Japan/East Sea

Shallow and Deep Current Variability in the Southwestern Japan/East Sea

Principal Investigators

D. Randolph Watts, University of Rhode Island
Mark Wimbush, University of Rhode Island
William Teague, Naval Research Laboratory, SSC

Funding for this project is supplied by the Office of Naval Research

Award Numbers: N000149810246, N000149910595, N0001498WX30245, and N0001400WX20337

Objectives

The scientific objective of this project is to understand the physics of the mesoscale circulation of the Japan/East Sea in the southwestern region. The goals of this project are:

  • Observe the time-varying transports in the branches of the Tsushima Current
  • Produce daily maps from observations of the upper layer circulation and path variability of the Offshore Branch and the East Korean Warm Current with mesoscale resolution
  • Understand the physical coupling between the shallow and deep currents and eddies within this region which contains large-amplitude meanders, steep loop formation, and ring pinch-off
  • At intermediate levels, quantify cross-frontal and vertical fluxes associated with mesoscale processes in the East Korean Warm Current
This figure shows the array of instruments deployed in the JES. Yellow diamond indicate inverted echo sounder equipped with bottom pressure gauges (PIES) sites. Magenta circles indicate the deep current meter mooring locations. Sites names are prefaced by either “P” or “M” to indicate the instrument type. The naming convention is such that the first number indicates the row and the second value the position relative to the Korean coast. “K” and “J” indicate the moorings maintained by the Koreans and Japanese, respectively. TOPEX/POSEIDON sub-orbital ground tracks are shown.
The bathymetry is color-coded with shallower depths indicated in green and deeper depths in blue. All instruments are moored at depths of at least 1000 m.
The instruments were deployed during June 1999 and were recovered during June/July 2001.

Field Program

From June 1999 to July 2001 a suite of instrumentation was moored within the Ulleung Basin of the Japan/East Sea.  The array consisted of 25 inverted echo sounders with pressure gauges (PIESs) arranged in a 5 by 5 array with 55-60 km spacing between sites. Deep current meters were placed nominally midway between the PIES sites. Four current meter moorings were maintained by scientists at the Korean Ocean Reasearch and Development Institute (KORDI) and one mooring was maintained by Japanese scientists at the Research Institute for Applied Mechanics (RIAM). The PIESs sites are indicated by the yellow diamonds and current meters by magenta circles. Site designations are indicated on a larger view of the array obtained by clicking on the figure.

It was particularly important to inform the Korean deep-crab fishing captains of our mooring positions. There is intense fishing and crabbing in the Ulleung Basin, including bottom fishing at depths as great as 2,000 meters. Scientists at KORDI took a lead role in periodically reminding the fishermen of the instrument locations.

 A full-depth CTD profile was obtained at each PIES site before its release, to provide additional information for calibration / verification. The data recovery rate (23 of 25 PIES and 12 of 13 RCMs), while not 100%, is more than adequate to meet our objectives of mapping the current and eddy fields. As we processed the data records, we found evidence that several of the PIES sites were dragged short distances during their mooring period. Both of the lost PIESs were in regions of relatively high fishing activity. Given that 7 of the recovered PIESs were hit and dragged numerous times, we feel fortunate not to have lost more than 2 instruments! 

This field program is just one of several studies conducted on the Japan/East Sea under the sponsorship of ONR. An overview of the full program can be found at http://jes.apl.washington.edu.

Data

Hourly and low-pass filtered acoustic travel time, pressure, temperature and current time series are available from the Japan/East Sea Data Archive and NODC.   Data reports describing the records and the processing steps are provided.

