ACCESS-OM2 Model Configurations

About

This repo contains standard global configurations for ACCESS-OM2, the ACCESS Ocean-Sea Ice model.

All confgurations were developed by COSIMA and adapted by ACCESS-NRI.

This is an "omnibus repository": it contains multiple related configurations, and each configuration is stored in a separate branch.

Branches utilise a naming scheme of specifiers separated by underscores (_):

{resolution}_{atmosforcing}_{forcingmode}[_{option}]

Where resolution is a representative "nominal resolution" because resolution typically varies across a global domain; atmosforcing is the atmospheric forcing product being used; forcingmode is how the forcing is applied over time; and option is additional options that are necessary to uniquely identify a configuration.

Some examples of possible values of the specifiers:

• resolution: 1deg (1°), 025deg (0.25°), 01deg (0.1°)
• atmosforcing: jra55, era5
• forcingmode: iaf (interannual forcing), ryf (repeat year forcing)
• option: bgc (Biogeochemistry)

Supported configurations

All available configurations are browsable under the list of branches.

and should also be listed below:

Branch	Configuration Description
release-1deg_jra55_ryf	Global 1° model forced with JRA55-do atmospheric reanalysis in repeat-year forcing mode
release-1deg_jra55_iaf	Global 1° model forced with JRA55-do atmospheric reanalysis in interannual forcing mode
release-1deg_jra55_ryf_bgc	Global 1° model with BGC forced with JRA55-do atmospheric reanalysis in repeat-year forcing mode
release-1deg_jra55_iaf_bgc	Global 1° model with BGC forced with JRA55-do atmospheric reanalysis in interannual forcing mode
release-01deg_jra55_ryf	Global 0.1° model forced with JRA55-do atmospheric reanalysis in repeat-year forcing mode
release-01deg_jra55_iaf	Global 0.1° model forced with JRA55-do atmospheric reanalysis in interannual forcing mode
release-01deg_jra55_ryf_bgc	Global 0.1° model with BGC forced with JRA55-do atmospheric reanalysis in repeat-year forcing mode
release-01deg_jra55_iaf_bgc	Global 0.1° model with BGC forced with JRA55-do atmospheric reanalysis in interannual forcing mode

There are more detailed notes contained in the respective branches for each configuration.

More supported configurations will be added over time.

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/accessom2-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-OM2 with payu.

CI and Reproducibility Checks

This repository makes use of GitHub Actions to perform reproducibility checks on ACCESS-OM2 config branches.

Config Branches

Config branches are branches that store model configurations of the form: release-<config> or dev-<config>, for example: release-1deg_jra55_iaf. For more information on creating your own config branches, or for understanding the PR process in this repository, see the CONTRIBUTING.md.

Config Tags

Config tags are specific tags on config branches, whose MAJOR.MINOR version compares the reproducibility of the configurations. Major version changes denote that a particular config tag breaks reproducibility with tags before it, and a minor version change does not. These have the form: release-<config>-<tag>, such as release-1deg_jra55_iaf-1.2.

So for example, say we have the following config tags:

• release-1deg_jra55_iaf-1.0
• release-1deg_jra55_iaf-1.1
• release-1deg_jra55_iaf-2.0
• release-1deg_jra55_iaf-3.0

This means that *-1.0 and *-1.1 are configurations for that particular experiment type that are reproducible with each other, but not any others (namely, *-2.0 or *-3.0).

*-2.0 is not reproducible with *-1.0, *.1.1 or *-3.0 configurations.

Similarly, *-3.0 is not reproducible with *-1.0, *-1.1 or *-2.0.

Checks

These checks are in the context of:

• PR checks: In which a PR creator can modify a config branch, create a pull request, and have their config run and checked for reproducibility against a 'ground truth' version of the config.
• Scheduled checks: In which config branches and config tags that are deemed especially important are self-tested monthly against their own checksums.

More information on submitting a Pull Request and on the specifics of this pipeline can be found in the CONTRIBUTING.md and README-DEV.md respectively.

For more information on the manually running the pytests that are run as part of the reproducibility CI checks, see model-config-tests.

Conditions of use

COSIMA request that users of this or other ACCESS-OM2 model code:

1. consider citing Kiss et al. (2020) (http://doi.org/10.5194/gmd-13-401-2020)
2. include an acknowledgement such as the following: The authors thank the Consortium for Ocean-Sea Ice Modelling in Australia (COSIMA; http://www.cosima.org.au) for making the ACCESS-OM2 suite of models available at https://github.com/COSIMA/access-om2.
3. let COSIMA know of any publications which use these models or data so they can add them to their list.