In this study the structure and seasonal variations of deep mean circulation in the East/lapan Sea （E/S） were numerically simulated using a mid-resolution ocean general circulation model with two different parameter...In this study the structure and seasonal variations of deep mean circulation in the East/lapan Sea （E/S） were numerically simulated using a mid-resolution ocean general circulation model with two different parameterizations for the eddy-topography interaction （ETI）. The strong deep mean circulations observed in the EIS are well reproduced when using the ETI parameterizations. The seasonal variability in the EIS deep layer is shown by using ETI parameterization based on the potential vorticity approach, while it is not shown in the statistical dynamical parameterization. The driving mechanism of the strong deep mean currents in the E/S are discussed by investigating the effects of model grids and parameterizations. The deep mean circulation is more closely related to the baroclinic process and potential vorticity than it is to the wind driven circulation.展开更多
Subinertial fluctuation of a strong northward deep current, which is referred to the Dokdo Abyssal Current （DAC） by Chang et al. （2009）, is investigated from current records for about 16.5 and 8.0 months in the Ul...Subinertial fluctuation of a strong northward deep current, which is referred to the Dokdo Abyssal Current （DAC） by Chang et al. （2009）, is investigated from current records for about 16.5 and 8.0 months in the Ulle- ung Interplain Gap of the East/lapan Sea. The current below 300 m is bottom-intensified and has nearly depth-independent flow. Near bottom, the spectral peaks of the current were found near 10, 20, and 60 d. The DAC variability near 10 d and 20 d is reasonably consistent with the linear theory of topographic Rossby waves （TRWs） in the following aspects： （1） The motion is columnar and bottom-intensified; （2） the theo- retical cutoff frequency is similar to the observation; （3） The observation-based angles of the wavenumber vector are in good agreement with the theoretical ones. The wavelengths of the TRWs with periods of near 10 d and 20 d near Dokdo are significantly shorter than those with similar timescales in the open oceans （100-250 km）. It is primarily due to the weak stratification below 300 m in the East Sea. The deep cur- rent fluctuations with periods of near 10 d and 20 d were accompanied by warm events in the upper layer resulting from eddying processes and/or meandering of the Tsushima Warm Current.展开更多
基金The Research Program on Climate Change Adaptation(RECCA)of the Ministry of Education,Culture,Sports,Science and Technology(MEXT)of Japan
文摘In this study the structure and seasonal variations of deep mean circulation in the East/lapan Sea （E/S） were numerically simulated using a mid-resolution ocean general circulation model with two different parameterizations for the eddy-topography interaction （ETI）. The strong deep mean circulations observed in the EIS are well reproduced when using the ETI parameterizations. The seasonal variability in the EIS deep layer is shown by using ETI parameterization based on the potential vorticity approach, while it is not shown in the statistical dynamical parameterization. The driving mechanism of the strong deep mean currents in the E/S are discussed by investigating the effects of model grids and parameterizations. The deep mean circulation is more closely related to the baroclinic process and potential vorticity than it is to the wind driven circulation.
基金The Ministry of Land, Transport and Maritime Affairs of Korean Govenment as part of the EAST-I (East Asian Seas Time-series,East/Japan Sea) and OCCAPA (Ocean Chimate Change-Analyses, Projections and Adaptation), through KIOST Project under contract No. PE98742as part of the Development of Technology for CO2 Marine Geological Storage project under contract No. PMS246B
文摘Subinertial fluctuation of a strong northward deep current, which is referred to the Dokdo Abyssal Current （DAC） by Chang et al. （2009）, is investigated from current records for about 16.5 and 8.0 months in the Ulle- ung Interplain Gap of the East/lapan Sea. The current below 300 m is bottom-intensified and has nearly depth-independent flow. Near bottom, the spectral peaks of the current were found near 10, 20, and 60 d. The DAC variability near 10 d and 20 d is reasonably consistent with the linear theory of topographic Rossby waves （TRWs） in the following aspects： （1） The motion is columnar and bottom-intensified; （2） the theo- retical cutoff frequency is similar to the observation; （3） The observation-based angles of the wavenumber vector are in good agreement with the theoretical ones. The wavelengths of the TRWs with periods of near 10 d and 20 d near Dokdo are significantly shorter than those with similar timescales in the open oceans （100-250 km）. It is primarily due to the weak stratification below 300 m in the East Sea. The deep cur- rent fluctuations with periods of near 10 d and 20 d were accompanied by warm events in the upper layer resulting from eddying processes and/or meandering of the Tsushima Warm Current.
