outputs of zeros, and only zeros, but no error messages

[SophieWard]

Hello again,

My ROMS application is finally running; however, all outputs are zero. I'm forcing the application with tides and have set up initial and bounary files too. To the best of my knowledge, all of these files have reasonable inputs and each variable has values(!), but my outputs are telling me otherwise. There is clearly some confliction somewhere but I've not been able to find examples of other users having similar outputs (i.e. nothing) without errors in tow.

Some information on my set-up:

Code: Select all

Physical Parameters, Grid: 01
 =============================

       5400  ntimes          Number of timesteps for 3-D equations.
     40.000  dt              Timestep size (s) for 3-D equations.
         10  ndtfast         Number of timesteps for 2-D equations between
                               each 3D timestep.
          1  ERstr           Starting ensemble/perturbation run number.
          1  ERend           Ending ensemble/perturbation run number.
          0  nrrec           Number of restart records to read from disk.
          F  LcycleRST       Switch to recycle time-records in restart file.
      10800  nRST            Number of timesteps between the writing of data
                               into restart fields.
         90  ninfo           Number of timesteps between print of information
                               to standard output.
         15  nSTA            Number of timesteps between the writing of data
                               the stations file.
          T  ldefout         Switch to create a new output NetCDF file(s).
         90  nHIS            Number of timesteps between the writing fields
                               into history file.
 1.0000E+01  nl_tnu2(01)     NLM Horizontal, harmonic mixing coefficient
                               (m2/s) for tracer 01: temp
 1.0000E+01  nl_tnu2(02)     NLM Horizontal, harmonic mixing coefficient
                               (m2/s) for tracer 02: salt
 5.0000E+00  nl_visc2        NLM Horizontal, harmonic mixing coefficient
                               (m2/s) for momentum.
 1.0000E-06  Akt_bak(01)     Background vertical mixing coefficient (m2/s)
                               for tracer 01: temp
 1.0000E-06  Akt_bak(02)     Background vertical mixing coefficient (m2/s)
                               for tracer 02: salt
 1.0000E-05  Akv_bak         Background vertical mixing coefficient (m2/s)
                               for momentum.
 5.0000E-06  Akk_bak         Background vertical mixing coefficient (m2/s)
                               for turbulent energy.
 5.0000E-06  Akp_bak         Background vertical mixing coefficient (m2/s)
                               for turbulent generic statistical field.

    3.000  gls_p           GLS stability exponent.
      1.500  gls_m           GLS turbulent kinetic energy exponent.
     -1.000  gls_n           GLS turbulent length scale exponent.
 7.6000E-06  gls_Kmin        GLS minimum value of turbulent kinetic energy.
 1.0000E-12  gls_Pmin        GLS minimum value of dissipation.
 5.4770E-01  gls_cmu0        GLS stability coefficient.
 1.4400E+00  gls_c1          GLS shear production coefficient.
 1.9200E+00  gls_c2          GLS dissipation coefficient.
-4.0000E-01  gls_c3m         GLS stable buoyancy production coefficient.
 1.0000E+00  gls_c3p         GLS unstable buoyancy production coefficient.
 1.0000E+00  gls_sigk        GLS constant Schmidt number for TKE.
 1.3000E+00  gls_sigp        GLS constant Schmidt number for PSI.
   1400.000  charnok_alpha   Charnok factor for Zos calculation.
      0.500  zos_hsig_alpha  Factor for Zos calculation using Hsig(Awave).
      0.250  sz_alpha        Factor for Wave dissipation surface tke flux .
    100.000  crgban_cw       Factor for Craig/Banner surface tke flux.
 3.0000E-04  rdrg            Linear bottom drag coefficient (m/s).
 3.0000E-03  rdrg2           Quadratic bottom drag coefficient.
 2.0000E-02  Zob             Bottom roughness (m).
 2.0000E-02  Zos             Surface roughness (m).
          1  Vtransform      S-coordinate transformation equation.
          1  Vstretching     S-coordinate stretching function.
 3.0000E+00  theta_s         S-coordinate surface control parameter.
 1.0000E+00  theta_b         S-coordinate bottom  control parameter.
      2.000  Tcline          S-coordinate surface/bottom layer width (m) used
                               in vertical coordinate stretching.
1025.000  rho0            Mean density (kg/m3) for Boussinesq approximation.
      1.000  dstart          Time-stamp assigned to model initialization (days).
      1.000  tide_start      Reference time origin for tidal forcing (days).
       0.00  time_ref        Reference time for units attribute (yyyymmdd.dd)
 0.0000E+00  Tnudg(01)       Nudging/relaxation time scale (days)
                               for tracer 01: temp
 0.0000E+00  Tnudg(02)       Nudging/relaxation time scale (days)
                               for tracer 02: salt
 0.0000E+00  Znudg           Nudging/relaxation time scale (days)
                               for free-surface.
 0.0000E+00  M2nudg          Nudging/relaxation time scale (days)
                               for 2D momentum.
 0.0000E+00  M3nudg          Nudging/relaxation time scale (days)
                               for 3D momentum.
 0.0000E+00  obcfac          Factor between passive and active
                               open boundary conditions.
          F  VolCons(1)      NLM western  edge boundary volume conservation.
          F  VolCons(2)      NLM southern edge boundary volume conservation.
          F  VolCons(3)      NLM eastern  edge boundary volume conservation.
          F  VolCons(4)      NLM northern edge boundary volume conservation.
     14.000  T0              Background potential temperature (C) constant.
     33.000  S0              Background salinity (PSU) constant.
   1025.000  R0              Background density (kg/m3) used in linear Equation
                               of State.
 1.7000E-04  Tcoef           Thermal expansion coefficient (1/Celsius).
 0.0000E+00  Scoef           Saline contraction coefficient (1/PSU).
      1.000  gamma2          Slipperiness variable: free-slip (1.0) or
                                                    no-slip (-1.0).
          T  Hout(idFsur)    Write out free-surface.
          T  Hout(idUbar)    Write out 2D U-momentum component.
          T  Hout(idVbar)    Write out 2D V-momentum component.
          T  Hout(idUvel)    Write out 3D U-momentum component.
          T  Hout(idVvel)    Write out 3D V-momentum component.
          T  Hout(idTvar)    Write out tracer 01: temp
          T  Hout(idTvar)    Write out tracer 02: salt
          T  Hout(idUbms)    Write out bottom U-momentum stress.
          T  Hout(idVbms)    Write out bottom V-momentum stress.

Output/Input Files:

             Output Restart File:  output/ocean_rst.nc
             Output History File:  output/ocean_his.nc
            Output Stations File:  output/ocean_sta.nc
                 Input Grid File:  roms_grid_nwess00.nc
    Input Nonlinear Initial File:  nwess_ini_0.nc
             Input Boundary File:  ocean_bry.nc
          Station positions File:  stations.in

...

 Lateral Boundary Conditions: NLM
 ============================

 Variable               Grid    West Edge   South Edge  East Edge   North Edge
 ---------              ----    ----------  ----------  ----------  ----------

 zeta                     1     Chapman     Chapman     Chapman     Chapman

 ubar                     1     Flather     Flather     Flather     Flather

 vbar                     1     Flather     Flather     Flather     Flather

 u                        1     Rad + Nud   Rad + Nud   Rad + Nud   Rad + Nud

 v                        1     Rad + Nud   Rad + Nud   Rad + Nud   Rad + Nud

 temp                     1     Rad + Nud   Rad + Nud   Rad + Nud   Rad + Nud

 salt                     1     Rad + Nud   Rad + Nud   Rad + Nud   Rad + Nud

 tke                      1     Gradient    Gradient    Gradient    Gradient


Activated C-preprocessing Options:

