Intensification of Eddy Energetics Modulates Seasonal Trends and Spatial Variability in the East Australian Current System

Abstract The East Australian Current (EAC) separates near 32°S, forming large, energetic eddies. While the seasonal cycle of the EAC system is well documented, the season‐specific long‐term trends in its separation latitude, eddy energetics, and their spatial heterogeneity remain poorly understood. Using 25‐year of satellite observations and high‐resolution model output, we find the significant southward shift in the EAC separation latitude is strongest in austral spring. Eddy kinetic energy (EKE) and mean‐to‐eddy energy conversion also show seasonal and spatial heterogeneity; decreasing strongly in the EAC retroflection during summer and increasing in the EAC southern extension during autumn. Barotropic instability dominates eddy generation year‐round in the retroflection, but only in autumn in the southern extension. EKE anomalies propagate southward with a 2–3 months lag. Our findings show that eddy energetics in the EAC system are characterized by spatial heterogeneity and seasonal dependence, accurately representing this spatiotemporal variability is essential for improving predictions.