Abstract
The Tushima Current in the east channel was measured in a site of the strong current between Tushima and Iki Islands for 43 days of the winter in 1986. The primary results are:
First, it was highly barotropic and flowed northeastward with a mean speed of about 20 cm sec−1. Second, it was decelerated by northeast winds rather than by northwest winds in a frequency range of 0.3 and 0.4 cpd. Third, the scale analysis showed that the Tushima Current is approximately in geostrophic balance. The best empirical relationship between the measured Tushima Current and cross-channel adjusted sea level difference is given by
whereV (cm sec−1) andΔη K−I (cm) denote the northeast current component and the adjusted sea level difference between the average of three tidal stations (Moji, Hakata, and Sasebo) and Izuhara. Finally, the annual variation of the Tushima Current estimated from coastal sea level data during the past 19 years using the above formula showed a much weaker seasonal change in the east strait than in the Korea Strait.
Similar content being viewed by others
References
Bendat, J.S. and A.G. Piersol (1971): Random data: Analysis and measurement procedures. Wiley-Interscience, 407 pp.
Bowden, K.F. (1983): Physical oceanography of coastal waters. Ellis Horwood Limited, 302 pp.
Hidaka, K. and T. Suzuki (1950): Secular variation of the Tsushima current. J. Oceanogr. Soc. Jap.16, 28–31.
Kawabe, M. (1982): Branching of the Tsushima current in the Japan Sea, Part I. Data analysis. J. Oceanogr. Soc. Japan,38, 95–107.
Kraus, E.B. (1972): Atmosphere-ocean interaction. Oxford Univ. Press, 275 pp.
Matsuyama, M. and T. Nazumi (1986): Characteristics of the current on the continental shelf off the Tajima coast in winter. Bulletin of the Japanese Fisheries,52, 1715–1718 (in Japanese).
Miita, T. (1973): Review on the flow pattern and variability of the Tushima currents across the Tushima straits. Report of Fukuoka Prefectural Fisheries Experimental Station,19, 1–33 (in Japanese).
Miita, T. and Y. Ogawa (1984): Tsushima currents measured with current meters and drifters. p. 67–76.In: Ocean Hydrodynamics of the Japan and East China Seas. ed. by T. Ichiye, Elsevier, Amsterdam.
Mizuno, S., K. Kawatate, and T. Mitta (1986): Current and temperature observations in the east Tsushima channel and the Sea of Genkai. Prog. Oceanogr.,17, 277–295.
Tawara, S., T. Miita, and T. Fujiwara (1984): The hydrography and variability in the Tushima straits. Bulletin on Coastal Oceanography,22, 50–58 (in Japanese).
Thompson, Rory O.R.Y. (1979): Coherence Significance Levels. J. Atmos. Sci.,36, 2020–2021.
Toba, Y., K. Tomizawa, Y. Kurasawa, and K. Hanawa (1982): Seasonal and year-to-year variability of the Tsushima-Tsugaru warm current system with its possible cause. La mer,20, 41–51.
Yi, Sok-U (1970): Variations of Oceanic condition and mean sea level in the Korea strait. pp. 125–141.In: The Kuroshio (A symposium on the Japan current), ed. by J. C. Marr, East-west Center Press.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Mizuno, S., Kawatate, K., Nagahama, T. et al. Measurements of east Tushima Current in winter and estimation of its seasonal variability. Journal of the Oceanographical Society of Japan 45, 375–384 (1989). https://doi.org/10.1007/BF02125142
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02125142