical units: 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 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 in terms of B alone, neglecting all other chemical constituents of A. Standard names also exist for the mole concentration of a number of components that make up the total zooplankton population, such as mesozooplankton, and microzooplankton.
I agree it's fine to have a generic zooplankton_expressed_as_nitrogen name, just as we do for phytoplankton. Your proposed name, units and definition all look fine to me so unless anyone objects within the next seven days, this name will be accepted for publication in the standard name table.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
Centre for Environmental Data Analysis Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Campus, Didcot, OX11 0QX, U.K.
> -----Original Message-----
> From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf
> Of Elodie Fernandez
> Sent: 27 April 2016 09:03
> To: cf-metadata at cgd.ucar.edu
> Subject: [CF-metadata] Copernicus Marine Service standard_names
>
> Dear all,
>
> This is my first post to the list, so I hope I'm doing things "right". I
> work at Mercator Ocean, for the European Copernicus Marine Service
> (http://marine.copernicus.eu/). I am now in charge of making sure that
> the products we disseminate are CF compliant, and a big part of that
> task is to ensure that our parameters follow the standard_name table.
> Most of what we use is already described and available in the table.
> Thanks for a great job maintaining this table! But some parameters are
> not yet described.
>
> I found these standard_names in the list of proposals. As far as I can
> tell, it seems to be agreed they should be added to the standard name
> table, but it hasn't happened yet. Can you tell me more about their status?
>
> - divergence_of_surface_downward_stress
> Proposed by Bruce Hackett on January 2016
> - curl_of_surface_downward_stress
> Proposed by Bruce Hackett on January 2016
> - sea_water_potential_temperature_at_sea_floor
> Proposed by Jonathan Gregory/Stephen Griffies in January 2015
>
> I also would like to suggest the addition of the following
> standard_name:
> "mole_concentration_of_zooplankton_expressed_as_nitrogen_in_sea_wat
> er".
> Standard_names already exist for the microzooplankton and the
> mesozooplankton, but not for the total zooplankton. A name also exists
> for the total zooplankton expressed as carbon in sea water. I tried
> building a definition using the already existing ones for micro and meso
> zooplankton.
>
> -
> mole_concentration_of_zooplankton_expressed_as_nitrogen_in_sea_water
> unit: mol/m3
> definition: 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 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 in terms of B alone, neglecting all other
> chemical constituents of A. Standard names also exist for the mole
> concentration of a number of components that make up the total
> zooplankton population, such as mesozooplankton, and microzooplankton.
>
> I am also working on preparing the next release of the European
> Copernicus Marine Service that will include waves. We are planning on
> introducing 35 variables, of which only 7 have already existing
> standard_names. What do you think is the best way to proceed? Start a
> new thread on this topic and propose for each variable a standard_name,
> unit and definition?
>
> Best regards,
> Elodie Fernandez
>
>
>
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Received on Wed Apr 27 2016 - 07:08:36 BST
