Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Introduce Andrew Brown (recently appointed Atmosphere WG co-chair)
From SVN to Git - A gentle introduction to contemporary suite development on GadiBen Schroeter, ACCESS-NRI (12+5mins)
CABLE development successfully transitioned from SVN to Git in 2023, paving the way to more robust and collaborative model development. Ben will share some lessons learned, a brief example of switching your suite over to git and how ACCESS-AM3 suite development fits into the broader development infrastructure at ACCESS-NRI.
ACCESS-AM2 aerosol sensitivity to dimethyl sulfide emissions associated with Antarctic sea iceAlanah Chapman (12+5mins)
The complex interactions between radiation, clouds and aerosol remains the largest source of uncertainty in estimates of climate sensitivity to anthropogenic emissions. In the remote Southern Ocean far from anthropogenic sources, climate models significantly underestimate the number of aerosol particles, which importantly affect cloud properties, precipitation and radiation. Efforts to improve aerosol representation have so far shown limited success, highlighting issues with the aerosol to cloud microphysical processes within climate models. Recent work has suggested that improving natural aerosol processes may be a key part to improving the modelling for this region. This work explores the sensitivity of ACCESS-AM2 to dimethyl sulfide (DMS) emissions from Antarctic sea ice, a source not represented in global climate models. Alanah will share recent results comparing observations and modelled DMS and aerosol, highlighting the high (unrealistic) emission DMS run shows improvements to modelled aerosol number concentrations. These results indicate issues in the simple DMS oxidation scheme and sulfate aerosol production pathways within ACCESS.
Atmosphere WG annual meeting: at 15:30-16:15 on 20 August (Day 2)
Agenda ideas/discussions?
EOI 2026: Visualisation Project with ACCESS-NRIHeidi Nettelbeck (5mins)
ACCESS-NRI is inviting expressions of interest from researchers to collaborate on a 3-6 month visualisation project. We’re offering technical support and expert guidance to help you bring your science to life.
Call open until 15 July 2026
UKCA science meeting
University of Leeds, 15-17 July. Sonya Fiddes (2mins)
Comprises a conference (remote attendance possible) followed by a hackathon (in-person only). More details: UKCA2026_flyer.pdf
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q2/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
Next Atmosphere WG meeting:July 2026
heidi
(Heidi Nettelbeck, ACCESS-NRI Atmosphere Modelling Team Lead)
47
!!Reminder: Atmosphere WG meeting 24.06.2026
For a calendar invite, simply click on the relevant calendar link below
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Introduce Andrew Brown (recently appointed Atmosphere WG co-chair)
From SVN to Git - A gentle introduction to contemporary suite development on GadiBen Schroeter, ACCESS-NRI (12+4mins)
CABLE development successfully transitioned from SVN to Git in 2023, paving the way to more robust and collaborative model development. Ben will share some lessons learned, a brief example of switching your suite over to git and how ACCESS-AM3 suite development fits into the broader development infrastructure at ACCESS-NRI.
ACCESS-AM2 aerosol sensitivity to dimethyl sulfide emissions associated with Antarctic sea iceAlanah Chapman (12+4mins)
The complex interactions between radiation, clouds and aerosol remains the largest source of uncertainty in estimates of climate sensitivity to anthropogenic emissions. In the remote Southern Ocean far from anthropogenic sources, climate models significantly underestimate the number of aerosol particles, which importantly affect cloud properties, precipitation and radiation. Efforts to improve aerosol representation have so far shown limited success, highlighting issues with the aerosol to cloud microphysical processes within climate models. Recent work has suggested that improving natural aerosol processes may be a key part to improving the modelling for this region. This work explores the sensitivity of ACCESS-AM2 to dimethyl sulfide (DMS) emissions from Antarctic sea ice, a source not represented in global climate models. Alanah will share recent results comparing observations and modelled DMS and aerosol, highlighting the high (unrealistic) emission DMS run shows improvements to modelled aerosol number concentrations. These results indicate issues in the simple DMS oxidation scheme and sulfate aerosol production pathways within ACCESS.
What should be included in a beta release of ACCESS-AM3-chem configuration on ACCESS-NRI 2026/27 Work plan?
