High resolution (2 Hz sampling frequency) wave observations were available from an oil platform in the North Sea when a fetch limited extreme wave event occurred between the 14 and 15th December 2012. A significant wave height of 12m and peak wave period of 13s was observed with 19 rogue waves. Current spectral wave models cannot simulate this event accurately, we shall investigate why. For example, is it because the wind field is not accurately resolved (in either space or time), or is it because of wave-tide interaction, or source terms within the wave model?
Data will also be collected from Bangor University’s waverider buoy, and a near-by 5-beam adcp, located in the North Wales tidal-stream energy demonstration zone. Analysis from both regions will be used to understand the sensitivity of wave growth terms in the SWAN spectral wave model, the accuracy of wave rider buoys in high tidal current regions, and the importance of wave-tide dynamic coupling. Results from our investigations will be presented to colleagues at the National Oceanographic Centre (Liverpool), and a planned research paper.
Outcomes and benefits
Research outputs from the proposed project will form the basis of a research paper to investigate the sensitivity of spectral wave models during fetch limited cases, which will lead to better parameterizations of wave growth terms and understanding of ocean-atmosphere interactions – building upon the work of two recent research papers:
- Gibson et al. (2014). The statistics of wave height and crest elevation during the December 2012 storm in the North Sea. Ocean Dynamics, 64(9), 1305-1317;
- Bricheno et al., (2013). Effect of High-Resolution Meteorological Forcing on Nearshore Wave and Current Model Performance. Journal of Atmospheric and Oceanic Technology, 30(6), 1021-1037
Furthermore, the results of analysis, including recommendations for wave observations in high tidal current sites, will be presented at the 14th International Workshop on Wave Hindcasting and Forecasting and 5th Coastal Hazards Symposium (Nov 2015).
The student will benefit from access and training to the hpcwales supercomputing system (www.hpcwales.co.uk), the SWAN wave model and time-series analysis with OCTAVE or MATLAB. Furthermore, they shall gain experience of working within the research environment of the School of Ocean Sciences.