Meridional Energy Flux Near an Eastern Boundary Within the Turning Latitudes of an Equatorial Basin

Abstract:

Analytical solutions for the reflection of an equatorial Kelvin wave from a meridional eastern boundary have long been known. A westward energy flux is carried by long Rossby modes with real zonal wavenumbers, and an infinite sum of modes with complex wavenumbers combine to carry energy flux poleward from the turning latitudes in coastal Kelvin waves. The meridional distribution of period-averaged westward energy flux carried by the real Rossby modes does not match the meridional distribution of eastward energy flux carried by the Kelvin wave, however. Additionally, the coastal Kelvin waves are only defined poleward of the turning latitudes, whereas the incident equatorial Kelvin wave energy flux is tightly trapped to the equator. We examine the interaction of modes required to resolve the apparent contradictions and to transfer energy flux smoothly from the incoming to outgoing waves.