[CF-metadata] standard names for FAFMIP passive tracers

From: Jonathan Gregory <j.m.gregory>
Date: Mon, 19 Mar 2018 18:31:45 +0000

Dear all

Martin and Alison have pointed out that four standard names needed for FAFMIP
haven't yet been proposed. That was my oversight. I would now like to propose:

sea_water_added_conservative_temperature, degC
A passive tracer in an ocean model whose surface flux does not come from the
atmosphere but is imposed externally upon the simulated climate system. The
surface flux is expressed as a heat flux and converted to a passive tracer
increment as if it were a heat flux being added to conservative temperature.
The passive tracer is transported within the ocean as if it were conservative
temperature. The passive tracer is zero in the control climate of the model.
The passive tracer records added heat, as described for the CMIP6 FAFMIP
experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas.
** Then repeat the definition of sea_water_conservative_temperature.

sea_water_added_potential_temperature, degC
A passive tracer in an ocean model whose surface flux does not come from the
atmosphere but is imposed externally upon the simulated climate system. The
surface flux is expressed as a heat flux and converted to a passive tracer
increment as if it were a heat flux being added to potential temperature. The
passive tracer is transported within the ocean as if it were potential
temperature. The passive tracer is zero in the control climate of the model.
The passive tracer records added heat, as described for the CMIP6 FAFMIP
experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas.
Potential temperature of sea water is the temperature a parcel of sea water
would have if moved adiabatically to sea level pressure.

sea_water_redistributed_conservative_temperature, degC
A passive tracer in an ocean model which is subject to an externally imposed
perturbative surface heat flux. The passive tracer is initialised to the
conservative temperature in the control climate before the perturbation is
imposed. Its surface flux is the heat flux from the atmosphere, not including
the imposed perturbation, and is converted to a passive tracer increment as
if it were being added to conservative temperature. The passivetracer is
transported within the ocean as if it were conservative temperature. The
passive tracer records redistributed heat, as described for the CMIP6 FAFMIP
experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas.
** Then repeat the definition of sea_water_conservative_temperature.

sea_water_redistributed_potential_temperature, degC
A passive tracer in an ocean model which is subject to an externally imposed
perturbative surface heat flux. The passive tracer is initialised to the
potential temperature in the control climate before the perturbation is
imposed. Its surface flux is the heat flux from the atmosphere, not including
the imposed perturbation, and is converted to a passive tracer increment
as if it were being added to potential temperature. The passive tracer is
transported within the ocean as if it were potential temperature. The passive
tracer records redistributed heat, as described for the CMIP6 FAFMIP
experiment (doi:10.5194/gmd-9-3993-2016), following earlier ideas.
Potential temperature of sea water is the temperature a parcel of sea water
would have if moved adiabatically to sea level pressure.

I note that in Table 3 of the paper cited we said "additional" temperature for
the standard names, but throughout the rest of the paper we referred to "added"
heat (not "additional"), following earlier literature, and in the existing
CF-netCDF data produced for FAFMIP we have used "added" in the standard names.
Hence I think this must have been a change of mind and should be regarded as
a mistake in the paper. We will make a note of it on the FAFMIP website once
this proposal has been decided upon.

Cheers

Jonathan
Received on Mon Mar 19 2018 - 12:31:45 GMT