Presenter: John Warner (US Geological Survey)

Description:
Prediction of extreme storms and their local effects on geomorphology, habitat, and infrastructure is crucial for management decisions and to provide early warning for evacuations and minimize loss of life and property. We have been developing the coupled COAWST numerical modeling system that can simulate both local and larger-scale ocean, wave, and atmosphere physical processes. The newly added nearshore infragravity wave model (InWave) is demonstrated to show how wave group patterns propagating from along the open boundary interact to enhance the variance of wave action density within the domain, thus providing a mechanism to generate infragravity wave motion. Sensitivity to boundary condition options and wave directional resolution are examined. The model is applied to an archived test case of the Delilah experiment (1990). Results are compared to observations of mean and infragravity waves and currents and demonstrates strong skill for propagation of wave parameters and generation of infragravity waves. The modeling system is then applied to investigate Hurricane Michael (2018) that impacted the northwest coast of Florida. Accurate assessment of impacts to these realistic systems requires high resolution nearshore and coastal information of landcover, bathymetry, topography, and oceanographic observations for comparison to model predictions. Sensitivity to model inputs and preliminary results are provided. This study demonstrates the importance of including the coupling of waves, currents, and nearshore morphological change to accurately simulate coastal impacts.