Use config option to determine whether to add coeffs_reconstruct to the stream

polaris/ocean/config/coeffs_reconstruct.yaml

@@ -0,0 +1,9 @@
+mpas-ocean:
+  streams:
+    coeffs_reconstruct:
+      type: output
+      filename_template: coeffs_reconstruct.nc
+      output_interval: 0000_00:00:01
+      clobber_mode: truncate
+      contents:
+      - coeffs_reconstruct

polaris/ocean/model/ocean_model_step.py

@@ -213,6 +213,22 @@ def dynamic_model_config(self, at_setup: bool) -> None:
         super().dynamic_model_config(at_setup)
         if self.update_eos:
             self.update_namelist_eos()
+        if self.config.has_option('ocean', 'write_coeffs_reconstruct'):
+            self.write_coeffs_reconstruct = self.config.get(
+                'ocean', 'write_coeffs_reconstruct'
+            )
+        else:
+            self.write_coeffs_reconstruct = False
+        if self.write_coeffs_reconstruct:
+            model = self.config.get('ocean', 'model')
+            if not model == 'mpas-ocean':
+                raise ValueError(
+                    'Coefficients for vector reconstruction can only be '
+                    'written for ocean model MPAS-Ocean'
+                )
+            self.add_yaml_file(
+                'polaris.ocean.config', 'coeffs_reconstruct.yaml'
+            )
 
     def constrain_resources(self, available_cores: Dict[str, Any]) -> None:
         """

polaris/ocean/mpas_ocean.cfg

@@ -1,5 +1,11 @@
 # This config file has default config options for MPAS-Ocean
 
+[ocean]
+
+# Whether to write coeffs for reconstructing vector quantities during
+# the forward run
+write_coeffs_reconstruct = True
+
 # The paths section points polaris to external paths
 [paths]