Dear Ute Ah, I see the problem. OK. Yes, I would understand surface_Xward_sea_water_ velocity to mean the velocity of the water, not the ice.
Best wishes Jonathan > This is a citation of the CF standard > > The surface called "surface" means the lower boundary of the atmosphere. > > "Water" means water in all phases, including frozen i.e. ice and snow. A > > velocity is a vector quantity. "Eastward" indicates a vector component > > which is positive when directed eastward (negative westward). < > > (http://cfconventions.org/Data/cf-standard-names/28/build/cf-standard-name-table.html) > > In our model we distinguish between ice velocity and the water velocity under > the ice in addition to the (average) water velocity in the upper layer. Guess > we would be fine if surface_eastward_sea_water_velocity and > surface_northward_sea_water_velocity would not include ice per definition. > > With kind regards / med vennlig hilsen, > Ute > > Ute Brönner > Research Scientist & Senior Project Manager > > Direct phone (+47) 998 98 987 > Consider the environment before printing. Less print-outs, more trees, > better planet. > > -----Original Message----- > From: CF-metadata [mailto:[email protected]] On Behalf Of > Jonathan Gregory > Sent: 01 June 2017 14:39 > To: [email protected] > Subject: [CF-metadata] standard names under ice velocity of water > > Dear Ute > > I share some of Roy's concerns, and I'm puzzled by your remark: > > > surface_eastward_sea_water_velocity and > > surface_northward_sea_water_velocity > > include the velocity of water and ice together > > Please could you explain what that means? Are the ice and water moving with > the same velocity or not? > > I think it may be OK to have a stdname for the "surface" velocity for sea > water, because there isn't a unique coordinate with which to label the > surface. > For the same reason, we have a standard name of surface_temperature. > > For the "underice" velocity of sea water, if this is different from the > surface velocity, it would be better to use the phrase at_sea_ice_base, for > consistency with several existing standard names containing that phrase. > > Best wishes > > Jonathan > > > ----- Forwarded message from "Lowry, Roy K." <[email protected]> ----- > > > Date: Wed, 31 May 2017 07:58:02 +0000 > > From: "Lowry, Roy K." <[email protected]> > > To: Ute Brönner <[email protected]>, "[email protected]" > > <[email protected]> > > CC: Tor Nordam <[email protected]>, Morten Omholt Alver > > <[email protected]>, Petter Rønningen > > <[email protected]> > > Subject: Re: [CF-metadata] standard names under ice velocity of water > > > > Dear Ute, > > > > > > There is a precedent in CF for not giving separate Standard Names to a > > single geophysical variable solely on the basis of its spatial > > distribution, the classic example being air temperature where the > > meteorological standard measurement '2m air temperature' has not been given > > its own Standard Name. > > > > > > I am also strongly against separate Standard Names for 'surface' unless > > they represent unique phenomena as has been argued for sea temperature and > > sea surface velocity. > > > > > > To me assigning separate Standard Names to currents in the top x metres of > > water that happens to be under ice sets a very dangerous precedent. If you > > decide to add extra water body layers to your model - say 10-50m, and > > 50-100m would you want different Standard Names for the currents in each of > > these? > > > > > > I can see two possible solutions to your problem of semantically > > differentiating the two water body layers in your model. > > > > > > 1) Use the long name parameter attribute > > > > 2) Include a z co-ordinate variable to describe each layer > > > > > > A third option would be to do both (1) and (2). > > > > > > Cheers, Roy. > > > > > > > > > > Please note that I partially retired on 01/11/2015. I am now only working > > 7.5 hours a week and can only guarantee e-mail response on Wednesdays, my > > day in the office. All vocabulary queries should be sent to > > [email protected]. Please also use this e-mail if your requirement is > > urgent. > > > > > > ________________________________ > > From: Ute Brönner <[email protected]> > > Sent: 31 May 2017 08:24 > > To: Lowry, Roy K.; [email protected] > > Cc: Petter Rønningen; Morten Omholt Alver; Tor Nordam > > Subject: RE: [CF-metadata] standard names under ice velocity of water > > > > > > Dear Roy, > > > > > > > > I think it's because of the fact that in the upper layer (10m or so) we may > > have