Abstract
Roles of horizontal processes in the formation of the density stratification in Hiuchi-Nada are investigated by means of a two-dimensional numerical model. In Hiuchi-Nada, vertically mixed and stratified regions are formed due to the regional difference of the tidal currents, and a tidal front is formed between the two regions. The horizontal mixing across the tidal front suppresses the development of the stratification, which is developed too much in the absence of the horizontal mixing. The moderate, realistic stratification cannot be realized in the model without the horizontal mixing. Density currents are formed due to the density distribution associated with the mixed and stratified states. These currents contribute to the horizontal mixing through the shear effect. Horizontal heat transfer from the outside water generates the vertical circulation and causes the stratification. This effect dominantly appears at the early and late stages of the stratified season. The stratification is initiated before the beginning of the surface heating and persists beyond the end, due to the horizontal heat transfer.
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References
James, I.D. (1977): A model of the annual cycle of temperature in a frontal region of the Celtic Sea. Estuarine, Coastal Marine Sci.,5, 339–353.
Munk, W.H. and E.R. Anderson (1948): Notes on a theory of the thermocline. J. Mar. Res.,7, 276–295.
Murakami, M., Y. Oonishi and H. Kunishi (1989): Heat and salt balances in the Seto Inland Sea. J. Oceanogr. Soc. Japan,45, 204–216.
Ochi, T. and H. Takeoka (1986): The anoxic water mass in Hiuchi-Nada. Part 1. Distribution of the anoxic water mass. J. Oceanogr. Soc. Japan,42, 1–11.
Simpson, J.H. and J.R. Hunter (1974): Fronts in the Irish Sea. Nature,250, 404–406.
Takeoka, H. (1985): Density stratification in the Seto Inland Sea. Umi to Sora (Sea and Sky),60, 145–152 (in Japanese).
Takeoka, H. and T. Yoshimura (1988): TheKyucho in Uwajima Bay. J. Oceanogr. Soc. Japan,44, 6–16.
Takeoka H,, T. Ochi and K. Takatani (1986): The anoxic water mass in Hiuchi-Nada. Part 2. The heat and oxygen budget model. J. Oceanogr. Soc. Japan,42, 12–21.
Tanaka, M. and C. Nakajima (1975): Heat balance at the sea surface over Hiuchinada in Seto Inland Sea. Ann. Disast. Prev. Res. Inst., Kyoto Univ.,18B, 589–595 (in Japanese).
Yanagi, T. and H. Higuchi (1981): Tide and tidal current in the Seto Inland Sea. Proc. 28th Conf. Coast. Eng., Japan Society of Civil Engineers, pp. 555–558 (in Japanese).
Yanagi, T. and A. Isobe (1987): Density inversion in the coastal sea. Umi to Sora (Sea and Sky),63, 79–89 (in Japanese).
Yanagi, T. and T. Koike (1987): Seasonal variation in thermohaline and tidal fronts, Seto Inland Sea, Japan. Continental Shelf Res.7, 149–160.
Yanagi, T. and K. Yoshikawa (1987): Tidal fronts in Hiuchi-Nada and Osaka Bay. Bulletin Japanese Soc. Fisheries Oceanogr.,51, 115–119 (in Japanese).
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Takeoka, H., Ohno, Y. & Inahata, N. Roles of horizontal processes in the formation of density stratification in Hiuchi-Nada. Journal of the Oceanographical Society of Japan 47, 33–44 (1991). https://doi.org/10.1007/BF02301753
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DOI: https://doi.org/10.1007/BF02301753