The horizontal circulation of annual wave energy in the tropical Atlantic Ocean as identified by a seamless analysis scheme

This study provides a view for the horizontal circulation of wave energy in the upper layers of the tropical Atlantic Ocean for the first time. Energy fluxes are calculated by applying a recently proposed diagnostic scheme to model output for three gravest baroclinic normal modes (BCMs) with climatological wind forcing. The scheme is validated as giving a proper approximation for energy flux of long equatorial waves with seasonal forcings in Atlantic basin. It is capable of tracing the group-velocity-based transfer routes of both mid-latitude and equatorial waves. The result of analysis completes the horizontal circulation of annual wave energy including both wind-input and reflection events. The meridional energy flux is examined concerning tropical-extratropical interactions. Wind-generated waves are able to be distinguished from reflection-generated waves by the analysis. The meridional energy flux at around 3^oN and 2^oS confirms the existence of equatorward energy transport by Rossby waves (RWs). The poleward meridional flux turns out to be an important energy sink compared with the local dissipation. The energy circulation in the 3rd BCM shows that wind input peaks appear in regions around 35^oW in September, 20^oW in June, and 10^oW in March, making multiple Kelvin wave (KW) beams pass the central and eastern parts of the basin in the same year. Reflection-generated KWs and wind-generated RWs are both found at the western boundary. The result of analysis also identifies a wind input event, previously unmentioned, inducing both mid-latitude RWs and inertial gravity waves (IGWs) in regions at 4^oS, west of around 10^oW.