swan

SWANyx w

c Nc N c N c N SN

t x y

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, 7649-7666.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, 7649-7666.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 40.41 User Manual, Delft University of Technology.

SWAN User's manual

http://swanmodel.sourceforge.net/online_doc/swanuse/swanuse.html

Input file - to run SWAN by itselfSWAN is driven by a

series of 'KEYWORDS' in the

input file.

'PROJECT''MODE'

'SET''CGRID'

'READGRID'

etcetc

Projects/Inlet_Test/Swanonly/swan_inlet_test.in

Keywords: Start-up

Keywords: model description

Keywords: Output and Run

Input file - control commandsPROJECT - 4 text lines

SET - DEPMIN to be same as Dcrit - INRHOG 1 !!!!!! - NAUTICAL !!!!

COORDINATES - SPHERICAL or CARTESIAN

MODE NONSTAT TWOD

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

Input file - input gridsINPGRID and READINP: Input grid for variables of bottom, waterlevel, currents, winds, etc.

This is for the BOTTOM (bathymetry)

Input file - to run SWAN by itselfINPGRID 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 inputsBOUND SHAPEBOUND SIDE or BOUND SEGMENT


THIS command uses I J indices along a segment


THIS command uses X Y indices along a segmentwith 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:endto 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) gridscreate_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 runroms2swan(x, y, depth, mask)

for example, the bottom of the create_roms_xy_gridcalls to roms2swan. This creates 2 files:

grid_coord.grd (goes with READGRID COORDS)swan_bathy.bot (goes with READINP BOTTOM)

3) wind forcingCan use Tools\mfiles\mtools\narr2romsnc.mAt 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.mTo read WW3 model output and create SWAN TPAR boundary forcing files.

5) INPUT

Projects/Inlet_Test/Swanonly/swan_inlet_test.in

6) coawst.bash7) 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 forcingis modified by ocean currents:

S(w) = f( Uwind – us ; Vwind – vs )

us, vs, , bath, Z0

Uwind , V

wind

WAV

OCN

ATM

2) Propagation

yx wc Nc N c N c N SN

t x y

– wave celerity in geographic space is modified by ocean currents cx = cgx + us ; cy = cgy + vs

, sin cos cos sin cos sin sin cossinh 2g

h h U U V VC

kh x y x y x y

– change of wave direction (refraction) due to , bathy, and currents:

To activate these processes in SWAN

Need to activate CURRENT

WLEVFRIC

to get data from ROMS

No READINP since this datais 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 interactionsWAVE

Hwave, Lmwave, Lpwave, Dwave,Tpsurf, Tmbott, Qb, Dissbot, Disssurf, Disswcap, Ubot

OCN

Hwave, Lmwave, Dwave,Tpsurf, Qb, Dissbot, Disssurf, Disswcap,

Water column

Stokes + VF

Hwave, Lpwave, Dwave, Tpsurf,

Hwave, Lmwave, Dwave,Tmbott, Ubot

Surface stress Bottom stress

s= f ( Zos ) Zoa

b = f ( Zob )

#define WEC_VF

#define CRAIG_BANNER#define CHARNOKor#define ZOS_HSIG#define TKE_WAVEDISS #define SSW_BBL

Hwave, Lpwave, Dwave, Tpsurf,

Surface tke flux

#define COARE_OOST#define COARE_TAYLOR_YELLAND#define DRENNANCRAIG_BANNER (default)

ATM interactions

OCN

ATM

WAV

SST

Hwave , L

pwave ,

Tpsurf ,

Sur

face

flu

xes

Momentum

Heat

Moisture

= f ( Hwave, Lpwave, Tpsurf )

SST OCN

WAV

SURFACE ROUGHNESS CLOSURE MODELSCurrently only in MYJSFC and MYNN

TAYLOR & YELLAND 2001: TY2001 (#define COARE_TAYLOR_YELLAND)

DRENNAN 2003: DGQH (#define DRENNAN)

OOST 2002: OOST (#define COARE_OOST)

4.50 1200ms p

s

zH L

H

- Wave steepness based parameterization.- Based on three datasets representing sea-state conditions ranging from strongly forced to shoaling.

3.40*3.35m

ps

zu C

H

4.50*

25.0mp

p

zu C

L

- 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.

0

*

*

significant wave height

ocean surface roughness

wind friction velocity

peak wave celerity

peak wave length

wave age

s

p

p

p

H

z

u

C

L

u

C

CHARNOCK 1955 (default)

2*0

0.011m

uz

g

Applications

- Nor Ida (Nov 2009) (waves)

http://www.hpc.ncep.noaa.gov/dailywxmap/

Nor’Ida Nov 2009

Bodie Island, NC

Wallops Island, VA

LL

LL

HH

8th Nov8th Nov

9th Nov9th Nov

10thNov10thNov

11thNov11thNov

13thNov13thNov

wind speed23 m/s (50 mph)


Before

Before

After

Afterhttp://

coastal.er.usgs.gov/hurricanes/norida/

Wav

e h

eigh

ts (m

)



OCEAN

ATMOSPHERE

WAVE

us, vs, , bath

Hsig, Lwave, Dwave,Tsurf, Tbott,Qb, Wdissip, Ub

MCT

Uwind, Vwind, P

atm, R

H, Tair,

cloud, ra

in, SW

rad, LW

rad, LHeat,

SHeat

SST

MCT

Uwind,

Vwind

MCT

WRF wind speed

LongitudeLa

titud

e

ROMS SSTSWAN Hsig

COAWST (Coupled Ocean – Atmosphere – Wave – Sediment Transport) Modeling System

Hsig, L

wave , ,

Twave ,

http://wrf-model.org/index.php

https://www.myroms.org/projects/cstm

SST

WRF + ROMS + SWANWRF + ROMSWRFGOES

WRF

WINDSWRF + ROMS + SWAN m/sWRF + ROMS

S

0.850.780.89

DATAWRF

WRF+ROMSWRF+ROMS+SWAN

Reduced wind speed with waves coupling.

WAVESWRF

WRF + SST +OOST WRF + SST

DATAWRF

WRF+ROMSWRF+ROMS+SWAN

WRF + ROMS + SWANWRF + ROMSWRF

S

0.800.740.88

m

Reduced waves with waves coupling.

WRF +SST + OOST m/s

SST + WRF

WINDSWRF + SST + TY2001 WRF + SST + DGQH

DATAWRF

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 +OOST m

WAVES

DATAWRF


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

m/s

WRF + SST + TY2001WRF + SST + OOST (TY)WRF + ROMS + SWAN( )

(OOST) (DGQH)

CODARIncreased current speed with waves coupling.

TY / DGQH best.

WRF + SST + DGQH

SURFACE CURRENTS

WRF + ROMS (charnock)

m/s


(OOST) (DGQH)

CODAR

RMSE (m/s) 0.24

RMSE (m/s) 0.14RMSE (m/s) 0.13RMSE (m/s) 0.26

Mod

el c

urre

nts

(m/s

)

CODAR currents (m/s) CODAR currents (m/s) CODAR currents (m/s)Increased current speed with waves coupling.

TY / DGQH best.

WRF+ SST + OOST m

WRF

STORM SURGE

DATAWRF


WRF + ROMS


(OOST) (DGQH)

Increased surge with waves coupling.TY / DGQH best?

swan

Documents

wind file

bathymetryinput file

swan model

windwave generation

generation wave model

readinp wind

wave directions

model descriptionkeywords