Current profiles are examined for evidence of nonlinear energy transfers from the M 2 internal tide to diurnal waves. The 6 month records, unlike shorter records, produce well-resolved velocity and shear spectra that consistently exhibit maxima at the diurnal tides O 1 and K 1 , with a minimum at the intermediate M 2 subharmonic, M 2 /2. The ratio of velocity spectral energy at M 2 /2 and M 2 is quantified, providing a needed modeling benchmark. Bispectra and bicoherences imply a negligible [ÀM 2 /2, ÀM 2 /2, ÀM 2 ] triad interaction, but possibly a significant interaction for the [ÀO 1 , ÀK 1 , ÀM 2 ] triad. Numerical simulations, however, indicate that O 1 and K 1 signals are from internal tides. Tests with synthetic data, linear tides plus random noise, reveal that bispectrum and bicoherence estimators can yield significant values, thus misleading results. Therefore, resolving the diurnal tides from M 2 /2 is essential to meaningfully assess nonlinear transfer of energy from M 2 to diurnal waves.

This paper summarizes the existing coastal hazard forecast methods of PacIOOS, such as wave-induced run-up, by focusing on the critical components that need to be addressed in order to improve these forecasts and make them more accurate and available to broader coastal communities. We then propose that a horizontally, twodimensional numerical modeling approach method should be adopted for developing future wave-induced coastal forecasts. To reach a future in which real-time twodimensional model-based forecasts are a reality, we identify existing technologies that could lead to improvements, such as: (i) more accurate, accessible and frequently updated bathymetry and topography datasets; (ii) increased computational and software capabilities; and, (iii) more accurate sea level datasets. These advances, combined with crowdsourced-based model-data validation, will result in faster and more accurate forecasting tools that could greatly benefit coastal communities in need of more efficient risk mitigation programs.

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Wave simulations from two Boussinesq-type models: BOSZ (Roeber & Cheung, 2012) and FUNWAVE (Shi et al., 2012), and a non-hydrostatic model: XBeach (Roelvink et al., 2009), are compared to observational data in a harbor and along the exposed coast of northwest O'ahu Island, Hawai'i, under highly energetic sea/swell forcing conditions. In the present comparison we attempt to address whether the models can (i) reproduce the observed spectra at different locations over a fringing reef and inside a harbor, and; (ii) draw a consistent 2-dimensional picture of the gravity and IG wave fields throughout the computational domain.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kbbOT0ZpnEo