An unstructured normal mode decomposition solver on real ocean topography for the analysis of storm tide hazard

In this study, we have developed an unstructured normal mode decomposition solver based on the finite element method for the purpose of normal mode analysis on natural basins. The normal mode analysis can be used to provide the site-specific storm hazard summary such as storm risk for a given basin. This information can provide a useful guideline during the storm events. The analysis of the two past storm events using the normal modes derived from the solver has been demonstrated in two different locations. The first event is tropical cyclone Linda (1997) in the Gulf of Thailand and the second one is tropical cyclone Melor (2009) in the Ise Bay, Japan. The analysis reveals a relation of the storm forward speed and the storm path to the spatial distribution of leading normal modes. We believe that our results can be used for the analysis of past storm events, and may be applied to future storm events.