Coupling and Validation of WAVEWATCH III and ADCIRC Using the NUOPC/ESMF Framework

WAVEWATCH III (Tolman et al. 2016) is a major wind-wave model that is widely used for both research and operations. Although initially designed for global modeling on a regular grid, in recent years it has been extended to unstructured meshes for coastal applications. Similarly, the unstructured-mesh ADvanced CIRCulation (ADCIRC, Luettich et al 1992) model is popular both for research and as an operational tide and surge model. Creating a coupling between these two widely-used models, using a community-based coupling infrastructure is therefore a valuable contribution to the field. In this work, we have coupled WAVEWATCH III and ADCIRC using the National Unified Operational Prediction Capability (NUOPC) framework, which is based on the Earth Systems Modeling Framework (ESMF). The primary application of this coupled system is the Named Storm Event Model (NSEM), which is a high-fidelity hindcast model designed to provide estimates of wind- and water-related damage due to landfalling hurricanes in compliance with the United States COASTAL Act of 2012. Each model component is included into the coupling framework via a software interface known as a model cap, which provides the NUOPC driver access to the underlying model variables and model advancing. Such model caps have been developed for ADCIRC (see Moghimi et al. 2017 and for WAVEWATCH III (this study). The model cap for WAVEWATCH III has been based on a new domain decomposition version of the model, which also features the option to use an implicit numerical scheme for coastal application at a high spatial resolution. This coupled wave-surge model has been validated for idealized laboratory cases as well as a number of major hurricanes, including Ike, Irma and Sandy. The latter tests were run on the operational HSOFS unstructured mesh featuring 2M nodes, with inundation potential of up to +10 m MSL. The coupled model shows improved performance compared to stand-alone model runs of WAVEWATCH III and ADCIRC. The dynamic exchange between the two models accurately reproduces the effects of wind waves and surge in the nearshore and overland regions at landfall.

References

Tolman, HL, et al (2016) The WAVEWATCH III development group (ww3dg), 2016: User Manual and system documentation of WAVEWATCH III version 5.16., College Park, MD, USA. NOAA/NWS/NCEP/MMAB Tech. Note 329:326

Luettich Jr RA, Westerink JJ, Scheffner NW (1992) ADCIRC: An advanced three-dimensional circulation model for shelves, coasts, and estuaries. Report 1. Theory and methodology of adcirc-2ddi and adcirc-3dl. Tech. rep., COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS

Moghimi et al. (2017) Development of a flexible coupling interface for ADCIRC model for coastal inundation studies, Technical note, NOS, NOAA.