Integral equation approach to tropical ocean dynamics: Part 2. Rossby wave scattering from the equatorial Atlantic western boundary

The authors develop a linear theory for the scattering of equatorial waves of a fixed frequency omega by islands and continental margins of arbitrary geometry by use of the boundary integral equation (BIE) method of Vianna and Holvorcem (Part I of this work). All the solutions of the equatorial beta -plane dispersion relations at frequency omega are treated explicitly through the extensive use of exact Green's functions, so that the approach is more general and more rigorous than previous attempts to solve equatorial scattering problems, many of which employ the low-frequency and long-wave approximations. The numerical solution of the BIE is obtained through application of the boundary element method. A numerical study of the scattering of Rossby waves with periods between 50 and 90 days from the equatorial Atlantic western boundary is presented. Some of the resulting interference patterns exhibit a sharp amplitude maximum, whose center lies between 3-9N, 35-47W. The position, width and intensity of this maximum all depend on wave period.