ESM working group: Meeting notes 2024

Earth System Working Group
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Notes from each meeting of the ESM Working Group are added as a reply to this topic.

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Archived meeting notes:

2023

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13 posts were merged into an existing topic: ESM working group: Meeting notes 2023 (Archived)

19

Date: 7/12/2023

Participants: 13

Chair: @LaurieM

Admin

  • For the next meeting (29th) we will have a shared meeting with Forecasting and Prediction Working Group to discuss the Triple La Niña experiment, and an ACCESS-S2 User Training Workshop. Will spend 20 minutes with some discussion of where to find the data, how to analyse and some discussion of analysis and ideas for where to focus that analysis.
  • @sebmckenna happy to talk about ACCESS-CM2 pacemaker experiments.

Shared experiments/ACCESS-NRI resources

  • ACCESS-NRI Merit Allocation guidelines are available. The requirements to access time are very minimal compared to MAS applications. Come and use the resources on offer!
  • ESM project lg87 /g/data storage: 30TB used out of 50TB. 116KSU used 758KSU remaining.
  • @ariaan could use some SUs. Will put up some information about them.
  • WG needs more /g/data storage space. Take to SAC.

Freshwater forcing in sub-polar North-Atlantic

Status of @gpontes experiment.

(Apologies, the top and bottom of the video have been clipped)

Freshwater forcing in sub polar northatlantic. Just esm-ssp585-45 computed under lg87. Including historical also under /g/data/lg87.

Some issues restarting historical experiments from other runs. Reported on hive. Ran another historical ensemble for historical. Also available.

Started 4-member ensemble for historical and SSP. HI-X-grm, ssp585-X-dgrm. 2-member ensemble ssp585-X-cgrm.

@tiloz is historical a new ensemble member? Restarted from a different time? Yes.

@tiloz asking if ssp585 is concentration driven. Confirmed yes, not emissions driven.

Was using the warm-start.sh to rebuild experiment for payu. Got a calendar error. Works fine if all processes using payu.

@ariaan did restart historical runs using payu from older non-payu runs. Might have been a date issue. @holger assisted.

@ariaan Are ensemble members of 2 and 4 enough? Need larger ensembles? Would it be good to have historical members branched further apart to have different AMOC states? Would be good to have more ensemble members.

@gpontes Could do so if community thinks it is useful. Ideally would be 10 members. Restarted experiments from 1950. Perturb IC and run 10 years, then begin FW perturbation.

@ariaan GFDL models have strong convection in southern ocean (Amundsen and Ross Seas). For some things in the deep ocean models have a specific path.

@gpontes Now investigating teleconnections between AMOC and southern ocean.

@RachelLaw ssp585 is the highest scenario. Plans for a more moderate scenario?

@gpontes Other scenarios not set up for payu. Mostly looking at coming decades. 20-30 years doesn’t matter too much. All simulations go to 2100. Focus on coming decades

@LaurieM Simuations quite idealised. Contentious about how to design the FW experiment.

@RachelLaw also having issues restarting payu from a different restart.

@gpontes could increase number of members If group wants to do it.

ACCESS-ESM1.5 – ACCESS-NRI supported release

@Aidan updated us on plans for an ACCESS-NRI supported version of ACCESS-ESM1.5. It will have:

  • spack build system
  • build-CI testing
  • released experimental configurations utilising payu
  • full experiment provenance
  • automated reproducibility testing

This topic on the forum gives an overview of the project and will be used as the main place to find information about the progress of the release

(Apologies, the top and bottom of the video have been clipped)

What’s going on?

@RachelLaw: the CMIP panel want feedback on the AR7 fast-track design

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

20

Date: 29/02/2024

Participants: 26

Apologies: @JulieA

Chair: @eunpalim

Shared Section

1. Introductions from each group

@debbie_h: Forecasting and Prediction Working Group incorporates Machine Learning (ML), Data Assimilation (DA), seasonal forecasting. Quite disparate groups, but try to do things for each group. Had a good ML session at last workshop, has led to good collaboration since.

No common infrastructure. Not supported by ACCESS-NRI. Working on how ACCESS-NRI could support those areas. Drafting two short papers for guidance: how ACCESS-NRI could support DA into the future, and another on how to support ML into the future.

@nathan-e difficult getting cohesion with these challenges.

@LaurieM co-chair. Earth System Modelling Working Group also somewhat disjointed. Focus on the use of the coupled models: ACCESS-ESM1.5, ACCESS-CM2, also ACCESS-S2. Also interested in coupled climate. Past, future and paleo climate. Ocean/atmos interactions for El Nino. Also for future climate.

Big focus on carbon cycle. Ocean and land carbon cycles.

Last few months trying to get to know each other, find out what others are doing. All want to push forward with ACCESS suite of models. One focus has been adding flexibility of framework. Modifying forcing, particularly ancillary files. Land-sea mask and bathymetry and orography.

Collaborating closely with ACCESS-NRI. Pushing for a more user friendly workflow to expand range of activities in models.

Also want to facilitate collaboration using ACCESS suite. All co-chairs from different institutions with different scientific focus.

2. Triple La Niña experiment

The Triple La Niña experiment that was a joint initiative of the ESM Working Group (Working Group) and F&P Working Group (Working Group )

Triple La Nina of 2020-2022/23. Unusual to persist for three years. Not particularly strong, but 3rd year Australia experience severe flooding and rainfall events.

Preceeded by black summer and Huna Tonga in Jan 2022 could have contributed to persistence.

ACCESS-S real-time forecasts skilfully capture the triple dips of the La Nina event at up to 4-month lead time.

Examine effect on forecast skill of atmospheric initial conditions. Examining forecast differences in topical SST and persistent SAM.

Need 3 datasets:

  • Hindcasts (retrospective forecasts). Used to compute climatology and std dev. Also can compare to previous La Nina to assess skill
  • Standard real-time forecasts with realistic Atmosphere initial conditions
  • Experimental forecasts with unrealistic Atmosphere initial conditions
  • How to access the outputs

Hindcasts are in

/g/data/ux62/access-s2/hindcast/raw_model/{atmos,ice,ocean}

Standard

/g/data/dx2/access-s[12]/rt/raw_model/atmos/{has,psl,ta,ts,ua,va,zg}

Experimental forecasts

/g/data/lg87/experiment/triple_la_nina/{atmos,ice,ocean}

18 week forecasts (4 months). 23-member ensembles for experimental forecast.

Should we pre-compute climatology and ensemble mean and store. Would require more space.

What should we do with this data?

Peer-reviewed paper? La Nina, SAM, Australian Rainfall? Encourage ECRs?

Announce availability?

Half-day hackathon?

Who might be interested in a group study?

@dkhutch: don’t want to speak for them, but @nicolamaher and @jemmajeffree couldn’t make it, but might be interested?

NESP planning a special effort on Triple Dip La Nina. This experiment came from discussion in NESP meeting. High customer demand to understand TLN and impact on Australian Climate.

Wanted to contribute to NESP

@eunpalim will Add slides to hive.

@ctychung Plan to have stakeholder based webinar around July/August. Would be good to have results from this presented.

@eunpalim Similar experiments done by @lynnzhou for wet 2022. Large magnitude of wetness was atmosphere driven. If not having large atmospheric impacts (smoke, volcano) how much of the La Nina can we reproduce? Which is most important driver? Atmosphere or Ocean. What more important IOD, SAM? Good opportunity for ECR to understand nature of forecast data and systems.

@aidan: How important is collaboration?

@debbie_h: ACCESS-S hindcast already available. Coordination not required, but coordination is an option if that is people’s wish.

Contributing this effort to NESP would be good.

Not thinking too deep an investigation at this stage. Any contribution welcome.

Discuss possible ACCESS-S2 Training. Gauge interest and requirements

Half-day hackathon? Look at some major events and analyse together?

Ensemble and climatology need more space. Certainly possible. @Aidan:ACCESS-NRI can support training activities.

@debbie_h: Some people want to run ACCESS-S2. Tricky. No documentation. Only 3 people at Bureau can run model. Only set up for forecasting. Limited knowledge of how to do this for sensitivity and scientific experiments. Getting ACCESS-NRI involvement depends on demand. Get in touch with @debbie_h to register interest in using ACCESS-S2.

