ACCESS-OM2-025 is COSIMA’s 1/4° ocean-sea ice model and is currently in the final stages of testing. It uses the MOM5.1 ocean with 0.25° lateral resolution at the Equator, tripolar in the north and Mercator projection down to 65°S, with 50 vertical levels. The sea ice model is CICE5.1, coupled with the OASIS3-MCT coupler. The model is forced with the JRA55-do v1.3 forcing dataset.
The model configuration is tracked with version control and is available as part of the ACCESS-OM2 suite at github.com/OceansAus/access-om. Full instructions for obtaining the source code, compiling and running the model are also at the same location.

Model Performance

Typical processor configurations for ACCESS-OM2-025 on Raijin are:

• 1455 cores for the MOM5.1 ocean;
• 280 cores for the CICE5 sea ice model;
• 1 core for the MATM atmosphere;
• totalling 1936 cores (or 1960 cores on the Broadwell nodes).

Default simulations use an 1800 second timestep, yielding runtimes of ~58 minutes per model year on the Broadwell nodes (~24 model years per day at full capacity).

Model Output

Results from the model are released freely for community use. Currently, preliminary spinup results are housed in /g/data3/hh5/tmp/cosima/access-om2-025/ on NCI.