Iris always save netCDF files with Conventions=CF-1.5

[ocefpaf]

According to the docs iris support CF.15, but it would be nice if iris could preserve the original metadata.

I have a bunch of CF-1.6 files that, after processing them with iris, are downgraded to CF-1.5.

Here is an example:

>>> import iris
>>> cube = iris.cube.Cube([1, 2, 3])
>>> units = iris.unit.Unit('m')
>>> metadata = dict(featureType='timeSeries', Conventions='CF-1.6')
>>> cube.attributes = metadata
>>> print(cube)
unknown / (unknown)                 (-- : 3)
     Attributes:
          Conventions: CF-1.6
          featureType: timeSeries

>>> iris.FUTURE.netcdf_no_unlimited=True
>>> iris.save(cube, 'tmp.nc')
>>> cube = iris.load_cube('tmp.nc')
>>> print(cube)
unknown / (1)                       (-- : 3)
     Attributes:
          Conventions: CF-1.5
          featureType: timeSeries

[ocefpaf]

I guess that even though reading 1.6 is OK saving will always be 1.5. Closing then.