Dipolar Trends of Eddy Kinetic Energy in the Kuroshio Extension Observed Over the Past Three Decades

Abstract Oceanic eddies play an important role in the transport, aggregation, and dispersion of heat, carbon, and nutrients, thereby regulating climate and marine ecosystems. In most western boundary current extensions (WBCEs), the integrated eddy kinetic energy (EKE) has increased significantly during the satellite era. However, the Kuroshio Extension exhibits pronounced spatial variations in its long‐term EKE trend, without a significant overall increase. Here, we show that EKE in the Kuroshio Extension exhibits a dipole trend pattern, with enhancement in the north and weakening in the south. This dipole trend pattern is driven by the increased stability of the Kuroshio Extension. As the Kuroshio Extension shifts northward due to increased stability, EKE generation via baroclinic energy conversion also shifts northward, whereas eddy activity decreases to the south owing to reduced baroclinic energy conversion. Furthermore, the increasing stability of the Kuroshio Extension is driven by a negative trend in wind stress curl anomalies across the North Pacific at corresponding latitudes, as quantitatively supported by a linear vorticity model. These findings highlight the distinct dynamics of EKE trends in the Kuroshio Extension in contrast to other WBCEs and provide insights for predicting future EKE changes.