Island wakes develop when flow encounters a blunt body in geophysical settings. Inspired by satellite imagery and field observations, I employed MITgcm to simulate the wakes downstream of Green Island (about 5 km in diameter) east of Taiwan, achieving patterns and periods aligned with field data. Our study revealed that (i) the wakes display sequentially detached recirculation cells with cold water upwelling, moving downstream; (ii) the island wakes resemble a von Kármán vortex street, influenced by inertial and barotropic instabilities; (iii) the hotspot of turbulent mixing is located where horizontal shear is most pronounced. Due to the island-shelf effect and vertical vorticity tilting, lateral shear partially converts to vertical shear, leading to turbulent diapycnal mixing. Compared to a circular cylinder, the conical shape of the realistic island generates more turbulence in the wake region, evident by overturned colder water (left figure).
