Re: [CF-metadata] SUGGESTED WAY FORWARD FOR CF-metadata:- lets finalize this discussion.
Dear Rpy In a standard name, Knudsen would be spelt all in lower case. We use only lower case in standard names. Cheers Jonathan ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] SUGGESTED WAY FORWARD FOR CF-metadata:- lets finalize this discussion.
Trevor, while I agree with all the arguments given below, I vote that we should additionally use Reference Salinity in the Baltic. We need a salinity measure that is expressed as a mass fraction, in contrast to psu, and that is calculated straight forward from CTD conductivity readings. I would reserve the term Absolute Salinity to values that include the salinity anomaly, but for the majority of applications this anomaly correction is not relevant. While we will measure and archive Practical Salinity as everywhere else in oceanography, S_R is a sufficiently good approximation of S_A to express, say, the total salt content of the Baltic, or the vertical salt transport across the halocline in papers or reports. Rainer - Original Message - From: Lowry, Roy K. r...@bodc.ac.uk To: trevor.mcdoug...@csiro.au; rainer.feis...@io-warnemuende.de; paul.dur...@csiro.au; j.m.greg...@reading.ac.uk Cc: stephen.griff...@noaa.gov; paul.bar...@csiro.au; King, Brian A. b...@noc.soton.ac.uk; r...@eos.ubc.ca; CF-metadata@cgd.ucar.edu Sent: Saturday, October 08, 2011 3:08 PM Subject: RE: [CF-metadata] SUGGESTED WAY FORWARD FOR CF-metadata:- lets finalize this discussion. Hello Trevor, We're now all saying the same thing. The important thing is that Alison gets new Standard Names into the system for practical_salinity , absolute_salinity and Knudsen_salinity (Jonathan: should it be Knudsen or knudsen?) in the next update so they are available for use for new data and for re-labelling legacy data by those with the inclination/resources to do so. We cannot physically stop further use of 'salinity' without causing issues for legacy data. All we can do, as Jonathan stated is take steps to strongly discourage its use through appropriate wording in its definition. Hopefully, case closed! Cheers, Roy. From: trevor.mcdoug...@csiro.au [trevor.mcdoug...@csiro.au] Sent: 08 October 2011 02:49 To: Lowry, Roy K.; rainer.feis...@io-warnemuende.de; paul.dur...@csiro.au; j.m.greg...@reading.ac.uk 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] SUGGESTED WAY FORWARD FOR CF-metadata:- lets finalize this discussion. Dear All, I think that the reason that we are facing a dilemma is simply because the word salinity now stands for a variety of things. That is, we have not been as careful with salinity as we now realize we should have been over the past 50 or 100 years. My understanding of oceanographic practice is that between the Knudsen equation of 1901 and the year 1978 any calculated salinity quantity would have tried to be Knudsen salinity, no matter if it was calculated via titration or via a conductivity measurement (as occurred in the 1960s and 1970s). Hence it is quite valid to call such an old data point a Knudsen_Salinity. Note that we do not reserve a name for a particular measurement technique. Hence, for example, the salinity out of a climate model is called Practical Salinity to date even though the value did not result from a conductivity measurement. Also a value of Absolute Salinity is still absolute salinity no matter whether it was calculated from either of the two recommended methods. SUGGESTED WAY FORWARD FOR CF-metadata So any new (=2010) data going into a data base should be labelled as either Knudsen Salinity, Practical Salinity or Absolute Salinity, and the name Salinity should most definitely not be available as an option for any new (=2010) data going into a data base, whether from a cruise, a mooring or from model output. I think this is quite clear, yes? I think there can be no argument about this, and to do otherwise would just cause confusion. Can you make this happen in CF-metadata Paul? This is essentially what we are being instructed to do by IOC, IAPSO and SCOR, and it makes perfect sense. But what should we do about the data in data bases that is presently called salinity. My suggestion now is that we just let this data sit there as is. We leave it up to the individual researcher to interpret what this data is. For example, in our research, Paul Barker and I get this data and interpret it as Knudsen Salinity if it was collected before 1st January 1978, and Practical Salinity if it was collected on or after 1st January 1978. Can we all agree on the last two paragraphs, and can you, Paul Durack and Nan, make this happen? Until we agree on this as a procedure, there is little point in worrying about the exact wording of the definitions of the variables. Can we all get back to each other with what we think about the suggested way forward that I describe in the above two paragraphs? Roy, I think what I wrote above is possibly the same as what you are suggesting, but I'm not sure what some of the technical words that you
Re: [CF-metadata] SUGGESTED WAY FORWARD FOR CF-metadata:- lets finalize this discussion.
