U.S. Geological Survey hydrodynamic model simulations for Barnegat Bay, New Jersey, during Hurricane Sandy, 2012

We used the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST; Warner and others, 2010) model to simulate ocean circulation, waves, and sediment transport in Barnegat Bay, New Jersey, during Hurricane Sandy. The simulation period was from October 27 to November 4, 2012. Initial conditions for the salinity and temperature fields in the domain were acquired from a 7-month simulation of the same domain (Defne and Ganju, 2018). We used a 2012 digital terrain model (Andrews and others, 2015) to prescribe the prestorm bathymetry. Wetting and drying was enabled, wave-current interaction was modeled with a boundary-layer formulation accounting for the apparent roughness of waves, and the vortex force formulation was used for wave-energy conservation. We used three noncohesive sediment classes to define the sediment bed (sand, very fine sand, and silt). Marshes and subaerial sediment were represented by an additional class that was coarser, non-erodible, and immobile. The hydrodynamic model requires forcing to be defined at the lateral open boundaries and the air-sea interface. Air-sea fluxes are specified by using a bulk flux parametrization and data from the North American Regional Reanalysis, supplemented with wind speed data from the U.S. Geological Survey weather station in Barnegat Light, N.J. The river inflow was specified as point sources at seven gages. Additionally, spectral wave data from the COAWST forecast system for the U.S. east coast and Gulf of Mexico were imposed at the eastern boundary. The lateral open boundary conditions included tidal water level and velocity amplitudes for the North Atlantic, detided barotropic velocity, and detided water level from the COAWST model of the U.S. east coast. Salinity and temperature boundary conditions were supplied by the COAWST model of the U.S. east coast. In addition to the baseline simulation (Storm), we developed a simulation representing the nonstorm conditions for the same period (nonStorm) by filtering the storm signal from the forcing fields. Additionally, we simulated the same period by systematically removing a selected forcing mechanism per simulation to analyze the influence of that mechanism in driving the estuarine response. Specifically, we first removed offshore waves (noSwell), then removed locally generated waves (noSW), and finally removed local wind (noSWW). For more details on the sources of model setup, see Defne and others (2019). Reference cited: Andrews, B.D., Miselis, J.L., Danforth, W.W., Irwin, B.J., Worley, C.R., Bergeron, E.M., and Blackwood, D.S., 2016, Marine geophysical data collected in a shallow back-barrier estuary, Barnegat Bay, New Jersey (ver. 1.1, September 2016): U.S. Geological Survey Data Series 937, 15 p., https://doi.org/10.3133/ds937. Defne, Z, and Ganju, N.K., 2018, USGS Barnegat Bay hydrodynamic model for March to September 2012: U.S. Geological Survey data release, https://doi.org/10.5066/F7SB44QS. Defne, Z, Ganju, N.K., Moriarty, J, 2019, Hydrodynamic and morphologic response of a back-barrier estuary to an extratropical storm: Journal of Geophysical Research: Oceans, https://doi.org/10.1029/2019JC015238. Warner, J.C., Armstrong, Brandy, He, Ruoying, and Zambon, J.B., 2010, Development of a coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system: Ocean Modelling, v. 35, issue 3, p. 230-244.