[CF-metadata] Standard names for CF trac ticket #143

alison.pamment at stfc.ac.uk alison.pamment at stfc.ac.uk
Thu May 18 05:37:54 MDT 2017


Dear Jonathan, All,

CF trac ticket #143 (https://cf-trac.llnl.gov/trac/ticket/143) has been agreed and will be included in CF 1.7. A number of new standard names are needed to support the implementation of this ticket. They are names for constants used in the formula_terms attribute of parameterized vertical coordinates.

The following names are proposed.

air_pressure_at_top_of_atmosphere_model (Pa)
' "Top of atmosphere model" means the upper boundary of the top layer of an atmosphere model.'

altitude_at_top_of_atmosphere_model (m)
'Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. "Top of atmosphere model" means the upper boundary of the top layer of an atmosphere model.'

reference_air_pressure_for_atmosphere_vertical_coordinate (Pa)
'For models using a dimensionless vertical coordinate, for example, sigma, hybrid sigma-pressure or eta, the values of the vertical coordinate at the model levels are calculated relative to a reference level. "Reference air pressure" is the air pressure at the model reference level. It is a model-dependent constant."

height_above_geopotential_datum_at_top_of_atmosphere_model (m)
' "Height_above_X" means the vertical distance above the named surface X. The "geopotential datum" is the geopotential reference level (level of zero geopotential) where this is not a specifically named level such as the geoid or a reference ellipsoid. "Top of atmosphere model" means the upper boundary of the top layer of an atmosphere model.'

height_above_geopotential_datum (m)
'"Height_above_X" means the vertical distance above the named surface X. The "geopotential datum" is the geopotential reference level (level of zero geopotential) where this is not a specifically named level such as the geoid or a reference ellipsoid.'

surface_height_above_geopotential_datum (m)
' "Height_above_X" means the vertical distance above the named surface X. The surface called "surface" means the lower boundary of the atmosphere. The "geopotential datum" is the geopotential reference level (level of zero geopotential) where this is not a specifically named level such as the geoid or a reference ellipsoid.'

sea_surface_height_above_geopotential_datum (m)
' "Height_above_X" means the vertical distance above the named surface X. The "geopotential datum" is the geopotential reference level (level of zero geopotential) where this is not a specifically named level such as the geoid or a reference ellipsoid. "Sea surface height" is a time-varying quantity.'

sea_floor_depth_below_geopotential_datum (m)
' "Depth_below_X" means the vertical distance below the named surface X. The "geopotential datum" is the geopotential reference level (level of zero geopotential) where this is not a specifically named level such as the geoid or a reference ellipsoid.'

sea_floor_depth_below_reference_ellipsoid (m)
' "Depth_below_X" means the vertical distance below the named surface X. A reference ellipsoid is a regular mathematical figure that approximates the irregular shape of the geoid. A number of reference ellipsoids are defined for use in the field of geodesy.'

height_above_sea_level (m)
' "Height_above_X" means the vertical distance above the named surface X. "sea_level" means mean sea level, which is close to the geoid in sea areas.'

I have based the definitions on my own reading of ticket #143 and on existing names. I'd welcome comments to improve them.

Best wishes,
Alison

------
Alison Pamment                                                       Tel: +44 1235 778065
Centre for Environmental Data Analysis         Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory     
R25, 2.22
Harwell Campus, Didcot, OX11 0QX, U.K.






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