ESM Working Group Section

3. ESM WG Admin

  • @sebmckenna has volunteered to talk on "SST and ENSO biases in ACCESS-CM2 pacemakers” for the next meeting (2024-03-14T02:00:00Z)

  • We need more speakers! Message any of the co-chairs or @Aidan if you’re keen

@eunpalim: Saw good talks at AMOS. Please feel free to recycle AMOS talks in this forum. Even if seen before, always good to see again and have better understanding.

@ShayneM: putting shallow water model into ACCESS coupled model. Will talk in next few months.

@dkhutch Maybe @Dietmar_Dommenget could present on the paper he is leading and which @dkhutch is collaborating. Collaboration came from ESM WG meetings.

@rachellaw also just had a paper accepted for CMIP7 overview. Could present some slides.

  • Report from Scientific Advisory Committee (@LaurieM). Next SAC Meeting 2024-03-21T03:00:00Z

Reminder of CMIP7 ESMValTool Hackathon. March 12-14 at Aspendale. Probably too late to register. Drop-in session tomorrow.

  • If you want to suggest a topic to cover in the ESM WG meetings reply to this topic and add your idea

  • Do you know anyone who you think would benefit from coming to these meetings? Please invite them! We definitely want ECRs and students to attend too.

4. ESM Shared experiments/ACCESS-NRI resources

  • See the guidelines for accessing working resources. The requirements to access time are very minimal compared to MAS applications. Come and use the resources on offer!

  • lg87 /g/data storage quota has been doubled to 100TB. Note that this is intended for short term storage only (generally maximum of 1 year).

  • ESM project lg87 /g/data storage: 27TB used out of 100TB. 117KSU used 757KSU remaining.

Probably still don’t have a clear process for how experiments that are proposed get resources to run. Filled in proposal. then what? @Aidan: bring it up at a meeting, volunteer to begin running experiment.

5. What’s going on?

CMIP7 fast-track consultation

Need survey by the middle of next week. Put feedback on hive, contact @RachelLaw or fill in survey.

@JulieA three level B positions for new CoE. UNSW advertised now. Another at UniMelb(?) one at Monash(?).

ACCESS Hackathon clashes with next meeting. @aidan will put up a poll to gauge interest.

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

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21

Date: 28/03/2024

Participants: 13

Apologies: @eunpalim @ShayneM @dkhutch

Chair: @tiloz

Agenda:

1. Admin

We have no speakers lined up for our next meeting or any subsequent meetings. Please volunteer to speak. Message @Aidan to discuss.

@tiloz Please advertise and invite people to talk. Particularly early career researchers.

@Dietmar_Dommenget can talk about change land-sea mask results with GFDL model. Might be able to talk about the ACCESS equivalent in May.

Remember to add any items you want this WG to discuss to ideas for topics

@tiloz SAC Meeting last week. All SAC meeting notes are publicly available on website slightly delayed.

@tiloz Will be ACCESS-NRI Workshop in September (2nd-5th). Also a COSIMA workshop beginning of July. Might reduce attendance to workshop. Call for people to join workshop program committee. Structure still to be decided.

Progress towards CMIP7 and model development plans. Largely on-track. Fast track timeline very challenging.

CMIP7 Hackathon hands-on meeting to evaluate ACCESS model output using ESMValTool and iLamb. Good intro and setup. Overview of existing recipes, look at what is required. May be a follow up at the workshop.

@LaurieM Would be good to have someone from ESM WG involved. @dkhutch and @wghuneke did it last year. Can be anyone, ECR or senior scientist.

2. Shared experiments/ACCESS-NRI resources

ESM project lg87 underutilised. 195KSU remaining out of 405KSU grant (rest reallocated to other projects). 30TB our of 100TB used of quota on /g/data/

@tiloz storage allocation is short-term for duration of experiment. Need to have a long term plan for where it will reside.

@clairecarouge presented plan to manage lg87 /g/data storage. Easier to manage storage if people write into a specific location for an experiment. Experiment folder created, can work however you want underneath.

Do want to have some data folders for slightly longer term storage. Would need to be of use to the community and decided by the working group.

To help with organisation will have a writer group, only those who are members can write by default. Others can only write to their own experiment folders to prevent data loss.

Was hoping to be ready for Q2, not quite ready yet. All admins will have write access to all data to enable clean-up.

Writer group will be some ACCESS-NRI, and hopefully some from community who want to be involved. Won’t be a large workload. No previous knowledge required.

Please put your experiment proposals on the hive. Great opportunity to access NCI compute resources. See guidelines for how to do this.

David (@dkhutch) and Dietmar (@Dietmar_Dommenget) are running experiments under lg87. @Dietmar_Dommenget: Running 4x400 CPU experiments. First test runs to confirm results obtained from GFDL model. Idealised ocean basin configurations. Seems to be working. Will do at least 15 experiments. Roughly 1MSU. Need to run 100 years. About ENSO. First 50 years trending. Changed ocean basin sizes. Used GFDL model. Submitted paper with interesting El Niño. Wanted to do with low-res ACCESS model. @dkhutch has looked at similar problems. Managed to run Miocene configuration in ACCESS-ESM1.5. Also testing with no continents in tropics, 1, 2 or 3 oceans basins. Only managing 10-15 model years/day.

@tiloz do current model proposals meet needs of community? Need to consult with community.

@JulieA is assistance to run models in scope for ACCESS-NRI? @clairecarouge if it is an experiment that is required for model development. Otherwise no.

@Dietmar_Dommenget new experiments should have ACCESS-NRI input. Learn what users are struggling with. More than providing CPU time. Particularly novel simulations. Spending months to just move land/sea boundaries.

@LaurieM Have to be careful what we suggest. Difference between running experiments versus flexibility/application of a model. Maybe not run the experiment, but be involved in helping/documenting and moving forward. @dkhutch invested a lot of time in learning how to configure the model. Spread the knowledge on GitHub. Should we include someone from ACCESS-NRI. Should be able to take it and improve it. Could help in the community.

@tiloz model development requires substantial changes to the code and model configuration. Support is required.

@Dietmar_Dommenget ACCESS-NRI needs the level of knowledge that @dkhutch has developed. Will not help someone with the next problem. ACCESS-NRI should do this sort of work. These are essential skills that we need.

@JulieA where is the boundary between science and infrastructure. Can be very difficult to configure the model.

@tiloz boundary is blurry between scientific and infrastructure. @LaurieM ACCESS-NRI has quite clear definition of what is in-scope.

3. Science talk

Sebastian McKenna (@sebmckenna) presented “SST and ENSO biases in ACCESS-CM2 pacemakers”

ENSO appears to be a more dominant factor in Indian Ocean variability than Pacifici Ocean mean state.

Added SST perturbation to restoring file to create ensembles.

Just finished all ensemble members, still need to analyse it all.

Initial results:

  • IOD doesn’t change under different El Niño conditions
  • Basin wide warming more likely with EP El Niño

More analysis required. Determine if we need more ensemble members.

@Dietmar_Dommenget biases in Indian Ocean seem more important? Can’t test with this experimental setup? @sebmckenna can’t test with this pacemaker experiment.

@Dietmar_Dommenget what do biases look like? Mean state winds

Too warm if east Pacific and cool around Arabian Sea. Biases are seasonal. A lot of mean-state bias related to biases in wind.

@gpontes Have you evaluated teleconnection between ENSO and IOD in the model? Correct strength of feedback. @sebmckenna did look at this. Do have internally forced, ones that happen during ENSO and not. Gets both type of events. Model is more independent in the model.

@Dietmar_Dommenget IOD independent modes are weak, too strong in the models? Too sensitive/unstable. @sebmckenna most coupled models have overly strong IOD bias. Not due to remote teleconnections. Some problem with the Indian Ocean in the model.

@gpontes investigated Indian Ocean dynamics? @sebmckenna only looked at surface ocean/atmosphere interaction. Not looked below the surface. Would be good to investigate.

@Dietmar_Dommenget Atlantic could also play a role. Warm biases could also influence the tropics.

@sebmckenna in literature a lot more about Pacific/Indian Ocean interactions. @Dietmar_Dommenget what matters is the relative differences in biases. It might not be relevant, but if you have the setup interesting to see if Atlantic mean state has any influence.

@sebmckenna study by @dhb599 of Atlantic pacemakers didn’t look at Indian Ocean. Might be interesting to look at the data from that.

