15.17. Rip Current

Rip currents are strong, seaward flows formed by longshore variation of the wave-induced momentum flux. They are responsible for the recirculation of water accumulated on a beach by a weaker and broader shoreward flow. Here, we consider longshore variation of the wave-induced momentum flux due to breaking at barred bottom topography with an imposed longshore perturbation, as in Weir et al. (2010) but in the 3D case. The basin is rectangular (768 m by 768 m) and the topography is constant over time and based on field surveys at Duck, North Carolina. Shore-normal, monochoromatic waves (1m, 10s) are imposed at the offshore boundary and propagate through the WKB wave model coupled with the 3D circulation model (Uchiyama et al., 2011). The domain is periodic in the alongshore direction. We assume that the nearshore boundary is reflectionless, and there is no net outflow at the offshore boundary.

Weir, B., Y. Uchiyama, E. M. Lane, J. M. Restrepo, and J. C. McWilliams (2011), A vortex force analysis of the interaction of rip currents and surface gravity waves, J. Geophys. Res., 116, C05001.

Related CPP options:

RIP

Idealized Duck Beach with 3D topography (default)

BISCA

Semi-realistic Biscarosse Beach (needs input files)

RIP_TOPO_2D

Idealized Duck with longshore uniform topography

GRANDPOPO

Idealized longshore uniform terraced beach (Grand Popo, Benin)

ANA_TIDES

Adds idealized tidal variations

WAVE_MAKER & NBQ

Wave resolving rather than wave-averaged case (#undef MRL_WCI)

CPP options:

# define RIP
# undef  BISCA
# undef  RIP_TOPO_2D
# undef  GRANDPOPO
# ifdef GRANDPOPO
#  define RIP_TOPO_2D
# endif
# undef ANA_TIDES
# undef  OPENMP
# undef  MPI
# define SOLVE3D
# define NEW_S_COORD
# define UV_ADV
# undef  NBQ
# ifdef NBQ
#  define NBQ_PRECISE
#  define WAVE_MAKER
#  define WAVE_MAKER_SPECTRUM
#  define WAVE_MAKER_DSPREAD
#  define UV_HADV_WENO5
#  define UV_VADV_WENO5
#  define W_HADV_WENO5
#  define W_VADV_WENO5
#  define GLS_MIXING_3D
#  undef  ANA_TIDES
#  undef  MRL_WCI
#  define OBC_SPECIFIED_WEST
#  define FRC_BRY
#  define ANA_BRY
#  define Z_FRC_BRY
#  define M2_FRC_BRY
#  define M3_FRC_BRY
#  define T_FRC_BRY
#  define AVERAGES
#  define AVERAGES_K
# else
#  define UV_VIS2
#  define UV_VIS_SMAGO
#  define LMD_MIXING
#  define LMD_SKPP
#  define LMD_BKPP
#  define MRL_WCI
# endif
# define WET_DRY
# ifdef MRL_WCI
#  define WKB_WWAVE
#  define WKB_OBC_WEST
#  define WAVE_ROLLER
#  define WAVE_FRICTION
#  define WAVE_STREAMING
#  define MRL_CEW
#  ifdef RIP_TOPO_2D
#   define WAVE_RAMP
#  endif
# endif
# ifndef BISCA
#  define ANA_GRID
# endif
# define ANA_INITIAL
# define ANA_SMFLUX
# define ANA_STFLUX
# define ANA_SSFLUX
# define ANA_SRFLUX
# define ANA_SST
# define ANA_BTFLUX
# if !defined BISCA && !defined ANA_TIDES
#  define NS_PERIODIC
# else
#  define OBC_NORTH
#  define OBC_SOUTH
# endif
# define OBC_WEST
# define SPONGE
# ifdef ANA_TIDES
#  define ANA_SSH
#  define ANA_M2CLIMA
#  define ANA_M3CLIMA
#  define ZCLIMATOLOGY
#  define M2CLIMATOLOGY
#  define M3CLIMATOLOGY
#  define M2NUDGING
#  define M3NUDGING
# endif
# ifdef BISCA
#  define BBL
# endif
# undef SEDIMENT
# ifdef SEDIMENT
#  define SUSPLOAD
#  define BEDLOAD
#  undef  MORPHODYN
# endif
# undef  DIAGNOSTICS_UV

Settings :

Results :

../_images/test_cases_rip.png

RIP results : velocity