Add the PI_mean ozone script to the collection of ozone scripts

CMIP7/esm1p6/atmosphere/ozone/cmip7_PI_mean_ozone_generate.py

@@ -0,0 +1,67 @@
+from argparse import ArgumentParser
+from pathlib import Path
+
+import iris.coord_categorisation
+from cmip7_ancil_argparse import (
+    grid_parser,
+    path_parser,
+)
+from cmip7_ancil_common import save_ancil
+from cmip7_ancil_constants import ANCIL_TODAY
+from ozone.cmip7_ozone import (
+    fix_cmip7_ozone,
+    load_cmip7_ozone,
+    ozone_parser,
+)
+
+
+def parse_args():
+    parser = ArgumentParser(
+        parents=[path_parser(), grid_parser(), ozone_parser()],
+        prog="cmip7_PI_mean_ozone_generate",
+        description=(
+            "Generate input files from 21 year mean of UK CMIP7 historical"
+            "ozone forcings"
+        ),
+    )
+    return parser.parse_args()
+
+
+def esm_pi_ozone_save_dirpath(args):
+    return (
+        Path(args.ancil_target_dirname)
+        / "modern"
+        / "pre-industrial-mean"
+        / "forcing"
+        / args.esm_grid_rel_dirname
+        / ANCIL_TODAY
+    )
+
+
+def save_cmip7_pi_mean_ozone(args, cube):
+    # Add a "month_number" variable.
+    iris.coord_categorisation.add_month_number(
+        cube, "time", name="month_number"
+    )
+    # Aggregate by "month_number" to obtain a mean for each month.
+    cube = cube.aggregated_by("month_number", iris.analysis.MEAN)
+    # Re-create the time bounds to ensure that time is contiguous.
+    time = cube.coord("time")
+    time.bounds = None
+    time.guess_bounds(bound_position=0.5)
+    # Remove the added "month_number" coordinate before saving.
+    cube.remove_coord("month_number")
+    # Save as an ancillary file
+    save_dirpath = esm_pi_ozone_save_dirpath(args)
+    save_ancil(cube, save_dirpath, args.save_filename, gregorian=False)
+
+
+if __name__ == "__main__":
+    args = parse_args()
+
+    # Load the CMIP7 datasets
+    ozone_cube = load_cmip7_ozone(args)
+    # Match the ESM1.5 mask
+    esm_cube = fix_cmip7_ozone(args, ozone_cube)
+    # Save the ancillary
+    save_cmip7_pi_mean_ozone(args, esm_cube)