Fair point Nan..
We should then do this..
Convert the current "sea_water_salinity" (to be discontinued in its use) to be an alias of the new standard name "sea_water_practical_salinity".
An updated definition for "sea_water_absolute_salinity" following your suggestion is included below, plus a new definition for "sea_water_practical_salinity".
I would recommend each of the new standard names also has an additional copy created, with the prefix "change_over_time_in_*"
***
sea_water_conservative_temperature
Definition: Conservative Temperature is potential enthalpy divided by a fixed value of the specific heat of seawater, namely cp_0 = 3991.86795711963 J kg-1 K-1. Conservative temperature is designed to be as close as possible to potential temperature, but is two orders of magnitude more conservative in the ocean. Because of this, Conservative Temperature can be regarded as being proportional to the heat content of seawater per unit mass.
Canonical units: K
Reference: www.teos-10.org
sea_water_absolute_salinity
Definition: Absolute Salinity, S_A, is the mass fraction of dissolved material in seawater. In fact TEOS-10 estimates Absolute Salinity as the salinity variable that, when used with the TEOS-10 expression for density, yields the correct density of a seawater sample even when the sample is not of Standard Composition. In practice Absolute Salinity is often calculated from Practical Salinity and a value of Absolute Salinity Anomaly which is found using computer software via a global look-up table.
Canonical units: g kg-1
Reference: www.teos-10.org
sea_water_practical_salinity
Definition: Practical Salinity, S_P, is defined on the Practical Salinity Scale of 1978 (PSS-78) and is calculated from the electrical conductivity of seawater (as well as temperature and pressure).
Canonical units: 1e-3, parts per thousand. Officially S_P is unitless, but often authors use psu, as in S_P = 35 psu.
Reference: www.teos-10.org
sea_water_preformed_salinity
Definition: Preformed Salinity is a salinity variable that is designed to be as conservative as possible, by removing the estimated biogeochemical influences on the seawater composition from other forms of salinity.
Canonical units: g kg-1
Reference: www.teos-10.org
sea_water_potential_enthalpy
Definition: Potential enthalpy is the enthalpy of a seawater parcel after an adiabatic and isohaline change in pressure from its in situ pressure to the sea pressure p = 0 dbar.
Canonical units: J kg-1
Reference: www.teos-10.org
***
So for clarity, the new proposed names are:
sea_water_conservative_temperature
sea_water_absolute_salinity
sea_water_practical_salinity
sea_water_preformed_salinity
sea_water_potential_enthalpy
change_over_time_in_sea_water_conservative_temperature
change_over_time_in_sea_water_absolute_salinity
change_over_time_in_sea_water_practical_salinity
change_over_time_in_sea_water_preformed_salinity
change_over_time_in_sea_water_potential_enthalpy
Cheers,
P
-----Original Message-----
From: cf-metadata-bounces at cgd.ucar.edu [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Nan Galbraith
Sent: Thursday, July 07, 2011 3:40 AM
To: cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] new TEOS-10 standard names
I agree that we probably need these names now. I'd like to
suggest, though, that the definition of absolute salinity should
start with the phrase 'mass fraction of salt in seawater', or
maybe 'concentration of salt in seawater'.
And while we're at it, we should probably consider revising the
definition of sea_water_salinity; currently all we have is: "The unit
of salinity is PSU, which is dimensionless. The units attribute
should be given as 1e-3 or 0.001 i.e. parts per thousand if
salinity is in PSU."
The units designation implies that we're using practical
salinity, but the definition should probably be more explicit.
We could add something like "Salinity ratio on the Practical Salinity
Scale."
Cheers - Nan
On 7/6/11 3:35 AM, Paul.Durack at csiro.au wrote:
> I'd like to propose a series of new standard names, these names are associated with the recent release of the Thermodynamic Equation Of Seawater 2010 (TEOS-10 - www.teos-10.org).
>
> Additional to these names, I would also like to propose the "change_over_time_in_*" prefixes are also created.
>
> The proposed new standard names, along with definition, units and reference details are below.
>
> ***
> sea_water_conservative_temperature
> Definition: Conservative Temperature is potential enthalpy divided by a fixed value of the specific heat of seawater, namely cp_0 = 3991.86795711963 J kg-1 K-1. Conservative temperature is designed to be as close as possible to potential temperature, but is two orders of magnitude more conservative in the ocean. Because of this, Conservative Temperature can be regarded as being proportional to the heat content of seawater per unit mass.
> Canonical units: K
> Reference: www.teos-10.org
>
> change_over_time_in_sea_water_conservative_temperature
>
> sea_water_absolute_salinity
> Definition: Absolute Salinity is the salinity variable that when used with the TEOS-10 expression for density yields the correct density of a seawater sample even when the sample is not of Standard Composition. In practice Absolute Salinity is often calculated from Practical Salinity and a value of Absolute Salinity Anomaly which is found using computer software via a global look-up table.
> Canonical units: g kg-1
> Reference: www.teos-10.org
>
> change_over_time_in_sea_water_absolute_salinity
>
> sea_water_preformed_salinity
> Definition: Preformed Salinity is a salinity variable that is designed to be as conservative as possible, by removing the estimated biogeochemical influences on the seawater composition from other forms of salinity.
> Canonical units: g kg-1
> Reference: www.teos-10.org
>
> change_over_time_in_sea_water_preformed_salinity
>
> sea_water_potential_enthalpy
> Definition: Potential enthalpy is the enthalpy of a seawater parcel after an adiabatic and isohaline change in pressure from its in situ pressure to the sea pressure p = 0 dbar.
> Canonical units: J kg-1
> Reference: www.teos-10.org
>
> change_over_time_in_sea_water_potential_enthalpy
> ***
>
> Cheers,
>
> P
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> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
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* Upper Ocean Processes Group Mail Stop 29 *
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Received on Wed Jul 06 2011 - 19:45:53 BST
