# CM3 Dev-Eval Working group: Meeting minutes
**URL:** https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393
**Category:** Working Group
**Tags:** model-evaluation, access-cm3, access-esm, development
**Created:** [13 October 2025 22:15 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393 "2025-10-13T22:15:17Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@cbull](https://forum.access-hive.org.au/u/cbull)
#### Post date: [13 October 2025 22:15 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/1 "2025-10-13T22:15:17Z")
### Meeting guidelines
Below are posts for each `CM3 Dev-Eval Working group meeting` currently focused on CM3. Before each meeting, we’ll create a placeholder post where participants are welcome to post:
1. discussion items;
2. links to GitHub issues in the CM3 evaluation repository that contain Figures;
3. figures or analysis that can then be discussed at the meeting.
The posts below are “wiki” posts mean anyone with a forum account can edit it (changes are tracked).
During the meeting, the post will be updated by a note taker such that the post forms the minutes for the meeting.
### Meeting table of contents
- [Tuesday on the 11th November at 10:30 am](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes-2025/5393/2);
- [internal meeting on 25/11/2025, on the managing and long term plans on the CM3/OM3/AM3 evaluation efforts](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes-2025/5393/4)
- [Tuesday 9 December at 10:30 am](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes-2025/5393/3).
- [Tuesday 20 January 2026 at 10:30](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes-2025/5393/5)
- [Tuesday 3 March 2026 at 10:30](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes-2025/5393/6)
- [Tuesday 31 March 2026 at 10:30](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes-2025/5393/7)
- [Tuesday 23 June at 10:30 am](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/8)
- [Tuesday 21 July](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/9)
- [Tuesday 18 August](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/10)
### @spencerwong role _immediately following_ each meeting
- Create new post in this thread with boilerplate [1];
- make it a wiki post;
- add it to the `meeting table of contents` as a link (section above);
- rollover any content from the previous meeting that we didn’t get to.
### @spencerwong role _before_ each meeting (say Monday before)
- announce next meeting on the [ESM announce page](https://forum.access-hive.org.au/t/esm-working-group-announce/567/67);
- include any current agenda items and remind people they can suggest items/figures.
### @kieranricardo role _before_ each meeting
- emphasise / find contributions from previous meeting;
- quick summary of workflow options for contributions;
- summary of [the last CM3 technical meeting](https://forum.access-hive.org.au/t/access-cm3-technical-meetings-announce/5418/3);
- look over GitHub cm3-paper-1 repo and see if there are any updates;
- check in with Chris/Heidi for the status of community contributions
### @kieranricardo role _during_ meeting
- quick summary of workflow options for contributions;
- _emphasise_ contributions from previous meeting;
- offer support (breakout room?) to people wanting to get involved / could set aside 10 minutes at end of meeting to answer questions.
[1]
#### **CM3 Dev-Eval Working group meeting minutes**
Date: **INSERT\_DATE at 10:30 am**
Participants:
Chair: @kieranricardo
Minutes: @spencerwong
#### Agenda:
- shout-out props for Figures from:
- offer support (breakout room?) to people wanting to get involved / could set aside 10 minutes at end of meeting to answer questions.
#### GitHub issue links:
-
#### GitHub issue links to OM3 figures for CM3:
-
#### Community figures
_Please paste here and include a caption!_
---
### Author:  [@cbull](https://forum.access-hive.org.au/u/cbull)
#### Post date: [14 October 2025 00:04 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/2 "2025-10-14T00:04:44Z")
#### **First CM3 Dev-Eval Working group**
Date: **Tuesday on the 11th November at 10:30 am**. [Meeting link](https://anu.zoom.us/j/86257758134?pwd=aXRqNzIvaU9FRHdnYnlseHhhS2JRUT09).
Participants: @cbull, @jemmajeffree, @wghuneke, @spencerwong, @rbeucher, @tiloz, @MartinDix, @ezhilsabareesh8, @paulleopardi, @CharlesTurner, @dgwyther, @aekiss, @heidi, @ZhiLiUNSW, @RachelLaw, Sienna Blanckensee, @Harun_Rashid, @lishx, @ongqingyee, @HIMADRI_SAINI, @peterdobro, @DeepashreeDutta
Coordination: @cbull
Chair: @cbull
Minutes: @spencerwong
Apologies: @nicolamaher @ctychung @dave
#### Agenda:
- shout-out props for Figures from: @ctychung @ezhilsabareesh8 @ongqingyee @kieranricardo @Harun_Rashid (?)
- quick summary of workflow options for contributions;
- current collaborators: abmhar, anton-seaice, ctychung, deepashreedutta, himadri14 (Himadri Saini), jemmajeffree, kieranricardo, ofa001 (Siobhan), ongqingyee (Ellie Ong), peterdobro, wghuneke (Wilma Huneke)
- update on datastores from @CharlesTurner (related [1](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/pull/45) [2](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/43) [3](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/12))
- summary of [the last CM3 technical meeting](https://forum.access-hive.org.au/t/access-cm3-technical-meetings-announce/5418/3) – @MartinDix @kieranricardo;
- @Harun_Rashid [python stats functions](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/blob/main/notebooks/sandbox-python/statsfuncs.py)
- offer support (breakout room?) to people wanting to get involved / could set aside 10 minutes at end of meeting to answer questions.
