diff --git a/lib/iris/_merge.py b/lib/iris/_merge.py
index 15a6933c49..14d17da6ee 100644
--- a/lib/iris/_merge.py
+++ b/lib/iris/_merge.py
@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2010 - 2012, Met Office
+# (C) British Crown Copyright 2010 - 2013, Met Office
 #
 # This file is part of Iris.
 #
@@ -582,7 +582,7 @@ def _is_dependent(dependent, independent, positions, function_mapping=None):
     return valid
 
 
-def _derive_separable_consistent_groups(relation_matrix, separable_group):
+def _derive_consistent_groups(relation_matrix, separable_group):
     """
     Determine the largest combinations of candidate dimensions within the
     separable group that are self consistently separable from one another.
@@ -656,7 +656,7 @@ def _build_separable_group(space, group, separable_consistent_groups, positions,
         participates in a functional relationship.
 
     Returns:
-        None.
+        Boolean.
 
     """
     valid = False
@@ -683,8 +683,8 @@ def _build_separable_group(space, group, separable_consistent_groups, positions,
     if valid:
         space.update({name: None for name in independent})
         space.update({name: tuple(independent) for name in dependent})
-    else:
-        raise iris.exceptions.NotYetImplementedError('No functional relationship between separable and inseparable candidate dimensions.')
+
+    return valid
 
 
 def _build_inseparable_group(space, group, positions, function_matrix):
@@ -820,7 +820,8 @@ def derive_space(groups, relation_matrix, positions, function_matrix=None):
           participates in a functional relationship.
 
     Returns:
-        A space dictionary describing the relationship between each candidate dimension. 
+        A space dictionary describing the relationship between each
+        candidate dimension. 
 
     """
     space = {}
@@ -829,22 +830,33 @@ def derive_space(groups, relation_matrix, positions, function_matrix=None):
         separable_group = _derive_separable_group(relation_matrix, group)
 
         if len(group) == 1 and not separable_group:
-            # This single candidate dimension is separable from all other candidate dimensions
-            # in the group, therefore it is a genuine dimension of the space.
+            # This single candidate dimension is separable from all other
+            # candidate dimensions in the group, therefore it is a genuine
+            # dimension of the space.
             space.update({name: None for name in group})
         elif separable_group:
-            # Determine the largest combination of the candidate dimensions 
+            # Determine the largest combination of the candidate dimensions
             # in the separable group that are consistently separable.
-            separable_consistent_groups = _derive_separable_consistent_groups(relation_matrix, separable_group)
-            _build_separable_group(space, group, separable_consistent_groups, positions, function_matrix)
+            consistent_groups = _derive_consistent_groups(relation_matrix,
+                                                          separable_group)
+            if not _build_separable_group(space, group, consistent_groups,
+                                          positions, function_matrix):
+                # There is no relationship between any of the candidate
+                # dimensions in the separable group, so merge them together
+                # into a new combined dimesion of the space.
+                _build_combination_group(space, group,
+                                         positions, function_matrix)
         else:
             # Determine whether there is a scalar relationship between one of
-            # the candidate dimensions and each of the other candidate dimensions 
-            # in this inseparable group.
-            if not _build_inseparable_group(space, group, positions, function_matrix):
-                # There is no relationship between any of the candidate dimensions in this 
-                # inseparable group, so merge them together into a new combined dimension of the space.
-                _build_combination_group(space, group, positions, function_matrix)
+            # the candidate dimensions and each of the other candidate
+            # dimensions in this inseparable group.
+            if not _build_inseparable_group(space, group,
+                                            positions, function_matrix):
+                # There is no relationship between any of the candidate
+                # dimensions in this inseparable group, so merge them together
+                # into a new combined dimension of the space.
+                _build_combination_group(space, group,
+                                         positions, function_matrix)
 
     return space
 
@@ -1064,7 +1076,8 @@ def _define_space(self, space, positions, indexes, function_matrix):
                     dim_by_name[name] = len(self._shape)
                     self._nd_names.append(name)
                     self._shape.append(len(cells))
-                    self._cache_by_name[name] = {cell:index for index, cell in enumerate(cells)}
+                    self._cache_by_name[name] = {cell: index for index, cell \
+                                                     in enumerate(cells)}
                 else:
                     # TODO: Consider appropriate sort order (ascending, decending) i.e. use CF positive attribute.
                     cells = sorted(indexes[name])
@@ -1086,7 +1099,8 @@ def _define_space(self, space, positions, indexes, function_matrix):
                         else:
                             self._dim_templates.append(_Template(dim, points, bounds, kwargs))
                         self._shape.append(len(cells))
-                        self._cache_by_name[name] = {cell:index for index, cell in enumerate(cells)}
+                        self._cache_by_name[name] = {cell: index for index, cell \
+                                                         in enumerate(cells)}
 
         # Second pass - Build the auxiliary coordinate templates for the space.
         for name in names:
@@ -1202,10 +1216,10 @@ def _build_coordinates(self):
 
         # Build the dimension coordinates.
         for template in self._dim_templates:
-            # sometimes its not possible to build a dim coord (for example, 
-            # if your bounds are not monotonic, so try building the coordinate,
-            # and if it fails make the coordinate into a aux coord. This will
-            # ultimately make an anonymous dimension. 
+            # Sometimes it's not possible to build a dim coordinate e.g.
+            # the bounds are not monotonic, so try building the coordinate,
+            # and if it fails make the coordinate into an auxiliary coordinate.
+            # This will ultimately make an anonymous dimension.
             try:
                 coord = iris.coords.DimCoord(template.points,
                                              bounds=template.bounds,
@@ -1214,10 +1228,10 @@ def _build_coordinates(self):
             except ValueError:
                 self._aux_templates.append(template)
 
