[CF-metadata] New standard names for NEMO ocean model output

Sebastien Villaume sebastien.villaume at ecmwf.int
Thu Mar 30 02:07:30 MDT 2017


Hi all,

I would like to reactivate this specific thread in order to reach an agreement and get these standard names accepted and published in the next version of the table.

I went through the whole thread and updated each proposed standard name according to the comments/suggestions made (please see below). 

I have also added two new standard names: one to deprecate an existing standard name that is not following the usual naming convention (integral_of_sea_water_potential_temperature_wrt_depth_in_ocean_layer_expressed_as_heat_content) and one derived from it to cover the whole sea water column case. It is the last two of the list below.

Since I am not an ocean model expert and in particular not a NEMO expert/user, I am welcoming any relevant comments/suggestions, especially from the NEMO community.

thanks

====================
NEMO variable: 
somixhgt
standard name: 
ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_threshold
(originally proposed as ocean_turbocline_depth)
units: 
m 

description: 
The mixed layer thickness is estimated using the depth at which the vertical eddy diffusivity coefficient (resulting from the vertical physics alone) fall below a given value defined locally. A coordinate variable or scalar coordinate variable with standard name ocean_vertical_diffusivity can be specified to indicate the value of the coefficient that was used to calculate the mixed layer thickness.

other action to take (suggested by Jonathan Gregory): 
rename the existing the standard name  ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity which refers to the level at which the diffusivity differs from its surface value by a certain amount, as ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_deficit


====================
NEMO variable:
sobpheig
standard name: 
sea_water_mass_per_unit_area_expressed_as_thickness
(originally proposed as bottom_pressure_equivalent_height)
units:
m 

description: 
This is the mass of the water column expressed as a thickness using a given reference density:

sea_water_mass_per_unit_area_expressed_as_thickness = ( sea_water_mass_per_unit_area / sea_water_density )

The thickness is the extent of a vertical column or layer. The sea water density used to do the conversion is assumed to be the density of water of standard temperature T=0°C and practical salinity S=35.0. Otherwise it should be provided as an auxiliary scalar using the standard name sea_water_density.


====================
NEMO variable:
sostheig
standard name:
ocean_steric_thickness
(originally proposed as ocean_steric_height)
units:
m 

description: 
The ocean steric thickness measures the height by which a column of water with standard temperature T=0°C and salinity S=35.0 expands if its temperature and salinity are changed to the observed values.


====================
NEMO variable:
vosthsal
standard name: 
ocean_halosteric_thickness
(originally proposed as ocean_steric_thickness_due_to_salinity)
units:
m 

description: 
The quantity with standard name ocean_halosteric_thickness is a measure of the change in thickness that would be undergone by a column of water of standard temperature T=0°C and practical salinity S=35.0 if its salinity were changed to the locally observed value. Thickness is the extent of a vertical column or layer.

====================
NEMO variable:
vosthtem
standard name: 
ocean_thermosteric_thickness
(originally proposed as ocean_steric_thickness_due_to_temperature)
units:
m 

description: 
The quantity with standard name ocean_thermosteric_thickness is a measure of the change in thickness that would be undergone by a column of water of standard temperature T=0°C and practical salinity S=35.0 if its temperature were changed to the locally observed value. Thickness is the extent of a vertical column or layer.

====================
NEMO variable:
vottrdmp
standard name: 
ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale
(originally proposed as temperature_profile_anomaly_correction)
units:
K s-1

description: 
This term is estimated as the deviation of the local sea water potential temperature from an ocean model with respect to an observation-based climatology (eg World Ocean Database) weighted by a user-specified relaxation coefficient in s-1 (1/(relaxation timescale)).

====================
NEMO variable:
vostrdmp
standard name: 
ratio_of_sea_water_practical_salinity_anomaly_to_relaxation_timescale
(originally proposed as practical_salinity_profile_anomaly_correction)
units:
s-1

description: 
This term is estimated as the deviation of the local sea water practical salinity from an ocean model with respect to an observation-based climatology (eg World Ocean Database) weighted by a user-specified relaxation coefficient in s-1 (1/(relaxation timescale)).

====================
NEMO variables:
sosal300, sosal700
standard name:
integral_of_sea_water_practical_salinity_wrt_depth_in_ocean_layer
(originally proposed as integral_of_sea_water_practical_salinity_wrt_depth)
 units:
1 

description: 
This quantity is calculated as the integral, of the sea water salinity with respect to depth, over the specified layer of the ocean from the surface to the level indicated by the vertical coordinate or scalar coordinate variable. "integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means "with respect to". "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Depth is the vertical distance below the surface. 

====================
NEMO variable:
sosalbtm
standard name:
ocean_integral_of_sea_water_practical_salinity_wrt_depth
(originally proposed as integral_of_sea_water_practical_salinity_wrt_total_depth)
units:
1 

description: 
This quantity is calculated as the integral, of the sea water salinity, over of the ocean from the sea surface to the sea bed. "integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means "with respect to". "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Depth is the vertical distance below the surface. 

====================
NEMO variables:
sohtc300, sohtc700
standard name:   
integral_of_sea_water_potential_temperature_wrt_depth_in_ocean_layer_expressed_as_heat_content
(already in the CF standard name table but should be deprecated because it does not follow usual naming convention, i.e. missing “in_ocean_layer”)
units:
J m-2 

description: 
This quantity is calculated as the integral, of the potential temperature with respect to depth, expressed as heat content, over the specified layer of the ocean from the surface to the level indicated by the vertical coordinate or scalar coordinate variable. "integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means "with respect to". "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Depth is the vertical distance below the surface. 

other action to take:
deprecate integral_of_sea_water_potential_temperature_wrt_depth_expressed_as_heat_content and set an alias to the new standard name.

=====================
NEMO variable:
sohtcbtm
standard name: 
ocean_integral_of_sea_water_potential_temperature_wrt_depth_expressed_as_heat_content
units:
J m-2 

description: 
This quantity is calculated as the integral, of the potential temperature with respect to depth, expressed as heat content, over of the ocean from the sea surface to the sea bed. "integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means "with respect to". "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Depth is the vertical distance below the surface. 

=====================
____________________________________ 

Dr. Sébastien Villaume 
Analyst 
ECMWF Shinfield Park, 
Reading RG2 9AX, UK 
+44 7825 521592 
sebastien.villaume at ecmwf.int 
____________________________________



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