Evaluating a down-scaled, coupled wave-surge modeling system in an operational environment

Jakob Maljaars
2:00 pm November 24 in Room 2552

As part of the development of the Nearshore Wave Prediction System (NWPS) a hindcast study was conducted for a hurricane event in the Hawaii region. The existing two-way coupling between the ADCIRC-model and the SWAN-model was employed in order to model the two-way wave-current interaction. Implementation issues and results of the hindcast study are discussed during this presentation.

Results show a good agreement between simulated and measured tidal constituents. Simulated tidal constituents were also in very good agreement with the large scale ESTOFS Pacific model data. However, in the down-scaled ADCIRC+SWAN-model a clear wave induced set-up is observed around landfall of the hurricane which is neither observed in the ESTOFS data nor in the ‘standalone’ ADCIRC simulations for the Hawaii region. It turns out that the wave influence on the surge level is strongly location dependent and sensitive to the used meteorological forcing. Therefore, a sensitivity test was performed using different grid resolutions and the quality of different meteorological models (GFS, NAM, HWRF) was assessed.  With the lessons learned a simple operational environment was built around the coupled ADCIRC+SWAN-model for the Hawaii region, ready for implementation in the NWPS.