To turn an ocean grid cell into a land point (from the ocean model point of view): the main things you need to do are
(1) edit the topog.nc, i.e. set an exisiting non-zero depth cell to zero.
(2) Re-run a tool that creates the grid_spec.nc input file based on the edited topog.nc.
I have outlined a procedure to do this for the GFDL CM2.1 model, in step 1 of this wiki. Since ACCESS-ESM uses the same ocean, the procedure is basically the same (for the ocean model side). You will just have to use the ACCESS-ESM grid input files rather than the ones I used in my example (it’s a different resolution).
The slight complication here is that MOM5 can accept the grid_spec.nc input file using the “old method”, where all grid variables are included in grid_spec.nc, or the “new method”, where grid_spec.nc specifies the grid files through mosaic files that point to individual grid inputs for each model component.
I have noticed that ACCESS-ESM1.5 uses the “old method”… whereas the tool I specified creates these inputs using the “new method”, i.e. using mosaic input files. It is entirely possible to go between the two methods of creating grid_spec.nc, and I’m endeavouring to do this as a test case. I am going to try to do that… will report back to this post when I have more info.