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.Mcdougall at csiro.au [mailto:Trevor.Mcdougall at csiro.au]
Sent: 05 October 2011 00:12
To: Lowry, Roy K.; j.m.gregory at reading.ac.uk; Paul.Durack at csiro.au
Cc: CF-metadata at cgd.ucar.edu; rich at eos.ubc.ca; King, Brian A.; Paul.Barker at csiro.au; rainer.feistel at io-warnemuende.de; Stephen.Griffies at 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:rkl at 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 at cgd.ucar.edu; rich at eos.ubc.ca; King, Brian A.; Barker, Paul (CMAR, Hobart); rainer.feistel at io-warnemuende.de; Stephen.Griffies at 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-bounces at cgd.ucar.edu [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Jonathan Gregory
Sent: 04 October 2011 14:13
To: Paul.Durack at csiro.au
Cc: Trevor.Mcdougall at csiro.au; CF-metadata at cgd.ucar.edu; rich at eos.ubc.ca; King, Brian A.; Paul.Barker at csiro.au; rainer.feistel at io-warnemuende.de; Stephen.Griffies at 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
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Received on Wed Oct 05 2011 - 01:53:05 BST
