CMIP7 forcing update to dev-historical+concentrations

[penguian]

1. Summary:

See ACCESS-NRI/CMIP7-Input#126 and ACCESS-NRI/CMIP7-Input#111

The CLMCHFCG namelist in atmosphere/namelists contains historical greenhouse gas concentrations. It was changed to interpolate concentrations to Jan 1 to match the UM time interpolation.

The generated branch is the result of /scratch/tm70/pcl851/cylc-run/u-dq819.trunk/run93 of the u-dq819/trunk CMIP7 ancillary suite. This run also produced the directory /g/data/tm70/pcl851/CMIP7/esm1p6_ancil/2026.03.03 which contains updated ancillary and input files including

/g/data/tm70/pcl851/CMIP7/esm1p6_ancil/2026.03.03/modern/historical/forcing/global.N96/2026.03.03/ozone_1849_2023_cmip7.anc

NOTE: Further changes are needed to this branch before merging. Therefore none of the items 3 to 9 have been fully addressed.

In particular, after the historical ozone file has been copied to its standard location (e.g.)

/g/data/vk83/configurations/inputs/access-esm1p5/modern/historical/atmosphere/forcing/global.N96/2026.03.03/ozone_1849_2023_cmip7.anc

or similar, the item

OZONE: INPUT/ozone_1849_2015_ESM1.anc

in atmosphere/um_env.yaml should be changed to

OZONE: INPUT/ozone_1849_2023_cmip7.anc

and line 54

/g/data/vk83/configurations/inputs/access-esm1p5/modern/historical/atmosphere/forcing/global.N96/2021.06.22/ozone_1849_2015_ESM1.anc

in config.yaml should be updated to

/g/data/vk83/configurations/inputs/access-esm1p5/modern/historical/atmosphere/forcing/global.N96/2026.03.03/ozone_1849_2023_cmip7.anc

or similar.

2. Issues Addressed:

• Produce Ozone ancillaries for the ACCESS-ESM1.6 piControl experiments CMIP7-Input#50
• Time interpolation of historical GHGs. CMIP7-Input#123

3. Dependencies (e.g. on payu, or model)

This change requires changes to (note pull request(s) where relevant):

• workflow manager (payu):
• model deployment (ACCESS-ESM1.6):
• model component or library dependency:
• input workflow:

4. Ad-hoc Testing

What ad-hoc testing was done? How are you convinced this change is correct (plots are good)?

5. CI Testing

• !test repro has been run

6. Reproducibility

Is this reproducible with the previous commit? (If not, why not?)

• Yes
• No - !test repro commit has been run.

7. Performance

Has the model performance (say, throughput of model-years/wall-day) changed?

• Yes
• No
• N/A (if selected, please add a brief explanation why performance testing is not necessary for this PR)

If yes, provide the numbers from your testing. Is the performance better or worse?

8. Manifests

Have you changed the executable, the input files and/or the restart files?

• Yes
• No

If yes, have you updated the manifests?

• Yes
• No

To update the manifests, run payu setup (in a cloned copy of your feature branch) with reproducibility tests turned off:

manifest:
  reproduce:
    exe: false
    input: false
    restart: false
runlog:
  enable: false

Then commit the newly created manifest files (under manifests/) only to the branch for this PR.

9. Documentation

Is the documentation updated? No

10. Merge Strategy

• Merge commit
• Rebase and merge
• Squash

[MartinDix]

GHG concentrations match those plotted in ACCESS-NRI/CMIP7-Input#126, so looks good.

[blimlim]

@penguian, @MartinDix, are you happy for me to push the ozone ancillary path changes directly to the branch in this PR?

[blimlim]

!test repro commit

[github-actions]

❌ The Bitwise Reproducibility Check Failed ❌

When comparing:

• gen-cmip7-historical+concentrations-642d90cf (checksums created using commit 3a79280), against
• dev-historical+concentrations (checksums in commit 1e64019)

🔧 The new checksums will be committed to this PR, if they differ from what is on this branch.

Further information

The experiment can be found on Gadi at /scratch/tm70/repro-ci/experiments/access-esm1.6-configs/3a79280d29aa6a551360b45515737f4a380d0b80, and the test results at https://github.com/ACCESS-NRI/access-esm1.6-configs/runs/65801923312.

The checksums generated by this !test command are found in the testing/checksum directory of https://github.com/ACCESS-NRI/access-esm1.6-configs/actions/runs/22694587053/artifacts/5770594038.

The checksums compared against are found here https://github.com/ACCESS-NRI/access-esm1.6-configs/tree/1e64019a9ab235d97ed9c1d5514e94298c821cf5/testing/checksum

Test summary:
❌ test_repro_historical
✅ test_repro_determinism

[blimlim]

@MartinDix, this PR now has the ozone added in, and should be ready for review

[MartinDix]

Looks good

[blimlim]

!cherry-pick 95e9333 3a79280 into dev-historical+concentrations+CN

[github-actions]

Automatic Git cherry-picking of commit(s) 95e9333 3a79280 into dev-historical+concentrations+CN was successful.

The new pull request can be reviewed and approved here.

[blimlim]

!cherry-pick 95e9333 3a79280 into dev-amip dev-amip+CN

[github-actions]

Automatic Git cherry-picking of commit(s) 95e9333 3a79280 into dev-amip+CN was successful.

The new pull request can be reviewed and approved here.

[github-actions]

Automatic Git cherry-picking of commit(s) 95e9333 3a79280 into dev-amip was successful.

The new pull request can be reviewed and approved here.