 NWESS_0             NWESS_O
 ADD_FSOBC           Adding tidal elevation to processed OBC data.
 ADD_M2OBC           Adding tidal currents to processed OBC data.
 ANA_BSFLUX          Analytical kinematic bottom salinity flux.
 ANA_BTFLUX          Analytical kinematic bottom temperature flux.
 ANA_SMFLUX          Analytical kinematic surface momentum flux.
 ANA_SSFLUX          Analytical kinematic surface salinity flux.
 ANA_STFLUX          Analytical kinematic surface temperature flux.
 ASSUMED_SHAPE       Using assumed-shape arrays.
 DJ_GRADPS           Parabolic Splines density Jacobian (Shchepetkin, 2002).
 DOUBLE_PRECISION    Double precision arithmetic.
 GLS_MIXING          Generic Length-Scale turbulence closure.
 MASKING             Land/Sea masking.
 MIX_S_TS            Mixing of tracers along constant S-surfaces.
 MIX_S_UV            Mixing of momentum along constant S-surfaces.
 MPI                 MPI distributed-memory configuration.
 NONLINEAR           Nonlinear Model.
 !NONLIN_EOS         Linear Equation of State for seawater.
 POWER_LAW           Power-law shape time-averaging barotropic filter.
 PROFILE             Time profiling activated .
 K_GSCHEME           Third-order upstream advection of TKE fields.
 RAMP_TIDES          Ramping tidal forcing for one day.
 !RST_SINGLE         Double precision fields in restart NetCDF file.
 SALINITY            Using salinity.
 SOLVE3D             Solving 3D Primitive Equations.
 SPHERICAL           Spherical grid configuration.
 SSH_TIDES           Add tidal elevation to SSH climatology.
 STATIONS            Writing out station data.
 TS_U3HADVECTION     Third-order upstream horizontal advection of tracers.
 TS_A4VADVECTION     Fourth-order Akima vertical advection of tracers.
 TS_DIF2             Harmonic mixing of tracers.
 UV_ADV              Advection of momentum.
 UV_COR              Coriolis term.
 UV_U3HADVECTION     Third-order upstream horizontal advection of 3D momentum.
 UV_C4VADVECTION     Fourth-order centered vertical advection of momentum.
 UV_LDRAG            Linear bottom stress.
 UV_TIDES            Add tidal currents to 2D momentum climatologies.
 UV_VIS2             Harmonic mixing of momentum.
 VAR_RHO_2D          Variable density barotropic mode.

...

and THESE are my outputs:

Code: Select all

   STEP   Day HH:MM:SS  KINETIC_ENRG   POTEN_ENRG    TOTAL_ENRG    NET_VOLUME
          C => (i,j,k)       Cu            Cv            Cw         Max Speed

      0     0 00:00:00  0.000000E+00  3.774337E+04  3.774337E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      DEF_HIS   - creating history file: output/ocean_his.nc
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000001
     90     0 01:00:00  0.000000E+00  3.772642E+04  3.772642E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000002
    180     0 02:00:00  0.000000E+00  3.772607E+04  3.772607E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000003
    270     0 03:00:00  0.000000E+00  3.772596E+04  3.772596E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000004
    360     0 04:00:00  0.000000E+00  3.772592E+04  3.772592E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000005
    450     0 05:00:00  0.000000E+00  3.772590E+04  3.772590E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000006
    540     0 06:00:00  0.000000E+00  3.772589E+04  3.772589E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000007
    630     0 07:00:00  0.000000E+00  3.772588E+04  3.772588E+04  4.971514E+15
          (000,000,00)  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
      WRT_HIS   - wrote history  fields (Index=1,1) into time record = 0000008

etc.

Have I got some odd preprocessor options selected? I've tried all sorts of timesteps, time vectors etc. I've not been able to find conflicting days/seconds time units anywhere. I've created my input netcdf files by adapting scripts in Roms_tools, if that adds anything. I've had other applications running on this system so I don't think it's a problem with that.

If it's something simple and/or obvious and/or daft to you then I'd be most grateful if you'd share it with me as I've hit a wall!

Thanks in advance,
Sophie

[kate]

That is quite odd. Do you have the output from all the GET_2DFLD and GET_NGFLD calls?

[SophieWard]

Hi Kate,

These are the outputs from those calls (and the bits just before and after):

Code: Select all

 Power filter parameters, Fgamma, gamma =  0.28400   0.00000

 Minimum X-grid spacing, DXmin =  3.91999986E+00 km
 Maximum X-grid spacing, DXmax =  6.54380119E+00 km
 Minimum Y-grid spacing, DYmin =  9.26107009E+00 km
 Maximum Y-grid spacing, DYmax =  9.26107009E+00 km
 Minimum Z-grid spacing, DZmin =  1.00000000E-01 m
 Maximum Z-grid spacing, DZmax =  4.11152772E+02 m

 Minimum barotropic Courant Number =  3.34828104E-03
 Maximum barotropic Courant Number =  2.17760037E-01
 Maximum Coriolis   Courant Number =  5.27089557E-03

