Dear Olivier,
Thank you for your proposals. I have some comments/questions (please see below).
> 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.
This name looks fine and is clearly related to the existing name global_average_sea_level_change. The units of m/year are sensible. We have used time units of years for one or two other names such as age_of_sea_ice. We should add the standard text for 'tendency' to the definition, i.e., ' "tendency_of_X" means derivative of X with respect to time.'
> tendency_of_local_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. Local means the
> quantity is depicted locally. "tendency_of_X" means derivative of X with respect to time.
This name looks fine. The units are OK. Again we need to add text to the definition regarding 'tendency'. By 'local' I assume you mean any area that is less than global and this would need to be indicated by adding bounds on the horizontal coordinate variables, or perhaps by using a coordinate variable with a standard name of 'region' if the area is something like the North Atlantic. We should add some explanatory text to the definition. Is this OK?
> global_average_sea_level_change_annual_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.
> global_average_sea_level_change_semiannual_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.
I wonder, do we really need "annual" and "semiannual" in the names? Presumably the date to which the amplitude applies would need to be specified by a time coordinate variable or scalar variable with bounds to indicate the averaging period. Couldn't we then have a general name of global_average_sea_level_change_amplitude without the need to specify annual or semiannual separately?
> global_average_sea_level_change_annual_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.
> global_average_sea_level_change_semiannual_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.
I'm not sure I understand what the phase quantities are. Do they indicate a seasonal cycle in sea level change? What is the datum for measuring the phase (i.e., what would a phase of zero degrees mean)? Also, as for the amplitude names, I wonder if we need separate 'annual' and 'semiannual' names for the phases?
Best wishes,
Alison
> Thanks for your comments!
>
> Best wishes
>
> Olivier.
>
>
>
> Olivier Lauret
> Project Engineer
> Satellite Oceanography Division
>
> E-mail: olauret at cls.fr
> Tel. +33 561 394 851; Fax +33 561 393 782
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Oxford, Didcot, OX11 0QX, U.K.
--
Scanned by iCritical.
Received on Mon Jul 02 2012 - 06:28:53 BST
