Abstract. A baroclinic shallow-water model is developed to investigate the eect of the orientation of the eastern ocean boundary on the behavior of equatorial Kelvin waves. The model is formulated in a spherical polar coordinate system and includes dissipation and nonlinear terms, eects which have not been previously included in analytical approaches to the problem. Both equatorial and middle latitude response are considered given the large latitudinal extent used in the model. Baroclinic equatorial Kelvin waves of intraseasonal, seasonal and annual periods are introduced into the domain as pulses of ®nite width. Their subsequent re¯ection, transmission and dissipation are investigated. It is found that dissipation is very important for the transmission of wave energy along the boundary and for re¯ections from the boundary. The dissipation was found to be dependent not only on the presence of the coastal Kelvin waves in the domain, but also on the period of these coastal waves. In particular the dissipation increases with wave period. It is also shown that the equatorial b-plane approximation can allow an anomalous generation of Rossby waves at higher latitudes. Nonlinearities generally have a small eect on the solutions, within the con®nes of this model.

Abstract. The eect of viscosity, non linearities, incident wave period and realistic eastern coastline geometry on energy¯uxes are investigated using a shallow water model with a spatial resolution of 1/4 degree in both meridional and zonal directions. Equatorial and mid-latitude responses are considered. It is found that (1) the in¯uence of the coastline geometry and the incident wave period is more important for the westward energy¯ux than for the poleward¯ux, and (2) the eect of the inclination of the eastern ocean boundary on the poleward energy¯ux, for the Paci®c and Atlantic Oceans, decline as the period of the incident wave increases. Furthermore, the model simulations suggest that the poleward energy¯uxes from meridional boundaries give plausible results for motions of seasonal and annual periods. For comparatively shorter periods, a realistic coastline geometry has to be included for more accurate results. It is recommended that any numerical model involving the re¯ection of baroclinic Rossby waves (of intraseasonal, seasonal or annual periods) on the eastern Paci®c or Atlantic Oceans, should consider the eect of the coastline geometry in order to improve the accuracy of the results.