#### Scheduling:
- See [this post](https://forum.access-hive.org.au/t/esm-working-group-announce/567/68) for the schedule of ESM WG and CM3 dev-eval meetings for the rest of the year. There will be an ESM WG meeting with a science presentation on Thursday 20 November at 1pm AEDT, and a CM3 dev-eval meeting on Tuesday 9 December at 10:30 am AEDT.
#### CM3 technical developments
- @MartinDix provided an update on the latest CM3 technical developments. Changes being tested include bathymetry changes to address Baltic salinity drift, and UM GC5 parameter changes. The parameter changes led to a worsening of the radiative imbalance, and tests using newer UM code will be carried out.
- Full minutes from the last technical meeting are available [here](https://forum.access-hive.org.au/t/access-cm3-technical-meeting-minutes/5429/2), and anyone is welcome to get involved in the meetings.
#### Python stats functions
- @Harun_Rashid has added a collection of python functions for statistical analysis to [the repository here](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/blob/main/notebooks/sandbox-python/statsfuncs.py). These might be useful in for anyone doing analysis, and feel free to reach out if you have questions.
#### Datastores for CM3 evaluation
- @CharlesTurner provided an update on creating datastores from CM2 and CM3 output. Most of the data from the latest CM3 run has been placed in a virtualised datastore, which significantly speeds up access and analysis.
- Virtualisation may not currently be viable for the CM2 data, and more specific workarounds will be required to optimise the speed of accessing the data.
- @MartinDix noted plans to split CM3 atmospheric output into single variable files which may also help.
#### Figure discussions:
- @ongqingyee [Evaluation: Global SST trend · Issue #16 · ACCESS-Community-Hub/access-cm3-paper-1 · GitHub](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/16) (experiment year 1-34 including spin up - _not historical_)
[The goal for this analysis was to compare the SST warming pattern in CM2 and CM3.](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/16#issuecomment-3478774048) The figure will be impacted by CM3’s cold start, however it does highlight significant warming in the southern ocean. SO warming biases could be important to investigate further.
- @kieranricardo: [Salinity time series for various ocean basins](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/48#issue-3589481181)
These figures show the average, maximum, and minimum salinity in several ocean basins. The Baltic shows a salinity drift, though this run did not include the latest bathymetry changes.
Discussion highlighted changes in variability in the maximum salinity timeseries, though this could be due to changes at individual points. It was noted that adding observations to the comparisons would be useful.
- @kieranricardo: [Sea-ice volume and area time series](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/49#issue-3589483210)
CM3 is currently showing a much higher NH sea ice volume than CM2. It may also be similarly high in OM3. Spatial plots could be useful to understand where the thick ice is occurring.
- @kieranricardo: [Global TOA and surface energy balance](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/21#issuecomment-3489531216)
There’s a good match between ocean and TOA heat fluxes, suggesting that conservation through the coupler is working well. The current imbalance is roughly similar to the expected ~0.7W/m2. It was noted that CM2 never quite reached equilibrium.
A PI control configuration is planned, where the imbalance should go to 0.
- @ctychung: [Monthly mean precipitation and surface temperature](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/30#issue-3542970098)
_Rolled over to next meeting_
- @ctychung: [ENSO and IOD power spectra](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/15#issue-3512247006)
_Rolled over to next meeting_
#### GitHub links to OM3 figures for CM3 (please include OM3 comparison links where practical) – @ezhilsabareesh8 :
- [Drake Passage Transport](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/42#issuecomment-3459426400)
The streamfunction is too high in CM3. OM3 matches observations well, while CM3 is too high and still increasing. @ezhilsabareesh8 will update the figures to use the CM2 025 degree simulation.
- ~~[Global Timeseries](https://github.com/ACCESS-Community-Hub/access-om3-paper-1/blob/ezhil/cm3_evaluation/notebooks/GlobalTimeseries.ipynb).~~ _These diagnostics are not quite ready yet._
- [SSS and SSS difference from WOA23](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/41#issuecomment-3459492881)
Large SSS biases were noted in the Arctic
- [SST and SST difference from WOA23](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/36#issuecomment-3459506775)
Large warm biases in the Southern Ocean were noted
#### Community figures
_Rolled over to next meeting_
@Harun_Rashid
> today I’d like to briefly talk about the ENSO power spectrum (slide 4) and the ENSO diagnostics table (slide 5). The table compares various ENSO diagnostics computed from the latest CM3 run with those calculated from observations, ACCESS-CM2 and other CMIP6 model simulations.
> The run length is 37 years, with seven years of data missing
> The simulation was done in August by Kieran at ACCESS-NRI
##### Others
Please paste here and include a caption!
