Dynamical partitioning of directional ocean wave spectra

•A new method for partitioning directional wave spectra is introduced.•It is based on a statespace formulation and Monte Carlo simulations.•It includes simple stochastic models to describe the dynamics of the wave systems.•The partition obtained at a given time uses the information available at the previous time step.•The method permits to track automatically the time evolution of the wave systems.

Directional wave spectra generally exhibit several peaks due to the coexistence of wind sea generated by local wind conditions and swells originating from distant weather systems. This paper proposes a new algorithm for partitioning such spectra and retrieving the various systems which compose a complex sea-state. It is based on a sequential Monte-Carlo algorithm which allows to follow the time evolution of the various systems. The proposed methodology is validated on both synthetic and real spectra and the results are compared with a method commonly used in the literature.