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  1. Summary
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  3. Tests
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Action OASIS_TESTCASE : create a test case for coupling with OASIS
PI(S) Claire Lévy
Digest Motivations and main tasks: create a simple testcase using OASIS to help building new coupled configurations
Dependencies OASIS
Branch source:NEMO/branches/2020/dev_r12565_VALID-11_clevy_OASIS_TESTCASE
Previewer(s) E. Maisonnave & Laure Coquart
Reviewer(s) E. Maisonnave & Laure Coquart
Ticket #2379


Create a simple testcase using OASIS to help building new coupled configurations.
Will use OASIS and a simplified fake atmosphere (TOY_ATM in OASIS wording.
May do more than only ocean-atmosphere coupling (to be discussed).
Useful as coupling demonstrator and for first level valisation of coupling with OASIS in future NEMO versions.


As for the test case defined in STEP1 (see below):

  • no changes in NEMO code
  • Changes in &namsbc_cpl namelist
  • Need to add the TOY_ATM software, as a simplified /fake atmosphere somewhere to be able tu run this test case

Documentation updates

Updates needed:


Error: Failed to load processor box
No macro or processor named 'box' found


STEP 1: Implement in the up-to-date version for 2020 the test case developed in 2018

Restarting from /ccc/work/cont003/gen7451/clevy/VALID_CPL_4.0/trunk/cfgs/CPL_TOYATM in irene computer, implment the CPL_TOYATM in the up-to-date NEMO version, as a test case (in trunk/tests).

CPL_TOYATM test case description:

  • Based on the ORCA2_ICE_PISCES reference configuration, activate coupling to a TOYATM (kindly offered by Eric M.) through OASIS
  • coupled fields (from &namsbc_cpl namelist):
&namsbc_cpl    !   coupled ocean/atmosphere model                       ("key_oasis3")
   nn_cplmodel   =     1   !  Maximum number of models to/from which NEMO is potentially sending/receiving data
   ln_usecplmask = .false. !  use a coupling mask file to merge data received from several models
   !                       !   -> file with the float variable called cplmask (jpi,jpj,nn_cplmodel)
   nn_cats_cpl   =     5   !  Number of sea ice categories over which coupling is to be carried out (if not 1)

   !             !        description       !  multiple  !    vector   !       vector         ! vector !
   !             !                          ! categories !  reference  !     orientation      ! grids  !
!***   send    ***
   sn_snd_temp   =   'weighted oce and ice' ,    'no'    ,     ''      ,         ''           ,   ''
!***  receive  ***

   sn_rcv_qsr    =   'conservative'         ,    'no'    ,     ''      ,         ''           ,   ''
   sn_rcv_qns    =   'oce and ice'          ,    'no'    ,     ''      ,         ''           ,   ''
   sn_rcv_emp    =   'conservative'         ,    'no'    ,     ''      ,         ''           ,   ''
  • The test cases needs OASIS and a simple TOYATM
  • Where should the TOYATM be installed? In the test case, in NEMO tools? elsewhere?
  • Validation of the test case remains to be defined more precisely (check OASIS output compared to ocean SST ?)

STEP 2: is this the final version of the expected test case?

  • Adding other couplings?
  • Checking sea-ice?

STEP 3: implement final test case

Implement the finalised test case as part of the usual validation testbed, and also in the github for NEMO test cases

Answer from reviewers is in the ticket #2379. For E. Maisonnave & L. Coquart, review is successful and development can start


This toy is able to validate a simplified OASIS based coupled configuration of NEMO in such a way that:

  • the OASIS library can be compiled on the targeted machine (OASIS libraries available in the OASIS directory)
  • the OASIS library can be linked with a coupled configuration of NEMO (the NEMO executable is available in the NEMO cfg directory) and an atmosphere toy model (executable available in the tools/TOYATM directory)
  • an MPI MPMD system (two executables at the same time) can be launched on the machine and a successful simulation can be achieved if :
  • a run.stat file is produced and includes 160 iterations:
nemo_iterations=wc -l run.stat | awk {'print $1'} | grep 160; [ -n "$nemo_iteration" ] && echo true
echo false
  • OASIS indicates a successful end of the run:
success=grep "SUCCESSFUL RUN" debug.root.0? | wc -l | grep 2; [ -n "$success" ] && echo true
echo false
  • the sea surface temperature (Tropical Pacific region) as seen by the toy atmosphere model is close to 300.20 K and the difference between the end and the beginning values doesn't exceed 0.5 K

This can be checked e.g. in the check file produced by the commands: ncks -h -v ATSSTSST -d nx,80,120 -d ny,0,10 ; ncwa -h -a nx,ny


Error: Failed to load processor box
No macro or processor named 'box' found



Error: Failed to load processor box
No macro or processor named 'box' found