problems in ROMS tide simulation

[baipeng_up]

Hi

I was running a real tide case recent days, and I only provide only 1 tide forcing file for the ROMS, no initial file, no climatory file, also no other foring files. Additionally, I used TPXO7 data for making the tide forcing file. But, the program was always blowing up, and the result seemed to be good when the program had ran for 0.8day,then the result becomed worse and worse. I had tried to smooth the grid file, set the "DT" (in the *.in file) smaller, the program could only run for a few steps further and then still blowing up.

Does anyone get into the same trouble with me?

Here is my *.h configuration：
/*
**
*/
#define UV_ADV /* Advection of momentum */
#define UV_COR /* Coriolis term */
#define UV_QDRAG /* Use quadratic bottom drag law */
#define UV_VIS2 /* Harmonic mixing of momentum */
#define UV_C4ADVECTION
#define DJ_GRADPS /* Splines Density Jacobian */
#define MIX_S_UV
#define MIX_S_TS /* Mixing of tracers along constant S-surfaces */
!#define MIX_GEO_TS
#define TS_DIF2 /* Harmonic mixing of tracers */
#define TS_U3HADVECTION /* Third-order upstream horizontal advection of tracers */
#define TS_C4VADVECTION /* Fourth-order centered vertical advection of tracers */
#undef TS_SVADVECTION
#undef TS_MPDATA /* ??? TS_U3HADVECTION TS_C4VADVECTION ??? */

#define SOLVE3D /* Solving 3D Primitive Equations */
#define SALINITY /* Using salinity */
#undef NONLIN_EOS /* Nonlinear Equation of State for seawater */
#define CURVGRID
#undef PROFILE /* Define for time profiling */
#undef SPHERICAL /* Define if lat/lon coordinates rather than x/y */
#undef SPLINES
#define MASKING /* Land/Sea masking */

#undef DIAGNOSTICS_UV /* define if writing out momentum diagnostics */
#undef DIAGNOSTICS_TS /* define if writing out tracer diagnostics */

#define AVERAGES /* ?Define to write out time-averaged model fields */

/*
** Vertical Mixing parameterization
*/
#undef FORWARD_MIXING
#define MY25_MIXING
#undef LMD_MIXING /* Large/McWilliams/Doney interior mixing */
#undef GLS_MIXING

#ifdef LMD_MIXING
# define LMD_RIMIX /* LMD diffusivity due to shear instability */
# define LMD_CONVEC /* LMD convective mixing due to shear instability */
# define LMD_SKPP /* KPP surface boundary layer mixing */
# define LMD_NONLOCAL /* LMD convective nonlocal transport */
#endif

#if defined GLS_MIXING
# define CHARNOK /* Charnok Surface Roughness From Wind Stress */
# define CRAIG_BANNER /* Craig and Banner Wave Breaking Surface Flux */
# define KANTHA_CLAYSON /* Kantha and Clayson stability function */
# define N2S2_HORAVG /* Horizontal Smoothing of Buoyancy/Shea */
# define CANUTO_A
#endif
#if defined MY25_MIXING
# define KANTHA_CLAYSON /* Define for Kantha and Clayson stability function. */
# define K_C2ADVECTION /* Define for 2th-order centered advection. */
# define K_C4ADVECTION /* Define for 4th-order centered advection. */
# define N2S2_HORAVG /* Horizontal Smoothing of Buoyancy/Shea */
#endif

/*
**Bottom boundary condition settings
*/

#define ANA_BTFLUX /* Analytical kinematic bottom temperature flux */
#define ANA_BSFLUX /* Analytical kinematic bottom salinity flux */

/*
**
*/
#define ANA_SMFLUX
#define ANA_STFLUX /* Analytical kinematic surface temperature flux */
#define ANA_SSFLUX /* analytical surface salt flux defaults to zero */

#define ANA_INITIAL

/*
**define UV_TIDES to specify boundary tidal currents from data e.g. ADCIRC
** undef UV_TIDES to compute tidal currents using reduced physics
*/