4. What’s going on?

@Aidan ACCESS-NRI ACCESS-ESM1.5 release is proceeding, but slower than hoped. Initially will target three configurations: pre-industrial control and two historical, concentration driven and emissions driven. Will consult the community in the near future about what configurations should be targeted once the intial release is done. This release is different from what is currently available as it will be a ground-up restructure of how the model is built, deployed and tested. Have developed the infrastructure with the ACCESS-OM2 release which is being finalised. Includes experiment provenance and tracking. In the medium term this will mean offering databases with experiment metadata that is searchable by anyone. Will apply the same methodology to ACCESS-ESM1.5. Configurations will use pre-built and deployed model binaries, but the system is very flexible and users in the community will benefit from the ability to easily build the model and change dependencies and model component versions easily. In addition these is an ACCESS-NRI supported model and configurations, so the community can ask for assistance. @tiloz this is very welcome for the development of future versions of ACCESS-ESM.

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

22

Date: 11/04/2024

Participants: 13

Apologies: @LaurieM @eunpalim

Chair: @ShayneM

Agenda:

1. Admin

  • @LaurieM has decided to step down as co-chair of the ESM Working Group. Thanks for all the work Laurie has put into establishing this working group.
  • Welcome to our new co-chair @dkhutch!
  • We currently have no volunteers to speak for the next meeting, or any subsequent meetings. Please volunteer to speak. Message @Aidan to discuss.

@spencerwong is willing to talk next (May 9th). @Dietmar_Dommenget on May 23rd.

Would like to have an interesting science talk for every meeting.

2. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 has used 638KSU out of 825KSU allocation.

@Dietmar_Dommenget can use 2MSU.

@AndyHoggANU used time in last quarter. COSIMA used the bulk of the time in the last week. Better off using the quota and ask for more.

@Dietmar_Dommenget can run right now. @AndyHoggANU prepare new ones, talk to @clairecarouge and switch resources in a couple of weeks.

  • 33TB our of 100TB used of quota on /g/data/

@Dietmar_Dommenget Need maybe 10TB. @dkhutch working on archiving process. Can make it much smaller. Only keep what is scientifically relevant. Might need to store for 1 year.

Proposals for experiments for next quarter?

@Dietmar_Dommenget Will give a presentation in 2 weeks. Repeated GFDL experiments with ESM1.5. Looked at second 50 years. Results looked to have similar characteristics to low resolution GFDL. Using idealised basins. Repeating with high resolution model. Not all characteristics. @dkhutch Dietmar has been running them, but we’ve collaborated with the model setup and configuration. Drastically changed land-sea mask and worked ok. Want to reconfigure river-runoff, so not changed in these experiments. Large scale fluxes will be ok, so reasonable for these purposes.

3. Science talk

Andrew King presented “Exploring climate stabilisation at different global warming levels in ACCESS-ESM1.5.”

  • Long simulations run under net-zero CO2 to understand stabilisation processes
  • Address modelling capabilities gap from CMIP6
  • Paris Agreement aims to limit warming well below 2°C about pre-industrial which imply net-zero emissions.
  • Despite this CMIP6 do not address this well to look at implications of missing these targets
  • Experiments to address this gap. Rather than use concentration pathway turn off emissions at different times to achieve different final warming levels
  • Run ACCESS-ESM1.5 simulations to do this. Ran 7 1000 year experiments turning off CO2 increases over 5 year SSP trajectory. Look at how these climates evolve
  • Non-CO2 GHGs are fixed at PI levels
  • CO2 concentrations are determined by interactive carbon cycle, emissions are set to zero, so total CO2 concentration drops
  • The longer we delay achieving net-zero the higher the final land-ocean temperature anomaly
  • SSTs continue to rise slowly. Full Depth ocean heat continues to heat very strongly
  • Sea ice extent different between Arctic and Antarctic. Delaying net-zero reduces arctic sea ice extent. Antartica has continued sea ice extent regardless of time of net-zero emissions, still worse the later it is done
  • Sea-ice free events: arctic is just a function of amount of total warming. Antarctica has a time component also
  • Sea ice extent representation in ESMs is often biased, so caution is needed.
  • Different local responses over land and ocean. Sydney experiences significant additional warming compared to northern hemisphere cities.
  • Significant local temperature and precipitation changes post net-zero, and these grow over time
  • Preprint available:

Lots of discussion! See the video.

4. What’s going on?

@JulieA did you do CMIP6 stratospheric ozone only? @tiloz have to total ozone. LESMIP are extension of CMIP6 runs. Maybe only did ozone runs for LESMIP, not CMIP6. DAMIP ozone only was stratosphere only. Not much SAM response which is intriguing. If thinking tropospheric and stratospheric separately would be great. @sofarrell ESM1.5 is UMv7, might be limited in what is possible.

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

23

Date: 9/5/2024

Participants: 20

Chair: @eunpalim

Agenda:

1. Admin

@dkhutch:

  • Only met once so far.
  • Plan is for a similar structure to the last workshop.
  • Want to know what things went well, and any other ideas send to @dkhutch or working group chairs. Want to know how it went, and how it could be better.
  • ESM Working Group got a lot of value out of a working group meeting at last workshop. Have indicated would like another WG meeting at this workshop. Ocean and Land unlikely to have a WG meeting at the workshop. Potentially an opportunity to entrain some of the community who might otherwise attend other WG meetings.
  • Need a student representative for the organising committee. Please suggest someone else or yourself.

2. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 has used 1.4MSU out of 1.9MSU allocation. We have asked, and received, two additional allocations of compute quota (total 1.1MSU extra).

Mostly used by @Dietmar_Dommenget and will use the remaining resources. There may be more resources available. @Dietmar_Dommenget could use another 1-2MSU if available.

@Dietmar_Dommenget will give a full report of the experiments in a presentation in the next meeting. Have done 3 experiments. Not yet analysed in depth, but seem to be working correctly.

3. Science talk

Spencer Wong: “Coupling a shallow water model to the UM atmosphere”

  • Couple a shallow water model (thermocline depth) to UM. Want UM interacting with thermocline anomalies the atmosphere model sees.
  • Aim is to couple a simple ocean model to a complex atmosphere, enabling idealised experiments
  • Shallow water model exists as a stand-alone implementation using a 1x1 degree between 51S and 51N. Using forced wind stress anomalies can reproduce ENSO behaviour.
  • Utilised an existing slab ocean implementation directly within UM, and replaced with shallow water model.
  • Many technical challenges: adding prognostic variables, grid differences, parallelisation issues
  • River routing model runs on a 1x1 degree grid, included prognostic variables, machinery for creating prognostic variables, serialising code and regridding routines. Copied and utilised this existing code.
  • Is a gather → calculate → scatter operation.
  • Performs much better than slab model
  • Peaks in Niño 3.4 autocorrelations are slimmer than in observations: El Niño/La Niña don’t persist as long as observed. More work required.
  • 2-3KSU for 50 year run. Throughput is 1-1.5 days per 50 years.

4. CMIP7 Update

@RachelLaw gave an update on plans for the ACCESS CMIP7 submission:

CMIP7-update-May2024.pdf (580.9 KB)

  • DECK is consistent with previous CMIP cycles with addition of historical. Note piControl and emissions-driven esm-piControl (interactive carbon cycle).
  • AR7 Fast Track is from a range of MIPs, but geared towards next IPCC report. Should be completed by end of 2026.
  • 6 scenarios. Recommendation to be emissions driven.
  • Thinking about feasible model development timeline. Still aiming for ESM3 for wider CMIP7. Hesitant about committing for fast-track.
  • ESM1.6 would derive cleanly from ESM1.5. Would be close to current configuration of CABLE but with some updates to land-use.
  • Thinking about a fast track submission with ESM1.6.
  • ESM1.6 1 degree ocean, CABLE3
  • ESM3 0.25 degree ocean, CABLE4
  • Don’t have resources for large changes to physics for ESM1.6. Do want to identify any outstanding issues or fixes.
  • The earlier the submission is in the more uptake from the community. Definitely want an ACCESS model in the fast-track. Don’t want to detract from ESM3.
  • Have not currently got the resources we would need for a more ambitious ESM3 on Fast Track timeline.
  • @JulieA Here’s a writeup from the recent CMIP meeting for those interested: https://wcrp-cmip.org/cmip-panel-meet-to-advance-cmip7-and-ar7-fast-track/
  • @Aidan Some bugs with Ocean BGC that need fixing. ESM3 should be done well, and not necessarily beholding to CMIP cycles. ESM3 might not run fast enough for Paleo work.
  • @RachelLaw scenario MIP is always higher priority and a lot of projection work flows from it. Community can run whatever MIP experiments were of interest.
  • @RachelLaw None of currently planned models go beyond N96 resolution because it is too expensive for CMIP7 but ESM3 would provide a code base for higher resolution work (e.g. for Weather of the 21st Century COE).

