Meeting minutes 11/11/2025
Chair @clairecarouge
Minutes @cbull
Participants: @cbull @anton @clairecarouge @MartinDix @sofarrell @inh599 @spencerwong @Jhan @Aidan @alexnorton @lachlanswhyborn @manodeep @paulleopardi @RachelLaw @rbeucher @tiloz @pearseb
Land and atmosphere build changes
Lachlan: build for version 2025.11.000 should be ready, in final review stage.
Manodeep: oasis3-mct change to upstream might come in after that release as need more time for testing.
sea ice changes
Anton: still confused about the snow on sea ice variables and how they want them averaged
Emailed the sea-ice mip people (Patricia Derepentigny) – no response. Also emailed someone from NCAR.
Martin: different to cmip6? Anton: don’t think it’s different.
BGC update – change in sinking rate
@pearseb. Now run for 150 years each of the sensitivity experiments. Will use CO2 flux as a benchmark. Who I send the parameter changes to? Response: @spencerwong. @pearseb by end of today/tomorrow.
@RachelLaw: perhaps we want to consider tacking Pearse’s run onto the end of the existing candidate? @tiloz part of the issue here is how long the sinking rate changes take to equilibrate. @pearseb ~200+ years. @tiloz : sounds like it’s worth considering then.
@tiloz. Having said that, whilst we’re still deliberating, still worth continuing the October B run.
@clairecarouge: who’s creating the combined restart? @pearseb hasn’t done this recently, but can look into it. @RachelLaw just fudge the date perhaps? @pearseb will likely have a chat to Spencer once he has a plan.
latest vegetation distribution
@RachelLaw: struggling to get a stable run with latest setup. Wondering what’s wrong with the restart file. @MartinDix is happy to have a look at that.
I think (!) these are the details from @RachelLaw
Martin - in this directory /scratch/p66/rml599/payu-tests/test-restart-nov10/restart410/atmosphere, restart_dump.astart.orig works, restart_dump.astart.new doesn’t work. The README gives the location of the file that I copied to restart_dump.astart.new.
@inh599 do we need to provide a number of active tiles? @MartinDix no, it will work that out at run time. @inh599 what about when the um reads the restart file? @MartinDix No, the restart file includes all files and the restart fraction.
@clairecarouge what is the status of the updated vegetation parameters tests? Do we want to include them in the configuration? @alexnorton: where did @Jhan get up to on that? @Jhan: been wondering where to take that.
@RachelLaw : we’ve changed one more of the c4 crop parameters (moving from a hardwired value). The test is really to make sure it’s stable (?). @Jhan and @alexnorton will follow up offline.
forcing update
all following up from @paulleopardi
- Nitrogen forcing for pre-industrial control
- working on the ozone forcing (was trying to make do without the temperature information but that has since come through)
- has a follow up meeting today
Misc
- @manodeep would appreciate an amip configuration for testing UM7 compiler flags - easier to check for bitwise reproducibility and performance in the amip model (rather than a coupled model).