SWAN cx, cy = propagation velocities (x- and y- directions)  = relative frequency  = wave direction S = source/sink term for: - wind-wave generation - wave breaking - bottom dissipation - nonlinear wave-wave interactions SWAN accounts for shoaling, diffraction, partial transmission, and reflection. N = wave action density (energy density / relative frequency) Booij, N., R.C. Ris and L.H. Holthuijsen, 1999, A third-generation wave model for coastal regions, Part I, Model description and validation, J.Geoph.Research, 104, C4, Booij, N., R.C. Ris and L.H. Holthuijsen, 1999, A third-generation wave model for coastal regions, Part II, Model description and validation, J.Geoph.Research, 104, C4, Booij, N., Haagsma, IJ.G., Holthuijsen, L.H., Kieftenburg, A.T.M.M., Ris, R.C., van der Westhuysen, A.J., and Zijlema, M. (2004). SWAN Cycle III version User Manual, Delft University of Technology.

SWAN User's manual

Input file - to run SWAN by itself SWAN is driven by a series of 'KEYWORDS' in the input file. 'PROJECT' 'MODE' 'SET' 'CGRID' 'READGRID' etc Projects/Inlet_Test/Swanonly/swan_inlet_test.in

Keywords: Start-up

Keywords: model description

Keywords: Output and Run

Input file - control commands PROJECT - 4 text lines SET - DEPMIN to be same as Dcrit - INRHOG 1 !!!!!! - NAUTICAL !!!! COORDINATES - SPHERICAL or CARTESIAN MODE NONSTAT TWOD

Input file - computational grid CGRID and READGRID: Defines the computational grid in x, y, freq, and theta space.

Input file - input grids INPGRID and READINP: Input grid for variables of bottom, waterlevel, currents, winds, etc. This is for the BOTTOM (bathymetry)

Input file - to run SWAN by itself INPGRID and READINP: Input grid for variables of bottom, waterlevel, currents, winds, etc. This is an example for WIND We typically use IDLA = 4

Input file - Boundary inputs BOUND SHAPE BOUND SIDE or BOUND SEGMENT

Input file - Boundary inputs BOUND SHAPE BOUND SIDE or BOUND SEGMENT THIS command uses I J indices along a segment

Input file - Boundary inputs BOUND SHAPE BOUND SIDE or BOUND SEGMENT THIS command uses X Y indices along a segment with input files

TPAR file Lists the date, Hsig, Period, Direction, and Spreading factor

Input file - Init files Can start SWAN with data from an init file. This file can be created from a STATIONARY run.

Input file - Physics

Input file - Output and run start dt end Can make this as STATIONARY, then don’t need start:dt:end to get init conditions files.

How to create a SWAN application  1) cppdefs.h  2) grids  3) wind forcing  4) boundary conditions  5) INPUT  6) coawst.bash  7) run it

1) cppdefs.h just do SWAN MODEL for now will ad refined grid later

2) grids create_roms_xy_grid 1) you can use the CGRID Regular command or 2) create a ROMS grid using any of the tools mentioned before, then run roms2swan(x, y, depth, mask) for example, the bottom of the create_roms_xy_grid calls to roms2swan. This creates 2 files: grid_coord.grd (goes with READGRID COORDS) swan_bathy.bot (goes with READINP BOTTOM)

3) wind forcing Can use Tools\mfiles\mtools\narr2romsnc.m At the end of this file, it creates the wind forcing file for SWAN. Need to add this wind file name to READINP WIND.

4) boundary conditions - TPAR Can use Tools\mfiles\swan_forc\ww3_swan_input.m To read WW3 model output and create SWAN TPAR boundary forcing files.

5) INPUT Projects/Inlet_Test/Swanonly/swan_inlet_test.in

6) coawst.bash 7) run it Build it by setting the Project name and paths in the coawst.bash. Run it by call to coawstM, but now need to explicitly state input file name mpiexec -np 4./coawstM Projects/Inlet_test/Swanonly/swan_inlet_test.in

SWAN with grid refinement  #define SWAN_MODEL  #define REFINED_GRID  comile with nested_grids = 2 (or however many)  need 2 (or more) INPUT files.  mpirun -np X./coawstM Projects/Inlet_test/Swanonly/swan_inlet_test.in Projects/Inlet_test/Swanonly/swan_inlet_test_ref5.in

SWAN Coupling Interactions to ocean and atm models. This will happen in you #define SWAN_MODEL and one more of: #define ROMS_MODEL #define WRF_MODEL

WAV interactions 1) Generation – wind speed forcing is modified by ocean currents: S(w) = f( U wind – u s ; V wind – v s ) u s, v s, , bath, Z 0 U wind, V wind WAV OCN ATM 2) Propagation – wave celerity in geographic space is modified by ocean currents c x = c gx + u s ; c y = c gy + v s – change of wave direction (refraction) due to , bathy, and currents:

To activate these processes in SWAN Need to activate CURRENT WLEV FRIC to get data from ROMS No READINP since this data is coming from ROMS Need to activate WIND to get data from WRF Grid dims don’t really matter. It gets the data from the other model thru MCT.

