COSIMA TWG Meeting Minutes 2026

COSIMA TWG
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Date: 1 Jul 2026

Attendees: @Aidan, @aekiss, @anton, @NoahDay, @cbull, @sofarrell, @ezhilsabareesh8, @dougiesquire

OM3 control directory restructure

Aidan has opened an issue suggesting that we add realm subdirectories to the configurations.

A similar restructure of the output would also be good, but it more difficult.

General agreement that the new structure is clearer.

Actions:

  • Dougie will scope out how much work is involved.

Replace panan4km+isf RYF with IAF

Shall we replace the panan4km+isf RYF configuration with an IAF equivalent?

No objections.

Actions:

  • Dougie will make the switch

25km releases todo

Dougie shared a todo list of things to be done before 25km releases

Suggested changes/additions:

  • Set MAX_DELTA_SRESTORE = 0.5 in RYF
  • Add 3D and 2D conservative temperature diagnostics

There is not currently enough space in ol01 to store the experiment output associated with the releases. Josh, Adele and others are working on moving ~50TB of data, hopefully soon.

Options for release:

  • Wait

  • Remove some old experiments

    $ du -hsc /g/data/ol01/outputs/access-om3-25km
4.0T    25km-iaf-test-for-AK-expt-7df5ef4c
4.7T    MC_25km_jra_iaf-1.0-beta-5165c0f8
2.0T    MC_25km_jra_iaf-1.0-beta-gm1-d968c801
2.2T    MC_25km_jra_iaf-1.0-beta-gm2-5dc49da6
2.1T    MC_25km_jra_iaf-1.0-beta-gm3-da330542
2.2T    MC_25km_jra_iaf-1.0-beta-gm4-9fd08880
2.2T    MC_25km_jra_iaf-1.0-beta-gm5-9b5dbfa9
2.1T    MC_25km_jra_iaf+wombatlite_bs1-mpudig-backscat1-4c21c151
2.1T    MC_25km_jra_iaf+wombatlite_bs2-mpudig-backscat2-0578cc36
11T     MC_25km_jra_iaf+wombatlite-test3v2-00532b88
5.2T    MC_25km_jra_iaf+wombatlite-test3v2-COARE-12fab415
2.4T    MC_25km_jra_ryf-1.0-beta-cdfb3543
6.3T    MC_25km_jra_ryf+wombatlite-81ad20e-c4347f5a
48T total

    Andrew wants to keep 25km-iaf-test-for-AK-expt-7df5ef4c (CHL-informed SW turned off) and potentially a few others. There was agreement that the following could be removed:

    2.0T    MC_25km_jra_iaf-1.0-beta-gm1-d968c801
2.2T    MC_25km_jra_iaf-1.0-beta-gm2-5dc49da6
2.1T    MC_25km_jra_iaf-1.0-beta-gm3-da330542
2.2T    MC_25km_jra_iaf-1.0-beta-gm4-9fd08880
2.2T    MC_25km_jra_iaf-1.0-beta-gm5-9b5dbfa9
6.3T    MC_25km_jra_ryf+wombatlite-81ad20e-c4347f5a

    but in the end we decided to wait a bit (I think)

  • Release without data. “Data will be available at these locations”

    May as well wait

  • Ask for more allocation

  • Ask for another project explicitly for control experiments

    Possibly a good idea regardless of immediate decision

Actions:

  • Dougie will press on with doing Github release and will only post to the forum once the data is available in ol01.

ACCESS-OM2 experiments repo

Dougie will soon start some ACCESS-OM2 control experiments using the latest releases.

Shall we do a single experiment directory or one for each experiment?

Agreed on single access-om2-experiments repo in the Community organisation

Actions:

  • Dougie will set up repo.
  • Dougie will make Forum post inviting people to suggest new diagnostics to include in experiments (promised here).

MOM6 dev meeting

  • PR from dev/ncar nearly merged. Large PR from dev/gfdl up next
  • Next meeting (4 weeks) will be annual default parameter change meeting
  • Ed Yang has a PR demonstrating a new blocking code structure (for the continuity solver, for now) that allows dynamically switching between CPU/GPU optimised layout. Performance is looking good