Hello Reiner/Trevor, I have no problem with introducing the term Knudsen salinity for salinities pre-dating PSS-78. A question to Reiner is does the term just apply to salinity by evaporation/titration or is it equally applicable to salinity data obtained by the STDs and CTDs with home-grown conductivity to salinity algorithms in use before PSS-78 brought some order to the world?
Note, that having a term for pre-78 data doesn't necessarily allow us to immediately deprecate the term 'salinity'. There's a lot of data out there marked up with 'salinity'. Anyone any views on how such deprecation should be managed? My vote would be to set up the new terms and modify the 'salinity' definition in the next Standard Names update, map all the new terms as narrowMatches to old one and then deprecate 'salinity' in a future Standard Names update. Cheers, Roy. -----Original Message----- From: Rainer Feistel [mailto:rainer.feis...@io-warnemuende.de] Sent: 06 October 2011 06:32 To: paul.dur...@csiro.au; j.m.greg...@reading.ac.uk; Lowry, Roy K.; trevor.mcdoug...@csiro.au Cc: stephen.griff...@noaa.gov; paul.bar...@csiro.au; King, Brian A.; r...@eos.ubc.ca; CF-metadata@cgd.ucar.edu Subject: Re: [CF-metadata] new TEOS-10 standard names Since the use of any "salinity" was discouraged in favour of chlorinity in 1940, all archived pre-78 salinities should be Knudsen salinities, originally calculated from chlorinity by the Knudsen formula derived from the evaporation experiments of Soerensen in 1900. Knudsen salinity is consistent with PSS-78 at about S = 35 but deviates systematically for brackish water, see our 2008 salinity paper in DSR. The term "Knudsen salinity" is well understood, I think. Rainer ----- Original Message ----- From: <trevor.mcdoug...@csiro.au> To: <r...@bodc.ac.uk>; <j.m.greg...@reading.ac.uk>; <paul.dur...@csiro.au> Cc: <CF-metadata@cgd.ucar.edu>; <r...@eos.ubc.ca>; <b...@noc.soton.ac.uk>; <paul.bar...@csiro.au>; <rainer.feis...@io-warnemuende.de>; <stephen.griff...@noaa.gov> Sent: Wednesday, October 05, 2011 11:17 PM Subject: RE: [CF-metadata] new TEOS-10 standard names Hello Roy, You make a good point about the pre 1978 data. Perhaps we need yet another name, such as "Pre78salinity" to indicate that it was probably obtained by chemical titration. By introducing such a salinity will have the advantage of reducing the present ambiguity which calls this older data by the same name as Practical Salinity, namely "salinity". Trevor -----Original Message----- From: Lowry, Roy K. [mailto:r...@bodc.ac.uk] Sent: Wednesday, 5 October 2011 6:53 PM To: McDougall, Trevor (CMAR, Hobart); j.m.greg...@reading.ac.uk; Durack, Paul (CMAR, Hobart) Cc: CF-metadata@cgd.ucar.edu; r...@eos.ubc.ca; King, Brian A.; Barker, Paul (CMAR, Hobart); rainer.feis...@io-warnemuende.de; stephen.griff...@noaa.gov Subject: RE: [CF-metadata] new TEOS-10 standard names Hello Trevor, I totally agree that we should stop using 'salinity' from now on. I also agree that virtually all post-1983 (not 1980: it took 5 years to get the 1978 Equation of State published by UNESCO) data labelled 'salinity' are in fact 'practical_salinity'. However, as an oceanographic data centre we have salinity data going back to the early 1900s and other centres such as ICES have data going back further than that. These have been determined by a variety of methodologies but are mostly chemical titrations or a variety of algorithmic determinations from conductivity that are significantly different from the PSS-78 scale. Replacing 'salinity' by 'practical_salinity' re-labels these data, which I believe is wrong. We certainly need to get 'practical_salinity' names in place and alter the definition for salinity to indicate that it means 'salt content by any method' with wording to strongly discourage its use for post-1983 data unless the data are known to be 'non-practical' (which exist: we have some). We also need to explain to the community that unless they change the labels on their data that are practical salinity from 'salinity' to 'practical_salinity' then their data will be regarded as useless for many physical oceanographic applications. Cheers, Roy. -----Original Message----- From: trevor.mcdoug...@csiro.au [mailto:trevor.mcdoug...@csiro.au] Sent: 05 October 2011 00:12 To: Lowry, Roy K.; j.m.greg...@reading.ac.uk; paul.dur...@csiro.au Cc: CF-metadata@cgd.ucar.edu; r...@eos.ubc.ca; King, Brian A.; paul.bar...@csiro.au; rainer.feis...@io-warnemuende.de; stephen.griff...@noaa.gov Subject: RE: [CF-metadata] new TEOS-10 standard names Dear all, At the risk of repeating ourselves, because there are now (at least) three different salinities, it is now ambiguous and confusing to call any salinity "Salinity". The Announcement of TEOS-10 that is now appearing in all 22 oceanographic journals specifically recommends that the use of the word "Salinity" cease immediately, and that either the words "Practical Salinity" or "Absolute Salinity" be used. The reason of course is to minimise ambiguity. So this is where the community (including CF-metadata) will have to end up:- we have been requested to do so by IOC, SCOR and IAPSO. So we may as well do it now, in my view. Note that all ocean models run to date have used Practical Salinity as their "Salinity" variable,, and all equations of state since 1980 have been in terms of Practical Salinity. So there is no slight-of-hand in calling these variables "Practical Salinity"; rather it is just being specific as to what this type of salinity always has been. That is "Practical Salinity" is simply the long-hand name of what we have been calling "Salinity" for 30 years. Trevor -----Original Message----- From: Lowry, Roy K. [mailto:r...@bodc.ac.uk] Sent: Wednesday, 5 October 2011 1:43 AM To: Jonathan Gregory; Durack, Paul (CMAR, Hobart) Cc: McDougall, Trevor (CMAR, Hobart); CF-metadata@cgd.ucar.edu; r...@eos.ubc.ca; King, Brian A.; Barker, Paul (CMAR, Hobart); rainer.feis...@io-warnemuende.de; stephen.griff...@noaa.gov Subject: RE: [CF-metadata] new TEOS-10 standard names Dear All, My feelings on this were (and still are) comfort with the addition of 'practical_salinity' names, but significant discomfort with the replacement of 'salinity' by 'practical_salinity' through deprecation of 'salinity'. Cheers, Roy. -----Original Message----- From: cf-metadata-boun...@cgd.ucar.edu [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of Jonathan Gregory Sent: 04 October 2011 14:13 To: paul.dur...@csiro.au Cc: trevor.mcdoug...@csiro.au; CF-metadata@cgd.ucar.edu; r...@eos.ubc.ca; King, Brian A.; paul.bar...@csiro.au; rainer.feis...@io-warnemuende.de; stephen.griff...@noaa.gov Subject: Re: [CF-metadata] new TEOS-10 standard names Dear Paul Alison (the manager of standard names) hasn't "ruled" yet on their inclusion, but I believe that the discussion concluded with no objections to adding the practical salinity names. It seems safe to assume they will be put in the table in due course. Best wishes Jonathan _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- This message (and any attachments) is for the recipient only. 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