File metadata needs adjustment before we can write to CEDA

[bnlawrence]

The file metadata written on Archer2 has a number of errors in it, insofar as there are missing elements, and some elements do not conform to the expected CMIP6 syntax (we did not try and use all of it, but we should conform where we can).

This is an example of what we have written:

Conventions CF-1.10
_FillValue -1073741800.0
activity_id CANARI-LE
branch_method continuation of parent CANARI LE HIST2 run
branch_time_in_child 2015
branch_time_in_parent 2015
contact 
creation_date 2024-Aug-24 14:52:07 GMT
description UM output
experiment SSP3-7.0
experiment_id 
forcing_index 1
frequency 
further_info_url https://github.com/NCAS-CMS/canari-data
grid Native N216 grid; 432 x 324 longitude/latitude
grid_label gn
initialization_index 5
institution NCAS
interval_offset 0ts
interval_operation 900 s
interval_write 1 h
license 
long_name LARGE SCALE RAINFALL RATE    KG/M2/S
missing_value -1073741800.0
name /mnt/lustre/a2fs-nvme/work/n02/n02/ros/cylc-run/u-df936/share/cycle/20961001T0000Z/df936a_24_1hr_
nominal_resolution 100km
online_operation average
owner rosalynhatcher
parent_activity_id 
parent_experiment_id HIST2
parent_mip_era CMIP6
parent_source_id CANARI-LE.NCAS.HadGEM3-GC31-MM.HIST2.r24i5p2f1
parent_time_units days since 1850-01-01
parent_variant_label r24i5p2f1
physics_index 2
project Coupled Climate
realization_index 24
realm atmos
source HadGEM3-GC31-MM (2016):
=aerosol: UKCA-GLOMAP-mode
=atmos: MetUM-HadGEM3-GA7.1 (N216; 432 x 324 longitude/latitude; 85 levels; top level 85 km)
=atmosChem: none
=land: JULES-HadGEM3-GL7.1
=landIce: none
=ocean: NEMO-HadGEM3-GO6.0 (eORCA025 tripolar primarily 0.25 deg; 1440 x 1205 longitude/latitude; 75 levels; top grid cell 0-1 m)
=ocnBgchem: none
=seaIce: CICE-HadGEM3-GSI8 (eORCA025 tripolar primarily 0.25 deg; 1440 x 1205 longitude/latitude)
source_index HadGEM3-GC31-MM
source_type AOGCM
standard_name stratiform_rainfall_flux
title [CANARI] GC3.1 N216 ORCA025 UM11.6
tracking_id 18d7d0dc-c47d-432d-9fcd-38801acb7714
units kg m-2 s-1
variant_id r24i5p2f1

Things to correct include:

• no frequency attribute
• source_index should be source_id
• the value of parent_source_id should be assigned to parent_activity_id and
• parent_source_id should be the correct CMIP6 source id (which will be the same as the source id for this run).
• It would be desirable to have a variable_label (e.g. tas)
• variant_id should be variant_label

[bnlawrence]

I have code to correct all of this except the addition of the variable_label already in the cfstore code base, and most of what is needed for the variant_label in the pp2nice code base.