Advertisement

Journal of Oceanography

, Volume 64, Issue 4, pp 595–603 | Cite as

Long-term variability of shelf water intrusion and its influence on hydrographic and biogeochemical properties of the Seto Inland Sea, Japan

  • Shiho KobayashiEmail author
  • Tateki Fujiwara
Original Articles

Abstract

The variability of the pathway of the Kuroshio is known to control that of the intensity of upwelling of the cold and nutrient-rich deep shelf water at the shelf-break point. This study has investigated the influences of the long-term variability of the hydrographical and biogeochemical conditions at the shelf-break point on those in the inner Seto Inland Sea. Results from observations conducted since 1972 by prefectural fisheries observatories showed a temporary decrease of temperature in the lower layer of the entrance of Kii Channel in summertime in the specific years when the Kuroshio pathway favored deep shelf water intrusion. A corresponding change in temperature was also found in the inner shelf sea, such as western Osaka Bay and Harima-Nada. The model developed in this study covers a 30-year period and well reproduces the temporal change in temperature. It also shows sufficient reproducibility in both seasonal behavior of hydrographical and biogeochemical properties and the inter-annual variability of hydrographical properties throughout the eastern Seto Inland Sea. It was found that the inter-annual variations of annual total flux through the section at the entrance to Kii Channel affect the inter-annual variation of the observed concentration of Dissolved Inorganic Nitrogen (DIN) in Harima Nada, but the effect was smaller than those of river input and other parameters.

Keywords

Nutrient transport shelf water intrusion inter-annual variability Kuroshio Seto Inland Sea 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Atkinson, L. P., G. A. Paffenhöfer and W. M. Dunstan (1978): The chemical and biological effect of a Gulf Stream intrusion off St. Augustine, Florida. Bull. Mar. Sci., 28, 667–679.Google Scholar
  2. Awaji, T., K. Akitomo and N. Imasato (1991): Numerical study of shelf water motion driven by the Kuroshio—Barotropic model. J. Phys. Oceanogr., 21, 11–27.CrossRefGoogle Scholar
  3. Fujiwara, T. (1986): Mass flux and mass balance in the Seto Inland Sea. Ph.D. Thesis, Tokyo University.Google Scholar
  4. Fujiwara, T. and Y. Yamada (2002): Inflow of oceanic water into a coastal embayment (Tokyo Bay) and generation of subsurface hypoxic water mass. J. Geophys. Res., 107(C5), 3045, doi:10.1029/2000JC000749.CrossRefGoogle Scholar
  5. Guerrero, R. A., E. M. Acha, M. B. Framinan and C. A. Lasta (1997): Physical oceanography of the Rio de la Plata Estuary, Argentina. Cont. Shelf Res., 17, 727–742.CrossRefGoogle Scholar
  6. Kakehi, S. and T. Fujiwara (2007): Dynamics of nutrients in Ise Bay: Seasonal variations of non-conservative change of nutrients. Oceanogr. Japan, 16, 437–453 (in Japanese with English abstract).Google Scholar
  7. Kaneda, A., H. Takeoka, E. Nagaura and Y. Koizumi (2002): Periodic intrusion of cold water from the Pacific Ocean into the bottom layer of the Bungo Channel in Japan. J. Oceanogr., 58, 547–556.CrossRefGoogle Scholar
  8. Kasai, A., T. Fujiwara, T. Kimura and H. Yamada (2004): Fort-nightly shift of intrusion depth of oceanic water into Ise Bay. J. Oceanogr., 60, 817–824.CrossRefGoogle Scholar
  9. Kobayashi, S., T. Fujiwara, M. Tada, H. Tsukamoto and T. Toyoda (2006a): The distributions of nitrogen, phosphate, silicon and nutrient ratio during the stratified season in the Seto Inland Sea. Oceanogr. Japan, 15, 283–297 (in Japanese with English abstract).Google Scholar
  10. Kobayashi, S., J. H. Simpson, T. Fujiwara and K. J. Horsburgh (2006b): Tidal stirring and its impact on water column stability and property distributions in a semi-enclosed shelf sea (Seto Inland Sea, