U.S. Dept. of Commerce / NOAA / OAR / PMEL / Publications
The eddy-resolving circulation model which we applied to the Shelikof Strait region is the rigid-lid semispectral primitive equation model (SPEM) of Haidvogel et al. [1991], which employs a topography-following ("sigma") vertical coordinate system. The horizontal grid is formulated in curvilinear-orthogonal coordinates, with 257 × 97 horizontal grid points and nine vertical levels. The full model domain is ~1500 × 500 km, with grid spacing telescoped (gradually increased) near the southern, eastern, and western boundaries. In the central, near-coastal region of interest, the mean grid spacing is ~4 km. Details of the model's implementation in this region are given by Hermann and Stabeno [this issue].
The density structure for each model run was initiated using salinity fields obtained from conductivity-temperature-depth (CTD) surveys [Reed, 1984; Reed et al., 1987; Johnson et al., 1988]. For each year studied the model was spun up from a state of rest starting in January of that year using the appropriate winds and the freshwater discharge. By the end of March the model was fully evolved, with strong flow throughout the sea valley. Velocity and salinity (low-pass filtered) at each grid point were stored at daily intervals. In addition, model results were stored at hourly intervals at the location of the moorings. Trajectories of floats were generated from the daily stored results of the model runs. These floats were constrained to remain at 40 m depth in conformance with the depth of the drogues for the satellite-tracked buoys.
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