Presentation on theme: "Wave-current Interaction (WEC) in the COAWST Modeling System Nirnimesh Kumar with John Warner, George Voulgaris, Maitane Olabarrieta *see Kumar et al.,"— Presentation transcript:
Wave-current Interaction (WEC) in the COAWST Modeling System Nirnimesh Kumar with John Warner, George Voulgaris, Maitane Olabarrieta *see Kumar et al., 2012 (third paper in your booklet) : Implementation of the vortex force formalism in the coupled ocean-atmosphere- wave-sediment transport (COAWST) modeling system for inner shelf and surf zone applications, Ocean Modelling, Volume 47, 2012, Pages 65-95, 10.1016/j.ocemod.2012.01.003. *also see Olabarrieta et al., 2012 (fourth paper for applications)
Wave-averaged Equations Wave-Current Interaction Description StCORStokes-Coriolis Force/Hasselmann Stress PG Pressure Gradient (Includes Bernoulli head, quasi-static pressure and vertical vortex force, Eqn. 5, 7, 9 and 13) HVFHorizontal Vortex Force BA+RABreaking & Roller Acceleration (Wave dissipation and roller induced flows) BtSt+SuStBottom & Surface Streaming (Can act as stress in bottom and surface layer)
Exchange of Data Field http://woodshole.er.usgs.gov/operations/modeling/COAWST/index.html
cppdefs.h (COAWST/ROMS/Include) WEC_MELLOR + Activates the Mellor (2011) method for WEC WEC_VF (preferred method for 3D) Activate WEC using the Vortex Force formalism ( Uchiyama et al., 2010 ) Wave-current Interaction (WEC) WEC_MELLOR (Mellor, 2011) WEC_VF (Uchiyama et al., 10) + Roller Model + Streaming + Dissipation (depth) + Roller Model + Wave mixing + Streaming Implemented in Kumar et al., 2011 Implemented in Kumar et al., 2012 *Processes in italics are optional
Dissipation (Depth-limited wave breaking) WDISS_THORGUZA Use depth-limited wave dissipation based on Thornton and Guza (1983). See Eqn. (31), pg-71 WDISS_CHURTHOR Activate depth-limited wave dissipation based on Church and Thornton (1993). See Eqn. (32), pg-71 WDISS_WAVEMOD Activate wave-dissipation from a wave model. If using SWAN wave model, use INRHOG=1 for correct units of wave dissipation Note: (a)Use WDISS_THORGUZA/CHURTHOR if no information about wave dissipation is present, and you can’t run the wave model to obtain depth-limited dissipation (b)If you do not define any of these options, and still define WEC_VF, the model expects a forcing file with information about dissipation
ROLLER MODEL (for Wave Rollers) ROLLER_SVENDSEN Activate wave roller based on Svendsen (1984). See Warner et al. (2008), Eqn. 7 and Eqn. 10. ROLLLER_MONO Activate wave roller for monochromatic waves from REF- DIF. See Haas and Warner, 2009. ROLLER_RENIERS Activate wave roller based on Reniers et al. (2004). See Eqn. 34-37 (Advection-Diffusion) Note: (a)If defining ROLLER_RENIERS, you must specify the parameter wec_alpha (α r in Eqn. 34, varying from 0-1) in the INPUT file. Here 0 means no percentage of wave dissipation goes into creating wave rollers, while 1 means all the wave dissipation creates wave rollers.