-        # there is the potential that there are still anonymous dimensions
-        # get a list of the dimensions which are not anonymous at this stage
-        covered_dims = [dim_coord_and_dim.dims 
-                        for dim_coord_and_dim in dim_coords_and_dims]
+        # There is the potential that there are still anonymous dimensions.
+        # Get a list of the dimensions which are not anonymous at this stage.
+        covered_dims = [dim_coord_and_dim.dims \
+                            for dim_coord_and_dim in dim_coords_and_dims]
 
         # Build the auxiliary coordinates.
         for template in self._aux_templates:
@@ -1271,6 +1285,10 @@ def _add_cube(self, cube, coord_payload):
         """Create and add the source-cube skeleton to the ProtoCube."""
 
         skeleton = _Skeleton(coord_payload.scalar.values, cube._data)
+        # Attempt to do something sensible with mixed scalar dtypes.
+        for i, metadata in enumerate(coord_payload.scalar.metadata):
+            if metadata.points_dtype > self._coord_metadata[i].points_dtype:
+                self._coord_metadata[i] = metadata
         self._skeletons.append(skeleton)
 
     def _extract_coord_payload(self, cube):
@@ -1301,10 +1319,14 @@ def _extract_coord_payload(self, cube):
         hint_dict = {name: i for i, name in zip(range(len(self._hints), 0, -1), self._hints[::-1])}
         # Coordinate axis ordering dictionary.
         axis_dict = {'T': 0, 'Z': 1, 'Y': 2, 'X': 3}
-        # Coordinate sort function - by coordinate hint, then by guessed coordinate axis, then
-        # by coordinate definition, in ascending order.
-        key_func = lambda coord: (hint_dict.get(coord.name(), len(hint_dict) + 1),
-                                  axis_dict.get(iris.util.guess_coord_axis(coord), len(axis_dict) + 1),
+        # Coordinate sort function.
+        key_func = lambda coord: (not np.issubdtype(coord.points.dtype,
+                                                    np.number),
+                                  not isinstance(coord, iris.coords.DimCoord),
+                                  hint_dict.get(coord.name(),
+                                                len(hint_dict) + 1),
+                                  axis_dict.get(iris.util.guess_coord_axis(coord),
+                                                len(axis_dict) + 1),
                                   coord._as_defn())
 