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

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24

Date: 23/5/2024

Participants: 14

Chair: @dkhutch

Agenda:

1. Admin

  • Speakers: Christine Chung from the Bureau has volunteered for the next meeting (June 6th). There are no speakers after that. Please do volunteer to present your science. Message co-chairs or @Aidan to discuss.
  • Remember to add any items you want to discuss in these meetings to ideas for topics
  • Save the date: ACCESS Community Workshop 2-5 September. The planning committee is seeking ideas for (a) invited speakers and (b) breakout topics. Need ESM ideas for both of those things.

@dkhutch on the planning committee. Please send @dkhutch or working group co-chairs for ideas or things you think worked well last year.

  • We need to form an organising committee for the ESM Working Group’s own workshop. Last year we had a half-day, with Wilma as lead organiser, but she is on parental leave this year.

Need ideas for topics! Please get in contact.

Plan to do a half-day ESM Workshop as same as last year.

@eunpalim Any theme? @dkhutch talking it through. One idea is CMIP7, but want to make as inclusive as possible, otherwise could exclude Paleo climate.

Will be $100 fee. Mostly about commitment and some cost recovery. Very small fraction of real cost.

@Aidan Could ACCESS-NRI cover costs for students? @dkhutch Good idea. Let them know if there is no funding.

@eunpalim After last workshop there was feedback sent to @wghuneke. Is that feedback report available? @dkhutch I’m sure we can ask Wilma for that.

2. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 has used 1.74MSU out of 1.9MSU allocation. We have asked, and received, two additional allocations of compute quota (total 1.1MSU extra). Unlikely to be more available this quarter
  • 26TB our of 100TB used of quota on /g/data/
  • Any proposals for shared experiments for next quarter? See guidelines for how to do this.

3. Science talk

Dietmar Dommenget: “ENSO and tropical basin interactions in idealized worlds”

  • Authors @Dietmar_Dommenget and @dkhutch
  • Motivation: model development and ENSO dynamics
  • ENSO Experiments: GFDL CM2.1 and ACCESS-ESM1.5
  • Submitted for publication
  1. Deep paleo study (Eocene 55MYA). Rearrange land and oceans
  • Much harder than you think. Not able to do this with ACCESS-N48. Still not working after 2 years.
  • @dkhutch got ACCESS-ESM1.5 working within 1 year
  • GFDL CM2.1 took ~1 month
  • MPI(1996) took 2 weeks to change bathymetry
  1. A fast CGCM
  • ACCESS-N48 coupled GCM
  • Model biases are on par with early CM2 version
  • Want fast model (100ys/day). Want to explore climate dynamics with many 100+ years simulations.
  • Want fast run, analysis cycle
  1. ENSO dynamics
  • Why is ENSO only in the Pacific?
  • Do the other ocean basis interact with ENSO?
  • Still don’t understand all dynamics of ENSO
  • Models have different behaviour
  • Belief that other ocean basis influence the Pacific and vice-versa, but some controversy
  • Theory: larger basin = larger SST variability, larger basin = longer periods, rest of the world is irrelevant
  • Reality looks different to theory
  1. GFDL CM2.1
  • Atmos: 3° x 3.75°, Ocean 1.0° x 1.5°
  • Single tropical basin, two tropical, and three tropical basin experiments.
  • Plan to simulate eocene, but noticed it was interesting for El Niño dynamics
  • GFDL model: 15 runs was ~1MCPU and 5 days
  • ACCESS-ESM1.5: 5MCPU and 20 days
  • Would take a year to reproduce CM2.1 runs with ACCESS-ESM1.5. Would not be feasible with CMIP like models such as ACCESS-ESM1.5
  • As size increases variability increases, peaks at Pacific size, drops and then increases again at full basin width. Unexpected, and not consistent with ENSO theory. Not expected from ocean perspective, but probably related to atmospheric dynamics. Currently being studied.
  • Power spectrum: peak moves to higher frequencies the bigger the basin. This is the exact opposite of theory. Frequency lowest at Pacific size, but increase with basin size with bigger sizes.
  • Twin ocean basin experiments: two twins hugely increases variability, if one is shallow it is damped.
  • Why is there such a strong change in ENSO if there is a second deep ocean basin?
  • Single basis land is positively correlated. With shallow twin there is no correlation. Two deep basins are very strongly anti-correlated.
  • Triple basin experiments: one larger basis suppresses variability in smaller basis. All identical size variability is similar in each.
  • ENSO does not get stronger with basin size
  • ENSO depends strongly on interaction with other basins
  • ENSO theory cannot explain this

Hypothesis tropical atmospheric dynamics control ENSO

  • Larger basins lead to atmospheric rearrangement and interfere
  • Dynamical ocean basins heat fluxes can provide heat sources/sinks that land cannot
  1. ACCESS-ESM1.5
  • @dkhutch made scripts to mimic these experiments, except for one small connection.
  • Did not repeat all experiments.
  • Generally weaker. Wider basin is much weaker than GFDL2.1. Disagreement with overall variability, especially with largest basin.
  • Peak frequency looks similar, fewer data points, not as strong, but similar patterns.
  • More variability in twins with shallow sea
  • Trio experiments look similar, and larger central also damps small neighbours
  • ACCESS generally has less variability than GDL2.1
  1. Summary

Screenshot 2024-05-23 at 1.36.38 pm
Screenshot 2024-05-23 at 1.36.38 pm1928Ă—1210 237 KB

Could use more resources to complete the experiments.

4. What’s going on?

@Aidan ACCESS-NRI release ACCESS-ESM1.5 progressing. ACCESS-ESM1.5 is building and deploying with ACCESS-NRI systems. Now working on configs: reorganising and adding testing and other quality control measures. Current estimate is a release at the end of June. Can then work on releasing other configurations, and will consult with this working group who will have to decide what configurations should be released and supported, and in what order.

@Dietmar_Dommenget runs crash all the time. Impinges 10 years/day rather than 90 years/day. High priority is a fast and simple model. Make it easier to change configurations easily.

All CMIP6 models are all too slow and complicated.

@gpontes are model crashes are ocean or atmosphere related? @Dietmar_Dommenget not reproducible, something with the operating system or opening files?

@gpontes have been having numeric and technical issues.

@aekiss can automatically sweep and re-run if the crashes are known and can be ignored.

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

25

Date: 6/6/2024

Participants: 18

Chair: @tiloz

Agenda:

1. Admin

  • Speakers: @HIMADRI_SAINI has volunteered to talk on the Fourth of July but we have no speaker for the next meeting (20th June).

@nicolamaher has volunteered to talk at the next meeting.

Please consider presenting, even work in progress that you’d like some feedback. Message co-chairs or @Aidan.

Good to have feedback and visibility on what people are working on.

If you have any suggestions for ideas to talk about please do add them to the topic.

Same format as last year. Training day, 2 days of workshop, and ESM half day meeting.

@dkhutch will contact @wghuneke and get feedback from last year. Need someone to lead the working group day. This year will have combined registration for workshop and ESM WG day. Will open June 27th. So need to be organised and have something ready by then. Potential themes: CMIP7, regional modelling, paleo and ice-sheets. Want to have invited speakers lined up in time for registration. CMIP7 will likely be around Australian contribution.

@tiloz doesn’t need a lot of work, just meeting enough. @dkhutch just need to get organised for registration deadline.

@aidan Training opportunities will be part of the registration process to gauge interest and help plan training delivered.

  • Next SAC Meeting is June 20th (same day as next WG Meeting). Are there any items the Working Group would like taken to SAC?

2. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 has used 1.74MSU out of 2.3MSU allocation. We have asked, and received, two additional allocations of compute quota (total 1.1MSU extra), and an additional top-up of approx 300KSU.
  • 35TB our of 100TB used of quota on /g/data/

Remember this is not intended for long-term storage, and there should always been a plan to either delete the data or move it o a long term location

3. Science talk

Christine Chung (@ctychung) (Bureau): “Projections of ENSO, IOD, and SAM change in CMIP6 models”

  • Summary of work done as part of a NESP project “Dry, Wet, Hot and Dry”, focussing on extreme wet and dry conditions.
  • Evaluating teleconnections of ENSO, IOD, SAM as main drivers of Australian seasonal rainfall variability and how they’re projected to change. Any model consensus? Is there a visible forced signal?
  • Compared CMIP5 and CMIP6. Improvement in ENSO, IOD teleconnections. Models capture asymmetry in EN?LN response and CP/EP. Simulation of SAM has improved, but teleconnection with Aus rainfall has got worse. There is a lot of internal spread among models and ensemble members. Large source of uncertainty.
  • ENSO N34 DJF. Changes in distribution, amplitude and frequency. Increase in variability and frequency.
  • El Nino internal variability twice that of La Nina. Little evidence of a forced response beyond internal variability in La Nina. Somewhat more for La Nina.
  • IOD: no clear trend in variability, or frequency, but some reduction in amplitude. Some more evidence of forced response.
  • SAM: significant shift to stronger events, but weaker in springtime. Most models show an increase in variability. Strong evidence of a forced response.
  • No consensus/consistent story.
  • Looked into concurrent events. No significant change obvious.
  • Looked into consecutive ENSO/IOD events. No forced signal obvious.

4. What’s going on?

@nicolamaher will talk at the next meeting.

@dkhutch started a forum topic to discuss what the next ESM1.5 configurations after initial ESM1.5 release.

@RachelLaw: thanks to everyone giving their feedback on the ESM1.6 scope topic.

@tiloz please contribute feedback to both topics on the forum. Plan is to complete ESM1.6 model development by the end of the year.

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

26

Date: 20/6/2024

Participants: 14

Chair: @ShayneM

1. Admin

There 8 topics. Would like you feedback.

  1. How to find and access datasets on NCI
  2. Running model experiments with Payu and Git
  3. How to debug common errors and tackle ancillaries when running ACCESS-CM
  4. Running a high-resolution regional model using a two-level nest
  5. 3d visualisation for earth systems data
  6. Advanced git & GitHub best practices for software developers
  7. How to handle large model output
  8. benchcab: scientific evaluation framework for CABLE
  9. CMIP7 Evaluation Hackathon

Anything not in training day will be covered as online training or similar.

Please reach out to @paigem if you want to discuss anything training related.

Aidan make a topic to get ideas for what to cover in ESM WG “day”.

@Harun_Rashid can we talk about biases in models? Utilise climate expertise to identify source of biases and attempt to remedy.

@ShayneM is there a list of metrics from hackathon to target/complete? Are model biases included in hackathon metrics?

@Harun_Rashid Romain has a new team to improve ESMValTool into people’s workflows. Is there a specific bias we could focus on to feedback to ACCESS-NRI to improve these. Not easy, will not solve every problem but would be beneficial for the model and the community.

@ShayneM agree this could be a useful target for ESM WG compute resources.

@nicolamaher this is important, evaluation only tells us good/bad, but no pathway to improve the model.

Evaluation planning is done through this topic:

@Harun_Rashid Met Office has such teams targeting biases in the UM/HadGEMx models. Here, we can do something similar focusing on improving the ACCESS model performance.

  • Workshop registration and call for abstract submission will open at the end of June or early July.

2. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 usage unchanged from last meeting. Dietmar can no longer utilise the extra compute resources, so they are being redistributed to other working groups.
  • Any proposals for shared experiments for next quarter? See guidelines for how to do this.

3. Science talk

@nicolamaher: “Using large ensembles to constrain temperature variability”

SMILE = Single Model Initial-Condition Large Ensemble

Value of SMILES comes quantifying forced response and internal variability. Can compare internal variability and forced response between SMILES.

Want to spruik involved with: MMLEAv2

  • New regridded archive of SMILES. Will be released an NCAR soon, already available at NCI.
  • 16 models & 11 variables
  • 2.5 x 2.5 degree common grid
  • Combination of CMIP5/6 forcing
  • Allows for easy initial analysis and interannual model comparison of SMILEs

Summary:

  1. Rank histograms applied to large ensembles are a useful tool to evaluate model’s forced response and variability
  2. When evaluating over IPCC regions in D]F/|JA find some models generally perform better than others
  3. DIF is better simulated than JJA - NAO? Summer processes harder to model?
  4. Regions such as North America / Europe evaluate well for most models, while regions such as
  5. Africa and South-East Asia are poorly represented in most models
  6. Constraint lowers the range of proiections
  7. Constraint lowers present day variability in models, but can either increase or decrease change in variability depending on whether detrended constraint is used
  8. In general model agreement on the sign of the change even with the constraint on variability proiections is poor - similar to the IPCC recent assessment

Overall: constraint can be used for present day, but does not improve agreement in proiections

Quality and coverage of observations are a limitation for this method.

Archive anything over 10 members. This study limited to ensembles > 20.

4. What’s going on?

@harun there is a membership opportunity for a WCRP Core Project: Earth System Modelling and Observations. See the link below (or contact me if you need more info): OpenCall-SSG-2024.pdf - Google Drive

Gives opportunity to mix and collaborate with many scientists around the world.

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

27

Date: 4/7/2024

Participants: 15

Chair: @dkhutch

1. Admin

  • Speakers: @HIMADRI_SAINI has deferred presenting until the next meeting (18th July). We have a speaker for the end of August, but we have no-one for the two meetings between. Please consider presenting, even work in progress that you’d like some feedback. Message co-chairs or @Aidan.
  • Remember to add any items you want this WG to discuss to ideas for topics

2. Shared experiments/ACCESS-NRI resources

3. ACCESS Community Workshop

  • Abstract submissions for the workshop are still open, and registrations will open on 2024-07-11T14:00:00Z. Check the ACCESS Community Workshop 2024 page for updates.
  • Registration is separate form. Oral abstract deadline is Jul28th. Poster might be more flexible.
  • The ESM WG has decided on a half day get together on the last day (Thursday) of the workshop. Don’t have a lead person for the day, volunteers welcome. Wilma doesn’t have the feedback from the last working group day. Need to contact ACCESS-NRI.

4. Improving Researcher/Developer Collaboration

@ctychung and @Harun_Rashid posted on the ideas for topics:

@Harun_Rashid led a discussion.

Often see model biases. Challenge for team developing coupled model to address biases. Need better connections between developers and scientists.

  • ACCESS-ESM1.5 ENSO simulation too regular, doesn’t match observations. PPE 17 atmospheric experiment improvement changed ENSO period.
  • 50 different parameters in PPE. Not all changed in PPE 17
  • Do cheap AMIP runs in first instance? @sofarrell not sure AMIP will work, think we need a coupled model to understand response.
  • @ShayneM would support using WG resources for this sort of work
  • @sofarrell UKMO has done PPEs with the ocean. NEMO very sensitive in North Atlantic, can switch states.
  • PPE 17 is particularly aimed at ENSO
  • Comparison of modellers view vs evaluators view
  • The aim is to establish a closer connection between model developers and evaluation scientists to facilitate model improvements
  • This connection can lead to a better understanding of needs of two groups
  • For example, what does it mean by “the simulated feedback (X) is weaker than that in observations”?
  • What is (are) the physics parameters) that can reduce the bias in feedback X?
  • ITCZ is longitudinally averaged over Pacific Sector
  • @Aidan need to identify who the evaluators and modellers are, identify problems to solve, work out experiment protocol to examine this and give developers a target/criteria for improvement.
  • Small team at CSIRO, a few at BoM. ACCESS-NRI refocussing on tuning part of model now ACCESS-NRI is taking care of infrastructure.
  • @ShayneM would be good to have standard metrics for models.
  • @Harun_Rashid Doing present-day control runs currently. Outputs CMORised.
  • @nicolamaher there was a list of metrics identified as part of the hackathon. Will be revised on the Monday before the workshop. Encourage all interested people to attend.
  • @ctychung need a coordinated evaluation effort. There is a NESP project, but would be great to have some community involvement.
  • @JulieA would be good to have a workflow to automatically generate metrics.
  • @ctychung MED trying to streamline ESMValtool to easily calculate metrics/statistics.
  • @JulieA CMIP fast-track simulations. Already running ESM1.6?
  • @tiloz CMIP7 fast-track deadline is end of 2026. All have to ready well before then to be processed and published. Decided to put together best change of contributing to fast-track. This is ACCESS-ESM1.6, based on ESM1.5 with improvements in BGC and land CABLE table, land use change scheme. Already testing new WOMBAT version on ESM1.5. Dave Bi is revising the iceberg scheme. Plan to have that version finalised by the end of the year. Spin-up at the beginning of 2025. Tuning and model dev work in the remainder of 2024. No major changes in physics, focussing on the carbon cycle.
  • @JulieA could ESM WG help with evaluating ESM1.6?

