Enable meridional ocean tracer transport diagnostics

CMIP7 CMIP7 development
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1

Greetings all,

A set of meridional heat and salt transport diagnostics was produced for CMIP6 but the required outputs are currently missing from ESM1.6.
The work to enable these outputs is just related to the experiment setup, but will still require some help.

The CMIP variables in question are htovgyre,htovovrt, sltovgyre, sltovovrt, which are gyre and overturning transport components, and within the files are values for different ocean basin systems.

MOM5 needs an ocean basin mask file to write the required output.
The file exists in an ESM1.5 configuration directory (/g/data/vk83/configurations/inputs/access-esm1p5/modern/share/ocean/basins/global.1deg/2020.05.19/basin_mask.nc) but doesn’t seem to be in the ESM1.6 directory.

MOM5 also needs to the told to use the basin mask with a flag in the namelist file, by adding “read_basin_mask=.true.” to &ocean_tracer_advect_nml in input.nml
(Note, this was actually missing for ESM1.5, a user/collaborator has just pointed out this bug.)

And then there are outputs to be added to the ESM1.6/MOM5 diag_table, e.g. temp_merid_flux_gyre_global, for temperature and salt, gyres and overturning, for the required basins (a full list is in the ESM1.5 diag_table).

Any help would be appreciated.
Cheers,

2

@matthew.chamberlain The ESM1.6 “team” has discussed this.
It turns out there is a reason why these diagnostics are not enabled in the current setup: we had to turn off the collation and these diagnostics don’t work without it, according to @spencerwong who worked on this.

We have a plan to review the ESM1.6 outputs in the coming weeks so we’ll consider this as well and see whether we can get this to work.