CSIRO - ACCESS-NRI standup minutes

CMIP7 CMIP7 development
37

Meeting Minutes

Date: 20 May 2025
Chair and Minutes: Chris Bull
Participants:
Chris Bull
Rachel
Anton
Ian
Pearse
Romain
Aidan
Dave Bi
Dougie
Harshula
Jemma Jeffree
Ian
Tilo
Micael
Manodeep
Lachlan
Martin

Large update discussion with multiple components/threads

  • Discussion on timing and bundling of changes. Suggestion: we start a forum table which everyone can edit will the following information: Priority,
    Target date for inclusion (afterthought: GitHub issue link). The following things could be considered:

    • Wombat changes
    • Forcing changes (Martin: aerosols will be ready in a day or two)
    • Australian PFTs
    • Canopy height
    • Root distribution
    • CICE5
    • Build system changes (see below)
    • cleaning up the vegetation distribution (so land use change is working)
    • code change radiation / bgc only experiments
      Rachel: once we have the suggested changes, a hackathon could be useful.

  • CMT Option Discussion:

    • Current run uses CMT=1; proposal to switch to CMT=0. Rachel: question of when to do this? Jhan already running for a while, could potentially drop the run with 1 and pick up from 0.
    • Ian: Concerns raised about discarding ~150 years of existing data as CMT=0 may lead to negative impacts on East Africa rainfall and Mediterranean salinity.
    • Ian and Tilo prefer to turn CMT=0 on at year 650 from the existing run. Rachel: would suggest looking closer at outputs before making a decision.

  • Other Land Updates:

    • Australian PFTs, canopy height, root distribution, and vegetation distribution updates.

Ocean & Biogeochemistry Updates

  • CICE 5 Experiment:

    • Dave Bi has had a look at Anton’s latest run in the mass imbalance looks like it has been fixed (Siobhan found an issue – one of the namelist options was incorrect update_ocn_f – ice’s view of the ocean salinity was not being updated). On Friday Anton started off from Jhan’s run, from year 685, years run ~40, will aim to get to 100. Will update the issue. Dave Bi is looking good: no salinity or mass imbalance drift.

  • Southern Ocean SST Bias:

    • Anton: question does esm1.6 have the southern ocean warm bias that is common in these kinds of models? Dave Bi: would expect it to be similar.

  • Mediterranean Salinity:

    • Anton has asked Ezhil/Chris to analyse transport between eastern and western basins, before and after code change.
    • Ian noted global surface salinity has levelled off but this does not necessarily imply local stabilization. A script has been shared that enables one to look at the more regional level.

4xCO₂ Run

  • Ian: 4x C02 would be helpful for a few meetings in a few weeks.
  • Tilo: 4x C02 is already running, Martin has been having a look. /scratch/p66/txz599/access-esm/archive/test_4xCO2-expt-862aa61d

Build System & Technical Updates

  • MOM5 Build System:

    • Dougie: two upcoming answer changes in the pipeline: updated mom5 build system (OASIS MCT) and grid format. Hoping that answer changes will not lead to drastic scientific change. Change will be coming in a couple of weeks.
    • Testing required before integration.
    • Dougie will add to above table

  • Manodeep’s Update:

    • Investigating Pi config crash using Valgrind; work in progress.

Action Items & Next Steps

  • Create a table of all proposed changes (Chris to initiate).
  • Review and validate the CMT=0 run before switching.
  • Continue running and analyzing CICE5 and 4xCO₂ experiments.
  • Monitor Mediterranean salinity and SST biases.
  • Prepare for potential hackathon or extended session to integrate changes.
  • Rachel and others will contribute to the checklist.

Afterthought! (not discussed) **

  • Next Meeting may be cancelled due to staff retreat. Will follow up with Rachel and others.