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [12 November 2025 01:57 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/3 "2025-11-12T01:57:16Z")
#### **CM3 Dev-Eval Working group meeting minutes**
Date: **Tuesday 9 December at 10:30 am**
Participants: @cbull, @jemmajeffree, @paocorrales, @RachelLaw, @ctychung, @kieranricardo, @MartinDix, @clairecarouge, @DeepashreeDutta, @Dietmar_Dommenget, @paulleopardi, @lachlanswhyborn, @sofarrell, @zoegillett27, @MATTENGLAND, @ShayneM, @heidi, @ClaireT, @gab563, @HIMADRI_SAINI, @ezhilsabareesh8, @lishx, @JulieA
Chair: @kieranricardo
Minutes: @spencerwong
Coord: [@cbull](https://forum.access-hive.org.au/u/cbull)
#### Agenda:
- shout-out props for Figures from: @Harun_Rashid @DeepashreeDutta [@ctychung](https://forum.access-hive.org.au/u/ctychung) [@DeepashreeDutta](https://forum.access-hive.org.au/u/deepashreedutta)
- quick summary of workflow options for contributions: see [here] for instructions for contributing scripts and notebooks to the repository, and reach out if you have any questions!
- summary of the dev-eval meetings ([Nov 19](https://forum.access-hive.org.au/t/access-cm3-technical-meeting-minutes/5429/3), [Dec 3](https://forum.access-hive.org.au/t/access-cm3-technical-meeting-minutes/5429/4))
- community contributions
- offer support (breakout room?) to people wanting to get involved / could set aside 10 minutes at end of meeting to answer questions.
#### Updates from the last CM3 technical development meeting:
Minutes from the last technical development meeting are available [here](https://forum.access-hive.org.au/t/access-cm3-technical-meeting-minutes/5429/4)
- Currently investigating issues with the Arctic sea ice. Both CM3 and OM3’s Arctic sea-ice is ~2x larger than observations and CM2, but the causes may be different. OM3 has an issue with stuck ice, which isn’t as prevalent in CM3. Other possible causes are differences in bottom melt, issues with where the winds are pushing the ice, meltpond differences, and possible CICE stability issues.
- @ezhilsabareesh8’s updates to the bathymetry have successfully resolved the Baltic salinity drift.
- Work going into updating the UM version to 13.8. This will allow for the full set of GC5 central parameter changes to be copied over, which should reduce the radiative imbalance.
- @CharlesTurner’s virtualised dataset significantly speeds up accessing the CM3 atmospheric data. Issues have come up applying this approach to the CM2 runs, and we are currently trying to work around this.
#### GitHub issue links:
- @ctychung: [Monthly mean precipitation and surface temperature](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/30#issue-3542970098)
The precipitation maps show that the model still has a double ITCZ bias, though precipitation in the Western Pacific may be slightly better in CM3 than CM2. Surface temperatures show several differences between the two models, especially in the northern hemisphere and over Antarctica.
- @ctychung: [ENSO and IOD power spectra](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/15#issue-3512247006)
We may need more data for a reliable power spectrum, however the amplitude of the spectrum is much higher for CM2 compared to both CM2 and HadISST. Likewise, Niño3.4 standard deviation is almost twice that from observations.
- [@DeepashreeDutta](https://forum.access-hive.org.au/u/deepashreedutta): [Comparison of cloud radiative effect (CRE) between ACCESS-CM3, ACCESS-CM2, and CERES observations](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/22#issuecomment-3625911541)
Zonal mean cloud radiative effects are roughly similar for CM2, CM3 and CERES observations, though CM3 shows some improvements compared to CM2. Maps show similar biases in many areas for both models, though CM3 may perform slightly better for high clouds, with reduced RMS error. CRE also looks better in CM3 compared to ESM1.5/1.6.
#### GitHub issue links to OM3 figures for CM3:
#### Community figures
##### Harun Rashid
@Harun_Rashid
> today I’d like to briefly talk about the ENSO power spectrum (slide 4) and the ENSO diagnostics table (slide 5). The table compares various ENSO diagnostics computed from the latest CM3 run with those calculated from observations, ACCESS-CM2 and other CMIP6 model simulations.
These figures also showed a high ENSO amplitude, and the fact that the Niño3.4 peak is higher than the Niño3 peak in the power spectrum suggested that it occurs too far to the west.
> The run length is 37 years, with seven years of data missing
> The simulation was done in August by Kieran at ACCESS-NRI
_Please paste here and include a caption!_
### Discussion
#### Timeline for new experiments:
Work is underway to upgrade the UM version to 13.8, incorporate the GC5 Central parameter changed (including cloud tuning), and incorporate changes from the latest release of OM3. The plan is to start a new run in January which includes these changes.
#### CMORisation
The ad-hoc nature of the current analysis was discussed, and it was noted that this may have to change each time that the model is updated. The long term strategy is to have CMORised output, and to create analysis scripts that work seamlessly across runs and models. Progress is being made, including using CMOR names for OM3 output, however there is still work with the MED team to be done.
