A Numerical and Experimental Investigation on the Interaction Between Meteorological Conditions and Ocean Waves

This thesis focuses on lesser investigated meteorological features, rainfall and atmospheric pressure, and their interaction with ocean waves. The work is carried out using experimental, observational, and numerical methods. After outlining the present state of the relevant literature, a description of the range of different instrumentation used throughout the experimental research is presented. Once the recording capabilities are defined, the wave measurements of a small data buoy and large meteorological buoy are compared with a long standing large data buoy off the west coast of Ireland. It is found that the small data buoy compares well with the larger buoys, and wave packets can be tracked between the two deployment locations. Next, the work investigated the effect of rainfall intensities on vertical surface displacements, as well as energy dissipation. Two different scales of experiment were deployed on the west of Ireland. One focused on small scale, high frequency waves in a lake, and the other investigated larger scale wave fields found at sea. While there were some issues with the original data collection,
including inaccurate data and loss of instrumentation, two new methodologies were devised for in-situ experiments pertaining to the effect of rainfall on waves. To build on this research, the first numerical investigation of rainfall on a monochromatic wave was designed and run. It was found that for non-breaking waves, an increase in rainfall intensity leads to increased energy dissipation. Finally, a study is presented following reports of strange tidal activity across north-west Europe in the summer of 2022. After analysing atmospheric pressure and tidal data, it can be concluded that the dramatic tidal activity witnessed by locals was in fact a series of meteotsunamis. With an emphasis on creating results as true to the real world as possible, this thesis creates a number of novel experimental and numerical methods, which will hopefully be built upon and expanded further in the future. Each chapter outlines the methodologies used to understand the interaction between the different meteorological conditions and the respective waves and describes how the analysis contributes to the understanding of the natural phenomena.