Add area of contour field on eddy detection

Author: AntSimi

src/py_eddy_tracker/__init__.py

@@ -235,6 +235,28 @@ def parse_args(self, *args, **kwargs):
             "the eddy and the SSH around the effective contour defining the eddy edge",
         ),
     ),
+    speed_area=dict(
+        attr_name="speed_area",
+        nc_name="speed_area",
+        nc_type="float32",
+        nc_dims=("obs",),
+        nc_attr=dict(
+            long_name="Speed area",
+            units="m^2",
+            comment="Area enclosed by speed contour in m^2",
+        ),
+    ),
+    effective_area=dict(
+        attr_name="effective_area",
+        nc_name="effective_area",
+        nc_type="float32",
+        nc_dims=("obs",),
+        nc_attr=dict(
+            long_name="Effective area",
+            units="m^2",
+            comment="Area enclosed by effective contour in m^2",
+        ),
+    ),
     speed_average=dict(
         attr_name="speed_average",
         scale_factor=0.0001,

src/py_eddy_tracker/dataset/grid.py

@@ -819,6 +819,12 @@ def eddy_identification(
                     obs.obs["radius_e"] = eddy_radius_e
                     obs.obs["shape_error_e"] = aerr_e
                     obs.obs["shape_error_s"] = aerr_s
+                    obs.obs["speed_area"] = poly_area(
+                        *coordinates_to_local(*xy_s, lon0=centlon_s, lat0=centlat_s)
+                    )
+                    obs.obs["effective_area"] = poly_area(
+                        *coordinates_to_local(*xy_e, lon0=centlon_s, lat0=centlat_s)
+                    )
                     obs.obs["lon"] = centlon_s
                     obs.obs["lat"] = centlat_s
                     obs.obs["lon_max"] = centlon_i

src/py_eddy_tracker/observations/observation.py

@@ -138,6 +138,8 @@ class EddiesObservations(object):
         "time",
         "shape_error_e",
         "shape_error_s",
+        "speed_area",
+        "effective_area",
         "nb_contour_selected",
         "num_point_e",
         "num_point_s",