Version 3 (modified by emalod, 4 months ago) (diff)

Name and subject of the action

Last edition: 06/08/20 15:49:00 by emalod

The PI is responsible to closely follow the progress of the action, and especially to contact NEMO project manager if the delay on preview (or review) are longer than the 2 weeks expected.

  1. Summary
  2. Preview
  3. Tests
  4. Review


Action OASIS coupling interface between TOP and NEMO
PI(S) E. Maisonnave
Digest We propose to shape the existing ocean/sea-ice interface to an ocean/biogeochemistry coupling, to make possible the computing of TOP/Pisces equations (Aumont et al. 2015) in a separate executable and its coupling to the rest of the NEMO model. This modularity is supposed to enhance the overall computing performances by allowing (i) to reduce the TOP/Pisces module horizontal resolution and (ii) to choose the best suited parallel decomposition for both components. Regardless to result modifications that have to be evaluated, computation of the two modules can be performed concurrently, reducing time to solution even more. The OASIS coupling library (Craig at al., 2017), basis of the existing ocean/sea-ice interface, will ensure the efficient (parallel) communication of 3D fields, the easy switch between sequential and concurrent modes and, possibly, the coupling field interpolation.
Dependencies Status of the ocean-BGC interface with AGRIF
Branch source:/NEMO/branches/{YEAR}/dev_r{REV}_{ACTION_NAME}
Previewer(s) Names
Reviewer(s) Names
Ticket #2150


Describe the goal of development and the methodology,
add reference documents or publications if relevant.


Describe flow chart of the changes in the code.
List the Fortran modules and subroutines to be created/edited/deleted.
Detailed list of new variables to be defined (including namelists),
give for each the chosen name and description wrt coding rules.

Documentation updates

Using previous parts, define the main changes to be done in the NEMO literature (manuals, guide, web pages, …).


Since the preview step must be completed before the PI starts the coding, the previewer(s) answers are expected to be completed within the two weeks after the PI has sent the request to the previewer(s).
Then an iterative process should take place between PI and previewer(s) in order to find a consensus

Possible bottlenecks:

  • the methodology
  • the flowchart and list of routines to be changed
  • the new list of variables wrt coding rules
  • the summary of updates in literature

Once an agreement has been reached, preview is ended and the PI can start the development into his branch.


Once the development is done, the PI should complete the tests section below and after ask the reviewers to start their review.

This part should contain the detailed results of SETTE tests (restartability and reproducibility for each of the reference configuration) and detailed results of restartability and reproducibility when the option is activated on specified configurations used for this test

Regular checks:

  • Can this change be shown to produce expected impact (option activated)?
  • Can this change be shown to have a null impact (option not activated)?
  • Results of the required bit comparability tests been run: are there no differences when activating the development?
  • If some differences appear, is reason for the change valid/understood?
  • If some differences appear, is the impact as expected on model configurations?
  • Is this change expected to preserve all diagnostics?
  • If no, is reason for the change valid/understood?
  • Are there significant changes in run time/memory?

  • Test case name: CPL_ORCA2_PISCES
  • Test case functionality: The test must ensure that ocean and BGC can be compiled seperately, linked with OASIS and can run concurrently
  • Test case setup : Based on ORCA2 grid, need OASIS
  • Test case verification value: Correct SST after a one month long simulation
  • Status of the test case as for now : not defined yet. Status of the official ocean-BGC interface must be clarified first


A successful review is needed to schedule the merge of this development into the future NEMO release during next Merge Party (usually in November).


  • Is the proposed methodology now implemented?
  • Are the code changes in agreement with the flowchart defined at preview step?
  • Are the code changes in agreement with list of routines and variables as proposed at preview step?
    If, not, are the discrepancies acceptable?
  • Is the in-line documentation accurate and sufficient?
  • Do the code changes comply with NEMO coding standards?
  • Is the development documented with sufficient details for others to understand the impact of the change?
  • Is the project literature (manual, guide, web, …) now updated or completed following the proposed summary in preview section?


Is the review fully successful? If not, please indicate what is still missing

Once review is successful, the development must be scheduled for merge during next Merge Party Meeting.