Seasonal variability of eddy kinetic energy in the East Australian current region

The East Australian Current (EAC) is an important western boundary current of the South Pacific subtropical Circulation with high mesoscale eddy kinetic energy (EKE). Based on satellite altimeter observations and outputs from eddy-resolving ocean general circulation model (OGCM) for Earth Simulator (OFES), seasonal variability EKE its associated dynamic mechanism in EAC region are studied. High mainly concentrated shear-region between poleward southern extension equatorward recirculation along Australia's east coast, which confined within upper (0-300 m). this area exhibits obvious variation, strong austral summer maximum (465±89 cm² s-²) February weak winter minimum (334±48 August. Energetics analysis OFES suggests that modulated by mixed instabilities composed barotropic baroclinic ocean, instability (baroclinic instability) main source (winter). process controlled zonal shear meridional velocities recirculation. synchronously strengthened (weakened) due to local positive (negative) sea level anomalies (SLA) under geostrophic equilibrium, dominated enhanced (slackened), results a (low) region.