5. Priorities for future ACCESS-NRI supported ESM configurations

@dkhutch posted a topic to initiate discussion on what are the priorities for ACCESS-NRI supported ESM model configurations and capabilities once the initial release is complete (targeting end of July):

Ran out of time so delayed for another meeting, but if any others want to respond to the topic above or create their own to canvas opinions about other (non-paleoclimate) configurations that would be great.

6. What’s going on?

Any news to share? Experiments being run? Ideas for collaborations?

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

28

Date: 18/7/2024

Participants: 10

Chair: @tiloz

Admin

Welcome and Speaker Call:
@tiloz welcomed attendees and reminded them of the importance of contributions for science presentations. Currently, only one speaker is confirmed for the end of August. Participants are encouraged to present, even if it’s work in progress. They should contact any co-chairs or @Aidan if interested.

Discussion Topics and Proposals:
Members are invited to add discussion topics to the hive ideas platform. They can also propose technical discussions instead of science presentations.

Resource Update:
For the shared experiments project (lg87), 125 KSU have been used out of 875 allocated. Storage remains stable at 35TB. Members are encouraged to submit proposals for experiments for this or next quarter.

Access Community Workshop:

  • Registration is open with a fee this year. It will be held at the Shine Dome with no current restrictions on numbers.
  • Abstract submissions are open until July 28th. Posters are automatically accepted; talks will be reviewed. The main themes are model development, high-resolution modeling, paleo climate, and ice sheet modeling, but other areas are also welcome.
  • An ESM working group session is planned for the day after the workshop. @dkhutch suggested signing up even if there’s only slight interest. The session will be informal, and members are encouraged to submit abstracts for oral presentations.
  • @dkhutch urged more abstract submissions to strengthen the workshop program.
  • The structure of the ESM working group session will be discussed further with the co-chairs.

Final Points:
@tiloz asked if there were any other administrative or general points. @dkhutch confirmed that there is still space for simulation proposals this quarter, with guidelines available on the hive. If resources run out, efforts will be made to secure more.

Science presentation

Overview

@HIMADRI_SAINI presented the ongoing work on simulating a glacial climate using the ACCESS-ESM1.5 model, specifically focusing on the millennial-scale abrupt climate events in Australia during the last glacial period, targeting the Heinrich Event 5 (around 49,000 years ago).

Objectives

  1. Simulation Goals: Investigate how abrupt climate changes during the last glacial period affected Australia’s climate.
  2. Data Comparison: Compare model simulations with new terrestrial and ocean data to understand global climate propagation and Australian natural history.

Methodology

  1. Orbital Parameters: Applied historical values for eccentricity, obliquity, and precession.
  2. Greenhouse Gases: COâ‚‚ at 200 ppm, CHâ‚„ at 461 ppb, and Nâ‚‚O at 231 ppb, reflecting glacial period levels.
  3. Ice Sheets & Vegetation: Incorporated ice sheet masks and vegetation changes based on reconstructions, adjusting the model to reflect ice sheets and bare ground where appropriate.
  4. Sea Level & Salinity: Adjusted for lower sea levels (about 444 meters lower) and increased global salinity by adding a negative freshwater flux.
  5. Bering Strait Closure: Implemented to reflect glacial sea level changes, though faced with computational issues like wall time exceeded errors.
  6. Topography & Orography: Modified topography based on reconstructions to reflect changes in ice sheets and landmasses.

Results

  1. Surface Air Temperature: Significant cooling compared to pre-industrial levels. Globally averaged surface air temperature dropped by 3.8°C, with more pronounced cooling in the Northern Hemisphere.
  2. AMOC (Atlantic Meridional Overturning Circulation): Showed a strong reduction, stabilizing to around 30 Sv, which is higher than some other model simulations.
  3. Precipitation & Sea Ice: Observed variability in precipitation patterns and sea ice extent. For example, increased rainfall in northern Australia and decreased in the south.
  4. Ongoing Analysis: Surface air temperature trends, AMOC strength, and precipitation patterns are still under review.

Challenges & Issues

  1. Leap Year Problem: Encountered issues with model simulations reaching 400 years, resolved by restarting counters.
  2. Wall Time Errors: Experienced computational issues related to closing the Bering Strait, occasionally resolved by deleting restart files or restarting the model.
  3. AMOC Strength: Noted stronger AMOC compared to other models, possibly due to strong cooling effects.

Next Steps

  1. Freshwater Simulation: To be conducted to assess how Australian climate changes under millennial-scale events.
  2. Further Analysis: Continue analyzing model outputs, particularly focusing on discrepancies and counterintuitive results.

Discussion

  • @gpontes noted that the ITCZ shift aligns with expectations due to stronger AMOC.
  • @dkhutch inquired about proxy data for Northern Australia, suggesting that comparisons with historical records could validate model results.
  • @jbrown questioned the strength of AMOC in the model compared to others, highlighting the need for further investigation.
  • @sofarrell observed counterintuitive results in sea ice retreat and temperature changes, recommending a closer look at these phenomena.

Conclusion

The presentation outlined the methods and results of simulating a glacial climate scenario with ACCESS-ESM1.5, including initial findings and challenges. Ongoing analysis and comparison with proxy data will help refine the understanding of glacial climate dynamics and improve model accuracy.

Other Business

Issues with the ACCESS-ESM1.5 model:

  1. Calendar Issues:
  • @dkhutch highlighted problems with leap years and calendar discrepancies in long-term simulations. Issues have been noted around year 400 and beyond.
  • @HIMADRI_SAINI mentioned that changing the date can sometimes circumvent these issues, and moving past the Gregorian calendar change (around 1500) might also help.
  • @tiloz noted that their simulations usually run beyond 1800 without encountering these problems but acknowledged the need for more investigation.
  1. Model Crashes and Wall Time Exceeded:
  • @HIMADRI_SAINI and @spencerwong discussed issues where models complete a year but exit without saving output, which might be related to wall time exceeded errors.
  • @tiloz suggested that these issues might be related to compute resources rather than the model itself but agreed that documenting and further investigation are necessary.
  1. Differences Between Payu and Script Versions:
  • @spencerwong and @tiloz discussed potential differences between the Payu version and the script-based version of the model that might affect calendar handling and restarts.
  • @RachelLaw and @gpontes suggested that the issue might be specific to certain users or configurations and emphasized the need to examine and compare versions.
  1. Testing and Troubleshooting:
  • @HIMADRI_SAINI will provide restart locations for further testing to @spencerwong to reproduce the issues.
  • @jemmajeffree proposed testing the model starting from year 399 directly to see if it consistently crashes.
  1. Action Items:
  • Check Payu Versions: Ensure that the latest Payu version is being used and look for any inadvertent fixes or updates.
  • Document Issues: Collect and document all major issues affecting workflows and model performance.

Meeting notes generated by chatgpt from zoom transcript, with additional manual layout changes.

This is a wiki post , if you want to update any of the details in these meeting notes, or to add your own recollection of what was discussed then edit me rather than replying.

29

Date: 15/8/2024

Participants: 15

Chair: @ShayneM

1. Opening and Welcome:

  • We have a speaker for the next meeting on August 29th. There are no speakers confirmed for future meetings beyond this date. Members are encouraged to reach out to Aidan or any co-chair if they are interested in presenting.
  • Future scientific presentations do not need to be fully polished; works in progress or discussion-based topics are welcome.
  • Members were reminded to add any items they want to discuss to the working group agenda via the Esm working group announcement page.

