Add a step for normalizing data iceberg and ice-shelf fluxes

This is needed for an Antarctic balance approach in which all
Antarctic solid runoff is converted into iceberg and ice-shelf
melt with the patterns from the Merino et al. (2020) and Paolo
et al. (2023) datasets.

compass/ocean/tests/global_ocean/files_for_e3sm/__init__.py

@@ -10,6 +10,9 @@
 from compass.ocean.tests.global_ocean.files_for_e3sm.e3sm_to_cmip_maps import (
     E3smToCmipMaps,
 )
+from compass.ocean.tests.global_ocean.files_for_e3sm.normalize_iceberg_ice_shelf_melt import (  # noqa: E501
+    NormalizeIcebergIceShelfMelt,
+)
 from compass.ocean.tests.global_ocean.files_for_e3sm.ocean_graph_partition import (  # noqa: E501
     OceanGraphPartition,
 )
@@ -113,12 +116,15 @@ def __init__(self, test_group, mesh=None, init=None,
         self.add_step(DiagnosticMaps(test_case=self))
         self.add_step(DiagnosticMasks(test_case=self))
 
+        self.add_step(RemapIcebergClimatology(
+            test_case=self))
+
         self.add_step(RemapIceShelfMelt(test_case=self, init=init))
 
-        self.add_step(RemapSeaSurfaceSalinityRestoring(
+        self.add_step(NormalizeIcebergIceShelfMelt(
             test_case=self))
 
-        self.add_step(RemapIcebergClimatology(
+        self.add_step(RemapSeaSurfaceSalinityRestoring(
             test_case=self))
 
         self.add_step(RemapTidalMixing(test_case=self))

compass/ocean/tests/global_ocean/files_for_e3sm/normalize_iceberg_ice_shelf_melt.py

@@ -0,0 +1,125 @@
+import os
+
+import numpy as np
+import xarray as xr
+from mpas_tools.io import write_netcdf
+
+from compass.io import symlink
+from compass.ocean.tests.global_ocean.files_for_e3sm.files_for_e3sm_step import (  # noqa: E501
+    FilesForE3SMStep,
+)
+
+
+class NormalizeIcebergIceShelfMelt(FilesForE3SMStep):
+    """
+    A step for for normalizing data iceberg and ice-shelf melt rates on the
+    MPAS grid to a total flux of 1.0 and staging them in ``assembled_files``
+    """
+    def __init__(self, test_case):
+        """
+        Create a new step
+
+        Parameters
+        ----------
+        test_case : compass.TestCase
+            The test case this step belongs to
+        """
+        super().__init__(test_case, name='normalize_iceberg_ice_shelf_melt',
+                         ntasks=1, min_tasks=1)
+
+        filename = 'Iceberg_Climatology_Merino_MPAS.nc'
+        subdir = 'remap_iceberg_climatology'
+        self.add_input_file(
+            filename=filename,
+            target=f'../{subdir}/{filename}')
+
+        filename = 'prescribed_ismf_paolo2023.nc'
+        subdir = 'remap_ice_shelf_melt'
+        self.add_input_file(
+            filename=filename,
+            target=f'../{subdir}/{filename}')
+
+    def setup(self):
+        """
+        setup input files based on config options
+        """
+        super().setup()
+        if self.with_ice_shelf_cavities:
+            self.add_output_file(filename='dib_merino_2020_normalized.nc')
+            self.add_output_file(filename='dismf_paolo2023_normalized.nc')
+
+    def run(self):
+        """
+        Run this step of the test case
+        """
+        super().run()
+
+        if not self.with_ice_shelf_cavities:
+            return
+
+        logger = self.logger
+
+        suffix = f'{self.mesh_short_name}.{self.creation_date}'
+
+        ds_dib = xr.open_dataset('Iceberg_Climatology_Merino_MPAS.nc')
+        ds_dismf = xr.open_dataset('prescribed_ismf_paolo2023.nc')
+
+        ds_mesh = xr.open_dataset('restart.nc')
+
+        area_cell = ds_mesh.areaCell
+
+        days_in_month = np.array(
+            [31., 28., 31., 30., 31., 30., 31., 31., 30., 31., 30., 31.])
+
+        weights = xr.DataArray(data=days_in_month / 365.,
+                               dims=('Time',))
+
+        total_dib_flux = (ds_dib.bergFreshwaterFluxData * weights *
+                          area_cell).sum()
+
+        total_dismf_flux = (ds_dismf.dataLandIceFreshwaterFlux *
+                            area_cell).sum()
+
+        total_flux = total_dib_flux + total_dismf_flux
+
+        logger.info(f'total_dib_flux:     {total_dib_flux:.1f}')
+        logger.info(f'total_dismf_flux:   {total_dismf_flux:.1f}')
+        logger.info(f'total_flux:         {total_flux:.1f}')
+        logger.info('')
+
+        for var in ['bergFreshwaterFluxData']:
+            ds_dib[var] = ds_dib[var] / total_flux
+
+        write_netcdf(ds_dib, 'dib_merino_2020_normalized.nc')
+
+        for var in ['dataLandIceFreshwaterFlux', 'dataLandIceHeatFlux']:
+            ds_dismf[var] = ds_dismf[var] / total_flux
+
+        write_netcdf(ds_dismf, 'dismf_paolo2023_normalized.nc')
+
+        norm_total_dib_flux = (ds_dib.bergFreshwaterFluxData * weights *
+                               area_cell).sum()
+
+        norm_total_dismf_flux = (ds_dismf.dataLandIceFreshwaterFlux *
+                                 area_cell).sum()
+
+        norm_total_flux = norm_total_dib_flux + norm_total_dismf_flux
+
+        logger.info(f'norm_total_dib_flux:     {norm_total_dib_flux:.3f}')
+        logger.info(f'norm_total_dismf_flux:   {norm_total_dismf_flux:.3f}')
+        logger.info(f'norm_total_flux:         {norm_total_flux:.3f}')
+        logger.info('')
+
+        prefix = 'Iceberg_Climatology_Merino_normalized'
+        dest_filename = f'{prefix}.{suffix}.nc'
+
+        symlink(
+            os.path.abspath('dib_merino_2020_normalized.nc'),
+            f'{self.ocean_inputdata_dir}/{dest_filename}')
+
+        prefix = 'prescribed_ismf_paolo2023_normalized'
+        dest_filename = f'{prefix}.{suffix}.nc'
+
+        symlink(
+            os.path.abspath('dismf_paolo2023_normalized.nc'),
+            f'{self.ocean_inputdata_dir}/{dest_filename}')