         # Order the coordinates by hints, axis, and definition.
diff --git a/lib/iris/etc/pp_rules.txt b/lib/iris/etc/pp_rules.txt
index 490e0d45cf..f63172d4af 100644
--- a/lib/iris/etc/pp_rules.txt
+++ b/lib/iris/etc/pp_rules.txt
@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2010 - 2012, Met Office
+# (C) British Crown Copyright 2010 - 2013, Met Office
 #
 # This file is part of Iris.
 #
@@ -356,7 +356,7 @@ f.lbvc == 65
 THEN
 #need orography field to calculate 3D array height coord
 ###,  coord_system=HybridHeightCS(Reference('orography')))
-CoordAndDims(AuxCoord(f.lblev, standard_name='model_level_number', attributes={'positive': 'up'}))
+CoordAndDims(DimCoord(f.lblev, standard_name='model_level_number', attributes={'positive': 'up'}))
 CoordAndDims(DimCoord(f.blev, long_name='level_height', units='m', bounds=[f.brlev, f.brsvd[0]], attributes={'positive': 'up'}))
 CoordAndDims(AuxCoord(f.bhlev, long_name='sigma', bounds=[f.bhrlev, f.brsvd[1]]))
 Factory(HybridHeightFactory, [{'long_name': 'level_height'}, {'long_name': 'sigma'}, Reference('orography')])
diff --git a/lib/iris/tests/results/file_load/theta_levels.cml b/lib/iris/tests/results/file_load/theta_levels.cml
index b597015916..68b22e83b5 100644
--- a/lib/iris/tests/results/file_load/theta_levels.cml
+++ b/lib/iris/tests/results/file_load/theta_levels.cml
@@ -30,11 +30,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[1.0, 0.994296]]" id="5f88ebd6" long_name="sigma" points="[0.997716]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -80,11 +80,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.994296, 0.985204]]" id="5f88ebd6" long_name="sigma" points="[0.990882]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -130,11 +130,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.985204, 0.971644]]" id="5f88ebd6" long_name="sigma" points="[0.979543]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -180,11 +180,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.971644, 0.95371]]" id="5f88ebd6" long_name="sigma" points="[0.963777]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -230,11 +230,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.95371, 0.931527]]" id="5f88ebd6" long_name="sigma" points="[0.943695]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -280,11 +280,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.931527, 0.905253]]" id="5f88ebd6" long_name="sigma" points="[0.919438]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -330,11 +330,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.905253, 0.875075]]" id="5f88ebd6" long_name="sigma" points="[0.891178]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -380,11 +380,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.875075, 0.841212]]" id="5f88ebd6" long_name="sigma" points="[0.859118]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -430,11 +430,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.841212, 0.803914]]" id="5f88ebd6" long_name="sigma" points="[0.823493]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -480,11 +480,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.803914, 0.763465]]" id="5f88ebd6" long_name="sigma" points="[0.784571]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -530,11 +530,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.763465, 0.720176]]" id="5f88ebd6" long_name="sigma" points="[0.742646]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -580,11 +580,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.720176, 0.674393]]" id="5f88ebd6" long_name="sigma" points="[0.69805]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -630,11 +630,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.674393, 0.626491]]" id="5f88ebd6" long_name="sigma" points="[0.651143]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -680,11 +680,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.626491, 0.576877]]" id="5f88ebd6" long_name="sigma" points="[0.602314]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -730,11 +730,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.576877, 0.525991]]" id="5f88ebd6" long_name="sigma" points="[0.551989]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -780,11 +780,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.525991, 0.474301]]" id="5f88ebd6" long_name="sigma" points="[0.50062]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -830,11 +830,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.474301, 0.42231]]" id="5f88ebd6" long_name="sigma" points="[0.448693]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -880,11 +880,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.42231, 0.370549]]" id="5f88ebd6" long_name="sigma" points="[0.396726]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -930,11 +930,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.370549, 0.319582]]" id="5f88ebd6" long_name="sigma" points="[0.345265]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -980,11 +980,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.319582, 0.270005]]" id="5f88ebd6" long_name="sigma" points="[0.294891]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1030,11 +1030,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.270005, 0.222443]]" id="5f88ebd6" long_name="sigma" points="[0.246215]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1080,11 +1080,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.222443, 0.177555]]" id="5f88ebd6" long_name="sigma" points="[0.199878]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1130,11 +1130,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.177555, 0.13603]]" id="5f88ebd6" long_name="sigma" points="[0.156554]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1180,11 +1180,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.13603, 0.0985881]]" id="5f88ebd6" long_name="sigma" points="[0.116948]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1230,11 +1230,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0985881, 0.0659808]]" id="5f88ebd6" long_name="sigma" points="[0.0817952]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1280,11 +1280,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0659808, 0.0389824]]" id="5f88ebd6" long_name="sigma" points="[0.0518637]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1330,11 +1330,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0389824, 0.0183147]]" id="5f88ebd6" long_name="sigma" points="[0.0279368]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1380,11 +1380,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0183147, 0.00487211]]" id="5f88ebd6" long_name="sigma" points="[0.0107165]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1430,11 +1430,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.00487211, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.00130179]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1480,11 +1480,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1530,11 +1530,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1580,11 +1580,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1630,11 +1630,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1680,11 +1680,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1730,11 +1730,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1780,11 +1780,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1830,11 +1830,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1880,11 +1880,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
diff --git a/lib/iris/tests/results/file_load/u_wind_levels.cml b/lib/iris/tests/results/file_load/u_wind_levels.cml
index 2bfdd01cab..b51d171d15 100644
--- a/lib/iris/tests/results/file_load/u_wind_levels.cml
+++ b/lib/iris/tests/results/file_load/u_wind_levels.cml