2. Shared Experiments and Usage:

  • The project has used 320 ksu out of the 900 ksu allocated for the quarter.
  • There are currently no new proposals submitted.
  • @dkhutch mentioned that a proposal for 440 ksu from @YanxuanD (Melbourne) is in place, and informal discussions with Gabriel Pontes about a Pliocene simulation might need follow-up.
  • @dkhutch is open to putting forward additional proposals but encourages others to contribute to avoid underutilization of resources.
  • Members have about 6 weeks remaining to use the allocated ksu.
  • Resource usage and allocation will be reviewed approximately 2 weeks before the end of the quarter to adjust as needed.
  • @JulieA raised proposals for the next quarter, including melt water experiments and stratospheric ozone experiments.
    • Melt Water Experiments: @JulieA is working with @MATTENGLAND , @ariaan and @tiloz on anomalous freshwater experiments. They are looking for resources and support, potentially from the NRI (National Research Institute). Technical support and implementation are needed, and they plan to use working group resources.
    • Stratospheric Ozone Experiments: @JulieA is also interested in running CMIP6 DAMIP experiments focused on stratospheric ozone. They may use working group allocations or clicks allocations.
  • @tiloz agreed on the importance of finding resources and support to implement these experiments and suggested putting proposals on the hive for better engagement and support.
  • @LaurieM clarified that while they have used observational constraints for the North Atlantic, they have not yet worked with the new datasets for the South and North Atlantic from recent workshops. They have focused on the North Atlantic but are interested in the new datasets for future experiments.
  • @gpontes confirmed that he has already run historical experiments with North Atlantic meltwater data and has provided experimental designs on the hive. His work is under review.
  • @JulieA explained that the anomalous freshwater forcing dataset is a new dataset developed by a group led by Gavin Schmidt to address missing meltwater in historical CMIP6 experiments. This dataset is intended to be used as a forcing for fast-track CMIP7 experiments. The current goal is to test the dataset with several models to validate its utility before it is officially approved for use.
  • @ShayneM noted that proposals need only a brief summary on the Esm working group page. A simple review by one or two members is required to approve them.
  • @sofarrell raised concerns about how the new anomalous freshwater data would fit with the existing iceberg scheme in ESM 1.6. The new data might complicate the current scheme, which aims to handle freshwater fluxes differently. Siobhan suggested sending links to Rachel for further review. @dhb599 commented that incorporating the new freshwater forcing into ESM 1.5 could be straightforward if the nature of the forcing data is understood. He noted that similar functions have been implemented before and can be adapted for the new data.
  • @JulieA and @dhb599 agreed to take discussions offline to address specific implementation details and integrate the new forcing data into existing models.
  • @JulieA will coordinate a proposal for the melt water experiments and share updates with the group.

3. ACCESS Community Workshop

  • The Earth System Modeling Group needs to finalize the agenda for the half-day workshop by Friday. @dkhutch and @Aidan outlined the current status:
  • Abstracts from the main program will be transferred to the working group day if not included in the main program.
  • There will be two sessions with 15-minute slots for talks (10 minutes plus 5 for Q&A) and additional time allocated for discussion.
  • Additional speakers are encouraged to submit abstracts quickly.
  • @ShayneM suggested the need to link model development and evaluation teams and to propose simulations for model testing and configuration and encouraged members to brainstorm and propose ideas that could unify the group’s efforts and address broader research goals.
  • Co-chairs will finalize the workshop agenda and handle abstract submissions.

4. Science Presentation

@gpontes presented “The Contribution of Meltwater to the 20th Century AMOC Weakening.”

  • Objective: To understand how anomalies related to the Atlantic Meridional Overturning Circulation (AMOC) can propagate to the Southern Hemisphere, focusing on high latitudes and the Southern Ocean.
  • Introduction: Gabriel provided an overview of the AMOC, emphasizing its impact on various climate features and its complex 3D structure. He highlighted the importance of both surface and subsurface currents in understanding AMOC dynamics.
  • Metrics and Observations:
    • Discussed metrics created to measure the warming of the Gulf Stream and the cooling of the Subpolar Gyre.
    • Noted the influence of Atlantic Multidecadal Oscillation (AMO) on AMOC observations and the complexities of evaluating AMOC state due to intrinsic linkages between AMOC and AMO.
  • Model Comparisons:
    • Reviewed reconstructions and measurements of AMOC from various sources, including satellite data and direct measurements.
    • Compared observational trends with climate models (CMIP5 and CMIP6), noting discrepancies, such as the weakening periods not captured by these models.
    • Highlighted a significant observational weakening between 2004 and 2015 that was not reflected in the CMIP models.
  • Study Findings:
    Idealized Experiments Results:
    • Conducted idealized simulations to understand AMOC responses to meltwater inputs.
    • Found that meltwater displaces isopycnals in the North Atlantic, causing AMOC weakening.
    • Models Used: ACCESS-ESM 1.5 and ACCESS-OM2 at quarter-degree resolution.
    • Findings:
      • Kelvin Waves: Meltwater-induced Kelvin waves are generated in the Subpolar Gyre, traveling along the western boundary of the Atlantic and crossing the equator.
      • Impact: These Kelvin waves weaken the Gulf Stream and North Brazil Current, leading to a rapid signal propagation from North to South Atlantic.
      • Rossby Waves: Fast teleconnection via Rossby waves modifies the signal in the South Atlantic, affecting heat transport and AMOC dynamics.
      • Negative Feedback: Rossby waves cause a negative feedback loop by deepening isopycnals in the North Atlantic, potentially strengthening AMOC over decades.
      • Propagation: The signal propagates to South America and North America, influencing both North and South Atlantic regions.
      • Salinity and Temperature Analysis:
        • Salinity Changes: Significant salinity changes observed in the North and South Atlantic, with convergence points influenced by both Kelvin and Rossby waves.
        • Model Comparison: ACCESS-ESM and ACCESS-OM2 models showed similar results regarding salinity dynamics and propagation timescales.
        • New Indices: Developed salinity and SST indices to capture AMOC-related changes more effectively.
    • Historical Data Analysis:
      • Kelvin Signal: Emergence of the Kelvin signal around 1975, with a noticeable trend indicating increasing salinity convergence in the South Atlantic.
      • Rossby Signal: The Rossby signal emerged approximately 20 years after the Kelvin signal, aligning with idealized simulation timescales.
      • SST Indices Comparison:
        • Classical Index: Based on subpolar gyre SST anomalies, showing high variability without significant trends.
        • Corrected Index: Adjusted for polar amplification, revealing a more consistent trend from 1950 onward.
        • Modified SST Dipole Index: Focused on Rossby wave signals, showing a notable emergence around 1975.
    • Model vs. Observations:
      • ACCESS-ESM Model Analysis: Comparison of SST indices from observations with ACCESS-ESM model results, focusing on the timing and magnitude of signal emergence.

Members discussed Gabriel Pontes’ findings, particularly the implications for understanding AMOC dynamics and model accuracy. There was interest in exploring these mechanisms further in ongoing and future research.

Note: These notes were generated by ChatGPT, so please amend as required.

Additional information

30

Date: 29/8/2024

Participants: 16

Chair: @eunpalim

Admin

  • @YanxuanD is using the bulk of the resources and requested more time.
  • @JulieA couldn’t attend but mentioned she has experiments pending a new hire.
  • Other projects have underutilized resources if people think they could use them.
  • Encouragement for proposals for shared experiments.
  • No working group meeting on September 12th due to the Access NRI Workshop.
  • Next meeting on September 26th, looking for a speaker.

Access Community Workshop

  • Scheduled for next week with 51 attendees (48-49 in person).
  • 8 speakers lined up.
  • Discussion on the possibility of having ad-hoc discussions after lunch due to high attendance.

ACCESS-ESM 1.5 Release

  • ACCESS-NRI supported release of ACCESS-ESM1.5

https://forum.access-hive.org.au/t/access-esm1-5-release-information/2352/3

  • @spencerwong will discuss it further during the workshop.
  • Thanks to @tiloz and CSIRO for developing the model.
  • Support for the model will be provided through the forum.

Speaker

  • Dr. Surendra Rauniyar (@sprbom) from the Bureau of Meteorology presented on the “Tinderbox Drought” in Southeast Australia and its future likelihood using climate models.

Tinderbox Drought Research:

  • Focus on the cool season (April to September).
  • Key questions addressed:
    • Severity of rainfall deficit relative to historical context and model variability.
    • Roles of anthropogenic forcings and internal variability.
    • Future likelihood of extremely dry periods.
    • Impact of greenhouse gas reduction on future drought likelihood.
  • Findings:
    • The recent decline in cool season rainfall is highly unusual.
    • According to climate models, the Tinderbox Drought (2017-2019) was dominated largely by internal climate variability, however it would not have been as large without the influence from increasing levels of GHGs in the atmosphere.
    • Future likelihood of extremely dry periods is higher due to climate change.
    • Models struggle to simulate the extreme dryness observed.
    • High emission scenarios significantly increase the likelihood of future droughts.
    • Even low emission scenarios show increased likelihood compared to pre-industrial levels.

Discussion Points:

  • Importance of soil moisture deficit and land surface coupling in the drought.
  • Potential insights from future CMIP7 runs.
  • Need for further investigation into model variability and forced response.
  • Examination of individual model responses and their dependence on warming.
  • Consideration of underlying climatologies of models before including them in analyses.

Notes were generated automatically by AI from a Zoom transcript.