#define SSH_TIDES /* read tidal SSH from file */
#undef UV_TIDES /* read tidal U and V from file */
#define FSOBC_REDUCED

#define ANA_FSOBC
#define ANA_M2OBC

#ifdef SSH_TIDES
# define ADD_FSOBC
#endif
#ifdef UV_TIDES
# undef FSOBC_REDUCED /* boundary pg is calculated using bounday zeta */
# define ADD_M2OBC
#endif

/*
** Boundary Condition Specifications
*/

#define RADIATION_2D
/* e.g. FSCHAPMAN FSGRADIENT FSRADIATION */
#define EAST_FSCHAPMAN
#define SOUTH_FSCHAPMAN /* Define for a Chapman condition on the free surface */
#define NORTH_FSCHAPMAN
#define WEST_FSCHAPMAN

/* e.g. M2FLATHER M2GRADIENT M2RADIATION */
#define EAST_M2FLATHER
#define SOUTH_M2FLATHER /* Define for a Flather condition on the 2-D momentum */
#define NORTH_M2FLATHER
#define WEST_M2FLATHER

#define EAST_M3RADIATION
#define SOUTH_M3RADIATION /* use if 3D momentum radiation condition*/
#define NORTH_M3RADIATION
#define WEST_M3RADIATION

/* e.g.TRADIATION TGRADIENT */
#define EAST_TRADIATION
#define SOUTH_TRADIATION /* Define for a radiation condition on tracers */
#define NORTH_TRADIATION
#define WEST_TRADIATION
#undef EAST_VOLCONS
#undef SOUTH_VOLCONS /* Define for Southern edge mass conservation enforcement */
#undef NORTH_VOLCONS
#undef WEST_VOLCONS

/* If you define SPONGE or allow for a nudging layer at the boundaries,
** you need to provide the appropriate "ana_hmixcoef.h" and "ana_nudgcoef.h"
** for your application. See examples in ROMS/Func
*/

#undef SPONGE /* Define to use SSH climatology as 2D inflow */[/color]

Thanks a lot!

Regards.

[kate]

If you are using TPXO, why not extract the velocities and use them too?

Many of us have troubles with ROMS, but there's more than one kind of trouble. Where do the fields go bad and how do they look?

[geo_ytwin]

What is the horizontal resolution and minimum water depth of your model? In my experience, increaing the hmin will also help the model integrate forward. In addition, you can try to reduce the resolution in the begining. When the model can run smoothly, then more detailed work is needed to refine the model and optimize the results.

[baipeng_up]

What is the horizontal resolution and minimum water depth of your model? In my experience, increaing the hmin will also help the model integrate forward. In addition, you can try to reduce the resolution in the begining. When the model can run smoothly, then more detailed work is needed to refine the model and optimize the results.

The horizontal resolution is 1/20° and the minimum water depth "DCRIT" was set to 3.0m.
Tanks for your suggestion, I'll try them later. What's more, I use the EASYGRID for generating the grid file, I set the maximum "r-factor value" to 0.3 in the *.m file, but the "smooth_bath" function can only limit the "r-value" to about 0.37, so I doubt may be the grid file I prepare for the ROMS is bad and could I know what tools do you usually use for generating the "_grd.nc" file? I appreciate it very much for all you replies!

[baipeng_up]

If you are using TPXO, why not extract the velocities and use them too?

Many of us have troubles with ROMS, but there's more than one kind of trouble. Where do the fields go bad and how do they look?

Tanks for your reply! I just want to see the result only forced by the "Amplitude" and the "Phase"，I think we could get a good result only by provide "H" and "g", and I'll add the tide velocities later.

I plot the "Zeta" (free surface height) of the ROMS result, and I can see regular rising-tide and falling-tide pattern at about 0.8day, this pattern will last for about 3 modeling days and then the "Zeta" field lose the regular pattern and become messy, what's more, my model ran for about 11 modeling days totally.