Publications

  • Chang, K.-I., W. J. Teague, S. J. Lyu, H. T. Perkins, D.-K. Lee, D. R. Watts, Y. B. Kim, D. A. Mitchell, C. M. Lee, and K. Kim. Circulation and currents in the southwestern East/Japan Sea: Overview and review. Progress in Oceanography, 61:105–156, 2004. (doi:10.1016/j.pocean.2004.06.005)
  • Mitchell, D. A., M. Wimbush, D. R. Watts, and W. J. Teague. The Residual GEM technique and its application to the southwestern Japan/East Sea. J. Atmos. Oceanic Technol., 21:1895–1909, 2004. (doi:10.1175/JTECH-1668.1)
  • Mitchell, D. A., W. J. Teague, M. Wimbush, D. R. Watts, and G. G. Sutyrin. The Dok Cold Eddy. J. Phys. Oceanogr., 35:273–288, 2005. (doi:10.1175/JPO-2684.1)
  • Mitchell, D. A., D. R. Watts, M. Wimbush, W. J. Teague, K. L. Tracey, J. W. Book, K.-I. Chang, M.-S. Suk, and J.-H. Yoon. Upper circulation patterns in the Ulleung Basin. Deep-Sea Res II, 52:1617–1638, 2005. (doi:10.1016/j.dsr2.2003.09.005)
  • Nam, S.-H., and J.-H. Park. Semidurnal internal tides off the east coast of Korea inferred from synthetic aperture radar images. Geophys. Res. Lett., 35(L05602), 2008. (doi:10.1029/2007GL032536)
  • Nam, S.-H., S.-J. Lyu, Y.-H. Kim, K. Kim, J.-H. Park, and D. R. Watts. Correction of TOPEX/Poseidon altimeter data for nonisostatic sea level response to atmospheric pressure in the Japan/East Sea. Geophysical Research Letters, 31, 2004. (doi:10.1029/2003GL018487)
  • Park, J.-H., and D. R. Watts. Near-inertial oscillations interacting with mesoscale circulation in the southwestern Japan/East Sea. Geophys. Res. Let., 32(L10611), 2005. (doi:10.1029/2005GL022936)
  • Park, J.-H., and D. R. Watts. Response of the southwestern Japan/East Sea to atmospheric pressure. Deep-Sea Res II, 52:1671–1683, 2005. (doi:10.1016/j.dsr2.2003.08.007)
  • Park, J.-H., and D. R. Watts. Internal tides in the southwestern Japan/East Sea. J. Phys. Oceanogr., 36:22–34, 2006. (doi:10.1175/JPO2846.1)
  • Park, J.-H., D. R. Watts, K. L. Tracey, and D. A. Mitchell. A multi-index GEM technique and its application to the southwestern Japan/East Sea. J. Atmos. Oceanic Technol., 22:1282–1293, 2005. (doi:10.1175/JTECH1778.1)
  • Park, J.-H., D. R. Watts, M. Wimbush, J. W. Book, K. L. Tracey, and Y. Xu.Rapid variability in the Japan/East Sea: basin oscillations, internal tides, and near-inertial oscillations. Oceanography, 19:76–85, 2006. (doi:10.5670/oceanog.2006.45)
  • Teague, W. J., G. A. Jacobs, D. A. Mitchell, M. Wimbush, and D. R. Watts. Decadal current variations in the southwestern Japan/East Sea. Journal of Oceanography, 60:1023–1033, 2004. (doi:10.1007/s10872-005-0010-x)
  • Teague, W. J., K. L. Tracey, D. R. Watts, J. W. Book, K.-I. Chang, P. J. Hogan, D. A. Mitchell, M.-S. Suk, M. Wimbush, and J.-H. Yoon. Observed deep circulation in the Ulleung Basin. Deep-Sea Res II, 52:1802–1826, 2005. (doi:10.1016/j.dsr2.2003.10.014)
  • Watts, D. R., M. Wimbush, K. L. Tracey, W. J. Teague, J.-H. Park, D. A. Mitchell, J.-H. Yoon, M.-S. Suk, and K. I. Chang. Currents, eddies, and a “fish story” in the southwestern Japan/East Sea. Oceanography, 19:64–75, 2006. (doi:10.5670/oceanog.2006.44)
  • Xu, Y., D. R. Watts, M. Wimbush, and J.-H. Park. Fundamental-mode basin oscillations in the Japan/East Sea. Geophysical Research Letters, 34, 2007. (doi:10.1029/2006GL028755)
  • Xu, Y., D. R. Watts, and J.-H. Park. De-aliasing of large-scale high-frequency barotropic signals from satellite altimetry in the Japan/East Sea. J. Atmos. Oceanic Technol., 25:1703–1709, 2008. (doi:10.1175/2008JTECHO582.1)
  • Xu, Y., D. R. Watts, and M. Wimbush. Coupled patterns between fields of dynamic height and bottom pressure in the Japan/East Sea. Ocean Science Journal, 44(1):35–44, 2009. (doi:10.1007/s12601-009-0005-4)

Conference Presentations

Ocean Sciences Meeting, Honolulu, Hawaii, February 2006

  • Xu, Y., D. R. Watts, M. Wimbush, and J.-H. Park. Basin mode oscillations in the Japan/East Sea. Eos Trans. AGU, 87(36), 2006. Ocean Sci. Meet. Suppl., Abstract OS36D-27. (PDF)

IAPSO/SCOR Ocean Mixing Conference, Victoria, BC, October 2004

  • Park, J.-H., and D. R. Watts. Interaction of internal gravity waves with mesoscale circulation observed in the southwestern Japan/East Sea. 2004.

