Technical Working Group Meeting, September 2016


Date: 6th September 2016

  • Marshall Ward (NCI, Chair)
  • Aidan Heerdegen (ARCCSS)
  • Justin Freeman and Mirko Velic (BoM)
  • Russ Fiedler and Matt Chamberlain (CSIRO Hobart)
  • Peter Dobrohotoff (CSIRO Aspendale)

General Discussion

  • Aidan described latest tenth model comparison runs, between GFDL50 and KDS75. Models are running well at an ocean time step of 450s, with excellent throughput on raijin. At 600s there is an instability related to a topographic feature off the northern tip of Severny Island. Some modification of the topography is required. Matt might be interested in looking at heat uptake and transport between the models.
  • Matt looking at surface parameterisations. Bulk formula etc. They have some warm biases that seem to be due to the choice of some of these parameters. Looking to optimise parameters to fix this.
  • Peter is working on ACCESS-CM2.. Working on UM 10.* model. Running Jules currently, but will run CABLE. Have run UM8.5/GA6 200+ years. Confusingly was also called ACCESS-CM2. 350 yrs on 0.25 ocean on GA6. All version 10.* versions are using the rose+cylc run architecture.

Model release strategy

  • Need MOM releases tagged.
  • Marshall and Aidan in favour of MOM having a release strategy (slightly separate issue).
  • Justin felt that the COSIMA model is MOM+CICE+OASIS. Don’t want to tag MOM with COSIMA release names.
  • Can use a sub-module approach, bring in specific model revisions.
  • When available, Justin would like Nic’s latest model definition repo to be communicated to the TWG.

New NCI hardware test

  • Marshall has done some very preliminary testing of MOM with a Knights Landing test cluster (~4k cores, 64 core / node Xeon Phi, 92GB/node). 1.3GHz cores. Faster interconnect (EDR v FDR). Supports AVX512 instruction set, so potentially double the number of floats/clock cycle. These are also lower power and cheaper, so could get many more cores than a traditional CPU architecture.
  • MOM is running, and it was very easy to do. Raijin binaries run fine, as does MPI.
  • Old binaries work fine. Ran 2.4x slower than raijin. As you would expect from clock speed alone.
  • Only ran 960 cores.
  • AVX512 enabled binary throws floating point errors a lot.


  • 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.
  • Marshall and Aidan to look at COSIMA model release — liase with Nic Hannah.

First meeting of the technical working group


Date: 2nd August 2016

  • Marshall Ward (NCI, Chair)
  • Aidan Heerdegen (ARCCSS)
  • Nic Hannah (ARCCSS/Breakaway Labs)
  • Justin Freeman (BoM)
  • Russ Fiedler and Matt Chamberlain (CSIRO Hobart)

Agreed to have monthly videoconference meetings.

COSIMA model definitions on website

  • Who is the audience? Agreed should pitch it at novice researcher/student with no links to existing community
  • Should start by using ourselves as the audience, define them for our use and expand from there
  • First test case should be the ACCESS-OM-025 (Quarter degree MOM+CICE+OASIS-mct)
  • CICE is currently housed on CWS github repo
  • Agreed we need consolidated location for model code. Nic suggested a git repo pulling in model components using submodules. This makes it clean to install and allows for control of versions via explicit commits or tags
  • COSIMA name is taken on github, so agreed to use existing OceansAus group
  • Minimal technical detail on website, instead point to github repo

Input data

  • Data store for model input files – decided to use the ua8 Ramadda location which is currently used for MOM5 test cases
  • Need data versioning


  • Need example outputs, and timings. Direct users to run the model and compare their outputs and timings to those supplied to verify model integrity and performance
  • Need continuous integration to test against these outputs. Nic currently running a dozen test cases on a Jenkins server for MOM5. Can add these tests too.
  • Essential to allow upgrading of model components with confidence they have not affected model integrity and performance.


  • Desirable to also have related tools and utilities on the OceansAus github site
  • Concerns that the site collect crufty tools, so make some standard for what constitutes a repo: utility, support and documentation?

Model Support

  • How do we support these models? Decided the existing MOM mailing list would suffice for general user questions. Stephen Griffies has been interested in supporting a MOM-CICE configuration. Also github issues can be used for specific code issues.

Mission Statement

  • Desirable to have a general mission statement about what the aims of the TWG
  • Any additional invitees? Perhaps Mirko from the BoM? Open invitation to anyone who wants to attend and contribute

General technical discussion

  • Aidan described progress with improving vertical grid in MOM-SIS 0.1 deg config
  • Justin working on making his real time flythrough data-vis software available on raijin, Maybe use Russ’ BRAN2015 reanalysis dataset with recent El Nino
  • Matt is adding sea-ice to the OFAM grid and tuning parameters to reduce SST biases. Turning off neutral physics helped.
  • Ben Evans wants a WOMBAT test case, perhaps use the 0.25 deg runs Matt did with Paul Spence?
  • Marshall has updated FMS and he and Nic have used Jenkins testing to find and fix bugs. Close to being added to master branch of MOM5

COSIMA website

  • A lot of enthusiasm for contributing blog posts to website from technical perspective.


  • Aidan to add Nic to OceansAus group
  • Nic to create initial ACCESS-OM-025 repo with submodules for MOM5/CICE/OASIS-mct
  • Justin volunteered to test out initial model config as “new user”
  • Marshall to write draft mission statement