Wind-Generated Waves in Fjords and Coastal Areas

• Published in: Ocean Modelling
• Main Author: Christakos, Konstantinos
• Other Authors: orcid:0000-0001-5615-9924
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: The University of Bergen 2021
• Subjects: Norwegian Sea; Norway
• Online Access: https://hdl.handle.net/11250/2771177

Accurate predictions of coastal and fjord wave conditions are vital for several sectors such as fish farming, fisheries, as well as coastal and maritime infrastructure. In complex coastlines such as the Norwegian coast with thousands of islands, islets, and narrow fjords, accurate wave prediction is challenging. In addition to the necessity of using a state-of-the-art nearshore wave model with high spatial resolution, there is a need for high quality and resolution of forcing fields such as wind, surface currents and bathymetry. Moreover, in such areas, satellite remote sensing techniques are not reliable due to the proximity to the land. The observations are thus mainly limited to point measurements, e.g., wave buoys. In recent years, the Norwegian Public Roads Administration has conducted one of the largest measurement campaigns for wind, wave, and current conditions along the Norwegian coast. The campaign aims to obtain the essential data to construct a ferry-free E39 highway route. It provides observations for advanced met-ocean studies in coastal areas and fjords that previously have not been possible. Using these unique measurements together with a high-resolution wave simulation system based on a spectral wave model, this thesis advances our knowledge about coastal and fjord waves. Papers I-III investigate wind-generated gravity waves in a complex coastal system with narrow fjords, partly exposed to some of the most energetic offshore waves at the western coast of Norway in the Norwegian Sea. In Paper I, we investigate the importance of wind forcing on coastal and fjord wave conditions. The results indicate that a high-resolution wind forcing is essential to obtain a realistic wind field in complex fjord topography. The best model performance is found at the exposed to open sea locations using high-resolution wind forcing. Local phenomena such as lee effects and wind channelling significantly affect the wave estimates. During extreme cases, simulations without wind forcing are unable to predict the wave ...