---
### Author:  [@lachlanswhyborn](https://forum.access-hive.org.au/u/lachlanswhyborn)
#### Post date: [26 November 2025 04:15 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/4 "2025-11-26T04:15:07Z")
# Meeting Summary
Meeting summary of the ACCESS-NRI internal meeting on 25/11/2025, on the managing and long term plans on the CM3/OM3/AM3 evaluation efforts.
## Quick Recap
The team discussed integrating OM3, AM3 and CM3 evaluation workflows using a submodule approach, where OM3 and AM3 would be submodules in the CM3 repository. Ideally notebooks written for AM3/OM3 would also work on CM3, but not a trivial exercise.
* * *
## Summary
### OM3/AM3 as submodules in CM3 repository
- Plan is to make OM3 a submodule within the CM3 repository. Prevents desync of scripts between repositories.
- Where would AM3 sit in this? Worked well for OM3, as evaluation workflow was already in place, but AM3 does not yet have this community effort. Most likely, we would have atmosphere analysis contained in CM3 repo for now, and moved to AM3 repo when model is established.
- How to handle inconsistencies between CM and OM/AM? Apply pre-processing step, depending on which repo was running the analysis?
- This could be done by MOPPy, but this would be some time in future- MOPPy work focused on ESM1.6 currently.
### OM3–CM3 Workflow Integration
- There are a number of issues which make generalisation of notebooks difficult- different variable names, time axes.
### Maintenance
- How do we make it easy for users to test their scripts across models and configurations? It’s likely some work would fall to us, but ideally scripts would be quite general before being added to the repo.
### AM3 / CM3 Meeting Integration
- Agreed to trial joint meetings with AM3 participants attending CM3 sessions.
- Considered structuring agendas so ocean discussion comes first, then atmosphere, so people can leave/show up when necessary.
## Next Steps
- AM3 Team
- OM3 Team
* * *
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [15 December 2025 01:41 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/5 "2025-12-15T01:41:59Z")
#### **CM3 Dev-Eval Working group meeting minutes**
[Meeting link](https://anu.zoom.us/j/86257758134?pwd=aXRqNzIvaU9FRHdnYnlseHhhS2JRUT09)
Date: **Tuesday 20 January 2026 at 10:30 AM AEDT**
Participants: @cbull, @wghuneke, @Dietmar_Dommenget, @kieranricardo, @MartinDix, @Harun_Rashid, @paocorrales, @jemmajeffree, @ctychung, @aekiss, @ariaan, @sofarrell, @ezhilsabareesh8, @paulleopardi
Chair: @kieranricardo
Minutes: @spencerwong
#### Agenda:
- Reminder about program committee nominations for ESM/CMIP7 focussed workshop in September.
- shout-out props for Figures from: @jemmajeffree @ctychung @wghuneke
- CM3 technical meeting updates ([Dec 17th](https://forum.access-hive.org.au/t/access-cm3-technical-meetings-announce/5418/6), …)
- offer support (breakout room?) to people wanting to get involved / could set aside 10 minutes at end of meeting to answer questions.
#### Program committee nominations for CMIP7/ESM focussed workshop in September
- ACCESS-NRI will be hosting a CMIP7/ESM focused workshop in early September in Melbourne. We are currently putting together a program committee to help plan the workshop. We are looking for people who would bring valuable expertise, perspectives, and commitment to shaping the workshop’s program. We also want to build a diverse committee that includes representation across career stages and institutions.
- If you are interested in being part of the program committee, please contact @spencerwong or the co-chairs for the ESM and Land working groups by **January 22, 2026.**
#### Updates from CM3 technical meetings
Minutes from previous technical meetings are available [here](https://forum.access-hive.org.au/t/access-cm3-technical-meeting-minutes/5429/4).
- @kieranricardo has been working on updating component versions for CM3’s ocean to bring them into line with OM3. The UM is also being updated to version 13.8 to allow for the full GC5 central configuration to be used.
- Tests with the UM13.8 and full GC5 central configuration showed sudden cooling, and took cloud forcing results further away from observations. Results will be compared with AMIP simulations from the UKMO.
- A new run will be done once the updates are completed, and this will also include improvements to the wind stress remapping which will likely have large influences on the model’s ENSO.
- There are still issues with excessive ice volume in the Northern Hemisphere. A similar problem exists in OM3 due to non-advective points in the grid, however the distribution of excessive ice in CM3 is quite different, indicating a seperate problem.
#### GitHub issue links:
- @jemmajeffree [ENSO and IOD power spectra & seasonal cycle re-visited](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/15#issuecomment-3645109752)
The Niño3.4 autocorrelation suggests too strong a 4 year cycle, while the ENSO amplitude is also much too high.
