Replication Data for: Dynamics of the Kuroshio separation, instability, and associated eddy formation off southern Japan

This dataset contains the observational and numerical modeling data (CMOMS and ROMS) used to reproduce the figures and dynamic analyses in the associated manuscript. Abstract:The Kuroshio is well-known for its variability south of Japan, where its complex dynamics lead to formation of meandering jet and eddies along the stream. In this study, we investigated the relevant processes and physical mechanism using a well-validated high-resolution China Sea Multiscale Ocean Modeling System and a process-oriented numerical modeling. We found that this variability is chiefly governed by the dynamics of the boundary jet separation along the Kuroshio. Our analysis shows that the Kuroshio detaches from the coast and forms a dipole eddy by an inverse pressure gradient force resulting from both the high nonlinearity of the Kuroshio and the inverse wind-driven Ekman transport. Typically, the separation occurs near protruding coastal capes where bottom pressure torque injects inverse vorticity into the separated current. An accumulation of shear vorticity on the shoreside/seaward side of the separated Kuroshio forms a cyclonic/anticyclonic eddy dipole. Through active dynamic adjustment along the jet, the increasing barotropic and baroclinic instabilities strengthen the meandering jet and eddy, thereby maintaining the separation. This study provides new insight into the dynamics of western boundary current variability.