SWAN

Nearshore

wind wave energy level per frequency per direction

Hm0

Tm02

wave force

Conservation of action density N(t,x,y,f,θ)

Generation by wind

Dissipation by depth-induced wave breaking

Dissipation by bottom friction

Dissipation by white capping

Non-linear wave-wave interaction (quadruplet and triad (shallow waters))

Refraction (by bottom and current gradient)

Blocking (by opposing current)

Blocking and transmission (due to obstacles and vegetation)

Default in physical and spectral space

fully absorbing for leaving wave energy

In coastal region

the deep water boundary is specified by the incoming wave energy

Shape of spectrum at the boundary of the computational grid could be:

JONSWAP spectrum,

Pierson-Moskowitz (PM) spectrum

Gaussian-shaped frequency spectrum

Simulated results provided by external model predictions (nested SWAN/WAM/WaveWatchIII)

Measured spectra (at KUL, with a small matlab routine)

For model set-up:

Bathymetry

Wind

e.g. ERA-interim (at KUL)

measured wind (at KUL)

For B.C.

Nesting on coarse WAM/SWAN/WW3 run

Measured 2d spectra (at KUL)

Model generated data:

Wave energy spectra

Integrated wave parameters Hs, Tm02,…

less efficient on oceanic scales

Comparison

Parametric (integrated spectral parameters, Hm0, Tm02)

Spectral (spectral score)

Calibration tools

Sources (wind generation coef.)

Sinks (bottom roughness, …)

Numerical (dt, conv. crit., …)

Discretization (dx, dy, df, dθ, …)

Parametric Comparison (Hm0, Tm02)

Multiple measurement stations in southern North Sea

Shallowest at ~5 m. MSL at Trapegeer

Spectral comparison (1D or 2D)

Directional (f-θ) and non-directional (freq. only) buoys