Turbulent Mixing induced by Cold Water Intrusion over the Southwestern East Sea

Along the southeastern coast of Korea the warm and salty Tsushima Warm Currents flows northeastward. During summer a southwestward cold water intrusion from the East Sea occurs along the bottom below the warm current. Thus, a strong shear and consequently strong turbulent mixing are expected along the boundary between the warm water and cold water. To quantify the mixing hydrographic surveys using a free falling microstructure profiler (VMP-500) were conducted. Enhanced dissipation of energy was indeed observed along the interface located between 15 degrees C to 20 degrees C layers. Along the bottom there was another layer with enhanced energy dissipation. These high energy dissipations resulted in high vertical diffusivities. The layers of high vertical mixing slanted upward toward the coast could supply nutrient to the surface layer to support high productivity along the Korean coast.