@@ -31,11 +31,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[1.0, 0.997716]]" id="5f88ebd6" long_name="sigma" points="[0.998858]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -82,11 +82,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.997716, 0.990882]]" id="5f88ebd6" long_name="sigma" points="[0.994296]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -133,11 +133,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.990882, 0.979543]]" id="5f88ebd6" long_name="sigma" points="[0.985204]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -184,11 +184,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.979543, 0.963777]]" id="5f88ebd6" long_name="sigma" points="[0.971644]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -235,11 +235,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.963777, 0.943695]]" id="5f88ebd6" long_name="sigma" points="[0.95371]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -286,11 +286,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.943695, 0.919438]]" id="5f88ebd6" long_name="sigma" points="[0.931527]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -337,11 +337,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.919438, 0.891178]]" id="5f88ebd6" long_name="sigma" points="[0.905253]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -388,11 +388,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.891178, 0.859118]]" id="5f88ebd6" long_name="sigma" points="[0.875075]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -439,11 +439,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.859118, 0.823493]]" id="5f88ebd6" long_name="sigma" points="[0.841212]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -490,11 +490,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.823493, 0.784571]]" id="5f88ebd6" long_name="sigma" points="[0.803914]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -541,11 +541,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.784571, 0.742646]]" id="5f88ebd6" long_name="sigma" points="[0.763465]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -592,11 +592,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.742646, 0.69805]]" id="5f88ebd6" long_name="sigma" points="[0.720176]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -643,11 +643,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.69805, 0.651143]]" id="5f88ebd6" long_name="sigma" points="[0.674393]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -694,11 +694,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.651143, 0.602314]]" id="5f88ebd6" long_name="sigma" points="[0.626491]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -745,11 +745,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.602314, 0.551989]]" id="5f88ebd6" long_name="sigma" points="[0.576877]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -796,11 +796,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.551989, 0.50062]]" id="5f88ebd6" long_name="sigma" points="[0.525991]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -847,11 +847,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.50062, 0.448693]]" id="5f88ebd6" long_name="sigma" points="[0.474301]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -898,11 +898,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.448693, 0.396726]]" id="5f88ebd6" long_name="sigma" points="[0.42231]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -949,11 +949,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.396726, 0.345265]]" id="5f88ebd6" long_name="sigma" points="[0.370549]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1000,11 +1000,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.345265, 0.294891]]" id="5f88ebd6" long_name="sigma" points="[0.319582]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1051,11 +1051,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.294891, 0.246215]]" id="5f88ebd6" long_name="sigma" points="[0.270005]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1102,11 +1102,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.246215, 0.199878]]" id="5f88ebd6" long_name="sigma" points="[0.222443]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1153,11 +1153,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.199878, 0.156554]]" id="5f88ebd6" long_name="sigma" points="[0.177555]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1204,11 +1204,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.156554, 0.116948]]" id="5f88ebd6" long_name="sigma" points="[0.13603]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1255,11 +1255,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.116948, 0.0817952]]" id="5f88ebd6" long_name="sigma" points="[0.0985881]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1306,11 +1306,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0817952, 0.0518637]]" id="5f88ebd6" long_name="sigma" points="[0.0659808]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1357,11 +1357,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0518637, 0.0279368]]" id="5f88ebd6" long_name="sigma" points="[0.0389824]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1408,11 +1408,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0279368, 0.0107165]]" id="5f88ebd6" long_name="sigma" points="[0.0183147]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1459,11 +1459,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0107165, 0.00130179]]" id="5f88ebd6" long_name="sigma" points="[0.00487211]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1510,11 +1510,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.00130179, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1561,11 +1561,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1612,11 +1612,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1663,11 +1663,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1714,11 +1714,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1765,11 +1765,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1816,11 +1816,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1867,11 +1867,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1918,11 +1918,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
diff --git a/lib/iris/tests/results/file_load/v_wind_levels.cml b/lib/iris/tests/results/file_load/v_wind_levels.cml
index 0ffb6ca612..a37f8621d0 100644
--- a/lib/iris/tests/results/file_load/v_wind_levels.cml
+++ b/lib/iris/tests/results/file_load/v_wind_levels.cml
@@ -31,11 +31,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[1.0, 0.997716]]" id="5f88ebd6" long_name="sigma" points="[0.998858]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -82,11 +82,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.997716, 0.990882]]" id="5f88ebd6" long_name="sigma" points="[0.994296]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -133,11 +133,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.990882, 0.979543]]" id="5f88ebd6" long_name="sigma" points="[0.985204]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -184,11 +184,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.979543, 0.963777]]" id="5f88ebd6" long_name="sigma" points="[0.971644]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -235,11 +235,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.963777, 0.943695]]" id="5f88ebd6" long_name="sigma" points="[0.95371]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -286,11 +286,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.943695, 0.919438]]" id="5f88ebd6" long_name="sigma" points="[0.931527]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -337,11 +337,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.919438, 0.891178]]" id="5f88ebd6" long_name="sigma" points="[0.905253]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -388,11 +388,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.891178, 0.859118]]" id="5f88ebd6" long_name="sigma" points="[0.875075]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -439,11 +439,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.859118, 0.823493]]" id="5f88ebd6" long_name="sigma" points="[0.841212]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -490,11 +490,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.823493, 0.784571]]" id="5f88ebd6" long_name="sigma" points="[0.803914]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -541,11 +541,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.784571, 0.742646]]" id="5f88ebd6" long_name="sigma" points="[0.763465]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -592,11 +592,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.742646, 0.69805]]" id="5f88ebd6" long_name="sigma" points="[0.720176]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -643,11 +643,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.69805, 0.651143]]" id="5f88ebd6" long_name="sigma" points="[0.674393]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -694,11 +694,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.651143, 0.602314]]" id="5f88ebd6" long_name="sigma" points="[0.626491]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -745,11 +745,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.602314, 0.551989]]" id="5f88ebd6" long_name="sigma" points="[0.576877]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -796,11 +796,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.551989, 0.50062]]" id="5f88ebd6" long_name="sigma" points="[0.525991]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -847,11 +847,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.50062, 