COSIMA Linkage Project funded

The Australian Research Council (ARC) recently announced $1.1M of funding for a new 4-year COSIMA project. The new project is funded under the ARC’s Linkage Project scheme, and is supported by 4 industry partners: The Department of Defence, Bureau of Meteorology, Australian Antarctic Division and CSIRO. This funding will continue to support the Australian ocean and sea ice modelling community to develop and distribute open source model configurations.

The aims of the proposal are to:

  1. Configure, evaluate and publish the next-generation MOM6 ocean model and CICE6 sea ice model, culminating in a new, world-class Australian ocean-sea ice model: “ACCESS-OM3”;
  2. Advance Australian capacity to model the ocean’s biogeochemical cycles and surface waves, including the feedback between waves, sea ice, biogeochemistry and ocean circulation; and
  3. Build on the success of COSIMA to establish deep ties between Australia’s leading ocean-sea ice modelling institutions, while maintaining ACCESS-OM2 for ongoing research projects and operational products.

Work on the new project is expected to begin in 2021, initially focussing on the adoption of the MOM6 ocean model for regional applications. A schematic of the intended workflow can be found in the figure below.

As well as developing new model configurations, the new COSIMA project will have a stronger emphasis on developing tools for data analysis, data sharing and publication. The new project will start with a kick-off meeting in the first half of 2021 (details to be announced).

COSIMA Model Output Collection

An increasingly important aspect of model simulations is to be able to share our data. Over the last few years we have been working on methods to routinely publish our most important simulations. This publication process is designed to allow any users, worldwide, to be able to pick up our model output and test hypotheses against our results. It will also allow journal publications to be able to cite our model output.

Currently we have  5 different datasets within the headline COSIMA Model Output Collection, which can be found here:

For users with NCI access this data is housed under the cj50 project.

We are planning to add new datasets in the coming months.

New Repeat Year Spinup

We are currently undertaking a new spinup simulation using our highest resolution ocean-sea ice model: ACCESS-OM2-01. Our goal is to run at least 50 years of this simulation in the third quarter of 2019, using the  1990-91 Repeat Year Forcing strategy (that we call RYF9091). After the first month of the quarter, we have managed to complete 23 years of the simulation.

Early indications are that temperature and ice biases are reduced in the new simulation (compared with our previous RYF8485 spinup) but that many large scale circulation metrics, such as ACC transport) are largely unchanged.

Globally Averaged temperature from RYF9091 spinup.
ACC Transport from RYF9091 spinup

For those who are interested, this simulation is being stored in /g/data3/hh5/tmp/cosima/access-om2-01/01deg_jra55v13_ryf9091. Timeseries describing the simulation, periodically updated, can be found here, and additional diagnostics are available upon request.

COSIMA IV, ANU, 3-4 Sept 2019

Announcing that our 4th Annual COSIMA workshop will be held at ANU on Tuesday 3rd and Wednesday 4th September.

The workshop will feature our regular mix of talks and discussions, covering a mix of physical oceanography, sea ice, model development and technical advances. Our workshops are not restricted to ACCESS-OM2/MOM users – we welcome contributions from all who consider themselves part of the COSIMA community.

Registration is now closed, but you can join via Zoom – see below.

We will begin with morning tea at about 10am on the first morning (3 Sept), with the first talk at about 10:30.

Click here for the workshop program (updated 1st Sept).

The workshop report provides slides from the presentations and a summary of the discussion. Shweta’s post on the workshop is here.

Joining via Zoom
The workshop will be streamed via Zoom. When joining via zoom, please mute your mic and hide your video. Unfortunately we probably won’t have an ability to take questions from remote participants.

Connection details:

Join from a PC, Mac, iPad, iPhone or Android device:

Join from a H.323/SIP room system:
Dial: +61 2 6222 7588
or H323:8232211676@ (From Cisco)
or H323: (From Huawei, LifeSize, Polycom)
or or (U.S.)

Meeting ID: 8232211676

ACCESS-OM2 at the CLEx Winter School

This week saw the ARC Centre of Excellence for Climate System Science hold its annual Winter School. This year’s edition is on modelling the climate system, hosted by the University of Melbourne. Yesterday was “Oceans Day” at the Winter School, and the highlight was an afternoon lab session based on ACCESS-OM2. Tasks included:

  • To run the ACCESS-OM2 model (about 65 of the 70 students managed to do this); and
  • To analyse some existing ACCESS-OM2 model output using the COSIMA cookbook (most students also completed this, with about a third of students producing great plots to show some new and intriguing results).

Progress was enabled by erstwhile helpers from CLEx’s CMS Team – Aidan, Claire Holger, Paola and Scott!

ACCESS-OM2 Workshop
Feverishly running ACCESS-OM2 at the 2019 CLEx Winter School.

