CABLE4 planning: meeting notes

Land Surface CABLE
13

April 18th

Apologies: Ian, Tilo

Previous actions status

For discussion

Notes

  • No meeting April 25th (Anzac day)
  • @Juergen reported on email exchange with Peter B around LUH2 processing and @RachelLaw reported on email from @inh599 with relevant notes here.
  • Discussion of shrubs - continuum in woody vegetation, short to tall. Arbitrary to discriminate shrubs and tree. Mallee/short savannah could be sparse woodland. ESM currently using shrub but perhaps better not to use. POP treats shrub as woody and runs for shrub. Check how shrubs differ - just in parameters. vcmax. Vegetation height prescribed in ESM but would come out of POP. ESM has different treatment of shrubs when cleared. Also relevant - treatment of bare ground - can it have LAI or not if precip occurs etc. Likely different assumptions in POP and ESM1.5.
  • Trendy_v12 in repository. Preparing POP branch for ESM1.5 met forcing. Transparent inputs rather than hard-wired. User provide template for dataset. Inspect netcdf attributes. Pass reader day/year. Applying to met inputs in POP branch. Iterate on template design. Question about dealing with cases that have different variables available e.g. diffusive fraction. One input method but not too restrictive, just CF compliant. Deal with calendar variable. Performance of I/O. Current default will be day by day read - safe option. User instructions for chunking data? Not yet. Get working first. LPG-Guess experience is chunk size, compression, ordering of dimensions makes big difference. Documentation and guidelines for best practice will also be prepared.
  • Who/what/where - NESP context. ESM1.6 for Fast Track but not with CABLE4 - importance of work on understanding how to use LUH data.
  • Refactorisation discussion. Worth doing. Restructure of directories and code modularised in parts. Only logical way forward to do CABLE-POP refactorisation. @jhan started work on this. ‘Plumbing’ issues rather than science code changes. Radiation/albedo can take mostly from CABLE3. Canopy/soilsnow more work. NRI could help as time-consuming - and NRI happy to help. @clairecarouge to think about who.
  • CABLE4 needs 27-tiles. Running OK, almost no performance penalty. Need to check output.
  • Jhan to start on CASA in AM3. Rachel to help. CABLE3 in ESM1.5 rplant bug fix still needs to be addressed. Documented in trac tickets.
  • IAV of carbon fluxes with CABLE3 still needs understanding. Suggest AMIP runs with AM3, ESM1.5 and ESM1.5 with CABLE3 to check GPP.

Action

  • @jhan to package up refactorisation work and organise handover to ACCESS-NRI with @clairecarouge .
  • @Jhan and @RachelLaw to meet April 24th (Aspendale) to look at AM3/CASA and set up of AMIP tests for GPP. [and site-based output].