0.448693]]" id="5f88ebd6" long_name="sigma" points="[0.474301]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -898,11 +898,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.448693, 0.396726]]" id="5f88ebd6" long_name="sigma" points="[0.42231]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -949,11 +949,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.396726, 0.345265]]" id="5f88ebd6" long_name="sigma" points="[0.370549]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1000,11 +1000,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.345265, 0.294891]]" id="5f88ebd6" long_name="sigma" points="[0.319582]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1051,11 +1051,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.294891, 0.246215]]" id="5f88ebd6" long_name="sigma" points="[0.270005]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1102,11 +1102,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.246215, 0.199878]]" id="5f88ebd6" long_name="sigma" points="[0.222443]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1153,11 +1153,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.199878, 0.156554]]" id="5f88ebd6" long_name="sigma" points="[0.177555]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1204,11 +1204,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.156554, 0.116948]]" id="5f88ebd6" long_name="sigma" points="[0.13603]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1255,11 +1255,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.116948, 0.0817952]]" id="5f88ebd6" long_name="sigma" points="[0.0985881]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1306,11 +1306,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0817952, 0.0518637]]" id="5f88ebd6" long_name="sigma" points="[0.0659808]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1357,11 +1357,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0518637, 0.0279368]]" id="5f88ebd6" long_name="sigma" points="[0.0389824]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1408,11 +1408,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0279368, 0.0107165]]" id="5f88ebd6" long_name="sigma" points="[0.0183147]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1459,11 +1459,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0107165, 0.00130179]]" id="5f88ebd6" long_name="sigma" points="[0.00487211]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1510,11 +1510,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.00130179, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1561,11 +1561,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1612,11 +1612,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1663,11 +1663,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1714,11 +1714,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1765,11 +1765,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1816,11 +1816,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1867,11 +1867,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1918,11 +1918,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
diff --git a/lib/iris/tests/results/file_load/wind_levels.cml b/lib/iris/tests/results/file_load/wind_levels.cml
index b53327b191..15ebd44c9c 100644
--- a/lib/iris/tests/results/file_load/wind_levels.cml
+++ b/lib/iris/tests/results/file_load/wind_levels.cml
@@ -31,11 +31,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[1.0, 0.997716]]" id="5f88ebd6" long_name="sigma" points="[0.998858]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -82,11 +82,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.997716, 0.990882]]" id="5f88ebd6" long_name="sigma" points="[0.994296]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -133,11 +133,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.990882, 0.979543]]" id="5f88ebd6" long_name="sigma" points="[0.985204]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -184,11 +184,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
         <auxCoord bounds="[[0.979543, 0.963777]]" id="5f88ebd6" long_name="sigma" points="[0.971644]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -235,11 +235,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.963777, 0.943695]]" id="5f88ebd6" long_name="sigma" points="[0.95371]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -286,11 +286,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
         <auxCoord bounds="[[0.943695, 0.919438]]" id="5f88ebd6" long_name="sigma" points="[0.931527]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -337,11 +337,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
         <auxCoord bounds="[[0.919438, 0.891178]]" id="5f88ebd6" long_name="sigma" points="[0.905253]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -388,11 +388,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
         <auxCoord bounds="[[0.891178, 0.859118]]" id="5f88ebd6" long_name="sigma" points="[0.875075]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -439,11 +439,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
         <auxCoord bounds="[[0.859118, 0.823493]]" id="5f88ebd6" long_name="sigma" points="[0.841212]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -490,11 +490,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.823493, 0.784571]]" id="5f88ebd6" long_name="sigma" points="[0.803914]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -541,11 +541,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
         <auxCoord bounds="[[0.784571, 0.742646]]" id="5f88ebd6" long_name="sigma" points="[0.763465]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -592,11 +592,11 @@
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       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.742646, 0.69805]]" id="5f88ebd6" long_name="sigma" points="[0.720176]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -643,11 +643,11 @@
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       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.69805, 0.651143]]" id="5f88ebd6" long_name="sigma" points="[0.674393]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -694,11 +694,11 @@
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       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.651143, 0.602314]]" id="5f88ebd6" long_name="sigma" points="[0.626491]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -745,11 +745,11 @@
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       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.602314, 0.551989]]" id="5f88ebd6" long_name="sigma" points="[0.576877]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -796,11 +796,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.551989, 0.50062]]" id="5f88ebd6" long_name="sigma" points="[0.525991]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -847,11 +847,11 @@
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       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.50062, 0.448693]]" id="5f88ebd6" long_name="sigma" points="[0.474301]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -898,11 +898,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
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@@ -949,11 +949,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -1000,11 +1000,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
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@@ -1051,11 +1051,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
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@@ -1102,11 +1102,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
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@@ -1153,11 +1153,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.199878, 0.156554]]" id="5f88ebd6" long_name="sigma" points="[0.177555]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1204,11 +1204,11 @@
         </dimCoord>
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       <coord>
-        <auxCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
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@@ -1255,11 +1255,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -1306,11 +1306,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -1357,11 +1357,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -1408,11 +1408,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -1459,11 +1459,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -1510,11 +1510,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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@@ -1561,11 +1561,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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@@ -1612,11 +1612,11 @@
