Application of the Nearshore Wave Model STWAVE to the North Atlantic Coast Comprehensive Study

Abstract

The U.S. Army Corps of Engineers (USACE) recently completed a detailed study to address the coastal storm and flood risk to vulnerable population, property, ecosystems, and infrastructure affected by Hurricane Sandy. One component of the North Atlantic Coast Comprehensive Study (NACCS) used a suite of high-fidelity numerical models to produce nearshore water level and wave estimates for the North Atlantic coast. Nearshore wave transformation for the NACCS was accomplished using the wave model Steady-State Spectral Wave (STWAVE). To represent rigorously the underlying physical processes of the modeled storm events, tight two-way coupling between an advanced circulation model and STWAVE was facilitated with a modeling system for coastal storms. Seven historical storm events, two extratropical and five tropical storms, were selected for evaluation of the STWAVE model. The storms selected were Hurricane Gloria (1985), extratropical 070 (January 1996), extratropical 073 (December 1996), Tropical Storm Josephine (1996), Hurricane Isabel (2003), Hurricane Irene (2011), and Hurricane Sandy (2012). Mining numerous data sources identified 30 buoys within the STWAVE domain. STWAVE results were compared to the existing measurements using both graphical and statistical methods, resulting in one of the most comprehensive nearshore wave model assessments to date. The performance of STWAVE improved significantly with more recent storms, particularly for Irene and Sandy. This improvement is likely the result of a combination of factors, such as, but not limited to, more accurate wind and offshore forcing, advancements in buoy technology, and a large measurement population.