대한해협 저층냉수 유입에 대한 조석효과

Abstract

The bottom cold waters have often been observed near the northeastern mouth of the Korea Strait southwestern East Sea (Japan Sea) mainly during the summer time. Hydrographic sections exhibit a dome-like isothermal feature near the edge of the continental shelf-slope, which seems to be associated with the intrusion of bottom cold water from the southwestern East Sea into the Korea Strait. Previous studies suggest possible causes of the bottom cold water intrusion, yet its mechanism is not clear. In this study, we investigate tidal effects on the bottom cold water intrusion using numerical simulations, which can include both wind-driven oceanic currents and tides simultaneously. We use a fine-resolution regional ocean model with 1/108-degree grids and s-coordinated 20 layers. Four different cases of numerical simulations are conducted with 1) no tidal forcing, 2) M2 tides only, 3) K1 tides only, and 4) all four major tides (M2, S2, K1 and O1). Our simulation results demonstrate that tides play an important role in generating the intrusion of bottom cold water in this region by both near-bottom ocean mixing and internal tidal residual currents. More details are under investigation and will be presented in the meeting.