- @ctychung [time series of CM3 (blue), 0.25 CM2 (green) and obs (orange)](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/15#issuecomment-3652452376)
Timeseries of the Niño3.4 anomaly show that a very strong El Niño and La Niña both occur in the first 10 years of the CM3 run. Plots omitting the first 10 years show that the Niño3.4 standard deviation remains too high even without these events.
- @wghuneke [OM3 vs CM3 Bottom age](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/37#issuecomment-3766398005)
OM3 shows improvements in DSW overflow compared to OM2. While CM3 also has some improvements in the DSW overflow compared to CM2, however it also has significantly excessive open ocean convection. This could be related to model spinup, and we’ll need to check how it looks later in a longer run.
#### Community figures
@Harun_Rashid
Comparing CM3’s ENSO statistics with CM2 and the CMIP6 ensemble. Two statistics that stand out are the thermocline depth and the thermocline depth standard deviation, both which are much higher than observations
_Please paste here and include a caption!_
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [20 January 2026 01:32 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/6 "2026-01-20T01:32:21Z")
#### **CM3 Dev-Eval Working group meeting minutes**
[Meeting link](https://anu.zoom.us/j/86257758134?pwd=aXRqNzIvaU9FRHdnYnlseHhhS2JRUT09)
Date: **Tuesday 3 March at 10:30 am AEDT**
Participants: @peterdobro, @kieranricardo, @JulieA, @RachelLaw, @wghuneke, @paulleopardi, @aekiss, @sofarrell, @ezhilsabareesh8, @zoegillett27, @DeepashreeDutta, @Harun_Rashid, @spencerwong, @Dietmar_Dommenget, @ShayneM
Chair: @kieranricardo
Minutes: @spencerwong
Subscribe to the ESM Working Group calendar as follows:
1. [ESM Working Group Meeting Calendar feed](https://outlook.office365.com/owa/calendar/463c5a6d0bba4c838dce9c57933398fb@anu.edu.au/3086e7a51b0d48ef85bee981a597274413647516456690471131/calendar.ics)(right click on the link and copy the URL)
2. Use calendar feed URL to [subscribe to the calendar](https://forum.access-hive.org.au/t/how-to-subscribe-to-a-calendar-feed/767)
#### Agenda:
- Description of new simulation. (Output at `/g/data/zv30/non-cmip/ACCESS-CM3/cm3-run-20-01-2026-om3-update/cm3-datastore/cm3-datastore.json`)
- The new simulation updates the ocean to the latest OM3 release, including parameter changes.
- Remapping wind stresses via the patch method removes artefacts in the ocean currents.
- Land ice fluxes improve the water balance and drift in sea surface hight, however increase the sea ice extent especially in the southern hemisphere.
- Work on the GC5 configuration is continuing to improve the energy balance.
- shout-out props for Figures from: @ctychung, @Harun_Rashid, @ezhilsabareesh8
- CM3 technical meeting updates ([Jan 28](https://forum.access-hive.org.au/t/access-cm3-technical-meetings-announce/5418/8), [Feb 11](https://forum.access-hive.org.au/t/access-cm3-technical-meetings-announce/5418/9), [Feb 25](https://forum.access-hive.org.au/t/access-cm3-technical-meetings-announce/5418/10))
#### GitHub issue links:
- @ctychung (new run) Monthly mean precipitation and surface temperature. [GHLINK](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/30#issuecomment-3924636321)
- Mean precipitation figures show a double ITCZ bias. Flux correction runs were suggested, where the coupled heat exchange would be manipulated to bring the SSTs closer to the observed mean state, as a way to address this bias, or as a way to investigate the sources of model biases. It may be possible to set up a flux correction run via the MOM settings.
- An AM3 evaluation repository is being set up, which will make it simpler to compare biases in coupled and atmosphere only simulations.
- ENSO and IOD variability [Evaluation: ENSO and IOD power spectra & seasonal cycle · Issue #15 · ACCESS-Community-Hub/access-cm3-paper-1 · GitHub](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/15)
#### GitHub issue links to OM3 figures for CM3:
- @ezhilsabareesh8 [Meridional transects of mean planetary geostrophic potential vorticity, potential density anomaly and max/min monthly mean MLD](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/66#issuecomment-3808474134)
- @ezhilsabareesh8 [Mean zonally integrated overturning circulation](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/67#issuecomment-3906283078)
- @ezhilsabareesh8 [Time series of AMOC. Compared with observational estimate of McCarthy et al. (2015)](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/67#issuecomment-3906287891)
- @ezhilsabareesh8 [Drake passage transport in CM3 new run](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/42#issuecomment-3987490185)
#### Community figures
@Harun_Rashid presented plots on:
- Sea surface height: The sea surface height drift seen in the previous CM3 run no longer occurs. This would be due to the addition of land ice fluxes which close the water budget.
- Biases in SAT: Compared to ERA5, CM3 SAT is much cooler, especially in the Arctic. This is similar to the biases in CM2 and other CMIP6 models.