Additional information

31

Date: 26/9/2024

Participants: 15

Chair: @dkhutch

1. Opening and Welcome:

  • There are no speakers confirmed for future meetings. Please consider presenting, or inviting a colleague to present. Members are encouraged to reach out to Aidan or any co-chair if they are interested in presenting.
  • Future scientific presentations do not need to be fully polished; works in progress or discussion-based topics are welcome.
  • Members were reminded to add any items they want to discuss to the working group agenda via the topic on the forum.

2. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 has used 754 KSU of its 875 KSU allocation for this quarter. /g/data storage steady at 35TB
  • Should be sufficient for current users, doesn’t matter if there is some unused.
  • Any more proposals for shared experiments for next quarter?See guidelines for how to do this. There are often used resources we can access if there are projects to use them.

3. Workshop Feedback

4. Speaker

@YanxuanD: “The impacts of an AMOC slowdown on Australian climate at 8.2 ka in ACCESS-ESM1.5 model”

[Video will be embedded when available]

@YanxuanD presented findings from freshwater forcing experiments simulating the 8.2 Ka event. The experiments aimed to investigate the climate response over Australia under 8.2 Ka climate conditions.

  • Setup: The background state was set by changing orbital parameters and greenhouse gas concentrations, while other forcings remained the same as pre-industrial.
  • Experiments: Included short-duration pulses (1, 5 years) and a time-varying long-term freshwater forcing to simulate the lake outburst hypothesis.
  • Findings:
    - Only the long-term experiment showed a significant weakening of the AMOC for over 160 years.
    - Northern and North Atlantic surface air temperatures decreased significantly, while the South Atlantic experienced significant warming.
    - The AMOC weakening led to a bipolar seesaw effect, with warming in the Southern Hemisphere and cooling in the Northern Hemisphere during recovery.
  • Climate Response Analysis: climate response over Australia and other regions during the AMOC minimum period.
    • Temperature Changes:
      • Significant cooling over Northern Australia and warming over Southern Australia and New Zealand.
      • Widespread warming in the Southern Hemisphere, indicating a bipolar seesaw effect.
    • Precipitation Changes:
      • Strengthened Indo-Australian summer monsoon and increased precipitation over Northern Australia and New Guinea.
      • Slight weakening of westerly winds in Southern Australia with non-significant precipitation changes.
      • ITCZ shifted southward over the Atlantic and Western Pacific during DJF, and weakened across all ocean basins during JJA.
    • Monsoon Analysis:
      • South Asia and East Asia summer monsoons slightly weakened.
      • South American monsoon showed a southward shift with increased precipitation on the eastern side.

5. Other Business:

  • @Aidan Encouraged follow-ups from the workshop and highlighted issue created for offline ocean BGC spin-up and ongoing work on orbital parameter changes.
  • Spencer Wong: Shared progress on implementing capability to specify orbital parameter changes through a namelist, while ensuring consistency with existing simulations. Needs some more testing, but then will be in a position to share with some users to test.

These notes were generated automatically by AI. If you notice any errors or omissions please feel free to modify directly, or message @aidan.

Additional information

32

Date: 24/10/2024

Participants: 12

Chair: @tiloz

1. Opening and Welcome:

  • There are no speakers confirmed for future meetings. Please consider presenting, or inviting a colleague to present. Members are encouraged to reach out to any co-chair or @spencerwong if they are interested in presenting.
  • Future scientific presentations do not need to be fully polished; works in progress or discussion-based topics are welcome.
  • Add any items they want to discuss to the working group agenda via the topic on the forum.

2. Meeting Structure and Frequency:

  • Regular Meetings: Difficulty in finding speakers for a meeting every fortnight was noted, and updates to the structure of the ESM WG meetings were brought up. Suggestions include:
    • Introducing a regular CMIP7 focussed discussion every second meeting, led by @RachelLaw, to keep the community up to date with plans and progress. This could begin from the next meeting on November 7.
    • Science presentations could be held on alternate meetings, so that a presentation would occur once per month.
    • Meetings could contain open discussions on technical issues, where for example students and post docs having trouble with the models could get help from the community. Ideas for discussions can be put forward in this Hive Forum topic.
    • Cross-working group interactions. The ESM working group interests overlap with many of other working groups, and there may be opportunities to hold combined meetings wth them. Interaction/collaboration with the Model Evaluation group would be of interest in particular for the lead up to CMIP7. There’s also overlap with the domain specific working groups such as land, ocean, and atmosphere.
    • Reaching out to more research groups, students and postdocs who are using the model and model data.

3. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 has used ~200 KSU of its 875 KSU allocation for this quarter. /g/data storage steady at 35TB
  • Should be sufficient for current users, doesn’t matter if there is some unused.
  • Do you have any proposals for shared experiments? See guidelines for how to do this. There are often used resources we can access if there are projects to use them.

4. Speaker
@Harun_Rashid: “Assessment of ENSO simulations in large ensembles through process evaluations and understanding”

[Presentation discussed preliminary work and recording not uploaded]

@Harun_Rashid presented his work on model evaluation using large ensembles to understand features and processes in climate models, specifically focusing on ENSO (El Niño-Southern Oscillation).

Harun discussed the use of correlation matrices across models to explore interrelationships between climate statistics and how these can help in understanding model biases and improving model tuning, and presented results for the CMIP6 historical ensembles, and ACCESS-CM2’s historical ensemble.

5. Access ESM 1.5 Updates:

  • Orbital Parameters: @spencerwong mentioned a new pre-release of Access ESM 1.5 that includes the capability to change orbital parameters at runtime. Details on the pre-release are available on this forum topic. A demo of setting up the new executables will be run at the next meeting.

Action Items

  • Next Meeting Agenda: Include a discussion on CMIP7 fast track organised by @RachelLaw and an update on Access ESM 1.5 from @spencerwong.

These notes were generated automatically by AI. If you notice any errors or omissions please feel free to modify directly, or message @spencerwong.

Additional information

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33

Date: 8/11/2024

Participants: 15

Chair: @eunpalim

1. Opening and Welcome:

  • There are no speakers confirmed for future meetings. Please consider presenting, or inviting a colleague to present. Members are encouraged to reach out to any co-chair or @spencerwong if they are interested in presenting.
  • Future scientific presentations do not need to be fully polished; works in progress or discussion-based topics are welcome.
  • Add any items they want to discuss to the working group agenda via the topic on the forum.

2. Summer meeting schedule:

  • Discussion was held on when to have the final meeting of the year. We will plan to have a regular science presentation on 21/11 and a CMIP7 fast track update on 5/11, and then have a break in meetings until February.

3. Shared experiments/ACCESS-NRI resources

  • ESM project lg87 has used ~435 KSU of its 875 KSU allocation for this quarter. /g/data storage steady at 35TB. Most of the compute allocation for this quarter has been allocated for experiments, however there may be a small amount currently unallocated.
  • The holiday period and beginning of the year typically have low compute usage. If you have ideas for experiments, it’s a good time to put forward any proposals. See guidelines for how to do this. There are often used resources we can access if there are projects to use them.
  • Guidelines around lg87 gdata storage usage were discussed. There currently is no policy, however ideas including 6 month storage limits, and a central spreadsheet for tracking experiments were proposed. The experiment proposal template will be updated to include sections on required storage time, and plans for the data once it’s removed.
  • ACCESS NRI is working on guidelines for WG shared resources which will address some of these issues.
  1. CMIP7 Fast Track update:
  • @RachelLaw presented updates on the development of ACCESS ESM 1.6 for the CMIP7 fast track.
  • Current work includes @pearseb’s updates to WOMBAT light using generic tracers, replacing CABLE 2.4 with CABLE3, testing convective momentum transport in the UM, swapping the sea ice component to CICE5, and making the MOM5 configuration better match OM2.
  • @arnoldsu and @RachelLaw shared results from testing convective momentum transport (CMT) in the UM, and from updating the land component to CABLE3.
  • @tiloz provided an update on on the recent forcings workshop, noting that forcing datasets for CMIP7 are starting to be made available, and noted the need for sustainable funding for this work.
  1. Orbital Parameters for ESM 1.5:
  • @spencerwong demonstrated how to set custom orbital parameters in ESM 1.5 using a new pre-release version of the executables. A tutorial on using the prerelease is available here.
  • An upcoming release of ESM1.5 will include these changes along with other updates.

These notes were generated automatically by AI. If you notice any errors or omissions please feel free to modify directly, or message @spencerwong.

Additional information

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