Second-Mode Internal Tides in the East China Sea Deduced from Historical Hydrocasts and a Model

Abstract

From historical hydrocasts in the Okinawa Trough region of the East China Sea (ECS), acoustic echo time from 700 dbar to the surface shows a tight relationship with temperature (T) except near the 100-200-dbar layer. This is caused by 2nd- or higher-mode baroclinic variations. Significant out-of-phase correlation between upper and lower layer T from the hydrocasts confirms that 2nd-mode variations are strong. Furthermore, the 2nd-mode variations are dominant during the ebb tide period, which suggests they are caused by 2nd-mode internal tides (ITs) generated at the continental shelf break. For comparison, we investigate historical hydrocasts southeast of the Ryukyu Islands, where no significant 2nd-mode variations are found. A model simulating the Mu2 IT agrees qualitatively with these observations: it predicts relatively strong 2nd-mode IT energy in the ECS, but weak energy in the region southeast of the Ryukyu Islands.

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Document Details

Document Type
Technical Report
Publication Date
Mar 16, 2005
Accession Number
ADA455205

Entities

People

  • D. R. Watts
  • Jae-Hun Park
  • Magdalena Andres
  • Mark Wimbush
  • Paul J. Martin

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Coefficients
  • Continental Shelves
  • Data Centers
  • Demographic Cohorts
  • East China Sea
  • Japan
  • Military Research
  • Observatories
  • Oceans
  • Rhode Island
  • Ryukyu Islands
  • Sea Level
  • Simulations
  • Sonar
  • Three Dimensional
  • Tidal Currents
  • Websites

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • East Asian Political and Security Studies within the Soviet Union
  • Materials Science.