Minutes

Date: 14th February 2017
Attendees:

  • Marshall Ward (NCI, Chair)
  • Aidan Heerdegen, Scott Wales (ARCCSS)
  • Nicholas Hannah (ARCCSS/Double Precision)
  • Justin Freeman and Mirko Velic (BoM)
  • Russ Fiedler and Matt Chamberlain (CSIRO Hobart)
  • Peter Dobrohotoff (CSIRO Aspendale)

COSIMA Models

  • Nic is working on a COSIMA configuration with 1/10th degree ocean. Currently setting up all the files for a coupled ice/ocean. Using the existing ARCCSS 1/10th degree MOM5 ocean, but there is no 1/10th degree CICE. Have not previously coupled 1/10th MOM5 with OASIS. Plan is to use JRA-55 forcing.
  • OASIS won’t work as it has in the past, creating remapping weights and regridding forcings on to a 1/10th grid. Too slow. Currently takes 2-3 hours for the 0.25 deg grid. They use SCRIP for regridding, which has limitations: uniprocessor, conservative remapping not accurate in tripolar, Not quantified. Not too bad for 1/0.25 deg.
  • New method is to use ESMF. Doesn’t do 2nd order conservative remapping. First order conservative ok for now. Maybe revisit. Nic has set up test and evaluation cases to compare SCRIP and ESMF.
  • OASIS isn’t that great at regridding/remapping. If we’re using another tool for remapping, what is OASIS doing for us? Nic has written an OASIS replacement: TANGO. Simple and basic as possible. Uses ESMF. Two step process: generate regridding weights, and then distribute fields. Might be faster than OASIS, but performance isn’t a big issue for this.
  • Nic is writing a model configuration development toolchain? Supports different models. Documented here.
  • Justin agreed that OASIS is poorly designed, difficult to work with and not well liked. Suggestions to replace it have met with resistance from BoM. Might be able to push something under the TWG umbrella.
  • Aidan unhappy with MATM. Code has been changed ad-hoc to support new forcing datasets. Nic is happy to rewrite MATM it if Andy Hogg wants to. TANGO supports python/fortran/C++. Maybe re-write MATM in python? Not performance critical. Aidan not a fan of introducing a new dependency on python.
  • Aidan: working on ACCESS-OM2-025+JRA55. Problems with generating iced restart files.
  • Marshall: Working on CM2 with Peter’s help. ROSE suite needs some work, but in a reasonable state. Just profiling. Slight bug in OASIS restart file generation. Model would hang occasionally. Just a random hang. Due to a bug in MOM that Marshall had fixed. Source code had been reverted to a version that was not patched. Dave Bi had earlier described a bug that might be the same one?
  • Marshall has Profiler working in all 3 sub models. Some prelim numbers.
  • Need to update MOM source inside CM2. Use main trunk version and see what blows up. Marshall and Peter to work offline on getting their version up to date.
  • Do we need ACCESS branch on MOM repo? Definitely want everyone on the same repo as there are issues with some people using out of data code. Can we have more rigorous tagging of bug fixes for example? Which would allow bug-fixes to be incorporated in other versions. Nic thought that now we have better communication this may not such a problem?

Updates

  • Peter is working on ACCESS-CM2 for CMIP6. Currently focussing on global atmosphere. MetOffice are atmosphere only, and incorporate into their coupled model. GA7.1 is next target for ACCESS-CM2. Not currently with CABLE. Prelim testing with GA7.1. PI will wait for UM10.6 for correct aerosol coding. Martin is focussing on 10.6. Won’t have a version of CM2 with 10.6 for a while. CABLE group working with 10.5, and always difficulty with incorporating CABLE in UM versions. CSIRO still doing present day in 10.3.
  • Russ found a resolution error when packing data that ended up destroying a 20 month assimilation run. Will be a complete spin up when restarted
  • Justin has been doing a lot of interpolation. Puddles natural neighbour library. Been using it a lot. Very flexible and nice library
  • Matt has provided WOMBAT code to Paul Spence so he can recompile with new libraries and with flags appropriate for new broadwell hardware on raijin.
  • Since shutdown Matt has also recompiled. Asks for 850 cpus, 6-7 hours / year. When processor count > 1.5K crashes too often.
  • Marshall: NCI trouble shooted 1.8.4 problems. MPI reduction operations no longer work 1.8.4.
  • Marshall: openmpi 2.0 is slower than 1.10.2.
  • Aidan reiterated: don’t use -03 with intel MPI.
  • Justin: BoM internal meeting regarding COSIMA project. All signed off. Developments over 1-2 year timeframe. Wavewatch 3 coupled into COSIMA code. Stefan and Mirko will be looking at that. Would like some feedback from TWG about assessing it, and getting back to the community. MOM+wavewatch coupled initially as a technical demo. Wavewatch 3 will be part of COSIMA. GFDL is interested in Wavewatch. Stephen Griffies was curious. People have coupled wave watch with MOM in past, so know it is possible. Maybe OASIS-MCT, or OASIS3. These were climate scale runs. Mark Hannah’s postdoc did this work.
  • Marshall: about github source for MOM under Breakaway Labs. Only custodian is Nic. Need some shared ownership of these codes? Move to GFDL? Justin: as an organisation BoM will look at the code more favourably if it is sitting under GFDL.

Actions

New:

  • Marshall will be away, Aidan to organise next meeting.
  • Update MOM source inside CM2 (Marshall).
  • Nic to present MATM code re-write proposal to TWG for feedback before sign-off. Will then be presented to Andy Hogg for approval.

Existing:

  • Add Peter’s CICE5.1 config to OceansAus github repo (Nic and Peter)
  • Port MOM5 build system to cmake (Aidan)
  • Push updated MATM code with JRA-55 support to OceansAus github (Aidan)
  • Get licensing for MOM5 input files (Marshall)
  • Work on hosting MOM5 input files on NCI THREDDS server (Marshall, Aidan)
  • Nic create a discussion document (on COSIMA?) to document current approaches and strategies for future
  • Move FMS to submodule of MOM5 github repo (Marshall). Liase with Nic on implementation?
  • Test Nic’s access-om model config on OceansAus (All)
  • Work up test cases to cover the nudging code (Justin, Mirko) and supply them to Nic.
  • Move to CICE5 on OceansAus repo (Nic).
  • Add new test cases to Jenkins test suite (Nic).
  • Aidan to provide Matt with location of tenth model test data. Check if capturing all the diagnostics Matt might be interested in.
  • Matt to provide Marshall with some test cases for the Xeon Phi test cases, maybe 1 deg configurations.