ACCESS-AM3 evaluation (N512): need your help!Heidi Nettelbeck (5mins)
W21C now has a 2-year high-resolution ACCESS-AM3 (N512) and need your help to evaluate the model by writing and sharing code! Currently, we’re collating a list of potential figures/analyses, where we’d need volunteers to write and share code on this AM3-evaluation GitHub repository . An AM3-evaluation meeting planned for 6 Aug, and a tutorial of how to contribute scripts on the AM3-evaluation GitHub repository is also planned.
Atmosphere WG annual meeting: at 15:30-16:15 on 20 August (Day 2)
Agenda ideas/discussions?
EOI 2026: Visualisation Project with ACCESS-NRIHeidi Nettelbeck (2mins)
ACCESS-NRI is inviting expressions of interest from researchers to collaborate on a 3-6 month visualisation project. We’re offering technical support and expert guidance to help you bring your science to life.
Call open until 15 July 2026
ACCESS-NRI documentation: Read the DocsHeidi Nettelbeck (2mins)
Over the next 2–3 weeks, ACCESS-NRI will be transitioning all of our documentation sites to a new hosting platform - Read the Docs. For most users, this should be barely noticeable and won’t change how you access or contribute to sites. You can read more about the transition in this Forum post.
UKCA science meeting
University of Leeds, 15-17 July. Sonya Fiddes (2mins)
Comprises a conference (remote attendance possible) followed by a hackathon (in-person only). More details: UKCA2026_flyer.pdf
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q2/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Introduce Bethan White, W21C, our recently appointed Atmosphere WG co-chair
Progress using ACCESS-rAM3 for the Sub-hourly Extreme Precipitation (SHEP) ProjectSam Dahl and Leena Sanjay Khadke, Centre/UNSW (15+5mins)
The SHEP project aims to use coordinated convective-permitting regional climate downscaling experiments to investigate past case events of short-duration extreme rainfall over eight Australian cities and Auckland. ACCESS-rAM3 is one of the models being used by members from the ARC Centre for Weather of the 21st Century, and evaluation of its performance for the case events is ongoing. Initial results over Sydney and Melbourne show that the model produces the extreme rain events with good accuracy, however some interesting nuances exist. Several of these nuances will be presented, as well as ongoing efforts to benchmark the simulations, and pseudo-global warming (PGW) simulations which aim to simulate the case events in a warmer climate.
ACCESS-AM3 evaluation (N512): need your help!Pao Corrales (10+5mins)
Pao will give a demo of a typical Git workflow to contribute a script (clone, add file, commit and push) and also how to upload a file from the web interface, including pros and cons.
AM3-evaluation meeting 10:30 on 4 Aug to discuss AM3 N512 vs N96 analysis, including a tutorial of how to contribute scripts on the AM3-evaluation GitHub repository.
Hackathon: CMIP7 and analysis of evaluation ACCESS models ESM1.6 , CM3 and AM3
Ask the community?? Sonya Fiddes (5mins)
Do you have a research question that you’ve exhausted ideas to find an answer to?
Here’s your chance to ask our Atmosphere community for their ideas!
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q3/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
Next Atmosphere WG meeting: ML/Atmosphere ACCESS Workshop on 20 August 2026
heidi
(Heidi Nettelbeck, ACCESS-NRI Atmosphere Modelling Team Lead)
49
Reminder!! Atmosphere WG meeting 29.07.2026
For a calendar invite, simply click on the relevant calendar link below
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Introduce Bethan White, W21C, our recently appointed Atmosphere WG co-chair
Progress using ACCESS-rAM3 for the Sub-hourly Extreme Precipitation (SHEP) ProjectSam Dahl and Leena Sanjay Khadke, Centre/UNSW (15+5mins)
The SHEP project aims to use coordinated convective-permitting regional climate downscaling experiments to investigate past case events of short-duration extreme rainfall over eight Australian cities and Auckland. ACCESS-rAM3 is one of the models being used by members from the ARC Centre for Weather of the 21st Century, and evaluation of its performance for the case events is ongoing. Initial results over Sydney and Melbourne show that the model produces the extreme rain events with good accuracy, however some interesting nuances exist. Several of these nuances will be presented, as well as ongoing efforts to benchmark the simulations, and pseudo-global warming (PGW) simulations which aim to simulate the case events in a warmer climate.
ACCESS-AM3 evaluation (N512): need your help!Pao Corrales (10+5mins)
Pao will give a demo of a typical Git workflow to contribute a script (clone, add file, commit and push) and also how to upload a file from the web interface, including pros and cons.
