Version 2 (modified by techene, 3 months ago) (diff)

Name and subject of the action

Last edition: 07/30/20 10:53:53 by techene

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 rearangemnt of the pressure gradient according to A19 from NEMO book 4.0.1
PI(S) Sibylle & Gurvan
Digest In accordance with NEMO documentation, using using the density anomaly in dynhpg routines avoid computing a surface presure gradient that is removed afterwards
Dependencies If any
Branch source:/NEMO/branches/2020/dev_r13333_techene_gm_HPG_SPG
Previewer(s) Names
Reviewer(s) Names
Ticket #2506


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

Current implementation of the pressure gradient… blablabla… We modify the implementation of the pressure gradient according to A19 from NEMO book 4.0.1 : in dynhpg routines we compute the specific pressure gradient with the density anomaly : when possible we merely remove the znad, otherwise we remove explicitely the surface pressure gradient (dynhpg_prj, dynhpg_djc). in dynspg routines we compute the surface pressure gradient with constant density systematically

Note that using a density anomaly only in dynhpg_isf, requires also changes in isfload and isfstp.


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.

Index: src/OCE/DYN/dynspg_exp.F90 compute the surface pressure gradient with constant density systematically

Index: src/OCE/oce.F90 Index: src/OCE/DYN/dynspg.F90 Index: src/OCE/DYN/dynspg_ts.F90 formatting and some optimisation

Index: src/OCE/DYN/dynhpg.F90 we compute the specific pressure gradient with the density anomaly dynhpg_zco dynhpg_zps dynhpg_sco dynhpg_djc dynhpg_prj dynhpg_isf

Index: src/OCE/ISF/isf_oce.F90 Index: src/OCE/ISF/isfload.F90 Index: src/OCE/ISF/isfstp.F90

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?

GYRE_PISCES for zco, sco, prj ISOMIP for isf

Because we change the arrangement of adding and subtractig the "surface pressure gradient" we do not expect to have the same results as before.


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.