fix time_bnds issue

Author: rhaegar325

src/access_moppy/ocean.py

@@ -55,10 +55,13 @@ def _get_dim_rename(self):
     def select_and_process_variables(self):
         """Select and process variables for the CMOR output."""
         input_vars = self.mapping[self.cmor_name]["model_variables"]
+        time_bnds = ["time_bnds"]
         calc = self.mapping[self.cmor_name]["calculation"]
 
-        required_vars = set(input_vars)
+        required_vars = set(input_vars + time_bnds)
         self.load_dataset(required_vars=required_vars)
+
+        dim_rename = self._get_dim_rename()
         self.sort_time_dimension()
 
         if calc["type"] == "direct":
@@ -70,7 +73,6 @@ def select_and_process_variables(self):
         else:
             raise ValueError(f"Unsupported calculation type: {calc['type']}")
 
-        dim_rename = self._get_dim_rename()
 
         dims_to_rename = {
             k: v for k, v in dim_rename.items() if k in self.ds[self.cmor_name].dims
@@ -88,11 +90,14 @@ def select_and_process_variables(self):
 
         self.grid_type, self.symmetric = self.infer_grid_type()
         # Drop all other data variables except the CMOR variable
-        self.ds = self.ds[[self.cmor_name]]
+        self.ds = self.ds[[self.cmor_name,time_bnds[0]]]
 
         # Drop unused coordinates
         used_coords = set()
-        for dim in self.ds[self.cmor_name].dims:
+        dims = list(self.ds[self.cmor_name].dims)
+        if time_bnds[0] in self.ds:
+            dims = list(dict.fromkeys(dims + list(self.ds[time_bnds[0]].dims)))
+        for dim in dims:
             if dim in self.ds.coords:
                 used_coords.add(dim)
             else:
@@ -102,6 +107,7 @@ def select_and_process_variables(self):
                         used_coords.add(coord)
         self.ds = self.ds.drop_vars([c for c in self.ds.coords if c not in used_coords])
 
+
     def update_attributes(self):
         grid_type = self.grid_type
         arakawa = self.arakawa