Use buttons below to load and run a simple animation of the development of a swell from a localised storm.
The initial storm is modelled as a circular region of incoherent random fluctuations. The disturbance is then evolved according to the dispersion relation for small amplitude waves in a deep ocean.
| (1) |
To compute the evolved distubance f(r,t) we fourier transform the initial disturbance f(r, t = 0) to obtain
| (2) |
| (3) |
The model is somewhat unrealistic in that the waves are freely propagating after the initial disturbance, but captures the essential features that the long wavelength components outrun the high frequency modes, resulting, at late times, in a locally quasi-monochromatic wave with a characteristic patters of relatively slowly modulated wave-trains or 'sets'.