Hello Trevor, We're now all saying the same thing. The important thing is that Alison gets new Standard Names into the system for practical_salinity , absolute_salinity and Knudsen_salinity (Jonathan: should it be Knudsen or knudsen?) in the next update so they are available for use for new data and for re-labelling legacy data by those with the inclination/resources to do so. We cannot physically stop further use of 'salinity' without causing issues for legacy data. All we can do, as Jonathan stated is take steps to strongly discourage its use through appropriate wording in its definition. Hopefully, case closed! Cheers, Roy. From: trevor.mcdoug...@csiro.au [trevor.mcdoug...@csiro.au] Sent: 08 October 2011 02:49 To: Lowry, Roy K.; rainer.feis...@io-warnemuende.de; paul.dur...@csiro.au; j.m.greg...@reading.ac.uk 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] SUGGESTED WAY FORWARD FOR CF-metadata:- lets finalize this discussion. Dear All, I think that the reason that we are facing a dilemma is simply because the word salinity now stands for a variety of things. That is, we have not been as careful with salinity as we now realize we should have been over the past 50 or 100 years. My understanding of oceanographic practice is that between the Knudsen equation of 1901 and the year 1978 any calculated salinity quantity would have tried to be Knudsen salinity, no matter if it was calculated via titration or via a conductivity measurement (as occurred in the 1960s and 1970s). Hence it is quite valid to call such an old data point a Knudsen_Salinity. Note that we do not reserve a name for a particular measurement technique. Hence, for example, the salinity out of a climate model is called Practical Salinity to date even though the value did not result from a conductivity measurement. Also a value of Absolute Salinity is still absolute salinity no matter whether it was calculated from either of the two recommended methods. SUGGESTED WAY FORWARD FOR CF-metadata So any new (=2010) data going into a data base should be labelled as either Knudsen Salinity, Practical Salinity or Absolute Salinity, and the name Salinity should most definitely not be available as an option for any new (=2010) data going into a data base, whether from a cruise, a mooring or from model output. I think this is quite clear, yes? I think there can be no argument about this, and to do otherwise would just cause confusion. Can you make this happen in CF-metadata Paul? This is essentially what we are being instructed to do by IOC, IAPSO and SCOR, and it makes perfect sense. But what should we do about the data in data bases that is presently called salinity. My suggestion now is that we just let this data sit there as is. We leave it up to the individual researcher to interpret what this data is. For example, in our research, Paul Barker and I get this data and interpret it as Knudsen Salinity if it was collected before 1st January 1978, and Practical Salinity if it was collected on or after 1st January 1978. Can we all agree on the last two paragraphs, and can you, Paul Durack and Nan, make this happen? Until we agree on this as a procedure, there is little point in worrying about the exact wording of the definitions of the variables. Can we all get back to each other with what we think about the suggested way forward that I describe in the above two paragraphs? Roy, I think what I wrote above is possibly the same as what you are suggesting, but I'm not sure what some of the technical words that you use mean:- deprecate, Narrowmatches, etc. With best wishes, Trevor -Original Message- From: Lowry, Roy K. [mailto:r...@bodc.ac.uk] Sent: Thursday, 6 October 2011 6:28 PM To: Rainer Feistel; Durack, Paul (CMAR, Hobart); j.m.greg...@reading.ac.uk; McDougall, Trevor (CMAR, Hobart) Cc: stephen.griff...@noaa.gov; Barker, Paul (CMAR, Hobart); King, Brian A.; r...@eos.ubc.ca; CF-metadata@cgd.ucar.edu Subject: RE: [CF-metadata] new TEOS-10 standard names 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
