Development of a high resolution wave climate modelling methodology for offshore, nearshore and onshore locations of interest

Abstract

The aim of this investigation was to develop a methodology to characterise the wave climate for offshore, nearshore and onshore locations of interest. The proposed methodology was applied to a domain located off the west coast of Ireland, adjacent to Loop Head, Co. Clare, and this was an area of interest for ocean energy development. A 3rd generation spectral wave model for the domain was developed, calibrated and validated using DHI’s MIKE 21 spectral wave modelling software along with sea state, met-ocean and bathymetric data obtained from a wide range of sources.

The model yielded information on a range of indices including annual mean wave power, exploitable wave power, maximum wave height, percentage occurrence of a range of sea states and wave directionality at off-shore, near-shore, and on-shore locations.

The models predictions were compared with local wave measurements for calibration and validation purposes obtained from a non-directional Datawell Waverider wave measurement buoy. The wave climate model predicted significant wave height and energy period at this location exhibiting a scatter index of less than 0.25 and a correlation coefficient greater than 0.85. The inclusion of a high resolution bathymetry dataset in the on-shore and coastal regions of the domain was the main driver in achieving this level of agreement between the data.

The spectral wave model developed in this research programme will be useful for future wave energy research. Results from this model indicate that the domain off County Clare possesses an exploitable resource with promising levels of energy for potential wave energy projects. They also show that the near-shore and on-shore environment in this domain maintains good levels of power with relative filtering of extreme waves.