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-        <auxCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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@@ -1663,11 +1663,11 @@
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-        <auxCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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@@ -1714,11 +1714,11 @@
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-        <auxCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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@@ -1765,11 +1765,11 @@
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-        <auxCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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@@ -1816,11 +1816,11 @@
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+        <dimCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1867,11 +1867,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1918,11 +1918,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -1969,11 +1969,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[1]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
         <auxCoord bounds="[[1.0, 0.997716]]" id="5f88ebd6" long_name="sigma" points="[0.998858]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2020,11 +2020,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[2]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
         <auxCoord bounds="[[0.997716, 0.990882]]" id="5f88ebd6" long_name="sigma" points="[0.994296]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2071,11 +2071,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[3]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
         <auxCoord bounds="[[0.990882, 0.979543]]" id="5f88ebd6" long_name="sigma" points="[0.985204]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2122,11 +2122,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[4]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.979543, 0.963777]]" id="5f88ebd6" long_name="sigma" points="[0.971644]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2173,11 +2173,11 @@
         </dimCoord>
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       <coord>
-        <auxCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[5]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.963777, 0.943695]]" id="5f88ebd6" long_name="sigma" points="[0.95371]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2224,11 +2224,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[6]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.943695, 0.919438]]" id="5f88ebd6" long_name="sigma" points="[0.931527]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2275,11 +2275,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[7]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.919438, 0.891178]]" id="5f88ebd6" long_name="sigma" points="[0.905253]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2326,11 +2326,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[8]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.891178, 0.859118]]" id="5f88ebd6" long_name="sigma" points="[0.875075]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2377,11 +2377,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[9]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.859118, 0.823493]]" id="5f88ebd6" long_name="sigma" points="[0.841212]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2428,11 +2428,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[10]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.823493, 0.784571]]" id="5f88ebd6" long_name="sigma" points="[0.803914]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2479,11 +2479,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[11]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.784571, 0.742646]]" id="5f88ebd6" long_name="sigma" points="[0.763465]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2530,11 +2530,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[12]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.742646, 0.69805]]" id="5f88ebd6" long_name="sigma" points="[0.720176]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2581,11 +2581,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[13]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.69805, 0.651143]]" id="5f88ebd6" long_name="sigma" points="[0.674393]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2632,11 +2632,11 @@
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       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[14]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
         <auxCoord bounds="[[0.651143, 0.602314]]" id="5f88ebd6" long_name="sigma" points="[0.626491]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2683,11 +2683,11 @@
         </dimCoord>
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       <coord>
-        <auxCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[15]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.602314, 0.551989]]" id="5f88ebd6" long_name="sigma" points="[0.576877]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2734,11 +2734,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[16]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
         <auxCoord bounds="[[0.551989, 0.50062]]" id="5f88ebd6" long_name="sigma" points="[0.525991]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2785,11 +2785,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[17]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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       <coord>
         <auxCoord bounds="[[0.50062, 0.448693]]" id="5f88ebd6" long_name="sigma" points="[0.474301]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2836,11 +2836,11 @@
         </dimCoord>
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       <coord>
-        <auxCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[18]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
         <auxCoord bounds="[[0.448693, 0.396726]]" id="5f88ebd6" long_name="sigma" points="[0.42231]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -2887,11 +2887,11 @@
         </dimCoord>
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       <coord>
-        <auxCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[19]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -2938,11 +2938,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[20]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -2989,11 +2989,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[21]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
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       <coord>
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@@ -3040,11 +3040,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[22]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -3091,11 +3091,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[23]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -3142,11 +3142,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[24]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -3193,11 +3193,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[25]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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       <coord>
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@@ -3244,11 +3244,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[26]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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@@ -3295,11 +3295,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[27]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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+        </dimCoord>
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@@ -3346,11 +3346,11 @@
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-        <auxCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[28]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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@@ -3397,11 +3397,11 @@
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-        <auxCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[29]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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@@ -3448,11 +3448,11 @@
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-        <auxCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[30]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
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@@ -3499,11 +3499,11 @@
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       <coord>