Additionally, I use the EASYGRID for generating the "_grd.nc" file, I set the maximum "r-factor value" to 0.3, but the "smooth_bath" function can not be up to the standard, I doubt may be the grid file is bad, so what tools do you usually use for generating the grid file? I appreciate it very much for all your replies!

[kate]

But does zeta go bad everywhere or just certain places? What sort of places? Is this a 2-D simulation or could things be going bad in some other way first? Why do you suspect your grid file of being bad?

[geo_ytwin]

Sometimes I use seagrid to generate my grid. Generally, I will directly make my grid by matlab.
Also,roms_tools downloaded from IRD is the toolbox I used.

[baipeng_up]

Sometimes I use seagrid to generate my grid. Generally, I will directly make my grid by matlab.
Also,roms_tools downloaded from IRD is the toolbox I used.

Ok, I get it.
Thanks a lot!

[baipeng_up]

But does zeta go bad everywhere or just certain places? What sort of places? Is this a 2-D simulation or could things be going bad in some other way first? Why do you suspect your grid file of being bad?

The zeta goes bad everywhere, and I checked the r-value of my grid, the result is too big. I haven't check other variables except zeta yet, I feel that it will be a long way for me to learn ROMS. I re-maked the grid file today, I want to get rid of the problems of the grid first, if the result was still bad, then I'll check other things.

Thanks a lot!

[LiuZHQ]

looks like you're adapting Flahter and Chapman to simulate the tidal current. To me, it is important that we provide tidal current (suggested by Kate) to this sort of OBC in Flather form (an "active" OBC in fact) to include both the tidal current and the tidal wave correctly.

Or, if you insist, use clamp for zeta OBC and radiation for all the other components. But, this kind of setup is bad and I can not grantee the resutls to be reasonable.

ZQ

[anthena]

Hi all

When I simulated the tide in Bohai Sea, I confront a problem: the phase of M2 S2 K1 O1 is not good(fig 01), compared to other results(fig NAO_m2),there are large errors. I know the topography and bottom firction are significant to tide. the depth of Bobai Sea is used the newest data ectracted from digital ocean atlas, the boundary condition is forced by 4 tides (M2 S2 K1 O1 )ecactracd from TPX07 tidal data, then modified with NAO99 data, the tidal forcing i checed is right, and i have tried to change the quadratic drag coefficient from 0.0015 to 0.005, the results were no good. I am confused that is there any other parameters needing to change? Give me some advice, please, thank you.
--

The following is my model setting:
Model Input Parameters: ROMS/TOMS version 3.7
SVN Revision : 671M
Resolution, Grid 01: 0146x0120x014, Parallel Nodes: 6, Tiling: 002x003

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

100800 ntimes Number of timesteps for 3-D equations.
30.000 dt Timestep size (s) for 3-D equations.
20 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.
T LcycleRST Switch to recycle time-records in restart file.
1440 nRST Number of timesteps between the writing of data
into restart fields.
1 ninfo Number of timesteps between print of information
to standard output.
T ldefout Switch to create a new output NetCDF file(s).
120 nHIS Number of timesteps between the writing fields
into history file.
2880 ndefHIS Number of timesteps between creation of new
history files.
1.0000E+01 nl_tnu2(01) NLM Horizontal, harmonic mixing coefficient
(m2/s) for tracer 01: temp
2.5000E+01 nl_tnu2(02) NLM Horizontal, harmonic mixing coefficient
(m2/s) for tracer 02: salt
2.0000E+01 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.
6.5000E-04 rdrg Linear bottom drag coefficient (m/s).
4.5000E-03 rdrg2 Quadratic bottom drag coefficient.
1.3000E-02 Zob Bottom roughness (m).
0.0000E+00 Zos Surface roughness (m).
2 Vtransform S-coordinate transformation equation.
4 Vstretching S-coordinate stretching function.
4.5000E+00 theta_s S-coordinate surface control parameter.
6.0000E-01 theta_b S-coordinate bottom control parameter.
3.000 Tcline S-coordinate surface/bottom layer width (m) used
in vertical coordinate stretching.
1025.000 rho0 Mean density (kg/m3) for Boussinesq approximation.
0.000 dstart Time-stamp assigned to model initialization (days).
0.000 tide_start Reference time origin for tidal forcing (days).
20120428.00 time_ref Reference time for units attribute (yyyymmdd.dd)
1.0000E+00 Tnudg(01) Nudging/relaxation time scale (days)
for tracer 01: temp
1.0000E+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.
2.0000E+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.
8.000 T0 Background potential temperature (C) constant.
31.000 S0 Background salinity (PSU) constant.
1027.000 R0 Background density (kg/m3) used in linear Equation
of State.
1.7000E-04 Tcoef Thermal expansion coefficient (1/Celsius).
7.6000E-04 Scoef Saline contraction coefficient (1/PSU).
1.000 gamma2 Slipperiness variable: free-slip (1.0) or
no-slip (-1.0).
Activated C-preprocessing Options:

BOHAI BohaiSeamodeling
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_FSOBC Analytical free-surface boundary conditions.
ANA_INITIAL Analytical initial conditions.
ANA_M2OBC Analytical 2D momentum boundary conditions.
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.
FSOBC_REDUCED Using free-surface data in reduced physics conditions
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.
RADIATION_2D Use tangential phase speed in radiation conditions.
!RST_SINGLE Double precision fields in restart NetCDF file.
SOLVE3D Solving 3D Primitive Equations.
SPLINES Conservative parabolic spline reconstruction.
SSH_TIDES Add tidal elevation to SSH climatology.
TS_C4HADVECTION Fourth-order centered horizontal advection of tracers.
TS_C4VADVECTION Fourth-order centered 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_QDRAG Quadratic bottom stress.
UV_TIDES Add tidal currents to 2D momentum climatologies.
UV_VIS2 Harmonic mixing of momentum.
VAR_RHO_2D Variable density barotropic mode.

RDRG2=0.003

01.jpg (34.85 KiB) Viewed 15795 times

[baipeng_up]

Hi all

When I simulated the tide in Bohai Sea, I confront a problem: the phase of M2 S2 K1 O1 is not good(fig 01), compared to other results(fig NAO_m2),there are large errors. I know the topography and bottom firction are significant to tide. the depth of Bobai Sea is used the newest data ectracted from digital ocean atlas, the boundary condition is forced by 4 tides (M2 S2 K1 O1 )ecactracd from TPX07 tidal data, then modified with NAO99 data, the tidal forcing i checed is right, and i have tried to change the quadratic drag coefficient from 0.0015 to 0.005, the results were no good. I am confused that is there any other parameters needing to change? Give me some advice, please, thank you.
--

The following is my model setting:
Model Input Parameters: ROMS/TOMS version 3.7
SVN Revision : 671M
Resolution, Grid 01: 0146x0120x014, Parallel Nodes: 6, Tiling: 002x003

