🐛 Bug Report

Iris pp save rules result in a LBLEV of 0 for a surface field (i.e. all the non-zero values are gated behind a check for a vertical coordinate: https://github.com/SciTools/iris/blob/master/lib/iris/fileformats/pp_save_rules.py#L653 ). F03, however, specifies a value of 9999 for surface fields: https://code.metoffice.gov.uk/doc/um/latest/papers/umdp_F03.pdf#page=27 In Ants, we rely on the pp save rules to set this value as we translate a cube into mule fields for saving ancillaries. We will put in a workaround in Ants to set this ourselves for an immediate fix, but it would be good if this could be fixed upstream.

How To Reproduce

Steps to reproduce the behaviour:

1. Use iris to load a surface field (e.g. SST or orography)
2. Save the surface field as pp file.
3. Inspect lookup header with e.g. mule-pumf --headers-only filename.pp | grep 'lblev'

Expected behaviour

LBLEV value of 9999 for surface fields.

Environment

• Iris Version: 2.3