- Linear trends in SAT: The CM3 run (using present day forcings) is currently cooling. The model contains an initial cool bias, and is expected to warm as it spins up. @wghuneke’s figures show similar behaviour in CM2 and 0.25 degree CM2, where an initial period of cooling was followed by a long period of warming.
- Regional means, standard deviations, and trends: SSTs in several regions show higher variability than observations, especially in the Niño3/3.4 regions of the Pacific.
- Power spectra: Niño power spectra shows a spectral peak at ~3.3 years, however the period is too regular and the overall variability is too high.
- ENSO metrics: Comparing several ENSO metrics against several CMIP6 models shows that the current CM3 run performs quite well. Biases in most metrics are small, though larger biases exist in the thermocline feedback, zonal wind forcing, sst standard deviation and sst skewness.
_Please paste here and include a caption!_
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [3 March 2026 00:46 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/7 "2026-03-03T00:46:55Z")
#### **CM3 Dev-Eval Working group meeting minutes**
[Meeting link](https://anu.zoom.us/j/86257758134?pwd=aXRqNzIvaU9FRHdnYnlseHhhS2JRUT09)
Date: **Tuesday 31 March at 10:30 am AEDT**
Participants: @RachelLaw, @MartinDix, @JulieA, @kieranricardo, @Harun_Rashid, @AndyHoggANU, @wghuneke, @Heather_Leasor, @Dietmar_Dommenget, @cbull, @sofarrell, @spencerwong, @DeepashreeDutta, @joshuatorrance, @ctychung, @zoegillett27, @jemmajeffree, @HIMADRI_SAINI
Chair: @kieranricardo
Minutes: @spencerwong
Subscribe to the ESM Working Group calendar as follows:
1. [ESM Working Group Meeting Calendar feed](https://outlook.office365.com/owa/calendar/463c5a6d0bba4c838dce9c57933398fb@anu.edu.au/3086e7a51b0d48ef85bee981a597274413647516456690471131/calendar.ics)(right click on the link and copy the URL)
2. Use calendar feed URL to [subscribe to the calendar](https://forum.access-hive.org.au/t/how-to-subscribe-to-a-calendar-feed/767)
#### Agenda:
- Updates from CM3 technical meetings: The previous simulation completed 100 years and has now been stopped. Work is going on to prepare for a new simulation which will include improvements to masks in the polar regions, and fixes for issues with wind stresses. The reproducibility bug has now been resolved, meaning that repeating identical runs will produce identical results.
- CMIP7 fast track and the IPCC Assessment Report:
- @AndyHoggANU discussed the timeline for evaluation papers to be included in the AR7 report. Fast track data will be coming out soon, and papers need to be submitted by March 2027 in order to be cited by the report. We would like to understand how NRI can support, encourage or help researchers write papers based on the fast track.
- Meetings/workshops are being planned later in the year, with one focused on the Australian region, and a NRI ESM and Land workshop planned for September, which will include CMIP as a focus.
- For ESM1.6, NESP will be planning an evaluation paper on ENSO, drivers, and mean states.
- shout-out props for Figures from: @AndyHoggANU, @sofarrell
- ESM and land community workshop:
- We are planning a 3 day ESM and Land workshop for early September, which will include science presentations, training, and likely a hackathon. If you have any ideas of things you would like to see, or ideas for invited speakers (for example someone visiting from abroad, or someone working in Australia) contact any member of the program committee (@wghuneke, @JulieA, @alexnorton, @lachlanswhyborn, @HIMADRI_SAINI, @spencerwong, @adisen99, @zoegillett27).
- offer support (breakout room?) to people wanting to get involved / could set aside 10 minutes at end of meeting to answer questions.
#### GitHub issue links:
#### GitHub issue links to OM3 figures for CM3:
#### Community figures
@AndyHoggANU
Freshening of Labrador sea and North Atlantic, from Arctic, Greenland and North America (via St Lawrence River) stabilizes the region and shuts off convection cools surface, showed strong trend since in last month trend plots, Arctic ice thickens to \> 8m. Also seen in CM2-025 but centuries to occur and FW flux to build up, different ocean mixing scheme used in CM2 (KPP). In CM3 (ePBL) mixing tends to increase stable ocean conditions with the FW flux.
Further to Wilma’s analysis from January, here is a figure I showed at the CMIP workshop recently. Confirms that OM3 gives improved Antarctic dense water at 25km resolution, but that CM3 is still not great. Not only is there excessive open ocean convection, but it is also very salty on the shelf.
MLD shows the open ocean convection.
Sea ice is also pretty different (causality isn’t clear to me).
There was discussion around whether the mixed layer depth figures suggest open ocean convection, or instead excessive mixing that is unrelated to large polynyas. Plotting the DSW exports was suggested as a way to confirm whether the younger bottom water in CM3 is caused by the deep offshore mixed layers, or if it’s instead coming from the shelves.