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

100800 ntimes Number of timesteps for 3-D equations.
30.000 dt Timestep size (s) for 3-D equations.
20 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.
T LcycleRST Switch to recycle time-records in restart file.
1440 nRST Number of timesteps between the writing of data
into restart fields.
1 ninfo Number of timesteps between print of information
to standard output.
T ldefout Switch to create a new output NetCDF file(s).
120 nHIS Number of timesteps between the writing fields
into history file.
2880 ndefHIS Number of timesteps between creation of new
history files.
1.0000E+01 nl_tnu2(01) NLM Horizontal, harmonic mixing coefficient
(m2/s) for tracer 01: temp
2.5000E+01 nl_tnu2(02) NLM Horizontal, harmonic mixing coefficient
(m2/s) for tracer 02: salt
2.0000E+01 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.
6.5000E-04 rdrg Linear bottom drag coefficient (m/s).
4.5000E-03 rdrg2 Quadratic bottom drag coefficient.
1.3000E-02 Zob Bottom roughness (m).
0.0000E+00 Zos Surface roughness (m).
2 Vtransform S-coordinate transformation equation.
4 Vstretching S-coordinate stretching function.
4.5000E+00 theta_s S-coordinate surface control parameter.
6.0000E-01 theta_b S-coordinate bottom control parameter.
3.000 Tcline S-coordinate surface/bottom layer width (m) used
in vertical coordinate stretching.
1025.000 rho0 Mean density (kg/m3) for Boussinesq approximation.
0.000 dstart Time-stamp assigned to model initialization (days).
0.000 tide_start Reference time origin for tidal forcing (days).
20120428.00 time_ref Reference time for units attribute (yyyymmdd.dd)
1.0000E+00 Tnudg(01) Nudging/relaxation time scale (days)
for tracer 01: temp
1.0000E+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.
2.0000E+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.
8.000 T0 Background potential temperature (C) constant.
31.000 S0 Background salinity (PSU) constant.
1027.000 R0 Background density (kg/m3) used in linear Equation
of State.
1.7000E-04 Tcoef Thermal expansion coefficient (1/Celsius).
7.6000E-04 Scoef Saline contraction coefficient (1/PSU).
1.000 gamma2 Slipperiness variable: free-slip (1.0) or
no-slip (-1.0).
Activated C-preprocessing Options:

BOHAI BohaiSeamodeling
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_FSOBC Analytical free-surface boundary conditions.
ANA_INITIAL Analytical initial conditions.
ANA_M2OBC Analytical 2D momentum boundary conditions.
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.
FSOBC_REDUCED Using free-surface data in reduced physics conditions
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.
RADIATION_2D Use tangential phase speed in radiation conditions.
!RST_SINGLE Double precision fields in restart NetCDF file.
SOLVE3D Solving 3D Primitive Equations.
SPLINES Conservative parabolic spline reconstruction.
SSH_TIDES Add tidal elevation to SSH climatology.
TS_C4HADVECTION Fourth-order centered horizontal advection of tracers.
TS_C4VADVECTION Fourth-order centered 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_QDRAG Quadratic bottom stress.
UV_TIDES Add tidal currents to 2D momentum climatologies.
UV_VIS2 Harmonic mixing of momentum.
VAR_RHO_2D Variable density barotropic mode.

The attachment 01.jpg is no longer available

Hi

From your post I know that your forcing file is generated according to the TPXO7 data. Recently, I was modeling tides of the Beibu Gulf(China), also, I use the TPXO7 data for making the tide forcing file, however the result is unsatisfying, so I checked the forcing file and found that are some abnormal values in some areas, so I suggest you should check your tide foring file first.

[anthena]

Hi baipeng_up, I know there are some errors in TPX07,in the model I used the amplitude and phase got from NAO99, but the tidal current components is from TPX07, is this the reason of bas simulation?

[baipeng_up]

Hi baipeng_up, I know there are some errors in TPX07,in the model I used the amplitude and phase got from NAO99, but the tidal current components is from TPX07, is this the reason of bas simulation?

Hi anthena, why not turnning off the "UV_TIDES" in the *.h file and just use the amplitude and phase as the forcing factors, as far as I know, we can get good result by only defining "SSH_TIDES", you could try this, if the result goes fine, you can say the tidal current components derived from TPX07 is bad. Additionaly, you could do more contrast numerical experiment, this will help you figure out the problem.

[Chang]

hello baipei_up
i am also runing roms application about bohai sea,i meet the same problem which the result of zeta and velocity is bad due adding tide forcing.can you tell me how you solve it.And can you tell me how to analyze the amplitude and phase of tide according the zeta?could you send me a copy of your program? thank you very much!my email address is 2454518664@qq.com