A validation of an operational wave and surge prediction system for the Dutch coast

Abstract

Abstract. Knowledge of the actual condition of hydrodynamics in the nearshore and coastal area is essential for coastal monitoring activities. To this end, a coastal operational model system can serve as a tool in providing recent and up-to-date, state-of-the-art hydrodynamics along the coast. In this paper, we apply CoSMoS (Coastal Storm Modeling System), a generic operational wave and tide-surge modelling system applied here to predict waves and water levels along the Dutch coast. The CoSMoS application is not limited to storm impact prediction on the Dutch coast, but can also be applied to other coastal hazards such as rip currents and coastal flooding, in other environments. In this paper, we present the set-up of the CoSMoS system and a validation of the wave and surge model, with deep-water wave buoy data and tidal gauge measurements as ground truth validation material. The evaluation is presented as monthly error measures between computed parameters and observed ones. Hindcast results over the whole year of 2009 show that the simulated wave parameters and surge elevation from the CoSMoS are in good agreement with data, with average root mean square (rms) error over the year of 0.14 m for the surge elevation and 0.24 m for the significant wave height. It is noted that there is a tendency of the wave model to underestimate the height of northerly waves with lower frequencies (swell). Additionally, when a wave separation algorithm is applied on the overall spectrum, results show consistent underestimation of the swell component by the model, which for the Dutch coast will mainly come from the north, where the North Sea is open to the Atlantic Ocean. In the proposed model system, the swell boundary can have a significant effect on the simulated wave results, suggesting room for improvement for the swell boundary conditions to the north and the swell propagation within the Dutch Continental Shelf Model. Finally, we show that in forecast mode, CoSMoS can provide reasonably good wave and surge prediction.

Extreme sea levels on the rise along Europe's coasts

“…According to the authors' knowledge, there is no continental-scale modeling system that simulates waves and ocean circulation in coupled mode. Few systems run on regional scales [Warner et al, 2010;Bertin et al, 2012;Zhang et al, 2013;Hashemi et al, 2015;Sembiring et al, 2015], producing short-term forecasts with simulation horizons that are orders of magnitude lower than in the case of climate change projections. For the above reasons, the approach of linearly adding ESL components has been used in similar studies and has been showing to result in acceptable accuracy [Lowe and Gregory, 2005;Sterl et al, 2009;Howard et al, 2010;Losada et al, 2013].…”

Projections of extreme storm surge levels along Europe

“…The model has been used successfully in similar applications in the past (Sembiring et al 2015). The Delft3D-Flow module set-up that has been adopted solves the 2D non-linear shallow water equations on a staggered Arakawa C-grid, according to an implicit finite difference approximation on a vertical σ-coordinate system.…”

Extreme Wave Height Events in NW Spain: A Combined Multi-Sensor and Model Approach

“…The wave model used as the base of this operating system is the MF-WAM. This model is based on the IFS-ECWAM (cycle 38R2) code, with changes according to dissipation by the wave breaking and the swell damping source terms as developed in Ardhuin et al As previous works have unequivocally revealed the importance of rigorous validation of operational wave forecasting systems [3,4] and the analysis of extreme wave height events using models [5,6] and shore-based high-frequency radar (HFR) [7,8], the objectives of this paper were twofold. The first objective was to analyze the main features of extreme wave height events in Galicia over the wintertime of a two-year period (2015-2016) by using HFR remote-sensed hourly wave parameters in tandem with predictions from an operational wave (WAV) forecasting system running in the Iberia-Biscay-Ireland (IBI) area, denominated IBI-WAV (Figure 1b).…”