[CF-metadata] Surfaces under ice vs. above ice : sea water surface vs surface in standard names.

From: Martin Juckes - UKRI STFC <martin.juckes>
Date: Thu, 7 Feb 2019 17:16:21 +0000

Dear All,


while reviewing CMIP6 metadata specifications I came across a few anomalies regarding the distinction between the upper surface of the liquid ocean (which may be under ice) vs. the lower surface of the atmosphere (which would be above the ice).

(1) sea_water_pressure_at_sea_water_surface and
net_downward_shortwave_flux_at_sea_water_surface;

The names of these two terms suggest that they are intended to be different from, for example, surface_net_downward_shortwave_flux. They have been requested by OMIP for diagnostics which are intended to represent the air/sea or ice/sea interface, on the air/ice interface. The problem is that the descriptions use the standard phrase 'The surface called "surface" means the lower boundary of the atmosphere', which is wrong in this case. Can this be changed to: 'The phrase "sea water surface" means the upper boundary of the liquid portion of an ocean or sea, including the boundary to floating ice if present.'

(2) surface_downward_x/y_stress and surface_downward_x/y_stress_correction;

There is nothing wrong with these terms, but they have been wrongly used to represent stresses applied to the liquid ocean. To correct this we need four new terms. I propose using the "_at_sea_water_surface" construction, based on the two terms above:

  * downward_x_stress_at_sea_water_surface
  * downward_y_stress_at_sea_water_surface
  * downward_x_stress_correction_at_sea_water_surface
  * downward_y_stress_correction_at_sea_water_surface

As above, the description should include the sentence:
'The phrase "sea water surface" means the upper boundary of the liquid portion of an ocean or sea, including the boundary to floating ice if present.'

regards,
Martin
Received on Thu Feb 07 2019 - 10:16:21 GMT