Fix Oyr.osaltdiff discovery with yearly-only aggregation

src/access_moppy/driver.py

@@ -498,6 +498,16 @@ def __init__(
         elif table in ("Oyr", "Oday", "Omon", "Ofx") or table.startswith(
             _mip_ocean_prefixes
         ):
+            # Ocean yearly tables can legitimately aggregate from higher-frequency
+            # inputs (for example monthly -> yearly). Keep explicit user control
+            # via enable_resampling, but auto-enable for yearly ocean requests.
+            ocean_enable_resampling = self.enable_resampling or table in (
+                "Oyr",
+                "OPyr",
+                "OPyrLev",
+                "OByr",
+                "OByrLev",
+            )
             if self.model_id in ("ACCESS-OM3", "ACCESS-CM3"):
                 # ACCESS-OM3 uses MOM6 (C-grid) — requires dedicated CMORiser implementation
                 # that handles C-grid supergrid logic, MOM6 metadata, and OM3-specific conventions
@@ -510,6 +520,9 @@ def __init__(
                     vocab=self.vocab,
                     variable_mapping=self.variable_mapping.to_dict(),
                     drs_root=drs_root if drs_root else None,
+                    validate_frequency=self.validate_frequency,
+                    enable_resampling=ocean_enable_resampling,
+                    resampling_method=self.resampling_method,
                 )
             else:
                 # ACCESS-OM2 uses MOM5 (B-grid) — handled by a separate CMORiser class
@@ -523,6 +536,9 @@ def __init__(
                     vocab=self.vocab,
                     variable_mapping=self.variable_mapping.to_dict(),
                     drs_root=drs_root if drs_root else None,
+                    validate_frequency=self.validate_frequency,
+                    enable_resampling=ocean_enable_resampling,
+                    resampling_method=self.resampling_method,
                 )
         elif table in ("SImon", "SIday") or table.startswith(_mip_seaice_prefixes):
             self.cmoriser = SeaIce_CMORiser(

src/access_moppy/file_discovery.py

@@ -191,8 +191,16 @@ def _build_patterns(
     # --- Per-variable explicit override ---
     explicit = var_entry.get("file_pattern")
     if explicit:
-        # Explicit patterns are already relative to input_root
-        return [explicit] if isinstance(explicit, str) else list(explicit)
+        # Explicit patterns are already relative to input_root.
+        # They can be:
+        # - a string: one pattern for all frequencies
+        # - a list: several patterns for all frequencies
+        # - a dict: frequency-specific override, e.g. {"yr": [...], "default": ...}
+        if isinstance(explicit, dict):
+            explicit = explicit.get(freq, explicit.get("default"))
+
+        if explicit:
+            return [explicit] if isinstance(explicit, str) else list(explicit)
 
     # --- Component-level config ---
     comp_cfg = file_discovery_cfg.get("components", {}).get(component)

src/access_moppy/mappings/ACCESS-ESM1-6_mappings.json

@@ -4940,6 +4940,12 @@
             "model_variables": [
                 "salt_vdiffuse_impl"
             ],
+            "file_pattern": {
+                "yr": [
+                    "output[0-9][0-9][0-9]/ocean/ocean-*-salt_vdiffuse_impl-1mon-mean-y_*.nc",
+                    "output[0-9][0-9][0-9]/ocean/ocean-*-salt_vdiffuse_impl-1monthly-*-ym_*.nc"
+                ]
+            },
             "calculation": {
                 "type": "direct",
                 "formula": "salt_vdiffuse_impl"

src/access_moppy/ocean.py

@@ -327,6 +327,9 @@ def __init__(
         vocab: CMIP6Vocabulary,
         variable_mapping: Dict[str, Any],
         drs_root: Optional[Path] = None,
+        validate_frequency: bool = True,
+        enable_resampling: bool = False,
+        resampling_method: str = "auto",
         # Backward compatibility
         input_paths: Optional[Union[str, List[str]]] = None,
     ):
@@ -338,6 +341,9 @@ def __init__(
             vocab=vocab,
             variable_mapping=variable_mapping,
             drs_root=drs_root,
+            validate_frequency=validate_frequency,
+            enable_resampling=enable_resampling,
+            resampling_method=resampling_method,
         )
 
         nominal_resolution = vocab._get_nominal_resolution(target_realm="ocean")
@@ -399,6 +405,9 @@ def __init__(
         vocab: CMIP6Vocabulary,
         variable_mapping: Dict[str, Any],
         drs_root: Optional[Path] = None,
+        validate_frequency: bool = True,
+        enable_resampling: bool = False,
+        resampling_method: str = "auto",
         # Backward compatibility
         input_paths: Optional[Union[str, List[str]]] = None,
     ):
@@ -410,6 +419,9 @@ def __init__(
             vocab=vocab,
             variable_mapping=variable_mapping,
             drs_root=drs_root,
+            validate_frequency=validate_frequency,
+            enable_resampling=enable_resampling,
+            resampling_method=resampling_method,
         )
 
         nominal_resolution = vocab._get_nominal_resolution(target_realm="ocean")

tests/unit/test_driver.py

@@ -630,6 +630,58 @@ def test_ocean_table_selects_om2_for_non_om3_source(self, valid_config, temp_dir
 
             mock_om2.assert_called_once()
 
