Technical Working Group Meeting, December 2016


Date: 13th December 2016

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


  • Justin met with Gary Brassington to discuss project goals (wrt MOM?)
  • What is ACCESS-OM repo in OceansAus, should BoM use it?
  • Need to sort out the input data hosting
  • Get KDS75 to Justin
  • Russ is looking at KDS75 layer. Considering a much shallower coastling in


  • Andy Hogg insists we must use CICE 5
  • Nic is working to update, but it is not a priority
  • Peter will pass to Nic, to host at OceansAus (Marshall volunteered to work on this during ACCESS-CM profiling)


  • Parallell NetCDF4 (pHDF5) implementation in MOM 5
  • Working, but performance is very slow (Since meeting: Performance is now comparable to MOM 5, other issues to sort out)
  • Vectorisation issues in MOM 5:
    1. 40×40 grid tiles too large to fit in L1, performance is mem bound (either higher cache or RAM)
    2. Small tiles (e.g. 6×6) fit in L1 but performance continues to be low
    3. gdb trace of asssembly shows frequent jumps outside of small loops constraining performance
  • Justin suggests long tiles in x-direction, Nic suggested 32-bit repr


  • Nic has implemented MOM 6 automated testing and bug tracking
  • Example tests: Output invariance to field transpose and rotations, esp. wrt arithmetic associativity



  • Get MOM01 KDS75 config to Justin (?)
  • Update MOM source inside CM2 (Marshall).


  • 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.