Discussion also centred around the iceberg spreading scheme. Currently, all freshwater is spread over a large pattern around the ice sheets, which may be contributing to the excessive salinity over the shelves. An updated scheme which allocates a fraction of the freshwater to the coast is being worked on. There is interest in performing a test run without the iceberg spreading, so that all freshwater is input around the coast. Additionally, interest was raised in comparing the total iceberg fluxes in CM3 and OM3.
@sofarrell
Over the coarse of the run there is strong surface freshening, especially in the Arctic. The CM2 025 simulation had a similar freshening kick in near the end of the run, whereas it happens quite quickly with CM3. Convection in the Labrador sea gets shut down and surface temperatures become much colder.
The age tracer at 30E shows ventilation at the coast, but not further out. Mixing extends to 500m in some regions but doesn’t appear to extend further down.
40W also shows water coming down the slope, but doesn’t show mixing to the bottom away from the coast.
At 160W 50 years into the run, a coastal polynya did occur around 76S. There is evidence of quite strong mixing down to ~400m in the temperature data. However there isn’t evidence of brine mixing in the salinity data.
The EPBL mixing scheme appears to keep things more stably stratified.
_Please paste here and include a caption!_
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [31 March 2026 01:04 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/8 "2026-03-31T01:04:28Z")
#### **CM3 Dev-Eval Working group meeting minutes**
[Meeting link](https://anu.zoom.us/j/86257758134?pwd=aXRqNzIvaU9FRHdnYnlseHhhS2JRUT09)
Date: **Tuesday 23 June 10:30 am**
Participants: @kieranricardo, @inh599, @MartinDix, @cbull, @wghuneke, @ariaan, @ShayneM, @ClaireT, @ezhilsabareesh8, @JulieA, @zoegillett27, @paulleopardi, @Heather_Leasor, @Harun_Rashid
Chair: @kieranricardo
Minutes: @spencerwong
Subscribe to the ESM Working Group calendar as follows:
1. [ESM Working Group Meeting Calendar feed](https://outlook.office365.com/owa/calendar/463c5a6d0bba4c838dce9c57933398fb@anu.edu.au/3086e7a51b0d48ef85bee981a597274413647516456690471131/calendar.ics)(right click on the link and copy the URL)
2. Use calendar feed URL to [subscribe to the calendar](https://forum.access-hive.org.au/t/how-to-subscribe-to-a-calendar-feed/767)
#### Agenda:
- Latest model developments and new simulation
- shout-out props for figures from @kieranricardo
- Discussion on the workshop hackathon.
#### New simulation and model developments
- A new CM3 simulation is currently underway. This includes a new ocean grid from OM3 to make the polar regions B grid compatible, which helps with the issue of tall sea ice towers. The simulation also includes the new iceberg spreading pattern from OM3. Snow accumulation over the ice sheets is now redistributed according to a climatological pattern. Minor fixes to the wind stresses are also include.
#### GitHub issue links:
#### GitHub issue links to OM3 figures for CM3:
#### Community figures
- @kieranricardo **iceberg flux in new simulation**
The figure above shows the 40 year mean iceberg water flux into the ocean. Half of the snow accumulation on the ice sheets is input along the coast (not shown) and the other half goes into the above iceberg flux. Latent heat is accounted for in both the coastal and iceberg melt. This doesn’t seem to cause as much of a problem of excessive sea ice thickness as seen in OM3. An interpolation issue at 180 degrees was identified in the above figure.
- @kieranricardo **bottom age tracer** :
The figure above compares the bottom age tracer in the previous CM3 simulation to OM3. It shows excessive bottom water formation in CM3, as discussed [previously](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/7).
The above figure shows the bottom water age in the new CM3 run. It looks slightly improved, however differences may be related to the short length of the run so far, and we will need to compare again after more years of output are available.
- @kieranricardo **Heat flux into ocean** :
- @kieranricardo **Sea ice area and thickness**
Sea ice area is improved in the new run (second figure) compared to the previous run (first figure)
#### Future plans
- Planning to put together a PI control run, with a goal of having it ready for the hackathon.
- Also plan to update the UM version to 13.8, allowing us to use the GC5 central configuration, and incorporate cable.
#### Hackathon at the September ACCESS Community Workshop on Land and Coupled Modelling:
- The third day of the workshop will be a hackathon/discussion day. There will be a session on evaluating the new ACCESS models including CM3. To support initial discussion during the session, we’re hoping community members will be able to bring some pre-prepared figures with them. Further analysis can be performed later in the session based on the initial discussion.
- We’ll need a new run ready a few weeks prior to the workshop to allow time for people to put together new analysis and figures.
- We’d love to get as much involvement in the hackathon as possible. Let us know if there’s any way we could help, such as areas for training.