 NLM: GET_STATE - Read state initial conditions,             t =     0 00:00:00
                   (File: nwess_ini_0.nc, Rec=0001, Index=1)
                - free-surface
                   (Min =  2.00000000E+00 Max =  5.00000000E+03)
                - vertically integrated u-momentum component
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
                - vertically integrated v-momentum component
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
                - u-momentum component
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
                - v-momentum component
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
                - potential temperature
                   (Min =  1.40000000E+01 Max =  1.40000000E+01)
                - salinity
                   (Min =  3.30000000E+01 Max =  3.30000000E+01)
    GET_NGFLD   - tidal period
                   (Min =  1.80000000E+04 Max =  1.80000000E+04)
    GET_2DFLD   - tidal elevation amplitude
                   (Min = -1.49860319E-14 Max =  4.14789167E+00)
    GET_2DFLD   - tidal elevation phase angle
                   (Min = -3.66520578E-14 Max =  6.26266314E+00)
    GET_2DFLD   - tidal current inclination angle
                   (Min =  0.00000000E+00 Max =  6.28318531E+00)
    GET_2DFLD   - tidal current phase angle
                   (Min =  0.00000000E+00 Max =  6.28318531E+00)
    GET_2DFLD   - maximum tidal current, ellipse major axis
                   (Min =  0.00000000E+00 Max =  1.37608271E+00)
    GET_2DFLD   - minimum tidal current, ellipse minor axis
                   (Min = -6.95244900E-01 Max =  8.14381660E-01)
    GET_NGFLD   - free-surface western boundary condition,   t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - free-surface eastern boundary condition,   t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
 GET_NGFLD   - free-surface southern boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - free-surface northern boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 2D u-momentum western boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 2D v-momentum western boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 2D u-momentum eastern boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
 GET_NGFLD   - 2D v-momentum eastern boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 2D u-momentum southern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 2D v-momentum southern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 2D u-momentum northern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 2D v-momentum northern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
 GET_NGFLD   - 2D v-momentum northern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 3D u-momentum western boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 3D v-momentum western boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 3D u-momentum eastern boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 3D v-momentum eastern boundary condition,  t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 3D u-momentum southern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
 GET_NGFLD   - 3D v-momentum southern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 3D u-momentum northern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - 3D v-momentum northern boundary condition, t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  0.00000000E+00 Max =  0.00000000E+00)
    GET_NGFLD   - temperature western boundary condition,    t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  1.40000000E+01 Max =  1.40000000E+01)
    GET_NGFLD   - salinity western boundary condition,       t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  3.30000000E+01 Max =  3.30000000E+01)
GET_NGFLD   - temperature eastern boundary condition,    t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  1.40000000E+01 Max =  1.40000000E+01)
    GET_NGFLD   - salinity eastern boundary condition,       t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  3.30000000E+01 Max =  3.30000000E+01)
    GET_NGFLD   - temperature southern boundary condition,   t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  1.40000000E+01 Max =  1.40000000E+01)
    GET_NGFLD   - salinity southern boundary condition,      t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  3.30000000E+01 Max =  3.30000000E+01)
    GET_NGFLD   - temperature northern boundary condition,   t =    30 00:00:00
                   (Rec=0030, Index=2, File: ocean_bry.nc)
                   (Tmin=          1.0000 Tmax=         30.0000)
                   (Min =  1.40000000E+01 Max =  1.40000000E+01)
 Maximum grid stiffness ratios:  rx0 =   9.950495E-01 (Beckmann and Haidvogel)
                                 rx1 =   1.137887E+02 (Haney)


 Initial basin volumes: TotVolume =  2.4828584322E+15 m3
                        MinVolume =  3.6416372822E+06 m3
                        MaxVolume =  2.4880608320E+10 m3
                          Max/Min =  6.8322587869E+03

As you can see my time is set as 1:1:30 in this run, but I get the same zero outputs starting from 0.

Thanks,
Sophie

[kate]

I find the GET_STATE report on surface elevation surprising. Do you really have that range? I'd expect it to cause flow and/or trouble.

Maybe check the RAMP_TIDES parameters or turn it off? I never use it.

[SophieWard]

Thanks Kate,

Good point about the free surface elevation, that was obviously wrongly defined. Unfortunately it doesn't appear to have been the thing upsetting my outputs.

Defining - or not - RAMP_TIDES doesn't seem to change anything, either.

Thanks again,
Sophie

[SophieWard]

If it's something simple and/or obvious and/or daft...

Problem solved: slight mix-up when defining tide_period in my forcing file. Ah well. I'm suprised it slipped through the errors net...

Thanks again for your help, Kate.