Regrid iceberg fluxes on OM3 grid

[anton-seaice]

Closes #119

This change adds a script to regrid iceberg flux climatology onto the OM3 grid.

The two input files are hardcoded:

AQ_MELT_PATTERN = "/g/data/av17/access-nri/OM3/Mankoff_2025_V9/AQ_iceberg_melt.nc"
GL_MELT_PATTERN = "/g/data/av17/access-nri/OM3/Mankoff_2025_V9/GL_iceberg_melt.nc"

and in the script, the melt pattern is combined for all regions, and hemispheres.

Example output in /g/data/tm70/as2285/making_inputs/om3-scripts/rof_pattern_generation/access-om3-100km-rofi-spread.nc

I've refactored regrid_forcing.py to generalise it a little and move into a separate file.

I regenerated SFe_Hamiltonetal2020_monthly_clim and checked the results matched:

[access-hive-bot]

This pull request has been mentioned on ACCESS Hive Community Forum. There might be relevant details there:

https://forum.access-hive.org.au/t/access-om3-development-highlights-updates/5902/3

[dougiesquire]

@anton-seaice, I tried to run this and got:

$ python3 generate_rofi_pattern.py --topog-file=/g/data/vk83/configurations/inputs/access-om3/share/grids/global.100km/2020.10.22/topog.nc --hgrid-filename=/g/data/vk83/configurations/inputs/access-om3/mom/grids/mosaic/global.100km/2020.05.30/ocean_hgrid.nc --output-filename=./test.nc
/g/data/xp65/public/apps/med_conda/envs/analysis3-26.03/lib/python3.12/site-packages/xesmf/backend.py:42: UserWarning: Input array is not F_CONTIGUOUS. Will affect performance.
  warnings.warn('Input array is not F_CONTIGUOUS. ' 'Will affect performance.')
/g/data/xp65/public/apps/med_conda/envs/analysis3-26.03/lib/python3.12/site-packages/xesmf/backend.py:42: UserWarning: Input array is not F_CONTIGUOUS. Will affect performance.
  warnings.warn('Input array is not F_CONTIGUOUS. ' 'Will affect performance.')
Traceback (most recent call last):
  File "/g/data/tm70/ds0092/software/om3-scripts/rof_pattern_generation/generate_rofi_pattern.py", line 229, in <module>
    main()
  File "/g/data/tm70/ds0092/software/om3-scripts/rof_pattern_generation/generate_rofi_pattern.py", line 172, in main
    weights_da = move_runoff_on_land(regrid.grid_dest, mask, forcing_regrid_glob)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/g/data/tm70/ds0092/software/om3-scripts/rof_pattern_generation/generate_rofi_pattern.py", line 67, in move_runoff_on_land
    grid_dest["mask"] = xr.DataArray(mask, dims=["ny", "nx"])
    ^^^^^^^^^
NameError: name 'grid_dest' is not defined. Did you mean: 'grid_mask'?

[anton-seaice]

I've re-run after the changes, and checked it produces the same netcdf files as previously for both the rof pattern and SFe forcing file.

[anton-seaice]

Thanks @dougiesquire - ready for another look

[anton-seaice]

Should be ready @dougiesquire

[dougiesquire]

Thanks @anton-seaice looks good (assuming you've tested using the latest version of the code)