-        <auxCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[31]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -3550,11 +3550,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[32]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -3601,11 +3601,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[33]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -3652,11 +3652,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[34]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -3703,11 +3703,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[35]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -3754,11 +3754,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[36]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -3805,11 +3805,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[37]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
@@ -3856,11 +3856,11 @@
         </dimCoord>
       </coord>
       <coord>
-        <auxCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
+        <dimCoord id="af0092b8" points="[38]" shape="(1,)" standard_name="model_level_number" units="Unit('1')" value_type="int32">
           <attributes>
             <attribute name="positive" value="up"/>
           </attributes>
-        </auxCoord>
+        </dimCoord>
       </coord>
       <coord>
         <auxCoord bounds="[[0.0, 0.0]]" id="5f88ebd6" long_name="sigma" points="[0.0]" shape="(1,)" units="Unit('1')" value_type="float32"/>
diff --git a/lib/iris/tests/results/merge/a_aux_b_aux.cml b/lib/iris/tests/results/merge/a_aux_b_aux.cml
new file mode 100644
index 0000000000..13c49ddfa3
--- /dev/null
+++ b/lib/iris/tests/results/merge/a_aux_b_aux.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <dimCoord id="9c870e8e" long_name="a" points="[0.0, 1.0, 2.0, 3.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[0]">
+        <dimCoord id="c499a7a6" long_name="b" points="[10.0, 11.0, 12.0, 13.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/a_aux_b_dim.cml b/lib/iris/tests/results/merge/a_aux_b_dim.cml
new file mode 100644
index 0000000000..13c49ddfa3
--- /dev/null
+++ b/lib/iris/tests/results/merge/a_aux_b_dim.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <dimCoord id="9c870e8e" long_name="a" points="[0.0, 1.0, 2.0, 3.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[0]">
+        <dimCoord id="c499a7a6" long_name="b" points="[10.0, 11.0, 12.0, 13.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/a_dim_b_aux.cml b/lib/iris/tests/results/merge/a_dim_b_aux.cml
new file mode 100644
index 0000000000..13c49ddfa3
--- /dev/null
+++ b/lib/iris/tests/results/merge/a_dim_b_aux.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <dimCoord id="9c870e8e" long_name="a" points="[0.0, 1.0, 2.0, 3.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[0]">
+        <dimCoord id="c499a7a6" long_name="b" points="[10.0, 11.0, 12.0, 13.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/a_dim_b_dim.cml b/lib/iris/tests/results/merge/a_dim_b_dim.cml
new file mode 100644
index 0000000000..13c49ddfa3
--- /dev/null
+++ b/lib/iris/tests/results/merge/a_dim_b_dim.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <dimCoord id="9c870e8e" long_name="a" points="[0.0, 1.0, 2.0, 3.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[0]">
+        <dimCoord id="c499a7a6" long_name="b" points="[10.0, 11.0, 12.0, 13.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/separable_combination.cml b/lib/iris/tests/results/merge/separable_combination.cml
new file mode 100644
index 0000000000..9ca61c352c
--- /dev/null
+++ b/lib/iris/tests/results/merge/separable_combination.cml
@@ -0,0 +1,56 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <auxCoord id="9c870e8e" long_name="a" points="[2005, 2005, 2005, 2026, 2026, 2026, 2002, 2002,
+		2002, 2002, 2002, 2002, 2502, 2502, 2502, 2502,
+		2502, 2502, 2502, 2502, 2502]" shape="(21,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[0]">
+        <auxCoord id="c499a7a6" long_name="b" points="[ECMWF, ECMWF, ECMWF, UK Met Office,
+		UK Met Office, UK Met Office, CERFACS, CERFACS,
+		CERFACS, IFM-GEOMAR, IFM-GEOMAR, IFM-GEOMAR,
+		UK Met Office, UK Met Office, UK Met Office,
+		UK Met Office, UK Met Office, UK Met Office,
+		UK Met Office, UK Met Office, UK Met Office]" shape="(21,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[0]">
+        <auxCoord id="45bcc281" long_name="c" points="[HOPE-E, Sys 1, Met 1, ENSEMBLES,
+		HOPE-E, Sys 1, Met 1, ENSEMBLES,
+		HOPE-E, Sys 1, Met 1, ENSEMBLES,
+		HadGEM2, Sys 1, Met 1, ENSEMBLES,
+		HadGEM2, Sys 1, Met 1, ENSEMBLES,
+		HadGEM2, Sys 1, Met 1, ENSEMBLES,
+		GELATO, Sys 0, Met 1, ENSEMBLES,
+		GELATO, Sys 0, Met 1, ENSEMBLES,
+		GELATO, Sys 0, Met 1, ENSEMBLES,
+		ECHAM5, Sys 1, Met 10, ENSEMBLES,
+		ECHAM5, Sys 1, Met 10, ENSEMBLES,
+		ECHAM5, Sys 1, Met 10, ENSEMBLES,
+		HadCM3, Sys 51, Met 10, ENSEMBLES,
+		HadCM3, Sys 51, Met 11, ENSEMBLES,
+		HadCM3, Sys 51, Met 12, ENSEMBLES,
+		HadCM3, Sys 51, Met 13, ENSEMBLES,
+		HadCM3, Sys 51, Met 14, ENSEMBLES,
+		HadCM3, Sys 51, Met 15, ENSEMBLES,
+		HadCM3, Sys 51, Met 16, ENSEMBLES,
+		HadCM3, Sys 51, Met 17, ENSEMBLES,
+		HadCM3, Sys 51, Met 18, ENSEMBLES]" shape="(21,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[0]">
+        <auxCoord id="74a4f5f6" long_name="d" points="[0.0, 1.0, 2.0, 0.0, 1.0, 2.0, 0.0, 1.0, 2.0,
+		0.0, 1.0, 2.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+		0.0, 0.0, 0.0]" shape="(21,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(21, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/string_a_b.cml b/lib/iris/tests/results/merge/string_a_b.cml
new file mode 100644
index 0000000000..f868af4d2d
--- /dev/null
+++ b/lib/iris/tests/results/merge/string_a_b.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <auxCoord id="9c870e8e" long_name="a" points="[a, b, c, d]" shape="(4,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[0]">
+        <auxCoord id="c499a7a6" long_name="b" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/string_a_with_aux.cml b/lib/iris/tests/results/merge/string_a_with_aux.cml
new file mode 100644
index 0000000000..323b9dac80
--- /dev/null
+++ b/lib/iris/tests/results/merge/string_a_with_aux.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <auxCoord id="9c870e8e" long_name="a" points="[a, b, c, d]" shape="(4,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[0]">
+        <dimCoord id="c499a7a6" long_name="b" points="[0.0, 1.0, 2.0, 3.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/string_a_with_dim.cml b/lib/iris/tests/results/merge/string_a_with_dim.cml
new file mode 100644
index 0000000000..323b9dac80
--- /dev/null
+++ b/lib/iris/tests/results/merge/string_a_with_dim.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <auxCoord id="9c870e8e" long_name="a" points="[a, b, c, d]" shape="(4,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[0]">
+        <dimCoord id="c499a7a6" long_name="b" points="[0.0, 1.0, 2.0, 3.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/results/merge/string_b_with_dim.cml b/lib/iris/tests/results/merge/string_b_with_dim.cml
new file mode 100644
index 0000000000..111147663f
--- /dev/null
+++ b/lib/iris/tests/results/merge/string_b_with_dim.cml
@@ -0,0 +1,21 @@
+<?xml version="1.0" ?>
+<cubes xmlns="urn:x-iris:cubeml-0.2">
+  <cube units="unknown">
+    <coords>
+      <coord datadims="[0]">
+        <dimCoord id="9c870e8e" long_name="a" points="[0.0, 1.0, 2.0, 3.0]" shape="(4,)" units="Unit('1')" value_type="float32"/>
+      </coord>
+      <coord datadims="[0]">
+        <auxCoord id="c499a7a6" long_name="b" points="[a, b, c, d]" shape="(4,)" units="Unit('1')" value_type="string"/>
+      </coord>
+      <coord datadims="[2]">
+        <dimCoord id="b0c4282a" long_name="x" points="[0, 1, 2, 3, 4]" shape="(5,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+      <coord datadims="[1]">
+        <dimCoord id="31e14d0d" long_name="y" points="[0, 1, 2, 3]" shape="(4,)" units="Unit('1')" value_type="int32"/>
+      </coord>
+    </coords>
+    <cellMethods/>
+    <data byteorder="little" dtype="float32" order="C" shape="(4, 4, 5)" state="loaded"/>
+  </cube>
+</cubes>
diff --git a/lib/iris/tests/test_merge.py b/lib/iris/tests/test_merge.py
index ab0cc8b68a..bf392cd454 100644
--- a/lib/iris/tests/test_merge.py
+++ b/lib/iris/tests/test_merge.py
@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2010 - 2012, Met Office
+# (C) British Crown Copyright 2010 - 2013, Met Office
 #
 # This file is part of Iris.
 #
@@ -27,7 +27,7 @@
 import iris
 import iris.cube
 import iris.exceptions
-from iris.coords import DimCoord
+from iris.coords import DimCoord, AuxCoord
 import iris.coords
 import iris.tests.stock
 
