동해 반일주조 내부조석의 계절 변동성

Abstract

Seasonal variation of semi-diurnal internal tides in the East/Japan Sea is studied using 2-year-long outputs from a real-time ocean forecasting system. The model generates energetic internal tides around the northern mouth of Korea Strait. The simulated amplitude and phase of internal tides agree well with two hourly-interval 25-hour-long CTD castings obtained at a site close to the generation region during spring and neap tidal periods. Converted energy from barotropic to baroclinic tides has seasonal variation ranging 0.4&#8722 0.5 GW during summer and 0.1&#8722 0.2 GW during winter due to stratification changes near the southwestern East/Japan Sea. The internal tides travel far to the northern part of the East/Japan Sea during summer but not during winter. Propagating distance of internal tide energy can be explained with both generation intensity and wavelength. Longer wavelength during summer makes internal tide energy dissipates less. Our result provides a case implying that spatio-temporal variation of internal-tide-induced mixing due to the seasonality of its generation, propagation, and dissipation should be considered to simulate more realistic water mass and circulation in the East/Japan Sea.The simulated amplitude and phase of internal tides agree well with two hourly-interval 25-hour-long CTD castings obtained at a site close to the generation region during spring and neap tidal periods. Converted energy from barotropic to baroclinic tides has seasonal variation ranging 0.4&#8722 0.5 GW during summer and 0.1&#8722 0.2 GW during winter due to stratification changes near the southwestern East/Japan Sea. The internal tides travel far to the northern part of the East/Japan Sea during summer but not during winter. Propagating distance of internal tide energy can be explained with both generation intensity and wavelength. Longer wavelength during summer makes internal tide energy dissipates less. Our result provides a case implying that spatio-temporal variation of internal-tide-induced mixing due to the seasonality of its generation, propagation, and dissipation should be considered to simulate more realistic water mass and circulation in the East/Japan Sea.