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


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:

Small image of JES array

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 .


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.


Conference Presentations

Annual Reports of ONR Sponsored Research

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Last Updated: May 4, 2009