Tidally Driven Mixing “Hot Spot” at the Entrance of the Japan/East Sea

Abstract

Mixing at the southwestern boundary of the Ulleung Basin (UB) in the Japan/East Sea was examined using combined ship‐based, moored, and quasi‐autonomous observations. These observations revealed strong tidal currents, high‐frequency internal wave packets, and energetic turbulence over the sill connecting the Korea/Tsushima Strait and the UB, especially when a supercritical flow becomes subcritical over the sill. In addition, strong velocity shear associated with the semidiurnal baroclinic tide was found near the bottom, where the bathymetry slope was critical to the semidiurnal tide. Large temperature fluctuations were observed during the subcritical phase of the flow, as hydraulically controlled flow generated internal‐wave packets and energetic turbulence with a turbulent‐kinetic‐energy dissipation rate of 10−4 Wkg−1, and a diapycnal diffusivity of 10−2 m2s−1. Our analysis suggests that the sill is a hot spot of mixing, which in turn can play an important role in the Japan/East Sea circulation.

Document Details

Document Type
Pub Defense Publication
Publication Date
Sep 17, 2022
Source ID
10.1029/2022gl100315

Entities

People

  • Conrad A. Luecke
  • David Wei Chi Wang
  • Ewa Jarosz
  • H. W. Wijesekera
  • Hong Sik Min
  • Jae Hak Lee
  • Kyungjae Lee
  • Kyung‐il Chang
  • SungHyun Nam
  • William J. Teague

Organizations

  • Korean Ocean Research and Development Institute
  • National Research Foundation of Korea
  • Office of Naval Research
  • Seoul National University
  • United States Naval Research Laboratory

Tags

Fields of Study

  • Environmental science

Readers

  • Coastal Oceanography
  • Fluid Mechanics and Fluid Dynamics.
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers