Stripes and marks in child N-E current (v)

[abiola]

Hi everyone,

I am running a one-way and two-way nesting model (5x refinement) where the child grid focuses on a strait with a high N-S velocity. However, after like 2 hours into the model run, there are observable stripes and mark on the v surface plot, and this extends down to the cross-sectional plot which causes a very significant stripe. These marks and stripes are not observed in the same area in the parent grid. I have tried several things like reducing the time step, reducing NDTFAST, trying different schemes like LMD, GMD, also trying different advection schemes like HSIMT, C4... I am indeed stuck on what next to do. I have attached the images and the header file. I will appreciate any help.

Thanks

Header file
#define NESTING
#define ONE_WAY
#define PULLEY
#define UV_ADV
#define UV_U3HADVECTION
#define UV_C4VADVECTION
#define UV_COR
#define UV_VIS2
#define UV_QDRAG
#undef TS_U3HADVECTION
#undef TS_C4VADVECTION
#define TS_MPDATA
#undef TS_A4HADVECTION
#undef TS_A4VADVECTION
#define TS_DIF2
#undef TS_DIF4
#define SALINITY
#define NONLIN_EOS
#define QCORRECTION
#define SCORRECTION
#define BULK_FLUXES
#define EMINUSP
#define LONGWAVE
#define SOLAR_SOURCE
#undef PJ_GRADPQ4
#define DJ_GRADPS
#define SOLVE3D
#define CURVGRID
#define MASKING
#undef BODYFORCE
#define AVERAGES
#undef DIAGNOSTICS_UV
#undef SPLINES_VVISC
#undef SPLINES_VDIFF
#undef PERFECT_RESTART
#undef RADIATION_2D
#define ANA_BSFLUX
#define ANA_BTFLUX
#define MIX_GEO_UV
#define MIX_GEO_TS


#define MY25_MIXING
#ifdef MY25_MIXING
# define N2S2_HORAVG
# define KANTHA_CLAYSON
# define K_C4ADVECTION
# define CANTON_A
# define RI_SPLINES
#endif
#undef LMD_MIXING
#ifdef LMD_MIXING
# define LMD_RIMIX
# define LMD_CONVEC
# undef LMD_SKPP
# undef LMD_BKPP
# define LMD_NONLOCAL
#endif
#undef GLS_MIXING
#ifdef GLS_MIXING
# define RI_HORAVG
# define RI_VERAVG
#endif

#define ROMS_TIDES
#ifdef ROMS_TIDES
# define SSH_TIDES
# define UV_TIDES
# define RAMP_TIDES
# define ADD_M2OBC
# define ADD_FSOBC
#endif

#define EP_VOLUME

#define WET_DRY
#define MASKING

#undef BIO_FENNEL
#ifdef BIO_FENNEL
# define ANA_SPFLUX
# define ANA_BPFLUX
# undef ANA_SRFLUX
# define CARBON
# define DENITRIFICATION
# undef BIO_SEDIMENT
# define OXYGEN
#endif
#define DIAGNOSTICS
#undef DIAGNOSTICS_BIO

#undef FLOATS
#undef FLOAT_VWALK