Dear Alison, Thank you for your comments.
> > 2) > > ratio_of_x_derivative_of_ocean_rigid_lid_pressure_to_sea_surface_densit > > y > > N kg-1 > > > > > ----------------------------------------------------------------------- > > --------- > > NB: x_derivative_of_ocean_rigid_lid_pressure is already a > > standard_name, > > and I'm proposing sea_surface_density in (1). > > > The relationship between this name and existing and proposed names is > clear. The term ratio is certainly used in standard names. Therefore I > think this name sounds reasonable (but please see the following > comments). > > Looking at the standard name table entries for ocean_rigid_lid_pressure > and x|y_derivative_of_ocean_rigid_lid_pressure which we introduced for > the NEMO model in version 10 of the table, I see that we gave them > canonical_units of N m-2 and N m-3 respectively. The usual practice in > standard names is to write N m-2 as Pa which would make the second unit > Pa m-1 and I think we should change the units of all three names in the > table. This is fine by me. > Please note that this does not in any way prevent you from > writing the quantities in a file using physically equivalent units. For > the current proposal, I think we should write the canonical units as m > s-2 which is exactly equivalent to N kg-1. Fine again - and better, I suppose, since m and s are fundamental in SI and N is derived. > M s-2 is the unit of > acceleration and I am wondering what is the physical interpretation of > the quantity you propose - does it express an acceleration in your > model? > Yes, it appears as a trend in the velocities. With a free surface height, it actually appears as g*grad(SSH), so perhaps a more suitable standard_name would be product_of_acceleration_due_to_gravity_and_x_derivative_of_sea_surface_height_above_geoid [m s-2] - but, apparently, acceleration_due_to_gravity (or anything like it) is not a CF standard_name. So we may as well stick to what I suggested before. Regards, Ian. -- Ian Culverwell B-2-81 Ocean and Sea Ice Modelling Met Office FitzRoy Road Exeter Devon EX1 3PB United Kingdom Tel: +44 (0)1392 884017 Fax: +44 (0)1392 885861 E-mail: [email protected] http://www.metoffice.gov.uk Met Office climate change predictions can now be viewed on Google Earth http://www.metoffice.gov.uk/research/hadleycentre/google/ _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