all four of them : > > > > > > > > 1) surface_eastward_sea_water_velocity and > > surface_northward_sea_water_velocity for water AND ice > > > > This is already a standard name with the definition that >"Water" means > > water in all phases"< so we can't use it for water only. > > > > 2) eastward_sea_ice_velocity and northward_sea_ice_velocity is the one > > we use for the ice only > > > > > > > > and > > > > > > > > 3) underice_eastward_sea_water_velocity and > > underice_northward_sea_water_velocity we propose for the water under the > > ice which is different from > > > > > > > > 4) eastward_sea_water_velocity and northward_sea_water_velocity which > > we use for the water body that is not at the surface (as the layer has > > several meters). > > > > > > > > We use the data for modelling of substances at the surface in the ice, so > > the separation of these data is important to us. > > > > > > > > > > > > With kind regards / med vennlig hilsen, > > > > Ute > > > > > > > > Ute Brönner > > > > Research Scientist & Senior Project Manager > > > > > > > > Direct phone (+47) 998 98 987 > > > > P Consider the environment before printing. Less print-outs, more trees, > > better planet. > > > > > > > > From: Lowry, Roy K. [mailto:[email protected]] > > Sent: 30 May 2017 17:50 > > To: Ute Brönner <[email protected]>; [email protected] > > Cc: Petter Rønningen <[email protected]>; Morten Omholt Alver > > <[email protected]>; Tor Nordam <[email protected]> > > Subject: Re: [CF-metadata] standard names under ice velocity of water > > > > > > > > Dear Ute, > > > > > > > > I would prefer the same Standard Name for the currents in a body of water > > whether or not it is covered by ice. What happens if you have a full year > > of data from a position where there is only ice for part of the year? Would > > you have a change of Standard Name for the water body currents when the ice > > melts? > > > > > > > > So, why not use 'eastward_sea_water_velocity' and > > 'northward_sea_water_velocity'? > > > > > > > > Cheers, Roy. > > > > > > > > Please note that I partially retired on 01/11/2015. I am now only working > > 7.5 hours a week and can only guarantee e-mail response on Wednesdays, my > > day in the office. All vocabulary queries should be sent to > > [email protected]<mailto:[email protected]>. Please also use this > > e-mail if your requirement is urgent. > > > > > > > > ________________________________ > > > > From: CF-metadata > > <[email protected]<mailto:[email protected]. > > edu>> on behalf of Ute Brönner > > <[email protected]<mailto:[email protected]>> > > Sent: 30 May 2017 15:39 > > To: [email protected]<mailto:[email protected]> > > Cc: Petter Rønningen; Morten Omholt Alver; Tor Nordam > > Subject: [CF-metadata] standard names under ice velocity of water > > > > > > > > Hei from Norway! > > > > Our institute produces metocean data including currents and ice with > > the variables > > > > eastward_sea_ice_velocity and northward_sea_ice_velocity > > surface_eastward_sea_water_velocity and > > surface_northward_sea_water_velocity > > > > The latter include the velocity of water and ice together: > > "Water" means water in all phases, including frozen i.e. ice and snow. A > > velocity is a vector quantity. "Eastward" indicates a vector component > > which is positive when directed eastward (negative westward). > > > > We are also storing the velocity of water under the ice (which one > > could assume as the difference of the two above, slightly more complicated > > I think). What would be the standard name for that velocity? If there isn't > > any yet, may we propose underice_eastward_sea_water_velocity and > > underice_northward_sea_water_velocity? > > > > With kind regards / med vennlig hilsen, Ute > > > > Ute Brönner > > Research Scientist & Senior Project Manager > > > > SINTEF Ocean > > Environmental Technology, Monitoring and Modelling > > www.sintef.no/DREAM<http://www.sintef.no/DREAM>, > > www.sintef.no/OSCAR<http://www.sintef.no/OSCAR> > > > > OSCAR – Oil Spill Contingency and Response - > > SINTEF<http://www.sintef.no/OSCAR> > > > > www.sintef.no<http://www.sintef.no> > > > > > > > > > > DREAM – Dose-related Risk and Effects Assessment Model - > > SINTEF<http://www.sintef.no/DREAM> > > > > www.sintef.no<http://www.sintef.no> > > > > > > > > > > Direct phone (+47) 998 98 987 > > Visiting: Brattørkaia 17C > > Post: SINTEF Ocean AS, Postbox 4762 Sluppen, N-7465 Trondheim > > > > • Consider the environment before printing. 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