Rip current predictions through model-data assimilation on two distinct beaches

Abstract

This paper describes the development of a physics-based rip current prediction system called CoSMoS. This system consists of a hydrodynamic prediction system which is composed of a train of surge and wave models from the global scale to the scale of a beach resort (order kilometers). For the beach resort scale model, it is of utmost importance to use a recent measured or remote-sensed estimated bathymetry in order to accurately predict morphologically-controlled rip currents. To obtain bathymetry estimates, the Beach Wizard system which makes use of Argus video data is applied to the macro-tidal coast of Perranporth UK and the meso-tidal coast of Egmond aan Zee, the Netherlands. The results for the UK site show that while the Brier Skill Scores of the estimated bathymetry are low, the resultant rip current location, strength and timing are well-predicted. For the Egmond case, the system produces good estimates of the bathymetry and of the rip current parameters. Finally, we demonstrate the potential and form of rip current warnings based on the application of the CoSMoS system for Egmond aan Zee.