Diagnostic Model for Steady Circulation of Onslow Bay, North Carolina

摘要

A three-dimensional numerical model was constructed to investigate the steady circulation in Onslow Bay, North Carolina. The curvature of the coastline and variable bottom topography are included in the analysis and are shown to modify the dynamics. To facilitate the irregular shape of the domain a stretched coordinate system is adopted in the numerical procedure. The linear equations for sea level and boundary conditions are solved by finite differencing over a curvilinear grid and using a combination of numerical schemes including Successive Over Relaxation, Gaussian Elimination and numerical integration. The model is forced by alongshore wind stress, offshore wind stress, wind stress curl, wind stress divergence, and the spatial variations of the density field. The results are discussed. The predictions of the model are compared with actual current meter observations and the results show favorable agreement. It is shown that the local orientation of the isobaths play a dominant role in the structure of the alongshore sea level gradients. Comparison of results indicate that in a region with a curved coastline and curved isobaths, a series of two-dimensional cross-sections are incapable of resolving the same velocity distribution as obtained from a three-dimensional model, thus three-dimensionality must be invoked. (ERA citation 11:041872)