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Welcome to the documentation for the ACCESS-ESM1.6 model configurations. This website contains information for running, modifying and understanding the ACCESS-ESM1.6 Earth System Model.

ACCESS-ESM1.6 Documentation Overview

Key sections to look for are:

  • Configurations: supported and updated collections of run-time configuration files to run the model
  • Experiments: results of using a single configurations to simulate climate
  • Infrastructure: details on modifying compiled model executables, and contributing changes to support configurations

access-esm1.6-configs Overview

ACCESS-ESM1.6 configurations are provided via branches in the access-esm1.6-configs GitHub repository. The access-esm1.6-configs repository contains configurations using the following components:

  • MOM5 ocean model
  • CICE5 sea ice model
  • UM7 atmosphere model
  • CABLE land surface model including CASA-CNP for the land biogeochemistry
  • WOMBATLite ocean biogeochemisty

All the configurations use the Payu workflow management tool, and pre-built executables available on NCI.

Repository structure

The main branch does not store any model configurations, only documentation.

Each configuration in github.com/ACCESS-NRI/access-esm1.6-configs repository is stored as a git branch.

Supported configurations are named according to the following naming scheme:

release-{scenario}

where release signifies this is the release branch that is tested, versioned and ready for use. {scenario} is the CMIP7 experiment. Scenario names exactly match CMIP7 experiment names. All configurations are global with nominal 1 degree resolution.

Development branches (dev-{scenario}) contain changes for future releases, and when merged into release branches create a release.

Feature branches contains tests, demonstrations and new features, and should be named using an issue number, scenario and other descriptors to disambiguate them.

Supported configurations

All supported configurations are browsable under the list of release branches. The current releases are for the CMIP7 piControl and historical configurations with concentrations and emissions driven CO₂ forcings. Releases for amip and some CMIP7 future scenarios are planned.

Development configurations

The configurations under active development, have dev- branches - findable through this list. It is recommended to use release- branches for experiments.

When changes are made, they should be applied to all dev- branches they are relevant to by pull requests.

Archived configurations

There were some configurations previously under development that have now been archived. These are available for reference as git tags.

These were +CN only, i.e. including the carbon and nitrogen cycles but excluding the phosphorus cycle in the land :

These configurations were used for CMIP7 experiments:

If you need assistance to use git to update these configurations, please ask on the ACCESS-Hive forum.

Comparing configuration branches

GitHub's branch comparison view can be used to see exactly what differs between any two configurations. This is useful, for example, to see how a dev-* configuration differs from the latest release-* configuration it's based on, or how two configurations at different resolutions differ.

To compare any two branches, visit a URL of the form:

https://github.com/ACCESS-NRI/access-om3-configs/compare/{base-branch}..{compare-branch}

replacing {base-branch} and {compare-branch} with the names of the branches you want to compare. This shows the diff between the {base-branch} and {compare-branch}. Lines shown in red are only present in {base-branch} (i.e. absent from {compare-branch}) and lines shown in green are only present in {compare-branch} (i.e. added relative to {base-branch}).

Note that the .. produces a "two-dot" diff directly between the two refs, rather than the "three-dot" diff (against their merge base) that GitHub uses for pull requests.

Tags or commit hashes can be used in place of branch names, which is useful for comparing against a specific released version or commit, rather than the (potentially newer) tip of a branch.

For example, to compare the release-MC_25km_jra_iaf-1.0-beta release tag with the dev-MC_25km_jra_iaf branch, visit:

https://github.com/ACCESS-NRI/access-om3-configs/compare/release-MC_25km_jra_iaf-1.0-beta..dev-MC_25km_jra_iaf

How to use this repository to run a model

All configurations use payu to run the model.

This repository contains many related experimental configurations to make support and discovery easier. As a user it does not necessarily make sense to clone all the configurations at once.

In most cases only a single experiment is required. If that is the case, choose which experiment and then run

git clone -b <experiment> https://github.com/ACCESS-NRI/access-esm1.6-configs <experiment>

and replace <experiment> with the branch name or tag of the experiment you wish to run.

ACCESS-Hive contains detailed instructions for how to configure and run ACCESS models with payu.