AM3-evaluation meeting 10:30 on 4 Aug to discuss AM3 N512 vs N96 analysis, including a tutorial of how to contribute scripts on the AM3-evaluation GitHub repository.
Hackathon: CMIP7 and analysis of evaluation ACCESS models ESM1.6 , CM3 and AM3
Ask the community?? Sonya Fiddes (5mins)
Do you have a research question that you’ve exhausted ideas to find an answer to?
Here’s your chance to ask our Atmosphere community for their ideas!
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q3/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
Next Atmosphere WG meeting: ML/Atmosphere ACCESS Workshop on 20 August 2026
heidi
(Heidi Nettelbeck, ACCESS-NRI Atmosphere Modelling Team Lead)
50
Atmosphere WG meeting 23.09.2026
For a calendar invite, simply click on the relevant calendar link below
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Placeholder for any updates from the atmosphere community.
Hybrid atmospheric model development - can ACCESS-NRI play a role?Steve Sherwood, UNSW (10+5mins)
A few hybrid modelling approaches are being pursued for improving weather and climate forecasting, where “hybrid” in general just means combining machine-learning and traditional modelling approaches somehow. A particular instance is hybrid climate models that replace sub-grid physics with ML surrogates, thereby attempting to keep known physical constraints while exploiting ML to fill gaps. We will review this strategy and how (or why) ACCESS-NRI might contribute to it by generating training data for surrogates and/or developing a sovereign hybrid modelling capability.
ML-Based Weather modelling at the Bureau of MeteorologyCatherine de Burgh-Day, BoM (20+5mins)
Machine learning has emerged as a powerful tool for weather prediction, with major meteorological centres and research organisations around the world investing in ML-based forecasting systems - both pure ML models, and hybrid physics-ML approaches. This presentation provides an overview of the evolving international landscape, highlighting scientific potential, and key developments including hybrid spectral nudging, foundation models, Direct from Obs Prediction (DOP), ensemble prediction, regional and multi-domain models, and progress in spatio-temporal downscaling.
The presentation will also outline the Bureau’s current activities and future plans in ML-based global and regional weather modelling, including evaluation of AIFS variants, operational prototyping of AIFS, and progress in developing a combined global-regional ML weather models for Australia.
DiscussionAndrew Brown (10mins)
How can we develop our community to better share ML techniques and expertise?
e.g., invited talks at Atmosphere and ML WG meeting
Ask the community?? Sonya Fiddes (5mins)
Do you have a research question that you’ve exhausted ideas to find an answer to?
Here’s your chance to ask our Atmosphere community for their ideas!
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q3/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Placeholder for any updates from the atmosphere community.
ML-Based Weather modelling at the Bureau of MeteorologyCatherine de Burgh-Day, BoM (20+5mins)
Machine learning has emerged as a powerful tool for weather prediction, with major meteorological centres and research organisations around the world investing in ML-based forecasting systems - both pure ML models, and hybrid physics-ML approaches. This presentation provides an overview of the evolving international landscape, highlighting scientific potential, and key developments including hybrid spectral nudging, foundation models, Direct from Obs Prediction (DOP), ensemble prediction, regional and multi-domain models, and progress in spatio-temporal downscaling.
The presentation will also outline the Bureau’s current activities and future plans in ML-based global and regional weather modelling, including evaluation of AIFS variants, operational prototyping of AIFS, and progress in developing a combined global-regional ML weather models for Australia.
Hybrid atmospheric model development - can ACCESS-NRI play a role?Steve Sherwood, UNSW (10+5mins)
A few hybrid modelling approaches are being pursued for improving weather and climate forecasting, where “hybrid” in general just means combining machine-learning and traditional modelling approaches somehow. A particular instance is hybrid climate models that replace sub-grid physics with ML surrogates, thereby attempting to keep known physical constraints while exploiting ML to fill gaps. We will review this strategy and how (or why) ACCESS-NRI might contribute to it by generating training data for surrogates and/or developing a sovereign hybrid modelling capability.
DiscussionAndrew Brown (10mins)
How can we develop our community to better share ML techniques and expertise?
e.g., invited talks at Atmosphere and ML WG meeting
Ask the community?? Sonya Fiddes (5mins)
Do you have a research question that you’ve exhausted ideas to find an answer to?
Here’s your chance to ask our Atmosphere community for their ideas!
