Adding recipe and diagnostics for Gier et al 2020

[bettina-gier]

Draft pull request for Code to recreate Gier et al 2020, Biogeosciences with diagnostics for all figures. Analysis for XCO2 (Column-averaged CO2).

Description

• Closes Implementing Gier et al 2020 #1915
• Link to documentation: https://esmvaltool--1914.org.readthedocs.build/en/1914/recipes/recipe_gier20bg.html

---

Before you get started

• ☝ Create an issue to discuss what you are going to do

Checklist

It is the responsibility of the author to make sure the PR is ready to review. The icons indicate whether the item will be subject to the 🛠 Technical or 🧪 Scientific review.

• 🛠 PR has a descriptive title for the changelog
• 🛠 Code follows the style guide
• 🛠 Documentation is available
• 🛠 YAML files pass pre-commit or yamllint checks
• 🛠 Circle/CI tests pass
• 🛠 Codacy code quality checks pass
• 🛠 Documentation builds successfully on readthedocs

New or updated recipe/diagnostic:

• 🛠 Provenance information has been added
• 🛠 New dependencies are added to the project requirements
• 🧪 Documentation for the recipe/diagnostic clearly describes what it calculates from a scientific point of view
• 🧪 Recipe runs successfully on @esmvalbot or some other machine without modification
• 🧪 Figure(s)/data look as expected
• 🧪 Code is well documented and scientifically sound

---

To help with the number pull requests:

• 🙏 We kindly ask you to review two other open pull requests in this repository

---

Draft pull request as some things still need to be done:

• Clean up recipe - done
• Add provenance to station_comparison.ncl -> done
• Change units to be taken from file, not variable info -> done
• Add cmorizer scripts for new data (ESRL but different format) -> done and merged
• Add core branch for fixes and XCO2 derivation script -> done and merged
• Add documentation - done
• Updated checklist to the new one ;)

Closes issue #1915

[bettina-gier]

Checked that it works with the new core release and the iris 3 in the esmvaltool! Ready for review @schlunma
ACCESS-ESM1-5 model commented out, as it requires regridding in the xco2 derivation script. Still left in as comment to show it was in the paper. As this reproduces a paper which went through full peer review, a detailed scientific examination is not necessary.

[schlunma]

Code looks good (one small comment on the changes in auxiliary.ncl), documentation looks good (some minor comments). Would it be possible to replace the figures in the documentation with lower-resolution versions? Some of them are pretty large (1.2 MB), and I don't think this high resolution is necessary here 😉

Running the recipe now for the scientific review!

[schlunma]

Plots, nc files and provenance look good, everything is similar to the paper! 👍