OCN interactions WAVE H wave, L mwave, L pwave, D wave, T psurf, T mbott, Q b, Diss bot, Diss surf, Diss wcap, U bot OCN H wave, L mwave, D wave, T psurf, Q b, Diss bot, Diss surf, Diss wcap, Water column Stokes + VF H wave, L pwave, D wave, T psurf, H wave, L mwave, D wave, T mbott, U bot Surface stressBottom stress s= f ( Z os )Zoa  b = f ( Z ob )  #define WEC_VF #define CRAIG_BANNER #define CHARNOK or #define ZOS_HSIG #define TKE_WAVEDISS #define SSW_BBL H wave, L pwave, D wave, T psurf, Surface tke flux #define COARE_OOST #define COARE_TAYLOR_YELLAND #define DRENNAN CRAIG_BANNER (default)

ATM interactions OCN ATM WAV SST H wave, L pwave, T psurf, Surface fluxes Momentum Heat Moisture = f ( H wave, L pwave, T psurf ) SST OCN WAV

SURFACE ROUGHNESS CLOSURE MODELS Currently only in MYJSFC and MYNN TAYLOR & YELLAND 2001: TY2001 (#define COARE_TAYLOR_YELLAND) DRENNAN 2003: DGQH (#define DRENNAN) OOST 2002: OOST (#define COARE_OOST) - Wave steepness based parameterization. - Based on three datasets representing sea-state conditions ranging from strongly forced to shoaling. - Wave age dependent formula but it also considers the effect of the wave steepness. - Wave age based formula to characterize the ocean roughness. - They combined data from many field experiments representing a variety of condition and grouped the data as a function of the wind friction velocity. CHARNOCK 1955 (default)

Applications - Nor Ida (Nov 2009) (waves)

Nor’Ida Nov 2009 Bodie Island, NC Wallops Island, VA L L H 8 th Nov 9 th Nov 10 th Nov 11 th Nov 13 th Nov wind speed 23 m/s (50 mph) wind speed 23 m/s (50 mph) Before After ov/hurricanes/norida/ Wave heights (m) wind speed 40 m/s (90 mph) wind speed 40 m/s (90 mph)

OCEAN ATMOSPHERE WAVE u s, v s, , bath H sig, L wave, D wave, T surf, T bott,Q b, W dissip, U b MCT Uwind, Vwind, Patm, RH, Tair, cloud, rain, SWrad, LWrad, LHeat, SHeat SST MCT Uwind, Vwind MCT WRF wind speed Longitude Latitude ROMS SST SWAN Hsig COAWST (Coupled Ocean – Atmosphere – Wave – Sediment Transport) Modeling System H sig, L wave,, T wave,

SST WRF + ROMS + SWAN WRF + ROMS WRF GOES

WRF WINDS WRF + ROMS + SWAN m/s WRF + ROMS S DATA WRF WRF+ROMS WRF+ROMS+SWAN Reduced wind speed with waves coupling.

WAVES WRF WRF + SST +OOST WRF + SST DATA WRF WRF+ROMS WRF+ROMS+SWAN WRF + ROMS WRF S m Reduced waves with waves coupling.

WRF +SST + OOST m/s SST + WRF WINDS WRF + SST + TY2001 WRF + SST + DGQH DATA WRF WRF+ROMS W+R+S (DGQH) W+R+S (TY2001) W+R+S (OOST) NAM (TY) WRF + ROMS + SWAN( ) (OOST) WRF + ROMS (DGQH) Reduced wind speed with waves coupling. OOST best.

WRF + SST +OOSTm WAVES DATA WRF WRF+ROMS W+R+S (DGQH) W+R+S (TY2001) W+R+S (OOST) NAM WRF + ROMS WRF + SST + TY2001 WRF + SST + DGQH (TY) WRF + ROMS + SWAN( ) (OOST)(DGQH) Reduced wave heights with waves coupling. OOST best.

WRF + SST + DGQH SURFACE CURRENTS WRF + ROMS (charnock) m/s WRF + SST + TY2001 WRF + SST + OOST (TY) WRF + ROMS + SWAN( ) (OOST)(DGQH) CODAR Increased current speed with waves coupling. TY / DGQH best.

WRF + SST + DGQH SURFACE CURRENTS WRF + ROMS (charnock) m/s (TY) WRF + ROMS + SWAN( ) (OOST)(DGQH) CODAR RMSE (m/s) 0.24 RMSE (m/s) 0.14 RMSE (m/s) 0.13 RMSE (m/s) 0.26 Model currents (m/s) CODAR currents (m/s) Increased current speed with waves coupling. TY / DGQH best.

WRF+ SST + OOST m WRF STORM SURGE DATA WRF WRF+ROMS W+R+S (DGQH) W+R+S (TY2001) W+R+S (OOST) WRF + ROMS (TY) WRF + ROMS + SWAN( ) (OOST)(DGQH) Increased surge with waves coupling. TY / DGQH best?