Advertisement

Journal of Oceanography

, Volume 50, Issue 3, pp 317–338 | Cite as

Structure of the Tsushima Current in the southwestern Japan Sea

  • Osamu Katoh
Article

Abstract

We discuss the structure of the Tsushima Current in the southwestern Japan Sea using ADCP data, which are taken by the quadrireciprocal method (Katoh, 1988) for removing tidal currents, and previous temperature data. The first, second and third branches described in the triple-branch view are recognized in three observational periods: June and August 1988 and in June 1989. The first branch basically flows eastward along the 100 m isobath. Its velocity is mostly 0.5–1.0 kt (26–51 cm s−1) and 0.4–0.6 kt (21–31 cm s−1) in the Eastern Channel of the Tsushima Strait and off the San'in Coast, respectively. In waters north of Mishima, however, a part of the first branch happens to flow northeastward, without turning clockwise along the 100 m isobath. In waters northwest of Izumo, the remainder of the first branch tends to join the second one. The second branch, which has velocities of 0.5–0.8 kt (26–41 cm s−1) in general, flows eastward along a bunch of crowded isotherms at 100 m depth. The observational results clearly illustrate the changeability of the second branch. The maximum velocity of the third branch must be larger than those of the other two branches. The Tsushima Current after leaving the Western Channel is very changeable spatially and temporally, probably because the bifurcation occurs intermittently or transiently resulting from the fluctuation of inflow through the Western Channel and from that of spread of the cold water. The bifurcation into the second and third branches becomes often obscure north of Hamada owing to confluences, even though it is recognized near the Western Channel.

