Version 8 (modified by cetlod, 10 years ago) (diff)

Last edited Timestamp?

Author : Christian Ethé

ticket : #842

Branch : 2011/dev_r2787_LOCEAN3_TRA_TRP


Merge of active and passive tracer advection/diffusion modules to avoid duplication of almost identical modules. Continuation of the work done in 2010

The merge has been done for transport routines, using a switch to avoid the suppression of T and S array at this time, See wiki:ticket/664_TRA_TRP?

Main tasks

(1) Merge dtatem-dtasal into dtatsd

In previous version of NEMO, the 3D field of T and S were used for (1) internal damping to levitus (key_tradmp) and (2) for sst and sss restoring. This was the reason why dta_tem and dta_sal where called at the beginning of step before the surface fluxes computation and the tra_dmp call. With the new surface module, the optional restoring to sst ans sss now uses another data file containing only the 2D temp and salinity data required for the sea surface restoring. The read of 3D field is now only required if the key_tradmp is defined (and in the initialisation, when starting from levitus). Therefore, the call to dta_tem and _sal can now be moved in tradmp module. Furthermore, we combine the two modules (dtatem & dtasal) into a single module ( dtatsd ) as they are almost identical.
Actions :

  • merge of dtatem.F90 & dtasal.F90 into dtatsd.F90
  • move the dta_tsd call from step.F90 to tradmp.F90
  • suppression of key_dtatem & key_dtasal and replace them by one namelist parameter ln_tsd_init
  • suppression of key_tradmp and replace it by a namelist parameter ln_tradmp


After the merge of TRA-TRP, we wanted to keep in the system the use of different transport scheme for active & passive tracers. But for lateral diffusion, it's not the case : the diffusive coefficient is only define in the namelist and it is the one which is used both for the active and passive tracers scheme.

Because of space varying of those coef - defining in the code by the use of statement function -

The idea is to multiply the existing coef defining in ldftra_substitute by a factor - rldf - which will be equal to

  • 1 for active tracers
  • rn_ahtrc0 / rn_aht0 ( the ratio between passive tracers and active tracers coef.)

In the code, we ensure that the 2 coef have the same sign ( < 0 for bilaplacian operator ; > 0 for laplacian operator )

#if defined key_traldf_c3d
!   'key_traldf_c3d' :                 aht: 3D coefficient
#       define   fsahtt(i,j,k)   rldf * ahtt(i,j,k)
#elif defined key_traldf_c2d
!   'key_traldf_c2d' :                 aht: 2D coefficient
#       define   fsahtt(i,j,k)   rldf * ahtt(i,j)
#elif defined key_traldf_c1d
!   'key_traldf_c1d' :                aht: 1D coefficient
#       define   fsahtt(i,j,k)   rldf * ahtt(k)
!   Default option :             aht: Constant coefficient
#      define   fsahtt(i,j,k)   rldf * aht0

(3) replace 3D T & S arrays by 4D array TS throughout the code

Actions :

  • replace in OPA_SRC subdirectories OBC/BDY/ASM/FLO
  • In the DYN
  • in AGRIF


Testing could consider (where appropriate) other configurations in addition to NVTK].

NVTK Tested'''YES/NO'''
Other model configurations'''YES/NO'''
Processor configurations tested[ Enter processor configs tested here ]
If adding new functionality please confirm that the
New code doesn't change results when it is switched off
and ''works'' when switched on

(Answering UNSURE is likely to generate further questions from reviewers.)

'Please add further summary details here'

  • Processor configurations tested
  • etc——

Bit Comparability

Does this change preserve answers in your tested standard configurations (to the last bit) ?'''YES/NO '''
Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended)'''YES/NO'''
Is this change expected to preserve answers in all possible model configurations?'''YES/NO'''
Is this change expected to preserve all diagnostics?
,,''Preserving answers in model runs does not necessarily imply preserved diagnostics. ''

If you answered '''NO''' to any of the above, please provide further details:

  • Which routine(s) are causing the difference?
  • Why the changes are not protected by a logical switch or new section-version
  • What is needed to achieve regression with the previous model release (e.g. a regression branch, hand-edits etc). If this is not possible, explain why not.
  • What do you expect to see occur in the test harness jobs?
  • Which diagnostics have you altered and why have they changed?Please add details here……..

System Changes

Does your change alter namelists?'''YES/NO '''
Does your change require a change in compiler options?'''YES/NO '''


&namdta_tem    !   surface boundary condition : sea surface restoring
!              !     file name                  ! frequency (hours) ! variable   ! time interpol. !  clim   !'yearly' or ! weights  ! rotation !
!              !                                !  (if <0  months)  !   name     !    (logical)   !  (T/F)  ! 'monthly'  ! filename ! pairing  !
  sn_tem       = 'data_1m_potential_temperature_nomask',  -1        , 'votemper' ,     .true.     , .true.  , 'yearly'   , ' '      , ' '
  cn_dir       = './'      !  root directory for the location of the runoff files 
&namdta_sal    !   surface boundary condition : sea surface restoring
!              !     file name                  ! frequency (hours) ! variable   ! time interpol. !  clim   ! 'yearly' or ! weights  ! rotation !
!              !                                !  (if <0  months)  !   name     !    (logical)   !  (T/F)  !  'monthly'  ! filename ! pairing  !
   sn_sal      =  'data_1m_salinity_nomask'     ,         -1        , 'vosaline' ,     .true.     , .true.  , 'yearly'    , ''       , ' '
   cn_dir      = './'      !  root directory for the location of the runoff files


&namtsd    !   data : Temperature  & Salinity     
!          ! file name ! frequency (hours)    ! variable ! time interp. ! clim  !'yearly' or ! weights  ! rotation !
!          !           !  (if <0  months)     !   name   !  (logical)   ! (T/F) ! 'monthly'  ! filename ! pairing  !
   sn_tem  = 'data_1m_potential_temperature_nomask', -1,'votemper',  .true.  , .true., 'yearly'   , ' '      , ' '
   sn_sal  = 'data_1m_salinity_nomask'             , -1,'vosaline',  .true.  , .true., 'yearly'   , ''       , ' '
   cn_dir        = './'     !  root directory for the location of the runoff files
   ln_tsd_init   = .true.   !  Initialisation of ocean T & S with T &S input data (T) or not (F)
   ln_tsd_tradmp = .true.   !  damping of ocean T & S toward T &S input data (T) or not (F)


''Please ''summarize'' any changes in runtime or memory use caused by this change……''

IPR issues

Has the code been wholly (100%) produced by NEMO developers staff working exclusively on NEMO?'''YES/ NO '''

If No:

  • Identify the collaboration agreement details
  • Ensure the code routine header is in accordance with the agreement, (Copyright/Redistribution? etc).Add further details here if required……….