Fix wind drift (#89)

* added wind_drift parameter

this allows for altering wind_drift_factor based on the parameter in the UI

* updated whats new

Author: kthyng

docs/whats_new.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 * Fixed bug so that horizontal diffusivity is now properly applied to model output.
+* Added `wind_drift` parameter which when False makes sure that `wind_drift_factor=0` so that wind drift is not on.
 
 ## 2.5.0 (March 9, 2026)
 

particle_tracking_manager/models/opendrift/config_opendrift.py

@@ -438,6 +438,15 @@ class OceanDriftModelConfig(OpenDriftConfig):
         },
     )
 
+    wind_drift: bool = Field(
+        default=True,
+        description="If on, elements at surface are moved with a fraction, the wind draft factor, of the wind speed from the surface down to the wind drift depth.",
+        title="Wind Drift",
+        json_schema_extra={
+            "ptm_level": 1,
+        },
+    )
+
     wind_drift_depth: float = Field(
         default=0.1,
         description="The direct wind drift (windage) is linearly decreasing from the surface value (wind_drift_factor) until 0 at this depth.",
@@ -507,6 +516,14 @@ class OceanDriftModelConfig(OpenDriftConfig):
         },
     )
 
+    @model_validator(mode="after")
+    def check_wind_drift(self) -> Self:
+        """If wind_drift is False, set wind_drift_factor to 0."""
+        if not self.wind_drift:
+            self.wind_drift_factor = 0
+            logger.debug("Setting wind_drift_factor to 0 because wind_drift is False.")
+        return self
+
 
 class OpenOilModelConfig(OceanDriftModelConfig):
     """OpenOil model configuration for OpenDrift."""

tests/test_config_opendrift.py

@@ -147,6 +147,24 @@ def test_OceanDrift_init():
     )
 
 
+def test_OceanDrift_wind_drift():
+    m = OceanDriftModelConfig(
+        drift_model="OceanDrift",
+        steps=1,
+        wind_drift=False,
+    )
+
+    assert m.wind_drift_factor == 0
+
+    m = OceanDriftModelConfig(
+        drift_model="OceanDrift",
+        steps=1,
+        wind_drift=True,
+    )
+
+    assert m.wind_drift_factor == 0.02
+
+
 def test_OceanDrift_parameters():
     """Make sure OceanDrift-specific parameters are present."""
     m = OceanDriftModelConfig(drift_model="OceanDrift", steps=1)