@@ -179,6 +179,186 @@ def test_multi_split(self):
         self.assertCML(cube, ('merge', 'multi_split.cml'))
 
 
+class TestCombination(tests.IrisTest):
+    def _make_cube(self, a, b, c, d, data=0):
+        cube_data = np.empty((4, 5), dtype=np.float32)
+        cube_data[:] = data
+        cube = iris.cube.Cube(cube_data)
+        cube.add_dim_coord(DimCoord(np.array([0, 1, 2, 3, 4], dtype=np.int32),
+                                    long_name='x', units='1'), 1)
+        cube.add_dim_coord(DimCoord(np.array([0, 1, 2, 3], dtype=np.int32),
+                                    long_name='y', units='1'), 0)
+        
+        for name, value in zip(['a', 'b', 'c', 'd'], [a, b, c, d]):
+            dtype = np.str if isinstance(value, basestring) else np.float32
+            cube.add_aux_coord(AuxCoord(np.array([value], dtype=dtype),
+                                        long_name=name, units='1'))
+
+        return cube
+
+    def test_separable_combination(self):
+        cubes = iris.cube.CubeList()
+        cubes.append(self._make_cube('2005', 'ECMWF',
+                                     'HOPE-E, Sys 1, Met 1, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2005', 'ECMWF',
+                                     'HOPE-E, Sys 1, Met 1, ENSEMBLES', 1))
+        cubes.append(self._make_cube('2005', 'ECMWF',
+                                     'HOPE-E, Sys 1, Met 1, ENSEMBLES', 2))
+        cubes.append(self._make_cube('2026', 'UK Met Office',
+                                     'HadGEM2, Sys 1, Met 1, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2026', 'UK Met Office',
+                                     'HadGEM2, Sys 1, Met 1, ENSEMBLES', 1))
+        cubes.append(self._make_cube('2026', 'UK Met Office',
+                                     'HadGEM2, Sys 1, Met 1, ENSEMBLES', 2))
+        cubes.append(self._make_cube('2002', 'CERFACS',
+                                     'GELATO, Sys 0, Met 1, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2002', 'CERFACS',
+                                     'GELATO, Sys 0, Met 1, ENSEMBLES', 1))
+        cubes.append(self._make_cube('2002', 'CERFACS',
+                                     'GELATO, Sys 0, Met 1, ENSEMBLES', 2))
+        cubes.append(self._make_cube('2002', 'IFM-GEOMAR',
+                                     'ECHAM5, Sys 1, Met 10, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2002', 'IFM-GEOMAR',
+                                     'ECHAM5, Sys 1, Met 10, ENSEMBLES', 1))
+        cubes.append(self._make_cube('2002', 'IFM-GEOMAR',
+                                     'ECHAM5, Sys 1, Met 10, ENSEMBLES', 2))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 10, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 11, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 12, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 13, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 14, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 15, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 16, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 17, ENSEMBLES', 0))
+        cubes.append(self._make_cube('2502', 'UK Met Office',
+                                     'HadCM3, Sys 51, Met 18, ENSEMBLES', 0))
+        cube = cubes.merge()
+        self.assertCML(cube, ('merge', 'separable_combination.cml'),
+                       checksum=False)
+
+
+class TestDimSelection(tests.IrisTest):
+    def _make_cube(self, a, b, data=0, a_dim=False, b_dim=False):
+        cube_data = np.empty((4, 5), dtype=np.float32)
+        cube_data[:] = data
+        cube = iris.cube.Cube(cube_data)
+        cube.add_dim_coord(DimCoord(np.array([0, 1, 2, 3, 4], dtype=np.int32),
+                                    long_name='x', units='1'), 1)
+        cube.add_dim_coord(DimCoord(np.array([0, 1, 2, 3], dtype=np.int32),
+                                    long_name='y', units='1'), 0)
+
+        for name, value, dim in zip(['a', 'b'], [a, b], [a_dim, b_dim]):
+            dtype = np.str if isinstance(value, basestring) else np.float32
+            ctype = DimCoord if dim else AuxCoord
+            coord = ctype(np.array([value], dtype=dtype),
+                          long_name=name, units='1')
+            cube.add_aux_coord(coord)
+
+        return cube
+
+    def test_string_a_with_aux(self):
+        templates = (('a', 0), ('b', 1), ('c', 2), ('d', 3))
+        cubes = [self._make_cube(a, b) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'string_a_with_aux.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), AuxCoord))
+        self.assertTrue(isinstance(cube.coord('b'), DimCoord))
+        self.assertTrue(cube.coord('b') in cube.dim_coords)
+
+    def test_string_b_with_aux(self):
+        templates = ((0, 'a'), (1, 'b'), (2, 'c'), (3, 'd'))
+        cubes = [self._make_cube(a, b) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'string_b_with_aux.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), DimCoord))
+        self.assertTrue(cube.coord('a') in cube.dim_coords)
+        self.assertTrue(isinstance(cube.coord('b'), AuxCoord))
+
+    def test_string_a_with_dim(self):
+        templates = (('a', 0), ('b', 1), ('c', 2), ('d', 3))
+        cubes = [self._make_cube(a, b, b_dim=True) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'string_a_with_dim.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), AuxCoord))
+        self.assertTrue(isinstance(cube.coord('b'), DimCoord))
+        self.assertTrue(cube.coord('b') in cube.dim_coords)
+
+    def test_string_b_with_aux(self):
+        templates = ((0, 'a'), (1, 'b'), (2, 'c'), (3, 'd'))
+        cubes = [self._make_cube(a, b, a_dim=True) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'string_b_with_dim.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), DimCoord))
+        self.assertTrue(cube.coord('a') in cube.dim_coords)
+        self.assertTrue(isinstance(cube.coord('b'), AuxCoord))
+
+    def test_string_a_b(self):
+        templates = (('a', '0'), ('b', '1'), ('c', '2'), ('d', '3'))
+        cubes = [self._make_cube(a, b) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'string_a_b.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), AuxCoord))
+        self.assertTrue(isinstance(cube.coord('b'), AuxCoord))
+
+    def test_a_aux_b_aux(self):
+        templates = ((0, 10), (1, 11), (2, 12), (3, 13))
+        cubes = [self._make_cube(a, b) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'a_aux_b_aux.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), DimCoord))
+        self.assertTrue(cube.coord('a') in cube.dim_coords)
+        self.assertTrue(isinstance(cube.coord('b'), DimCoord))
+        self.assertTrue(cube.coord('b') in cube.aux_coords)
+
+    def test_a_aux_b_dim(self):
+        templates = ((0, 10), (1, 11), (2, 12), (3, 13))
+        cubes = [self._make_cube(a, b, b_dim=True) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'a_aux_b_dim.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), DimCoord))
+        self.assertTrue(cube.coord('a') in cube.aux_coords)
+        self.assertTrue(isinstance(cube.coord('b'), DimCoord))
+        self.assertTrue(cube.coord('b') in cube.dim_coords)
+
+    def test_a_dim_b_aux(self):
+        templates = ((0, 10), (1, 11), (2, 12), (3, 13))
+        cubes = [self._make_cube(a, b, a_dim=True) for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'a_dim_b_aux.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), DimCoord))
+        self.assertTrue(cube.coord('a') in cube.dim_coords)
+        self.assertTrue(isinstance(cube.coord('b'), DimCoord))
+        self.assertTrue(cube.coord('b') in cube.aux_coords)
+
+    def test_a_dim_b_dim(self):
+        templates = ((0, 10), (1, 11), (2, 12), (3, 13))
+        cubes = [self._make_cube(a, b, a_dim=True, b_dim=True) \
+                     for a, b in templates]
+        cube = iris.cube.CubeList(cubes).merge()[0]
+        self.assertCML(cube, ('merge', 'a_dim_b_dim.cml'),
+                       checksum=False)
+        self.assertTrue(isinstance(cube.coord('a'), DimCoord))
+        self.assertTrue(cube.coord('a') in cube.dim_coords)
+        self.assertTrue(isinstance(cube.coord('b'), DimCoord))
+        self.assertTrue(cube.coord('b') in cube.aux_coords)
+
+
 class TestTimeTripleMerging(tests.IrisTest):
     def _make_cube(self, a, b, c, data=0):
         cube_data = np.empty((4, 5), dtype=np.float32)