Dear John, All, There have been no further comments in the last seven days so sea_water_turbidity (1) is now accepted for inclusion in the standard name table and will be added at the next update.
Best wishes, Alison ------ Alison Pamment Tel: +44 1235 778065 NCAS/British Atmospheric Data Centre Email: [email protected] STFC Rutherford Appleton Laboratory R25, 2.22 Harwell Oxford, Didcot, OX11 0QX, U.K. > -----Original Message----- > From: CF-metadata [mailto:[email protected]] On Behalf > Of [email protected] > Sent: 11 March 2013 12:37 > To: [email protected] > Subject: Re: [CF-metadata] sea_water_turbidity > > Dear All, > > I think we have now reached consensus on this name: > sea_water_turbidity (units of '1' i.e. dimensionless) > 'Turbidity is a dimensionless quantity which is expressed in NTU > (Nephelometric Turbidity Units). Turbidity expressed in NTU is the > proportion of white light scattered back to a transceiver by the particulate > load in a body of water, represented on an arbitrary scale referenced > against measurements made in the laboratory on aqueous suspensions of > formazine beads. Sea water turbidity may also be measured by the quantity > with standard name secchi_depth_of_sea_water.' > > Unless further comments are received within the next seven days this name > will be accepted and included in the next update of the standard name > table. > > A cross-reference to the new name will be added to the definition of > secchi_depth_of_sea_water: 'Sea water turbidity may also be measured by > the quantity with standard name sea_water_turbidity.' > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/British Atmospheric Data Centre Email: [email protected] > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > > From: CF-metadata [mailto:[email protected]] On Behalf > Of [email protected] > Sent: 07 March 2013 12:17 > To: [email protected] > Subject: Re: [CF-metadata] sea_water_turbidity > > Dear John, > > Thanks for checking. I'm happy with the units of 1 and your amended > definition. > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/British Atmospheric Data Centre Email: [email protected] > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > > From: CF-metadata [mailto:[email protected]] On Behalf > Of John Maurer > Sent: 07 March 2013 01:19 > To: [email protected] > Subject: [CF-metadata] sea_water_turbidity > > Thanks, Alison. After further consideration as well as discussion with some > of our water quality colleagues, I think the dimensionless units of NTU may > be better expressed in UDUNITS as "1" instead of "1e-3" (parts per > thousand) since the values normally range in the 0-10+ range (rather than > 0.001-0.01+). So, I would modify the units to "1" and slightly modify your > proposed definition to the following: > > 'Turbidity is a dimensionless quantity which is expressed in NTU > (Nephelometric Turbidity Units). Turbidity expressed in NTU is the > proportion of white light scattered back to a transceiver by the particulate > load in a body of water, represented on an arbitrary scale referenced > against measurements made in the laboratory on aqueous suspensions of > formazine beads. Sea water turbidity may also be measured by the quantity > with standard name secchi_depth_of_sea_water.' > > Cheers, > John > > Message: 2 > Date: Wed, 6 Mar 2013 12:08:09 +0000 > From: <[email protected]> > To: <[email protected]> > Subject: Re: [CF-metadata] sea_water_turbidity > Message-ID: > <[email protected]. > ac.uk> > Content-Type: text/plain; charset="iso-8859-1" > > Dear John and Roy, > > Thanks for your comments. Based on the explanations you have provided I > suggest that the wording of the definition should be 'Turbidity is a > dimensionless quantity which is expressed in NTU (Nephelometric Turbidity > Units), which are normally given as 1e-3 or 0.001 i.e. parts per thousand. > Turbidity expressed in NTU is the proportion of white light scattered back to > a transceiver by the particulate load in a body of water, represented on an > arbitrary scale referenced against measurements made in the laboratory on > aqueous suspensions of formazine beads. Sea water turbidity may also be > measured by the quantity with standard name secchi_depth_of_sea_water.' > > I suggest also that we