CSIRO - ACCESS-NRI standup minutes

CMIP7 CMIP7 development
60

Meeting minutes (21/10/2025)

Participants: @anton @inh599 @MartinDix @sofarrell @tiloz @adfraser @clairecarouge @manodeep @RachelLaw @Jhan @cbull

Chair: @clairecarouge

Minutes: @cbull

Claire: Perhaps a small attendance due to eResearch?

Confusion of water flux signs in cice/um

Anton: Been looking at evaporation diagnostics in cice/um (surface_snow_and_ice_sublimation_flux: ['fld_s03i298']). In both cases, they are not sign definite. Martin thinks it might include dew. Ian suggested tracking back to look is it evaporation or is it flux of water into/out the atmosphere (which allows both signs), be careful about phases too! Ian: thinking about surface_snow_and_ice_sublimation_flux, it could be: snow pack → atmosphere or depositon of frozen ice crystals onto snow pack (i.e. allowing both signs). In general (Ian) most of the fluxes in these context can be either sign.

Martin: note esm1.5 had sublimation wrong (in terms of units Ian)

spin-up updates: which experiment to choose?

Update post

Ian: year 30 of spin up experiment B has done something strange.

Tilo: have you considered re-running? Ian: yes, it’s possible, we’d need to re-run year 20-30 due to restart file availability. Tilo: would like us to re-consider keeping more restarts in the future. Jhan/Anton: it’s possible to change this in the config.yaml as one of the runtime options. Tilo: yes, would be helpful with future science applications, probably less important for the current run but helpful in the future (Tilo will consider opening an issue). FYI: the model is restart reproducible but not reproducible across different restart boundaries..

Test B appears to be more stable. Claire: do we need longer? Do we want to make a decision? More analysis of the ocean output? Siobhan: been looking at September A/C, both are looking at least 1 degree cooler in deep ocean . Martin: did some hovmollers, showing warmer southern ocean/cooler north atlantic (80-100 variability Labrador and Greenland sea), once the albedo change is switched on pacific doesn’t yet have an emerging signal but that would have expected as timescales there are 1500-2000 years. Next up is to look at September B but expecting it to look worse. Similarly for October across all runs. Siobhan would be curious about what’s happening with BGC (no one on the call). Rachel: would we expect all of them to eventually equilibrate at the same point? Siobhan: not sure at this point or ready to choose at this point.

CICE updates

@anton has been working on CICE diagnostics but he’s not sure of the deadline? @sofarrell has gone through the output and the code and it’s looking okay. @anton still wants to fix temperature, @sofarrell has looked into this from BL99 and mushy but is unsure how to apply similar fixes to zero layer model.

Rachel: on timing. We’re thinking early November we need to switch across to an “official” PI control and that would give us ~500 years. Tilo: that assumes all the other things are finalised (CABLE as a library, data request etc.)

Planned updates before the official pi control

@clairecarouge suggested a summary of required changes would be helpful, first try at a list:

We have <2 weeks to do this!

Re: next week’s standup. Next week people have some training/NESP commitments, we can move the standup if that’s useful? Just let @clairecarouge know.

@RachelLaw @clairecarouge @cbull are meeting at 3pm today to talk docs, all welcome. Get in touch with @cbull for an invite.