Meeting minutes (15/07/2025)
Participants:
@MartinDix
@Aidan
@anton
@spencerwong
@manodeep
@paulleopardi
@RachelLaw
@rbeucher
@tiloz
@alexnorton
@jemmajeffree
@dougiesquire
@dhb599
@inh599
@harshula
CICE5:
@anton has run ~130 years of a 4xCO2 run with a CICE5 config. Results for SAT and TOA radiation are nearly identical compared to the AprilSpinup 4XCO2 run. Climate sensitivity is ~3.357 K for the AprilSpinup configuration and 3.290 K for the CICE5 run, and the difference is possibly within sampling noise.
Unclear on when to make the swap to CICE5. Masking changes will require a change to add_lprec, however potential updates to the UM will change this again. Should the swap be done at the same time as the UM changes and the change to oneAPI?
@Aidan in favour of swapping to CICE5 sooner rather than later, as it reduces the problem space.
OneAPI
@manodeep: The oneAPI has reached performance parity with the classic compilers. Results are not bit for bit identical, which is to be expected. We are now ready to do long runs to evaluate the science impacts of the change.
Cable: Australian PFTs
@inh599 has met with the Hawkesbury Institute at UWS who will be helping with parameter values. Some work is needed on this.
On the code side, @Jhan has found that runs which shuffle the indexes and should be bitwise identical are not. This seems to trigger differences in random places such as over the ocean, even though the code changes should only effect land.
@MartinDix to follow up with @Jhan, and suggests a memory overwrite could be happening somewhere.
Ambition is to finalise the Australian PFT work before the proper control run.
@RachelLaw: Aside from the Australian PFTs, we also want to change the vegetation distribution. @alexnorton is working on this. Additionally, there are problems in the CO2 seasonality especially at high latitudes, suggesting problems with leaf respiration that need to be chased down.
Cable: Library
@inh599 notes that work on cable as a library is still ongoing. @lachlanswhyborn is investigating bit reproducibility problems. Simultaneous developments on Cable main make it complicated to coordinate this work.
1pct CO2 configuration
A 1pct CO2 configuration is now available here, which @tiloz is testing. Temperature and CO2 are going up as expected.
It would be useful to add a convenient way of checking the gas concentrations that the model actually sees. Currently it’s difficult to confirm whether config changes are being picked up by the model.
Ancillary generation
@paulleopardi will set up a new branch on the ESM1.6 configs repository to test out generating forcings for the Historical configuration.
CMIP7 data request
@rbeucher has read through the CMIP7 data request and produced a spreadsheet of the requested variables, and their current status in ESM1.6. Please look over the spreadsheet (linked here )and add comments.
Fast track timeline
@Tilo notes that the fast track deadline is end of 2026. As we have a relatively fast model, and various configurations in runnable states, that allows us some more time to finalise the code. However we don’t want to drag it out for too long.
NetCDF conversion failures
netCDF conversion failures have been encountered by everyone running the model. @jo-basevi is investigating the causes and will submit an nci help request. @spencerwong has started a forum topic here to collect reports of the failures. Please add a comment with details of any failures you encounter. Reports close to the time of the crash would be especially useful.