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q3/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
Next Atmosphere WG meeting:October 2026
heidi
(Heidi Nettelbeck, ACCESS-NRI Atmosphere Modelling Team Lead)
52
Atmosphere WG meeting 21.10.2026
For a calendar invite, simply click on the relevant calendar link below
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Placeholder for any updates from the atmosphere community.
The ‘Black Summer’ Currowan fire: insights from a case studyMika Peace, BoM (15+5mins)
On New Years Eve 2019, the ’Black Summer’ fires flared across southeastern Australia. One of the most impactful fires was the Currowan fire, which jumped the six-lane Princes Highway and burned into communities near Lake Conjola. Numerous homes were lost and there were three fatalities. We have conducted a detailed case study of the Currowan fire near Conjola, including coupled fire-atmosphere simulations using ACCESS-Fire.
The case study highlights the importance of dynamic mesoscale meteorological processes during impactful events. Preparedness and situational awareness during future extreme events will benefit from enhanced use of high-resolution NWP for understanding meteorological processes.
From Cylc 7 to Cylc 8: Migrating UM SuitesMartin Dix, ACCESS-NRI (15+5mins)
This talk will walk through how to migrate UM suites from Cylc 7 to Cylc 8. Martin will cover the main technical changes, including moving from suite.rc to flow.cylc and changes to scheduling and task control. Troubleshooting, including things to watch out for when migrating existing cylc suites, will also be mentioned.
Ask the community?? Sonya Fiddes (5mins)
Do you have a research question that you’ve exhausted ideas to find an answer to?
Here’s your chance to ask our Atmosphere community for their ideas!
ACCESS-NRI EOI call for ESM3 dev-evalHeidi Nettelbeck (5mins)
Expressions of Interest from qualified research teams and individuals to work with ACCESS-NRI in testing and evaluation of ACCESS-ESM3 and its components. The ACCESS-ESM3 forward plan requires both technical development (primarily done by ACCESS-NRI) and improvements in model quality. Improving the quality of the model involves an iterative cycle of model testing and evaluation that will benefit from expertise in the research community. Due 31st October 2026!
BARRA v3 user survey
The BoM is seeking your input for the design of BARRA v3, the Bureau’s next generation atmospheric re-analysis that will based on ERA6. See here for more information.
UKMO authentication for CSIRO and BoM usersHeidi Nettelbeck (2mins) A BoM/CSIRO Workflow has been created to authenticate BoM and CSIRO users to access UKMO licensed material (models and configurations) that ACCESS-NRI deploys and supports on NCI. ACCESS-NRI has given CSIRO and BoM employees access to UKMO licensed materials on vk83 based on their historical access to the NCI MOSRS mirror via the ki32_mosrs subgroup. This access will be removed in the future.
7th Momentum Partnership Convective-Scale Modelling WorkshopSingapore, 2-6 Nov 2026
Registration is now open for the 7th Momentum Partnership Convective-Scale Modelling Workshop. See here for more info.
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q4/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
clairecarouge
(Claire Carouge, ACCESS-NRI Land Modelling Team Lead)
53
!! Attention ACCESS-rAM3 users This message is relevant to you if you are interested in using ACCESS-rAM3.
For the next release, ACCESS-NRI is planning to migrate ACCESS-rAM3 to GitHub. This is required following the UK Met Office’s plans to retire the current SVN-based system, MOSRS.
Migrating to GitHub means users must have access to the Met Office’s GitHub organisation before they can access the ACCESS-rAM3 configurations and source code. This requirement is enforced by GitHub and cannot be bypassed. Only users who meet this requirement will have access to future ACCESS-rAM3 releases. The current release will remain available through MOSRS until the system is retired (date TBA).
Note that, starting in 2027, the rosie system used for version-controlling user configurations will become read-only. All configuration changes will then need to be made through GitHub.
As access to the Met Office’s GitHub organisation can take time, we encourage you to start the process now by following these instructions.
Are you able to give a rough timeline for when this GitHub release will be available?
Also, is there any plan to also migrate the current release to GitHub? We have many live, working suites in the fcm system that are branches of the current rAM3, and to retain ongoing read-write access to them after rosie is closed, as well as easily update them to the new rAM3 release when it is made, I think it would be helpful to have both the current and next rAM3 releases in GitHub.
I also suspect it will take some time for us to migrate everything, so any indication of timelines would be great.
