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: [email protected] [mailto:[email protected]] On Behalf Of Nan Galbraith Sent: Thursday, July 07, 2011 3:40 AM To: [email protected] 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, [email protected] 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 > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > -- ******************************************************* * Nan Galbraith (508) 289-2444 * * Upper Ocean Processes Group Mail Stop 29 * * Woods Hole Oceanographic Institution * * Woods Hole, MA 02543 * ******************************************************* _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
