For all cases DT=20s ndtfast=20 with EAST, WEST, and SOUTH boundaries treated

the same. NORTH boundary is a solid wall. The following cpp options were used

for each of the FSCLAMPED open boundary cases.

Code: Select all

```
ATM_PRESS Impose atmospheric pressure onto sea surface.
ANA_BSFLUX Analytical kinematic bottom salinity flux.
ANA_BTFLUX Analytical kinematic bottom temperature flux.
ANA_RAIN Analytical rain fall rate.
ANA_SSFLUX Analytical kinematic surface salinity flux.
ASSUMED_SHAPE Using assumed-shape arrays.
BULK_FLUXES Surface bulk fluxes parametererization.
CURVGRID Orthogonal curvilinear grid.
DJ_GRADPS Parabolic Splines density Jacobian (Shchepetkin, 2002).
DOUBLE_PRECISION Double precision arithmetic.
KANTHA_CLAYSON Kantha and Clayson stability function formulation.
LONGWAVE_OUT Compute outgoing longwave radiation internally.
MASKING Land/Sea masking.
MPI MPI distributed-memory configuration.
MY25_MIXING Mellor/Yamada Level-2.5 mixing closure.
NONLINEAR Nonlinear Model.
NONLIN_EOS Nonlinear Equation of State for seawater.
N2S2_HORAVG Horizontal smoothing of buoyancy and shear.
PERFECT_RESTART Processing perfect restart variables.
POWER_LAW Power-law shape time-averaging barotropic filter.
PROFILE Time profiling activated .
K_GSCHEME Third-order upstream bias advection of TKE fields.
RADIATION_2D Use tangential phase speed in radiation conditions.
!RST_SINGLE Double precision fields in restart NetCDF file.
SALINITY Using salinity.
SOLVE3D Solving 3D Primitive Equations.
SPLINES Conservative parabolic spline reconstruction.
STATIONS Writing out station data.
TS_U3HADVECTION Third-order upstream bias horizontal advection of tracers.
TS_SVADVECTION Parabolic splines vertical advection of tracers.
TS_NATURAL Advective open boundary condition for tracers.
TS_PSOURCE Tracers point sources and sinks.
UV_ADV Advection of momentum.
UV_COR Coriolis term.
UV_U3HADVECTION Third-order upstream bias advection of momentum.
UV_SADVECTION Parabolic splines vertical advection of momentum.
UV_LOGDRAG Logarithmic bottom stress.
Z0_SVAR Variable Bottom Roughness.
MET_OUT (Pair,Uair,Vair) station/history file output.
UV_PSOURCE Mass point sources and sinks.
VAR_RHO_2D Variable density barotropic mode.
Case 1: Model blow-up after order 2 to 2.5 days ~15000 time steps
FSOBC_REDUCED Using free-surface data in reduced physics condtions
FSCLAMPED free-surface, Clamped condition.
M2REDUCED 2D momentum, reduced-physics condition.
M3RADIATION 3D momentum, radiation condition.
TNUDGING tracers, passive/active outflow/inflow.
TRADIATION tracers, radiation condition.
Case 2: Model blow-up after order 1000 time steps
FSCLAMPED free-surface, Clamped condition.
M2GRADIENT 2D momentum, gradient condition.
M3RADIATION 3D momentum, radiation condition.
TNUDGING tracers, passive/active outflow/inflow.
TRADIATION tracers, radiation condition.
Case 3: Model blow-up after order 1000 time steps
FSCLAMPED free-surface, Clamped condition.
M2GRADIENT 2D momentum, gradient condition.
M3GRADIENT 3D momentum, gradient condition.
TNUDGING tracers, passive/active outflow/inflow.
TRADIATION tracers, radiation condition.
```

cppdef options using the following OBCS:

FSCHAPMAN

M2FLATHER

M3RADIATION

TNUDGING

TRADIATION

However, the water level signals near the boundary differed from the specified

water level signals significantly in the C&D Canal along the WEST open boundary

and to correct this I sought to investigate the FSCLAMPED boundary condition.

Any advice or suggestions would be much appreciated.