Sorry, I think there's a confusing point about item 4. The term wave in your definition has many definitions, including in physical oceanography (see http://en.wikipedia.org/wiki/Wave_(disambiguation) for a longer list). Can we clarify its use refers not to an oceanographic wave, but (presumably) to a wave function representing the rate of sea level change? (Or does it actually relate to ocean waves? In which case I don't understand what it has to do with sea level change.) John
On Jul 16, 2012, at 03:01, Lauret Olivier wrote: > > Dear Jonathan, > > I think following the previous exchanges > > 1. tendency_of_global_average_sea_level_change (m/year) > Global average sea level change is due to change in volume of the water in > the ocean, caused by mass and/or density change, or to change in the volume > of the ocean basins, caused by tectonics etc. It is sometimes called > "eustatic", which is a term that also has other definitions. It differs from > the change in the global average sea surface height relative to the centre of > the Earth by the global average vertical movement of the ocean floor. Zero > sea level change is an arbitrary level. "tendency_of_X" means derivative of X > with respect to time. > > 2. tendency_of_sea_surface_height_above_sea_level (m/year) > “Sea_level means mean sea level, which is close to the geoid in sea areas. > "Sea surface height" is a time-varying quantity. "tendency_of_X" means > derivative of X with respect to time.” > > > 3. global_average_sea_level_change_amplitude (m) > “Global average sea level change is due to change in volume of the water in > the ocean, caused by mass and/or density change, or to change in the volume > of the ocean basins, caused by tectonics etc. It is sometimes called > "eustatic", which is a term that also has other definitions. It differs from > the change in the global average sea surface height relative to the centre of > the Earth by the global average vertical movement of the ocean floor. Zero > sea level change is an arbitrary level. Amplitude is the magnitude of a wave > modeled by a sinusoidal function.” > > > 4. global_average_sea_level_change_phase (degree) > “Global average sea level change is due to change in volume of the water in > the ocean, caused by mass and/or density change, or to change in the volume > of the ocean basins, caused by tectonics etc. It is sometimes called > "eustatic", which is a term that also has other definitions. It differs from > the change in the global average sea surface height relative to the centre of > the Earth by the global average vertical movement of the ocean floor. Zero > sea level change is an arbitrary level. Phase is the initial angle of a wave > modeled by a sinusoidal function.” > > ..could be added as new standard names. > > There is still one problem to be solved, it’s about how to mention that it > is for example annual, or semi-annual, or 60 days amplitude and phase of the > signal. You suggested to precise it into coordinates variables and introduce > a standard name such as “harmonic_period”. Shall we use seconds units for > that quantity, which are canonical units? > For the definition, CF already provides “A period is an interval of time, or > the time-period of an oscillation.”. > > Thanks! > > Olivier > > > -----Message d'origine----- > De : CF-metadata [mailto:[email protected]] De la part de > Jonathan Gregory > Envoyé : jeudi 12 juillet 2012 15:57 > À : [email protected] > Objet : Re: [CF-metadata] Standard names for sea level change > > Dear Olivier > > > Yes, 'tendency_of_sea_surface_height_above_sea_level' is fine for me. I > > confirm the "sea_level" part of the standard name is a time mean sea level. > > Very good. Is this now the only new standard name you are proposing? > > Cheers > > Jonathan > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > Cliquez sur l'url suivante > https://www.mailcontrol.com/sr/OmYi9y4JosPTndxI!oX7UuwsCvtBvNjW4fPpH+hXuRZaEULIFOIvJYSBpeuTGVZ00xS3LQ2e9AtPbv5+FCDqIw== > > si ce message est indésirable (pourriel). > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ---------------- John Graybeal <mailto:[email protected]> phone: 858-534-2162 Product Manager Ocean Observatories Initiative Cyberinfrastructure Project: http://ci.oceanobservatories.org Marine Metadata Interoperability Project: http://marinemetadata.org
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