Ocean Sciences Meeting, Portland, Oregon, January 2004

  • Mitchell, D. A., W. J. Teague, M. Wimbush, and D. R. Watts. The Dok cold eddy. Eos Trans. AGU, 84(52), 2004. Ocean Sci. Meet. Suppl., Abstract OS41B-08.
  • Park, J.-H., and D. R. Watts. Internal tides in the southwestern Japan/East Sea. Eos Trans. AGU, 84(52), 2004. Ocean Sci. Meet. Suppl., Abstract OS41F-04.
  • Teague, W. J., G. A. Jacobs, D. A. Mitchell, M. Wimbush, and D. R. Watts. Decadal connections of mesoscale current variability in the Ulleung Basin.Eos Trans. AGU, 84(52), 2004. Ocean Sci. Meet. Suppl., Abstract OS41B-05.

IUGG/IAPSO Symposium, Sapporo, Japan, June 2003

  • Park, J.-H., D. A. Mitchell, K. L. Tracey, K.-I. Chang, M.-S. Suk, and D. Watts. Intermediate water circulation in the southwestern Japan/East Sea. 2003.

CREAMS/PICES Symposium, Seoul, Korea, August 2002

  • Chang, K.-I., K. Kim, H. Perkins, W. Teague, R. Watts, D. Mitchell, M.-S. Suk, S. J. Ly, D.-K. Lee, and J.-H. Yoon. Currents and circulation in the Ulleung Basin and the Korea/ Tsushima Strait. 2002.

Ocean Sciences Meeting, Honolulu, Hawaii, February 2002

  • Mitchell, D. A., W. J. Teague, D. R. Watts, M. Wimbush, and K. Tracey. Daily maps of temperature, salinity, and velocity in the southwestern Japan/East Sea. Eos Trans. AGU, 2002. Ocean Sci. Meet. Suppl., Abstract OS21Q-07.
  • Watts, D. R., M. Wimbush, K. L. Tracey, D. A. Mitchell, W. J. Teague, J. W. Book, M.-S. Suk, and J.-H. Yoon. Shallow and deep current variability in the southwestern Japan/East Sea. Eos Trans. AGU, 2002. Ocean Sci. Meet. Suppl., Abstract OS21Q-05.
  • Wimbush, M., K. L. Tracey, D. R. Watts, D. A. Mitchell, J. W. Book, and W. J. Teague. Tides of the southwest Japan/East Sea determined from an array of 23 bottom pressure recorders. Eos Trans. AGU, 2002. Ocean Sci. Meet. Suppl., Abstract OS21Q-06.

CREAMS/PICES Symposium, Honolulu, Hawaii, February 2001

  • Mitchell, D. A., M. Wimbush, and D. R. Watts. Determining gravest empirical modes from hydrographic data in the southwest Japan/East Sea. 2000.

AGU Meeting, San Francisco, California, December 2000

  • Mitchell, D. A., W. J. Teague, D. R. Watts, and M. Wimbush. Gravest empirical modes determined from historical hydrographic observations in the southwestern Japan/East Sea. Eos Trans. AGU, 81(48), 2000. Fall Meet. Suppl., Abstract OS12B-04.

Annual Reports of ONR Sponsored Research

  • Watts, D.R., M. Wimbush, W.J. Teague, and Z. Hallock, “Shallow and deep current variability in the Southwestern Japan/East Sea.” 1999   2000
  • Watts, D.R., M. Wimbush, and W.J. Teague, “Shallow and deep current variability in the Southwestern Japan/East Sea.” 2001   2002   2003
  • Watts, D.R. and M. Wimbush, “Variability in the Japan/East Sea: processes governing scales from hours to years.” 2004   2005

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