Keywords

Japan Cold Water Temperature Data Maximum Velocity Tidal Current 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Fisheries Agency of Japan (1980–1989):The Results of Fisheries Oceanographical Observation (1976–1985).Google Scholar
  2. Fisheries Research and Development Agency, Korea (1977–1988, 1990–1992):Annual Report of Oceanographic Observations (1976–1990).Google Scholar
  3. Isoda, Y. and S. Saitoh (1993): The northward intruding eddy along the east coast of Korea.J. Oceanogr.,49, 443–458.CrossRefGoogle Scholar
  4. Kaneko, A., S.-K. Byun, S.-D. Chang and M. Takahashi (1991): An observation of sectional velocity structures and transport of the Tsushima Current across the Korea Strait. p. 179–195. InOceanography of Asian Marginal Seas ed. by K. Takano, Elsevier, Amsterdam.Google Scholar
  5. Katoh, O. (1988): Measurement of residual current using the Doppler sonar.Bull. Seikai Reg. Fish. Res. Lab.,66, 59–67 (in Japanese with English abstract).Google Scholar
  6. Katoh, O. (1993): Detailed current structures over the continental shelf off the San'in Coast in summer.J. Oceanogr.,49, 1–16.CrossRefGoogle Scholar
  7. Katoh, O. (1994): Short-term fluctuations of the Tsushima Current in waters northwest of Yamaguchi Prefecture.J. Oceanogr.,50, 51–64.CrossRefGoogle Scholar
  8. Kawabe, M. (1982a): Branching of the Tsushima Current in the Japan Sea. Part I. Data analysis.J. Oceanogr. Soc. Japan,38, 95–107.CrossRefGoogle Scholar
  9. Kawabe, M. (1982b): Branching of the Tsushima Current in the Japan Sea. Part II. Numerical experiment.J. Oceanogr. Soc. Japan,38, 183–192.CrossRefGoogle Scholar
  10. Kawabe, M. (1986): Study on the Kuroshio and the Tsushima Current—variations of the current path.J. Oceanogr. Soc. Japan,42, 319–331 (in Japanese with English abstract).CrossRefGoogle Scholar
  11. Kawai, H. (1974): Transition of current images in the Japan Sea. p. 7–26. InThe Tsushima Current—Oceanic Structure and Fishery, ed. by Japan. Soc. Sci. Fish., Koseisha-Koseikaku, Tokyo (in Japanese).Google Scholar
  12. Kawai, H. (1991): Current structures as the environment for marine lives. p. 1–51. InCurrents and Lives—Special Lectures on Fisheries Oceanography, ed. by H. Kawai, Kyoto University Press, Kyoto (in Japanese).Google Scholar
  13. Kuwahara, A., K. Washio and S. Suzuki (1983): The movements of the high salinity water and low salinity water in the surface waters of the Tsushima Warm Current region.Bull. Kyoto Ocea. Fish. Sci.,7, 41–47 (in Japanese with English abstract).Google Scholar
  14. Miita, T. (1973): Flow condition and fluctuation of the Tsushima Current in the Tsushima Strait derived from past researches.Reports on Research and Affair in the 1971 Fiscal Year, Fukuoka Pref. Fukuoka Fish. Exp. Sta., 1–33 (in Japanese).Google Scholar
  15. Miita, T. (1976): Symposium on transportation of fish eggs and larvae in sea area west of Kyushu. 2-2 Current characteristics measured with current meter at the fixed stations.Bull. Japan. Soc. Fish. Oceanogr.,28, 33–58 (in Japanese).Google Scholar
  16. Mizuno, S., K. Kawatate and T. Miita (1984): Oceanographic observations in the Eastern Channel of the Tsushima Strait and its adjacent waters.Bull. Res. Inst. Appl. Mech. Kyushu Univ.,60, 445–454 (in Japanese).Google Scholar
  17. Moriyasu, S. (1972): The Tsushima Current. p. 353–369. InKuroshio—Its Physical Aspects, ed. by H. Stommel and K. Yoshida, Univ. Tokyo Press, Tokyo.Google Scholar
  18. Naganuma, K. (1973): On discussions on the existence of the third branch of the Tsushima Current.Newsl. Japan Sea Reg. Fish. Res. Lab.,266, 1–3 (in Japanese).Google Scholar
  19. Naganuma, K. (1977): The oceanographic fluctuations in the Japan Sea.Mar. Sci./Mon.,9, 137–141 (in Japanese with English abstract).Google Scholar
  20. Naganuma, K. (1985): Symposium on the larval fishes and oceanography in the coastal waters of western part of Japan Sea. 1. Characteristics of oceanography in the western part of Japan Sea.Bull. Japan. Soc. Fish. Oceanogr.,47–48, 60–63 (in Japanese).Google Scholar
  21. Naganuma, K. and M. Ichihashi (1993): Monthly mean and standard variation of temperature at the surface, 50 m, 100 m and 200 m depths in the Japan Sea for thirty years 1961–1990.Contrib. Fish. Res. Japan Sea Block,26, 1–117 (in Japanese).Google Scholar
  22. Ogawa, Y. (1971):Oceanographic Condition in the Southwestern Japan Sea. Yamaguchi Prefectural Open-Sea Fish. Exp. Sta., 42 pp. (in Japanese).Google Scholar
  23. Ogawa, Y. (1981): Hydrography of coastal waters in the southwestern Japan Sea and its fishery-biological significance.Bull. Yamaguchi Pref. Open-Sea Fish. Exp. Sta.,18, 1–96 (in Japanese with English synopsis).Google Scholar
  24. Ogawa, Y., T. Miita, A. Ichihara, Y. Hasegawa and N. Inoue (1978): Fluctuations of the Tsushima Current measured with the current drogue.Bull. Seikai Reg. Fish. Res. Lab.,51, 13–44.Google Scholar
  25. Shimane Prefectual Fisheries Experimental Station (1988–1992):Bulletin of Shimane Prefectural Fisheries Experimental Station in the 1986–1990 Fiscal Years (in Japanese).Google Scholar
  26. Shimomura, T. and K. Miyata (1957): The oceanographical conditions of the Japan Sea and its water systems, laying stress on the summer of 1955.Bull. Japan Sea Reg. Fish. Res. Lab.,6, 23–119 (in Japanese with English abstract).Google Scholar
  27. Shoji, D., K. Iwasa, K. Hasuike and T. Masumoto (1971): I. Study on oceanographic structure in the Japan Sea and its influence on weather condition and biological productivity—study on water circulation. p. 11–27. InResearch Papers of the Composite Studies on the Japan Sea, supported by aid for promoting and arranging special studies in the 1969 fiscal year, the Science and Technology Agency of Japan (in Japanese).Google Scholar
  28. Suda, K. and K. Hidaka (1932): Results of the second oceanographical observations in the southern region of the Japan Sea. Part I.J. Oceanogr. Imp. Mar. Observ.,3, 291–375 (in Japanese).Google Scholar
  29. Suda, K., K. Hidaka, Y. Matsudaira, E. Kurashige, H. Kawasaki and T. Kubo (1932): Results of the third oceanographical observations in the main region of the Japan Sea.J. Oceanogr. Imp. Mar. Observ.,4, 1–173 (in Japanese).Google Scholar
  30. Tanioka, K. (1968): On the East Korean Warm Current (Tosen Warm Current).Oceanogr. Mag.,20, 31–38.Google Scholar
  31. Uda, M. (1934): Oceanographic conditions in the Japan Sea and its adjacent waters (the results of simultaneous oceanographical investigations in the Japan Sea and its adjacent waters in May and June, 1932).J. Imp. Fish. Exp. Sta.,5, 57–190 (in Japanese with English abstract).Google Scholar
  32. Yamaguchi Prefectural Open-Sea Fisheries Experimental Station (1987–1991):Reports on Affairs for Forecasting Fishery and Oceanographic Conditions in the 1986–1990 Fiscal Years (in Japanese).Google Scholar
  33. Yoon, J.-H. (1982a): Numerical experiment on the circulation in the Japan Sea. Part I. Formation of the East Korean Warm Curent.J. Oceanogr. Soc. Japan,38, 43–51.CrossRefGoogle Scholar
  34. Yoon, J.-H. (1982b): Numerical experiment on the circulation in the Japan Sea. Part II. Influence of seasonal variations in atmospheric conditions on the Tsushima Current.J. Oceanogr. Soc. Japan,38, 81–94.CrossRefGoogle Scholar
  35. Yoon, J.-H. (1982c): Numerical experiment on the circulation in the Japan Sea. Part III. Mechanism of the nearshore branch of the Tsushima Current.J. Oceanogr. Soc. Japan,38, 125–130.CrossRefGoogle Scholar

Copyright information

© Oceanographic Society of Japan 1994

Authors and Affiliations

  • Osamu Katoh
    • 1
  1. 1.Seikai National Fisheries Research InstituteNagasakiJapan

Personalised recommendations