3D Numerical Simulation of Kuroshio-induced Wake Near Green Island, Taiwan

Abstract

In this research, Kuroshio-induced vortex shedding in the lee of Green Island was numerically studied using the three-dimensional Princeton Ocean Model. The temporal and spatial characteristics of the vortex street were analyzed at different tidal levels, wind fields and water depths. The numerical results were validated by comparing with in-situ measurements from the Green Island tidal station, shipboard acoustic doppler current profiler (ADCP), conductivity-temperature-depth (CTD) profiler, and moderate resolution imaging spectroradiometer (MODIS) satellite image datasets. Also, the three-dimensional results of velocity, temperature, and salinity fields were compared well with observational data. Furthermore, the influence depths of the wind effect and vortex shedding were found to be approximately 100 and 300 m, respectively. The aspect ratio and dimensionless width were evaluated to be 3.64 and 1.46, respectively. In addition, the temporal scales (Strouhal numbers), and propagation speeds were analyzed at various water depths. Finally, the elongation of the Kuroshio-induced vortex street was studied under wind and tide effects at various water depths.