Version 7 (modified by gm, 3 years ago) (diff)

ENHANCE-5_Gurvan — RK-3 time stepping


Action ENHANCE-5_Gurvan — RK-3 time stepping
PI(S) Gurvan Madec


Introduce an optional RK3 time-stepping scheme. The scheme will:

  1. be a valuable alternative to the current Modified Leap-Frog (MLF, Leclair and Madec OM2009) scheme,
  2. prepare the futur introduction of a compensated time-space scheme,
  3. allow AGRIF to be exactly conservative, and
  4. make much more easier to use time coarsening of TRC and OFF-line variable volume calculation

In practice the work is to :

  • add all time varying fields as argument of all DYN and TRA routines (as RK3 schemes uses the same tendency terms as the Leap-Frog scheme, but it calls them several times by time step)
  • introduce a stpRK3.F90 time-stepping module (which will contain a stp_RK3 routine)
  • move the existing Modified Leap-Frog time stepping (step.F90) in stpMLF.F90 module (containing stp routine renamed stp_MLF)
  • change the CALL to stp routine in memogcm.F90 by a CALL to either stp_MLF or stp_RK3 depending of namelist parameters
Dependencies no
Target 2017 merge party
Trac Ticket #1911
SVN branch dev_r7881_ENHANCE09_RK3
Previewer(s) Names
Reviewer(s) Names
Status To be developed

'.' => '/nemo/wiki/2017WP/ENHANCE-05_Gurvan-RK3'


This section should be completed before starting to develop the code, in order to find agreement on the method beforehand.



Reference manual and web pages updates

Updated on 11/29/2017 12:19:21 by gm

Once the PI has completed this section, he should send a mail to the previewer(s) asking them to preview the work within two weeks.


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 his request.
For each question, an iterative process should take place between PI and previewer(s) in order to reach a "YES" answer for each of the following questions.

Questions Answer Comment
Does the previewer agree with the proposed methodology?
Does the previewer agree with the proposed flowchart and list of routines to be changed?
Does the previewer agree with the proposed new list of variables, including agreement with coding rules?
Does the previewer agree with the proposed summary of updates in reference manual?
… … …

Updated on 08/09/2020 17:40:43 by anonymous

Once all "YES" have been reached, the PI can start the development into his development branch.


Once the development is done, the PI should complete this section below and ask the reviewers to start their review in the lower section.

Questions Answer Comment
Can this change be shown to produce expected impact? (if option activated)?
Can this change be shown to have a null impact? (if option not activated)
Detailed results of restartability and reproducibility when the option is activated. Please indicate the configuration used for this test
Detailed results of SETTE tests (restartability and reproducibility for each of the reference configuration)
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 !ticket describing in detail the impact this change will have 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?
… … …

Updated on 08/09/2020 17:40:43 by anonymous


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

Code changes and documentation

Question Answer Comment
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 !ticket of development documented with sufficient details for others to understand the impact of the change?
Are the reference manual tex files now updated following the proposed summary in preview section?
Is there a need for some documentation on the web pages (in addition to in-line and reference manual)?
If yes, please describe and ask PI. A yes answer must include all documentation available.
… … …

Review Summary

Is the review fully successful?

Updated on 08/09/2020 17:40:44 by anonymous

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