Wave breaking induced mixing TKE_WAVEDISS ZOS_HSIG Activate enhance vertical viscosity mixing from waves within framework of GLS. See Eq. 44, 46 and 47. The parameter α w in Eq. 46 can be specified in the INPUT file as ZOS_HSIG_ALPHA (roughness from wave amplitude) Parameter C ew in Eqn. 47 is specified in the INPUT file as SZ_ALPHA (roughness from wave dissipation) Note: Sensitivity tests for wave-mixing were done in Kumar et al. (2012). The enhanced mixing is sensitive to C ew
Bottom and Surface Streaming BOTTOM_STREAMING Bottom streaming due to waves using Uchiyama et al. (2010) methodology. See Eqn. 22-26. This method requires dissipation due to bottom friction. If not using a wave model, then uses empirical Eq. 22. BOTTOM_STREAMING _XU_BOWEN Bottom streaming due to waves based on methodology of Xu and Bowen, 1994. See Eq. 27. SURFACE_STREAMING Surface streaming using Xu and Bowen, 1994. See Eq. 28. Note: (a)BOTTOM_STREAMING_XU_BOWEN was tested in Kumar et al. (2012). It requires very high resolution close to bottom layer. Suggested Vtransform=2 and Vstretching=3
[0,0] [1000,-12] z x y H sig = 2m T p = 10s θ = 10 o Shoreface Test Case (Obliquely incident waves on a planar beach) Wave field computed using SWAN One way coupling (only WEC) Application Name: SHOREFACE Header file: COAWST/ROMS/Include/shoreface.h Input file: COAWST/ROMS/External/ocean_shoreface.in
Forcing file for one way coupling Data/ROMS/Forcing/swan_shoreface_angle_forc.nc Should contain the following variables Wave HeightHwave Wave DirectionDwave Wave LengthLwave Bottom Orbital Vel.Ub_Swan Depth-limited breakingDissip_break Whitecapping induced breakingDissip_wcap Bottom friction induced dissip.Dissip_fric Time PeriodPwave_top/Pwave_bot
Code Compilation:coawst.bash./coawst.bash –j N Application Name Number of Nested Grids ROOT and Project Directory Define Message Passage Interface (MPI), Fortran Compiler, NETCDF4 Header (*.h) & Analytical (ana_*.h) Files
Running the Shoreface Test Case np = number of processors coawstM = Executable created after compilation Input file = ROMS/External/ocean_shoreface.in Serial./coawstS.exe ROMS/External/ocean_shoreface.in Parallel mpiexec/run -np 4./coawstM.exe ROMS/External/ocean_shoreface.in
Results (I of III) Significant Wave Height Sea surface elevation
Results (II of III) Depth-averaged Velocities Cross-shore Vel.Longshore Vel.
Results (III of III) Cross-shore Longshore Vertical EulerianStokes
WEC related Diagnostics Terms (i.e., contribution to momentum balance) Terms in momentum balance DefinitionOutput Variable Local Acc. u_accel/ ubar_accel Horizontal Advection u_hadv/ubar_hadv Vertical Advection u_vadv Coriolis Forceu_cor/ubar_cor Stokes-Coriolisu_stcor/ubar_stcor Pressure Gradient u_prsgrd/ubar_prs grd Vortex Forceu_hjvf/ubar_hjvf Vortex Forceu_vjvf
Inlet Test Case (WEC in a tidal inlet) Wave field computed using SWAN Two way coupling (WEC and CEW) Application Name: INLET_TEST Header file: COAWST/Projects/Inlet_test/Coupled/ inlet_test.h Input file: COAWST/Projects/Inlet_test/Coupled/ ocean_inlet_test.in COAWST/Projects/Inlet_test/Coupled/ swan_inlet_test.in COAWST/Projects/Inlet_test/Coupled/ coupling_inlet_test.h SOUTH NORTH
Running the Inlet_Test Case np = number of processors coawstM = Executable created after compilation Input file = Projects/Inlet_Test/Coupled/coupling_inlet_test.in Serial./coawstS.exe Projects/Inlet_test/Coupled/coupling_inlet_test.in Parallel mpiexec/run -np 4./coawstM.exe Projects/Inlet_test/Coupled/coupling_inlet_test.in
References Kumar et al., 2012: Implementation of the vortex force formalism in the coupled ocean- atmosphere-wave-sediment transport (COAWST) modeling system for inner shelf and surf zone applications, Ocean Modelling, Volume 47, 2012, Pages 65-95, 10.1016/j.ocemod.2012.01.003. Kumar et al., 2011: Implementation and modification of a three-dimensional radiation stress formulation for surf zone and rip-current applications, Coastal Engineering, Volume 58, Issue 12, December 2011, Pages 1097-1117, 10.1016/j.coastaleng.2011.06.009. Olabarrieta, M., J. C. Warner, and N. Kumar (2011), Wave-current interaction in Willapa Bay, J. Geophys. Res., 116, C12014, doi:10.1029/2011JC007387. Warner et al., 2008: Development of a three-dimensional, regional, coupled wave, current, and sediment-transport model, Computers & Geosciences, Volume 34, Issue 10, October 2008, Pages 1284-1306, ISSN 0098-3004, 10.1016/j.cageo.2008.02.012. Haas and Warner, 2009: Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and ROMS, Ocean Modelling, Volume 26, Issues 1–2, 2009, Pages 91-103, ISSN 1463-5003, 10.1016/j.ocemod.2008.09.003.