Thanks!
heidi
(Heidi Nettelbeck, ACCESS-NRI Atmosphere Modelling Team Lead)
55
!!Reminder: Atmosphere WG meeting 21.10.2026
For a calendar invite, simply click on the relevant calendar link below
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Placeholder for any updates from the atmosphere community.
From Cylc 7 to Cylc 8: Migrating UM SuitesMartin Dix, ACCESS-NRI (15+5mins)
This talk will walk through how to migrate UM suites from Cylc 7 to Cylc 8. Martin will cover the main technical changes, including moving from suite.rc to flow.cylc and changes to scheduling and task control. Troubleshooting, including things to watch out for when migrating existing cylc suites, will also be mentioned.
The ‘Black Summer’ Currowan fire: insights from a case studyMika Peace, BoM (15+5mins)
On New Years Eve 2019, the ’Black Summer’ fires flared across southeastern Australia. One of the most impactful fires was the Currowan fire, which jumped the six-lane Princes Highway and burned into communities near Lake Conjola. Numerous homes were lost and there were three fatalities. We have conducted a detailed case study of the Currowan fire near Conjola, including coupled fire-atmosphere simulations using ACCESS-Fire.
The case study highlights the importance of dynamic mesoscale meteorological processes during impactful events. Preparedness and situational awareness during future extreme events will benefit from enhanced use of high-resolution NWP for understanding meteorological processes.
Ask the community?? Sonya Fiddes (5mins)
Do you have a research question that you’ve exhausted ideas to find an answer to?
Here’s your chance to ask our Atmosphere community for their ideas!
ACCESS-NRI EOI call for ESM3 dev-evalHeidi Nettelbeck (5mins)
Expressions of Interest from qualified research teams and individuals to work with ACCESS-NRI in testing and evaluation of ACCESS-ESM3 and its components. The ACCESS-ESM3 forward plan requires both technical development (primarily done by ACCESS-NRI) and improvements in model quality. Improving the quality of the model involves an iterative cycle of model testing and evaluation that will benefit from expertise in the research community. Due 31st October 2026!
BARRA v3 user survey
The BoM is seeking your input for the design of BARRA v3, the Bureau’s next generation atmospheric re-analysis that will based on ERA6. See here for more information.
UKMO authentication for CSIRO and BoM usersHeidi Nettelbeck (2mins) A BoM/CSIRO Workflow has been created to authenticate BoM and CSIRO users to access UKMO licensed material (models and configurations) that ACCESS-NRI deploys and supports on NCI. ACCESS-NRI has given CSIRO and BoM employees access to UKMO licensed materials on vk83 based on their historical access to the NCI MOSRS mirror via the ki32_mosrs subgroup. This access will be removed in the future.
7th Momentum Partnership Convective-Scale Modelling WorkshopSingapore, 2-6 Nov 2026
Registration is now open for the 7th Momentum Partnership Convective-Scale Modelling Workshop. See here for more info.
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q4/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
Next Atmosphere WG meeting:November 2026
heidi
(Heidi Nettelbeck, ACCESS-NRI Atmosphere Modelling Team Lead)
56
Atmosphere WG meeting 25.11.2026 — Wed, 25 Nov 2026, 11:30 am
Admin: Volunteer for taking today’s meeting minutes to post here on the Forum.
ACCESS Community updates: (5mins)
Placeholder for any updates from the atmosphere community.
Sensitivity of explosive cyclogenesis to latent heating using ACCESS-rAM3Chenhui Jin (20+5mins)
Convection-Permitting Modelling Workshop 2027
Workshop to be held at UNSW, Sydney, February 1-4, 2027, with additional side events on the February 5th. Abstracts submissions welcome (oral and poster) across the full range of high-resolution modelling at kilometre resolutions or higher. Registration now open!
Ask the community?? Sonya Fiddes (5mins)
Do you have a research question that you’ve exhausted ideas to find an answer to?
Here’s your chance to ask our Atmosphere community for their ideas!
Compute/storage resources:Heidi Nettelbeck (2mins)
Any experiment proposals for Q4/2026 (2 MSU allocation)?
→ See here for how to apply for Atmosphere WG Resources.
See Ben’s video: detailed instructions on working with Git delivered to the Land Surface community
Sonya Fiddes (5mins)
!! Attention ACCESS-rAM3 users