ACCESS-OM2 Evaluation Paper

A community paper evaluating the performance of ACCESS-OM2 has been submitted to Geoscientific Model Development (GMD).  The paper has 30 authors from across the Australian community. GMD has an open review process, so you can track its progress.

This paper outlines the performance of ACCESS-OM2 at three different model resolutions, as indicated in the figure below.  It aims to spell out which versions of the model are suitable for different types of studies, and highlights the performance of the 0.1° resolution configuration (referred to as ACCESS-OM2-01). The paper shows that ACCESS-OM2 does a good job of representing many features of the ocean. Historical sea ice extent trends are well-represented, and the surface properties and transects in each ocean basin compare well with the observational record. The large scale overturning circulation, flow through the Indonesian archipelago and patterns of boundary currents are realistic, supporting the notion that this suite of models is competitive with similar models from other institutions. Areas for improvement include the relatively weak barotropic transport in the midlatitude gyres, particularly in the Pacific Ocean, the weaker than observed Drake Passage transport and the weak AMOC in the 1° configuration. For full details, feel free to browse the paper!

Kiss, A. E., Hogg, A. McC., Hannah, N., Boeira Dias, F., Brassington, G. B., Chamberlain, M. A., Chapman, C., Dobrohotoff, P., Domingues, C. M., Duran, E. R., England, M. H., Fiedler, R., Griffies, S. M., Heerdegen, A., Heil, P., Holmes, R. M., Klocker, A., Marsland, S. J., Morrison, A. K., Munroe, J., Oke, P. R., Nikurashin, M., Pilo, G. S., Richet, O., Savita, A., Spence, P., Stewart, K. D., Ward, M. L., Wu, F., and Zhang, X.: ACCESS-OM2: A Global Ocean-Sea Ice Model at Three Resolutions, Geosci. Model Dev. Discuss.,, in review, 2019.


Over the last day we have completed initial spinup runs of the ACCESS-OM2 model.
The model has been run at 3 different resolutions, as listed below:

ACCESS-OM2 = [MOM5.1 + CICE5.1 + OASIS3-MCT + YATM + JRA55v13-do]


  • 1° resolution, 50 levels
  • 252 cores
  • 48 yrs/day – 160 SU/yr
  • 5 InterAnnual Forcing (IAF) cycles complete
  • Numerous Repeat Year Forcing (RYF) cases


  • 0.25° resolution, 50 (KDS) levels
  • 1824 cores
  • 16 yrs/day – 2800 SU/yr
  • 5 IAF cycles complete
  • Additional IAF and RYF cases run


  • 0.1° resolution, 75 (KDS) levels
  • 5744 cores
  • 2.2 yrs/day – 63 kSU/yr (provided dt=600 sec)
  • Minimal config with 2064 cores, ~1 yr/day
  • 40-year RYF spinup with variable parameters, tweaks, date fixes during spinup.
  • Single IAF run from 1985 to 2017

For a full recount of today’s COSIMA meeting presentation, see the COSIMA Update slides.

COSIMA 2018 Workshop Details

The 2018 COSIMA workshop will be held on 7 & 8 May at the Australian Centre for China in the World on ANU Campus.

You can download the latest draft of the COSIMA Workshop Program (updated 3rd May). The program includes instructions for uploading your talk, guidelines on how to contribute to our discussion and some preparatory homework for anyone attending the COSIMA Cookbook Tutorial.

Please contact Andy Hogg or Andrew Kiss if you have any queries.


Over the last few months, COSIMA folks have been working hard on releasing our ACCESS-OM2 suite of models. The current status is that we have now completed a 500 year spinup for 3 different cases using the JRA55-do (Tsujino et al., 2017, personal communication) forcing dataset. Some preliminary results can be seen in the figures below. We are also spinning up a CORE-NYF comparison case. For a more complete analysis have a look in the COSIMA Cookbook.

Plans in the coming weeks are to finalise spinups of our 0.25° case (ACCESS-OM2-025), and to begin running our flagship 0.1° simulation, ACCESS-OM2-01.


COSIMA Linkage Project

The COSIMA consortium is partly supported by an ARC Linkage Project. This project is now active, following sign-off from all partners in December 2016. The management committee for the project formally met for the first time on Friday 9th December. Following are abbreviated minutes from the meeting which outline our plans for 2017:

  1. To advertise for a Postdoctoral/Research Fellow to coordinate COSIMA projects.
  2. To enhance the vertical resolution of existing MOM5-SIS 0.1° model, with no change in horizontal resolution;
  3. To enhance model bathymetry in coastal regions to take advantage of reduced minimum depth stemming from vertical resolution changes;
  4. To couple MOM5 with CICE at 0.1° using OASIS3-MCT (we have a contract with Nic Hannah from Double Precision to perform this work);
  5. To evaluate, refine, optimise and document the new model configuration.

Furthermore, we have confirmed that the 2017 COSIMA meeting will be in Sydney on May 25-26.