Internal Tides in the Southwestern Japan/East Sea

Abstract This paper investigates the internal tidal energy distribution in the southwestern Japan/East Sea using vertical round-trip travel time (τ) data from 23 pressure-sensor-equipped inverted echo sounders (PIES). The τ records are analyzed by bandpass filtering to separate time-dependent variability of the semidiurnal and diurnal bands. The semidiurnal internal tides exhibit a horizontal beam pattern of high energy, propagating into the open basin. They originate from a restricted portion of the shelf break where the Korea Strait enters the Ulleung Basin. The generation appears to occur at ∼200-m water depth near 35.5°–35.7°N and 130°–131°E, where the slope of bottom topography matches that of the wave characteristics, coinciding with the location where the semidiurnal barotropic cross-slope tidal currents are strongest. Maximum vertical displacement of the thermocline interpreted as a long-wave first baroclinic mode from the measured τ is about 25 m near the generation region. Annual and monthly var...

[1]  H. Lie,et al.  On the Intermediate Water in the Southwestern East Sea (Sea of Japan) , 1991 .

[2]  Craig M. Lee,et al.  Japan/East Sea Intrathermocline Eddies , 2002 .

[3]  G. Mitchum,et al.  Coherence of Internal Tide Modulations Along the Hawaiian Ridge , 2000 .

[4]  G. Jeans,et al.  Along-slope generation as an explanation for some unusually large internal tides , 2002 .

[5]  D. Mitchell,et al.  The Dok Cold Eddy , 2005 .

[6]  Bruce M. Howe,et al.  Barotropic and Baroclinic Tides in the Central North Pacific Ocean Determined from Long-Range Reciprocal Acoustic Transmissions , 1995 .

[7]  S. Rintoul,et al.  A Two-Dimensional Gravest Empirical Mode Determined from Hydrographic Observations in the Subantarctic Front , 2001 .

[8]  Diurnal shelf waves off Hamada on San'in Coast , 1993 .

[9]  D. Randolph Watts,et al.  Measuring Dynamic Heights with Inverted Echo Sounders: Results from MODE , 1977 .

[10]  P. Pistek,et al.  Data Assimilation Modeling of the Barotropic Tides in the Korea/Tsushima Strait , 2004 .

[11]  C. Wunsch.  Internal tides in the ocean , 1975 .

[12]  A. E. Gill.  Atmosphere-Ocean Dynamics , 1982 .

[13]  S. Chiswell.  Energy Levels, Phase, and Amplitude Modulation of the Baroclinic Tide off Hawaii , 2002 .

[14]  D. Cartwright.  The tidal signal in inverted echo-sounder records , 1982 .

[15]  W. Munk,et al.  Tidal spectroscopy and prediction , 1966, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[16]  D. Mitchella,et al.  Upper circulation patterns in the Ulleung Basin , 2005 .

[17]  Walter H. F. Smith,et al.  Global Sea Floor Topography from Satellite Altimetry and Ship Depth Soundings , 1997 .

[18]  Yz Miropol’sky,et al.  Dynamics of Internal Gravity Waves in the Ocean , 2001 .

[19]  P. Baines.  On internal tide generation models , 1982 .