Modeling of Storm-Induced Hurricane Inundation through a Comprehensive Flexible Coupling Framework.

To enable flexible model coupling in storm surge studies, a coupled application in the modeling framework called the NOAA Environmental Modeling System (NEMS), which utilizes NUOPC/ESMF, was developed. This NEMS framework allows for seamless communication while driving a coupled model efficiently in massively parallel environments. All model components advertise their imported and exported fields at run time, and connect to each other for exchanging data based on the availability of the advertised fields. This occurs via code interfaces referred to as model caps. The coupling strategy provides dynamic interaction between the wave (WAVEWATCH III) and storm surge (ADCIRC) models. The data communication between models take place interactively by sending spatiotemporal water level and current fields from the storm surge component to the wave component, and in turn send radiation stress gradients from the wave component to the storm surge component. The system is forced by high-resolution wind and pressure fields derived from the HWRF model, and tidal constituents at the boundaries of the surge model. This coupled system was evaluated using the case study of Hurricane Ike (September 2008), the 3rd most costliest Atlantic hurricane in the U.S., which swept through portions of the Greater Antilles and Northern America westward with significant impact on Cuba. It finally strengthened to a peak intensity through the Gulf of Mexico and made its final landfall on Galveston, Texas. The modeling system was run in both uncoupled and coupled modes to assess the impact of the exchanges on the individual model components. Inclusion of the wave radiation stresses in the surge component was found to increase the coastal and overland water levels along the Galveston coastline. Conversely, including these water levels in the wave model component increases nearshore significant wave heights, reducing the negative model biases found when running in stand-alone mode.