`RFNC1` should be explained [here](https://github.com/ACCESS-NRI/MOM6/blob/df33a6743d0bf4a0ea9d710e9dd18319ac63d4d9/src/ALE/MOM_regridding.F90#L344-L361). Might also need to be added [here](https://github.com/ACCESS-NRI/MOM6/blob/df33a6743d0bf4a0ea9d710e9dd18319ac63d4d9/src/ALE/MOM_regridding.F90#L700-L709) and [here](https://github.com/ACCESS-NRI/MOM6/blob/df33a6743d0bf4a0ea9d710e9dd18319ac63d4d9/src/ALE/MOM_regridding.F90#L766-L775), and made consistent?
