Nonlinear wind-waves, their modification by tidal currents, and application to Norwegian coastal waters.

This project aims at making fundamental advances in the understanding of wave climate in coastal waters, with particular application to Norwegian waters that can have strong inhomogeneous tidal currents. This will be achieved by developing and using suit able phase-resolving deterministic nonlinear wave models for Monte--Carlo simulations with relevant coastal wave and current conditions. We will ask questions that are beyond the capabilities of todays operational models such as WAM, SWAN or STWAVE. We seek the qualitative statistical distributions of surface elevation, wave height and period, wave kinematics (the velocity and acceleration fields below the free surface), and how these statistical distributions are affected by strong inhomogeneous tidal currents, various depths and various fetches. We want to understand the spatial shapes of extreme waves such as crest length and curvature, and how these may differ between coastal and open sea environments. Furthermore, we want to understand how the pr ocess of establishing a quasi-steady wave spectrum in a coastal environment is different from the open sea. The spatial scales for inhomogeneity of the tidal current may be shorter than the spatial scales for the development of a quasi-steady spectrum, i mplying that a conventional spectral description may not work well. The phase-resolved deterministic description will handle this situation, providing the spectrum as one of its predictions. The new knowledge gained may substantially increase our unders tanding of navigational conditions in coastal waters. There may be important benefits to the estimation of risk and fatigue for marine structures in coastal waters (aquaculture, off-shore wind turbines, wave- and tidal power). This type of wave modeling may have important implications for future operational forecasting of waves in coastal and off-shore waters. The results will be ideal for popularized publication,