Variations in ocean-driven dynamics in the Kuroshio Extension and their representation in high-resolution climate models
The Kuroshio Extension (KE) is an intense eastward inertial jet of the Kuroshio current, characterized by intense mesoscale eddy activity and air-sea interactions. The coupled KE dynamical system interacts with the extratropical storm tracks and may significantly impact Pacific climate variability and extremes. In this study, we combine satellite-derived and reanalysis data products with high-resolution climate models, to investigate the coupled KE mode of variability focusing on its relationship with the air-sea turbulent heat fluxes. The results show that seasonally dependent air-sea coupling drives the KE effects on large-scale climate, with some suggestions of potential temporal nonstationarity. Furthermore, we examine the representation of coupled KE dynamics in high-resolution climate models compared to their low-resolution counterparts to assess their realism and dependence on ocean model resolution. Changes in ocean-driven air-sea dynamics also appear in high-resolution models, with decadal variations in this behavior comparable with observations. The potential for connections with modes of decadal variability is discussed.