+    @pytest.mark.unit
+    def test_ocean_yearly_auto_enables_resampling(self, valid_config, temp_dir):
+        with (
+            patch("access_moppy.driver.load_model_mappings") as mock_load,
+            patch("access_moppy.driver.Ocean_CMORiser_OM2") as mock_om2,
+        ):
+            mock_load.return_value = {"osaltdiff": {"units": "kg m-2 s-1"}}
+            mock_om2_instance = MagicMock()
+            mock_om2_instance.ds = xr.Dataset()
+            mock_om2.return_value = mock_om2_instance
+
+            ACCESS_ESM_CMORiser(
+                input_paths=["test.nc"],
+                compound_name="Oyr.osaltdiff",
+                source_id="ACCESS-ESM1-5",
+                output_path=temp_dir,
+                experiment_id=valid_config["experiment_id"],
+                variant_label=valid_config["variant_label"],
+                grid_label=valid_config["grid_label"],
+                activity_id=valid_config["activity_id"],
+            )
+
+            kwargs = mock_om2.call_args.kwargs
+            assert kwargs["enable_resampling"] is True
+
+    @pytest.mark.unit
+    def test_ocean_monthly_does_not_auto_enable_resampling(
+        self, valid_config, temp_dir
+    ):
+        with (
+            patch("access_moppy.driver.load_model_mappings") as mock_load,
+            patch("access_moppy.driver.Ocean_CMORiser_OM2") as mock_om2,
+        ):
+            mock_load.return_value = {"tos": {"units": "K"}}
+            mock_om2_instance = MagicMock()
+            mock_om2_instance.ds = xr.Dataset()
+            mock_om2.return_value = mock_om2_instance
+
+            ACCESS_ESM_CMORiser(
+                input_paths=["test.nc"],
+                compound_name="Omon.tos",
+                source_id="ACCESS-ESM1-5",
+                output_path=temp_dir,
+                experiment_id=valid_config["experiment_id"],
+                variant_label=valid_config["variant_label"],
+                grid_label=valid_config["grid_label"],
+                activity_id=valid_config["activity_id"],
+            )
+
+            kwargs = mock_om2.call_args.kwargs
+            assert kwargs["enable_resampling"] is False
+
     @pytest.mark.unit
     def test_unsupported_table_raises_value_error_with_supported_list(
         self, valid_config, temp_dir

tests/unit/test_file_discovery.py

@@ -164,6 +164,34 @@ def test_per_variable_file_pattern_overrides_component_config(self):
         patterns = _build_patterns(var_entry, "ocean", "mon", self.fd_cfg)
         assert patterns == ["output*/ocean/ocean-2d-surface_temp-1mon-mean-y_*.nc"]
 
+    def test_per_variable_file_pattern_freq_specific_override(self):
+        var_entry = {
+            "model_variables": ["salt_vdiffuse_impl"],
+            "file_pattern": {
+                "yr": [
+                    "output*/ocean/ocean-*-salt_vdiffuse_impl-1mon-mean-y_*.nc",
+                ]
+            },
+        }
+        patterns = _build_patterns(var_entry, "ocean", "yr", self.fd_cfg)
+        assert patterns == [
+            "output*/ocean/ocean-*-salt_vdiffuse_impl-1mon-mean-y_*.nc",
+        ]
+
+    def test_per_variable_file_pattern_freq_specific_falls_back(self):
+        var_entry = {
+            "model_variables": ["salt_vdiffuse_impl"],
+            "file_pattern": {
+                "yr": [
+                    "output*/ocean/ocean-*-salt_vdiffuse_impl-1mon-mean-y_*.nc",
+                ]
+            },
+        }
+        patterns = _build_patterns(var_entry, "ocean", "mon", self.fd_cfg)
+        assert len(patterns) == 2
+        assert all("salt_vdiffuse_impl" in p for p in patterns)
+        assert all("1mon" in p or "1monthly" in p for p in patterns)
+
     def test_unknown_component_raises(self):
         with pytest.raises(FileDiscoveryError, match="No file_discovery config"):
             _build_patterns({}, "nonexistent_component", "mon", self.fd_cfg)