동해 남서부 대륙사면 해역에서 조석에 의해 강화된 저층냉수 유입

Abstract

The bottom cold water in Korea Strait has often been observed mainly during summer. Hydrographic sections exhibit a dome-like isothermal feature near the edge of the continental shelf-slope region, which appears to be related with the intrusion of the bottom cold water from the deep basin of the southwestern East/Japan Sea into the Korea Strait. Although previous studies have suggested possible causes of the bottom cold water intrusion, its mechanism is not clear yet. Here we investigate the influence of tides on the bottom cold water intrusion using numerical simulations, which 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. To investigate detail physical processes influencing the bottom cold water intrusion, numerical simulations are conducted as following five cases: 1) wind forcing only without tides, 2) M2 tides only with wind forcing, 3) K1 tides only with wind forcing, 4) all four major tides (M2, S2, K1 and O1) with wind forcing, and 5) all four major tides without wind forcing. Our simulation results demonstrate that tides play a crucial role in enhancing the intrusion of the Korea Strait bottom cold water by both near-bottom ocean mixing and internal tidal residual currents. Detail physical processes are under investigation and will be presented in the meeting.sion of the bottom cold water from the deep basin of the southwestern East/Japan Sea into the Korea Strait. Although previous studies have suggested possible causes of the bottom cold water intrusion, its mechanism is not clear yet. Here we investigate the influence of tides on the bottom cold water intrusion using numerical simulations, which 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. To investigate detail physical processes influencing the bottom cold water intrusion, numerical simulations are conducted as following five cases: 1) wind forcing only without tides, 2) M2 tides only with wind forcing, 3) K1 tides only with wind forcing, 4) all four major tides (M2, S2, K1 and O1) with wind forcing, and 5) all four major tides without wind forcing. Our simulation results demonstrate that tides play a crucial role in enhancing the intrusion of the Korea Strait bottom cold water by both near-bottom ocean mixing and internal tidal residual currents. Detail physical processes are under investigation and will be presented in the meeting.