New generate-history utility for creating synthetic history files

[ceblanton]

Description
New pip-installed tool that uses pyfms to drive the FMS diag manager and produce synthetic but usable NetCDF history files without running a real model. It supports three grid types — regular lat/lon, cubed-sphere atmosphere (6-tile gnomonic, via mpirun -n 6), and tripolar ocean — and for each native grid it also writes the FMS mosaic and supergrid files needed to regrid the output with fregrid.

How Has This Been Tested?
I pip installed following the README instructions and used this example diag-yaml:

title: test_diag_manager
base_date: 2 1 1 1 1 1
diag_files:
- file_name: annual
  freq: 12 months
  time_units: days
  unlimdim: time
  varlist:
  - module: atmos
    var_name: tas
    reduction: average
    kind: r4
- file_name: annual_inst
  freq: 12 months
  time_units: days
  unlimdim: time
  varlist:
  - module: atmos
    var_name: tas
    reduction: none
    kind: r4

Then, I created 3 flavors of "history" output:

1. Generic lat/lon

generate-history diag_table.yaml --nx 32 --ny 32 --nz 2 --calendar noleap --nsteps 8 --output-dir out.regular

2. Cubed-sphere

mpirun -n 6 generate-history diag_table.yaml --grid-type cubed-sphere --ntile 6 --calendar=noleap --output-dir out.cubed --nsteps 8 --ntile 96

3. Tripolar

generate-history diag_table.yaml --grid-type tripolar --nx 60 --ny 40 --nz 2 --calendar noleap --nsteps 8 --output-dir out.tripolar

The output looked plausible in all 3 cases. Then I regridded the cubed-sphere and tripolar files, with usable mosaic files generate along with the history files.

4. Cubed-sphere to lat/lon

fregrid --input_mosaic C96_mosaic.nc --input_file annual --scalar_field tas --output_file regridded.nc --nlat 90 --nlon 180

5. Tripolar to lat/lon

fregrid --input_mosaic ocean_mosaic.nc --input_file annual --scalar tas --output_file regridded.nc --nlat 90 --nlon 180

fregrid worked in both cases.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included

[ceblanton]

Installation instructions for GFDL systems:

module load gcc mpich netcdf-c netcdf-fortran

# install libyaml from source (https://pyyaml.org/wiki/LibYAML)
wget http://pyyaml.org/download/libyaml/yaml-0.2.5.tar.gz
tar -xf yaml-0.2.5.tar.gz
cd yaml-0.2.5
./configure --prefix=$HOME/local
make
make install
setenv PKG_CONFIG_PATH $HOME/local/lib/pkgconfig
setenv CPATH $HOME/local/include

python3.12 -m venv ~/python-envs/pyfms
source ~/python-envs/pyfms/activate

pip install -v -e '.[dev]'