could improve the definition of the secchi_depth > name to make it clearer that the quantity relates to turbidity and add a > cross-reference to the new name: > secchi_depth_of_sea_water - ' Depth is the vertical distance below the > surface. A Secchi disk is a patterned disk that is used to measure water > transparency, also called turbidity, in oceans and lakes. The disk is lowered > into the water and the depth at which the pattern is no longer visible is the > called the secchi depth. Sea water turbidity may also be measured by the > quantity with standard name sea_water_turbidity.' > > Do you agree? > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/British Atmospheric Data Centre Email: [email protected] > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > > From: CF-metadata [mailto:[email protected]] On Behalf > Of John Maurer > Sent: 05 March 2013 00:23 > To: [email protected] > Subject: [CF-metadata] sea_water_turbidity > > Yes, I agree with Roy's assessment. Thank you. > Cheers, > John > > Date: Wed, 27 Feb 2013 21:19:01 +0000 > From: "Lowry, Roy K." <[email protected]> > To: "[email protected]" <[email protected]>, > ? ? ? ? "[email protected]" <[email protected]> > Subject: Re: [CF-metadata] sea_water_turbidity? > Message-ID: > ? ? ? ? > <[email protected] > .uk> > Content-Type: text/plain; charset="Windows-1252" > > Hello Alison, > > I had been hanging back waiting for John to respond to Jonathan's comment, > because nephelometric turbidity is a phenomenon that I've seen described > - but not necessarily defined - in a couple of different ways. ?However, > whilst both turbidity and secchi disk depth (and attenuance to the matter) > have values related to the SPM load in the water body, they differ markedly > for a given SPM load and so I think a new standard name is justified. > > As a prompt, I'll give one of my understandings of turbidity in NTU, which is > 'The proportion of white light scattered back to the transceiver by the > particulate load in a body of water, represented on an arbitrary scale > referenced against measurements made in the laboratory on aqueous > suspensions of formazine beads.' ?Before going any further we need John > to either confirm that this is what he means or come up with an alternative. > ?Others might also have their own ideas.... > > Cheers, Roy. > ______________________________ > __________ > From: CF-metadata [[email protected]] On Behalf Of > [email protected] [[email protected]] > Sent: 27 February 2013 14:04 > To: [email protected] > Subject: Re: [CF-metadata] sea_water_turbidity? > > Dear John, > > Thank you for your proposal. > > We currently have one existing standard name relating to turbidity of sea > water, secchi_depth_of_sea_water, which has units of metres and is > defined as ?Depth is the vertical distance below the surface. A Secchi disk is > a patterned disk that is used to measure water transparency in oceans and > lakes. The disk is lowered into the water and the depth at which the pattern > is no longer visible is the called the secchi depth.? > > I agree with Jonathan that it would be helpful if you could provide a (fairly > brief) definition for the new name or perhaps a suitable reference. > > Best wishes, > Alison > > ------ > Alison Pamment ? ? ? ? ? ? ? ? ? ? ? ? ?Tel: +44 1235 778065 > NCAS/British Atmospheric Data Centre ? ?Email: > [email protected]< > mailto:[email protected]> > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > > From: CF-metadata [mailto:[email protected]] On Behalf > Of John Maurer > Sent: 21 February 2013 00:52 > To: [email protected] > Subject: [CF-metadata] sea_water_turbidity? > > Dear CF-Metadata, > I would propose the addition of "sea_water_turbidity" to the CF Standard > Names. This has units of NTU (Nephelometric Turbidity Units), which would > be represented in UDUNITS as "1e-3" (similar to how sea_water_salinity is in > PSS (or PSU) and commonly represented as 1e-3). > Thanks, > John Maurer > Data System Administrator > Pacific Islands Ocean Observing System (PacIOOS) > University of Hawaii at Manoa > > -- > Scanned by iCritical. > > -- > Scanned by iCritical. > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- Scanned by iCritical. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
