Journal of Oceanography

, Volume 46, Issue 6, pp 296–306 | Cite as

Direct measurements of mid-depth circulation in the Shikoku basin by tracking SOFAR floats

  • Keisuke Taira
  • Shoji Kitagawa
  • Katsuto Uehara
  • Hiroshi Ichikawa
  • Hiroyuki Hachiya
  • Toshihiko Teramoto


Mid-depth circulation of the Shikoku Basin was measured by tracking four SOFAR floats drifting at the 1,500 m layer. Two floats were released on 17 April 1988 at 30°N, 135°59′E and tracked for 433 days. Another two were released on 3 November 1988 at 29°52′N and 133°25′E, and tracked for 234 days. Two floats flowed clockwise around the Shikoku Warm Water Mass with a diameter of 400 km centered at 31°N and 136°E and a mean drift speed of 4.5 cm sec−1. One of the floats showed about ten counterclockwise rotations with a period of about 8 days and a maximum speed of 80 cm sec−1 in the sea area west to the Izu Ridge. In the east to Kyushu, a southward flow was observed under the northward flowing Kuroshio. The southward flow of 4 cm sec−1 drift speed was considered to be a part of the counterclockwise circulation at deep layers along the perimeter of the Shikoku Basin. One float remained for 234 days in a limited area of 100 km by 150 km in the western part of the basin.


Sound Speed Mooring Line Glass Ball Kuroshio Path Drift Speed 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Baker, J. (1981): Ocean instruments and experiment design. pp. 396–433.In: Evolution of physical oceanography, ed. by B.A. Warren and C. Wunsch, The MIT Press, 623 p.Google Scholar
  2. Benthos Inc. (1987): Deep sea glass spheres. North Falmouth Massachusetts, U.S.A., 8 pp.Google Scholar
  3. Fofonoff, N.P. and R.C. Millard (1983): Algorithms for computation of fundamental properties of seawater. Unesco Technical Papers in Marine Sciences,44, 53 pp.Google Scholar
  4. Fukasawa, M., T. Teramoto and K. Taira (1986): Abyssal current along the periphery of Shikoku Basin. J. Oceanogr. Soc. Japan,42, 459–472.CrossRefGoogle Scholar
  5. Ishizaki, H., O. Asaoka, S. Konaga, and M. Takahashi (1983): Direct measurement of near-bottom current on the continental slope off Omaezaki, central Japan. Pap. Met. Geophys.,33, 257–268.CrossRefGoogle Scholar
  6. Kawai, H. (1969): Statistical estimation of isotherms indicative of the Kuroshio axis. Deep Sea. Res.,16, (supplement), 117–124.Google Scholar
  7. MODE Group, The (1978): The Mid-Ocean Dynamics Experiment. Deep-Sea Res,25, 859–910.CrossRefGoogle Scholar
  8. Munk, J.W. (1983): Acoustics and ocean dynamics. pp. 109–135.In: Oceanography—the present and future, ed., by P.G. Brewer, Springer-Verlag, pp. 392.Google Scholar
  9. Nakamura, S. (1986): A note on sound speed fields around the Kuroshio south of Japan. La mer,24, 42–47.Google Scholar
  10. Nishida, H. and S. Kuramoto (1982): Deep current of the Kuroshio around the Izu Ridge—Large meander of the Kuroshio in 1975–1980 (IV), Rept. Hydrogr. Res., Tokyo, No. 17, 241–255.Google Scholar
  11. Ollitraut, M. (1987): Traitment des donnees de flotteurs lagrangiens SOFAR. Rapports Scientifique IFREMER, no 7, pp. 202.Google Scholar
  12. Richardson, P.L., D. Walsh, L. Armi, M. Schroeder and J.F. Price (1989): Tracking three Meddies with SOFAR floats. J. Phys. Oceanogr.,19, 371–383.CrossRefGoogle Scholar
  13. Riser, S.C. and H.T. Rossby (1982): Quasi-Lagrangian structure and variability of the subtropical western North Atlantic circulation. J. Mar. Res.,41, 127–162.CrossRefGoogle Scholar
  14. Rossby, H.T. (1983): Eddies and the general circulation. 137–161.In: Oceanography—the present and future, ed. by P.G. Brewer, Springer-Verlag, pp. 392.Google Scholar
  15. Rossby, H.T. and D. Webb (1971): The four month drift of a swallow float. Deep-Sea Res.,18, 1035–1039.Google Scholar
  16. Shimamura, K. (1989): Topography and sedimentary facies of the Nankai Deep Sea Channel. p. 529–556.In: Sedimentary facies in the active plate margins, ed. by A. Taira and F. Masuda, Terra Scientific Publishing Company, Tokyo.Google Scholar
  17. Stommel, H. (1954): Direct measurements of subsurface currents. Deep-Sea Res.,2, pp. 284–285.Google Scholar
  18. Sugimoto, T., T. Ishimaru and M. Kobayashi (1986): Circulation and water exchange in the anticyclonic gyre off Shikoku. Deep-Sea Res.,33, 1641–1652.CrossRefGoogle Scholar
  19. Taft, B.A. (1978): Structure of the Kuroshio south of Japan. J. Mar. Res.,16, 77–117.Google Scholar
  20. Taira, K. and T. Teramoto (1981): Velocity fluctuations of the Kuroshio near the Izu Ridge and their relationship to current path. Deep-Sea Res.,28, 1187–1197.CrossRefGoogle Scholar
  21. Taira, K. and T. Teramoto (1985): Bottom currents in Nankai Trough and Sagami Trough. J. Ocanogr. Soc. Japan,41, 388–398.CrossRefGoogle Scholar
  22. Taira, K. and T. Teramoto (1986): Path and volume transport of the Kuroshio Current in Sagami Bay and their relationship to cold water masses near Izu Peninsula. J. Oceanogr. Soc. Japan,42, 212–223.CrossRefGoogle Scholar
  23. Worthington, L.V. and H. Kawai (1972): Comparison between deep sections across the Kuroshio and the Florida Current and Gulf Stream. p. 371–385,In: Kuroshio, its physical aspects, ed. by H. Stommel and K. Yoshida, University of Tokyo Press.Google Scholar

Copyright information

© Oceanographical Society of Japan 1989

Authors and Affiliations

  • Keisuke Taira
    • 1
  • Shoji Kitagawa
    • 1
  • Katsuto Uehara
    • 1
  • Hiroshi Ichikawa
    • 2
  • Hiroyuki Hachiya
    • 3
  • Toshihiko Teramoto
    • 4
  1. 1.Ocean Research InstituteUniversity of TokyoTokyoJapan
  2. 2.Faculty of FisheriesKagoshima UniversityKagoshimaJapan
  3. 3.Research Institute for Precision MechanicsTokyo Institute of TechnologyYokohamaJapan
  4. 4.Faculty of ScienceKanagawa UniversityHiratsukaJapan

Personalised recommendations