MOM6 vgrid support

[aekiss]

These tools currently assume a MOM5 vgrid is used, which has 2n+1 values for an n-level grid. They therefore produce incorrect results if a MOM6 vgrid with n+1 levels is used.

Perhaps an option should be provided to use MOM6 vertical grids?

[micaeljtoliveira]

@aekiss Could you briefly explain the differences between the MOM5 and MOM6 vertical grids?

[aekiss]

MOM5 ocean_vgrid.nc (e.g. /g/data/vk83/experiments/inputs/access-om2/ocean/grids/vertical/global.1deg/2020.10.22/ocean_vgrid.nc) is a supergrid, with 2n+1 interleaved cell boundaries and centres.

MOM6 ocean_vgrid.nc (e.g. /g/data/vk83/experiments/inputs/access-om3/mom/grids/vertical/global.1deg/2023.07.28/ocean_vgrid.nc) has only n+1 cell boundaries and is missing cell centres.

[micaeljtoliveira]

@aekiss I've got a PR that adds support for MOM6 vertical grids here: #35