Table 1. Wave Measurement and Model Validation Sources
Water Depth, m
Pressure Gauge Array
Fire Island Inlet
To be determined
Pressure Gauge Array
WAVE MODELING SYSTEM
A regional calculation domain extending over the entire south shore was established for
the nearshore wave directional transformation model STWAVE, which includes provision
for nested grids at inlets. The model configuration allows the offshore wave boundary
conditions to be specified either from numerical models (hindcast, nowcast, and forecast
modes) or from offshore measurements such as at Buoy 44025. The offshore wave
information and wind measurements drive a coarse-resolution STWAVE model that saves
information at the offshore boundaries for local fine-resolution grids along the coast.
Simulations cover nearshore modeling for 1998 and 1999, when data were collected at
Shinnecock Inlet and Westhampton. Objectives of the modeling include:
Evaluation of the appropriateness of directional spectral boundary conditions
synthesized from parametric buoy data or obtained directly from a new large-scale
Atlantic Ocean wave hindcast. Because offshore hindcast wave data are often applied
in coastal engineering studies and designs, the quality of new and improved hindcasting
methods is of interest.
Evaluation of the adequacy of the STWAVE directional spectral wave model in
transforming offshore wave conditions to nearshore locations based upon buoy
measurements and newly-hindcast offshore wave conditions.
Assessment of model skill, such as that of STWAVE, in simulating wave
transformations over a large geographic domain (herein referred to as a "regional"
model) of Long Island with a reasonable grid resolution.
Bathymetry and Modeling Grids
Three wave models are operated. The first is called the Regional Long Island (Fig. 2)
model having a 64 x 115 grid, oriented such that 0 deg in STWAVE corresponds to due
north, with a grid spacing of 1829.27 m. Depths were developed from NOAA nautical
chart data. The offshore boundary of this "regional grid" corresponds to the approximate
latitude of Buoy 44025, where offshore boundary wave conditions are specified.
A second model grid was created by eliminating the southern 14 rows of the regional
grid. This created an offshore boundary that coincides with the approximate latitude where
newly-hindcast Atlantic Ocean waves have been made available as part of the Corps of
Engineers' re-calculated Wave Information Study (WIS). The directional wave spectra are
generated with AES-40 wind fields on a 5-nautical mile grid resolution.