Abstract
In this study, physical mechanisms of nutrient supply to the Kuroshio are investigated using numerical simulations and field observations. During the observations across the Kuroshio Extension Front in October 2009, a nitrate-doming structure is found on the north side of the Kuroshio Extension, with low-saline water subducting along the sloping isopycnal of the front, which are most likely modulated with mesoscale frontal meanderings. In the mixed layer, intense turbulence and upward diapycnal nitrate flux are found on the south side of the Kuroshio, which are probably caused by downfront wind stress. Observations in July 2013 using a microstructure profiling float reveal that, along the Kuroshio Extension Front over 900km, vertical diffusion of tracers including nutrients seems to be dominated by double-diffusive convection below150m depth.
