Initializing T+S with a restart file

This section describes how to initialize the salinity and temperature fields with data from a restart file. This is useful for taking the stratification from a spin-up or nowcast run.

First, in the SalishSea.yaml file provide an initial conditions forcing link that points to the path of the directory that contains the restart file. For example, the restart file SalishSea_00069120_restart.nc is in /ocean/dlatorne/MEOPAR/SalishSea/results/spin-up/18oct25oct/, so the forcing section of the .yaml files should contain:

forcing:
  ...
  initial_strat:
    link to: /ocean/dlatorne/MEOPAR/SalishSea/results/spin-up/18oct25oct/
         ...

Next, modify the &namtsd section of namelist.domain so that NEMO reads in the restart file. For example:

&namtsd    !   data : Temperature  & Salinity
!-----------------------------------------------------------------------
!          ! file name                          ! freq (hr)  ! variable  !  time  !  clim  ! period  ! weights  ! rotation !
!          !                                    ! (<0 == mo) !   name    ! interp !  (T/F) !         ! filename ! pairing  !
sn_tem  = 'SalishSea_00069120_restart.nc',          -12,         'tb',     .false., .true.,  'yearly', '',        ''
sn_sal  = 'SalishSea_00069120_restart.nc',          -12,         'sb',     .false., .true.,  'yearly', '',        ''
cn_dir        = 'initial_strat/'  ! directory containing initial condition files
ln_tsd_init   = .true.            ! Initialisation of ocean T & S with T &S input data (T) or not (F)
ln_tsd_tradmp = .false.           ! damping of ocean T & S toward T &S input data (T) or not (F)
/

The file name must be modified to the restart file’s name. Additionally, since restart files have a different naming convention for the field variables, ensure that 'tb' and 'sb' are used for temperature and salinity in the variable name section.

Considerations

  • Bathymetry should be consistent between the restart file and the run you are initializing.

  • There may be issues of continuity between the restart T + S data and the boundary conditions at Juan de Fuca, depending on the date chosen for a restart.