Version 1 (modified by cbricaud, 10 months ago) (diff)

Name and subject of the action

Last edition: 12/20/19 16:05:56 by cbricaud

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 Develop on multi-grid algorithm for passive tracer transport ( coarsening)
PI(S) Clément Bricaud
Digest Work on the design and starts the development
Dependencies If any
Branch source:/NEMO/branches/{YEAR}/dev_r{REV}_{ACTION_NAME}
Previewer(s) Names
Reviewer(s) Names
Ticket #XXXX


No actions are considered to make the preliminary development on AGRIF to make coarsening with AGRIF

In IMMERSE, a task has started to runs a coupled OCE+ICE+BGC with 2 seperate executable, coupled with OASIS

2 options are possible:

  • OPTION 1: OCE+ICE+BGC in a single executable ( =no OASIS); this the one already developed in NEMO 3.6

It can be improve by avoiding duplication of routines ( the rewriting of the code for the 2LTS can help), replace the "e3t_max_crs" by the former "facvol" )

It might work also with s-coordinates

They are probably others ways of improvment

  • OPTION 2 : OCE+ICE+BGC with 2 seperate executables, coupled with OASIS

In a first time, the coarsened variables can be computed by the algo developped in OPTION 1

and OASIS send the coarsened variables to the BGC component, instead of the HR variables

In a second time, the coarsened variables can be computed by OASIS

Here the work is to design and develop OPTION 1 and take of the compatibility with OPTION 2


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?


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.