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [28 June 2026 23:04 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/9 "2026-06-28T23:04:26Z")
#### **CM3 Dev-Eval Working group meeting minutes**
Date: **Tuesday 21 July at 10:30 am**
Participants: @kieranricardo, @MATTENGLAND, @AndyHoggANU, @cbull, @wghuneke, @ariaan, @dkhutch, @sofarrell, @nicolamaher, @ezhilsabareesh8, @ctychung, @saanvi, @ShayneM, @spencerwong, @ClaireT, @aekiss, @Harun_Rashid
Chair: @kieranricardo
Minutes: @spencerwong
#### **Agenda:**
- shout-out props for Figures from: @ezhilsabareesh8 and @kieranricardo
- CM3 development updates
#### CM3 development updates:
- Several bugs were identified around the tripole fold. These included an error in the CICE angles, a problem with the wind stress remapping, and an issue with updating array halos. These have been fixed in the currently running simulations and resolve the excessive sea ice volumes previously seen in the Arctic.
- @kieranricardo is working on updating the UM version from 13.0 to 13.8 and swapping to the GC5 central scientific configuration.
- Still has a strong radiative imbalance and the SST cold bias is stronger.
- Testing out the CICE C grid, which appears to be stable with the tripole fixes and runoff spreading.
- Present day and preindustrial test simulations are both currently running and will be available for analysis for the upcoming hackathon.
#### **GitHub issue links to OM3 figures for CM3:**
- @ezhilsabareesh8 [Total meridional heat transport](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/78#issuecomment-5022333841)
- @ezhilsabareesh8 [Time series of annual mean transport through the Indonesian straits](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/75#issuecomment-5019235944)
- @ezhilsabareesh8 [Zonally integrated overturning](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/67#issuecomment-5019391743)
- @ezhilsabareesh8 [Timeseries of global averages](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/77#issuecomment-5021846764)
- @ezhilsabareesh8 [Hovmoller (depth-time) of horizontally averaged temperature drift](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/35#issuecomment-5022190146)
- @ezhilsabareesh8 [Surface current speed](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1/issues/76#issuecomment-5019846784)
**Note on configuration and code used for the CM3 simulation:**
- The ocean configuration used in the CM3 simulation matches [this commit](https://github.com/ACCESS-Community-Hub/access-om3-experiments/tree/MC_25km_jra_iaf%2Bwombatlite-test4-d28e0359) in the OM3 configurations repository, though omits the changes from the commits [here](https://github.com/ACCESS-NRI/access-om3-configs/commit/a7042b040bcca4df7c759c6876d4fee9ca0175c5) and [here](https://github.com/ACCESS-NRI/access-om3-configs/commit/fc3dabde9622cbb8fd632a3b5ca8e51bf0a8d5d0).
- There are also differences in the model code versions, as shown [in this diff](https://github.com/ACCESS-NRI/ACCESS-OM3/compare/2026.05.002..f5d40a69fd31052448b80b157e37d361118092ff).
#### **Community figures**
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [27 July 2026 04:50 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/10 "2026-07-27T04:50:44Z")
#### **CM3 Dev-Eval Working group meeting minutes**
Date: **Tuesday 18 August at 10:30 am**
Participants: @kieranricardo, @dkhutch, @wghuneke, @Dietmar_Dommenget, @cbull, @nicolamaher, @Harun_Rashid, @MartinDix, @paulleopardi, @ShayneM, @spencerwong, @aekiss, @AndyHoggANU
Chair: @kieranricardo
Minutes: @spencerwong
#### Agenda:
##### CM3 simulations for the workshop hackathon day
- A present day control run and a pre-industrial control using the latest CM3 code have both completed 50 years of simulation. Paths for the output data for these runs are listed in the `17/08/2026` and `18/08/2026` of the [CM3 experiments table](https://access-cm3-configs.readthedocs.io/Experiments/). This data is now ready for community analysis!
- These two runs include the latest tripolar bug fixes and the GC5 central atmosphere configuration
##### Hackathon planning
- @wghuneke outlined the plan for the hackathon day at the [ACCESS Community Workshop on Land and Coupled Modelling](https://www.access-nri.org.au/event/access-community-workshop-on-land-and-coupled-modelling/):
- A discussion was held on analysis the community would like to prioritise for the hackathon. The Planton ENSO metrics were raised as a priority.
- If you are working on analysis for the hackathon, the [CM3 evaluation repository](https://github.com/ACCESS-Community-Hub/access-cm3-paper-1) is the recommended location to share it. You are also welcome to get in contact with @kieranricardo who can help with adding your figures to a appropriate location.
---
### Author:  [@spencerwong](https://forum.access-hive.org.au/u/spencerwong)
#### Post date: [14 September 2026 02:02 UTC](https://forum.access-hive.org.au/t/cm3-dev-eval-working-group-meeting-minutes/5393/11 "2026-09-14T02:02:32Z")
#### **CM3 Dev-Eval Working group meeting minutes**
Date: **13 October at 10:30 am**
Participants:
Chair: @kieranricardo
Minutes: @spencerwong
#### Agenda:
- shout-out props for Figures from:
- offer support (breakout room?) to people wanting to get involved / could set aside 10 minutes at end of meeting to answer questions.
#### GitHub issue links:
-
#### GitHub issue links to OM3 figures for CM3:
-
#### Community figures
_Please paste here and include a caption!_