Abstract:

A recent set of experiments sponsored by the Office of Naval Research has been conducted in the vicinity of the Mid-Atlantic Bight shelf break region off the coast of New Jersey. The environment in this region is highly variable in both range and bearing due to the shelf break slope and its associated front. One of the goals of this Shelf Break Primer project is a determination of the influence of azimuthal coupling on the 3-D propagation. By using a fully 3-D PE model and comparing with results from the associated 2-DxN PE approximation, a quantitative assessment of the influence of azimuthal coupling can be made. Some sample benchmark cases are performed to illustrate this method. Using this approach, the significance of both the sloping bathymetry and the shelf break front will be considered separately and combined. In addition, the influence on the arrival time structure of a broadband pulse, similar to a signal employed during the experiments, will be determined. Characteristic features of such 3-D effects in the pulse propagation will then be explored in the available data sets. [This work is supported by the Office of Naval Research, Code 321OA.]