Make MeshCoords immutable and sync updates with the attached mesh

lib/iris/coords.py

@@ -8,6 +8,7 @@
 from collections import namedtuple
 from collections.abc import Container
 import copy
+from datetime import datetime
 from functools import lru_cache
 from itertools import zip_longest
 import operator
@@ -98,6 +99,8 @@ def __init__(
         if not hasattr(self, "_metadata_manager"):
             self._metadata_manager = metadata_manager_factory(BaseMetadata)
 
+        self._mesh_parents = []
+
         #: CF standard name of the quantity that the metadata represents.
         self.standard_name = standard_name
 
@@ -569,6 +572,17 @@ def reindent_data_string(text, n_indent):
 
         return "\n".join(output_lines)
 
+    def __setattr__(self, key, value):
+        if getattr(self, "_mesh_parents", None) is not None:
+            for parent in self._mesh_parents:
+                parent.timestamp = datetime.now()
+
+        prop = getattr(type(self), key, None)
+        if isinstance(prop, property):
+            prop.__set__(self, value)
+        else:
+            super.__setattr__(self, key, value)
+
     def __str__(self):
         return self.summary()
 

lib/iris/cube.py

@@ -2785,7 +2785,7 @@ def shape(self) -> tuple[int, ...]:
 
     @property
     def dtype(self):
-        """The data type of the values in the data array of this :class:`~iris.cube.Cube`."""
+        """The dtype of the values in the data array of this :class:`~iris.cube.Cube`."""
         return self._data_manager.dtype
 
     @property