EFFECTS OF THE HORIZONTAL COMPONENT OF THE EARTHS ROTATION ON WAVE-PROPAGATION ON AN F-PLANE

Scaling arguments are used to show that effects due to the horizontal component of the Coriolis force should be taken into account as a first correction to the traditional hydrostatic theory, before frequency dispersion due to vertical acceleration and nonlinearity are included. It is shown analytically that wave propagation of the f-(f) over tilde-plane becomes anisotropic and that amphidromic systems do not exist in their usual definition. Another important consequence is the existence of free wave solutions at subinertial frequencies. The inclusion of the horizontal component of the Coriolis force is further investigated numerically for effects on various forms of wave propagation (barotropic, baroclinic, internal and topographic). Using a sigma-coordinate ocean circulation model, the analytically derived results are extended to more general cases including stratification and topography. A series of idealized process studies is performed to show the modified wave properties. These concentrate on the eigen-oscillations of closed basins, the internal wave response to a single pulse and forced seamount trapped waves. Implications for local and regional models of ocean circulation are considered.