Particles clustering in water waves

Inertial particles drifting through flows with multiscale eddies show rich dynamical properties, which have been a subject of extensive investigation. A simpler realization of the multiscale nature of the eddies is achieved by observing the motion of inertial particles drifting through a water wave field. Here we study inertial particles advected by a water wave. We observe a spatially locked distributions of evolving particle clusters. We characterize the clustering behavior of the particles and present a theoretical model to predict the behavior as function of particle and flow parameters. The results may be of relevance to understanding the transport and subsurface lifetimes of bubbles and microplastics.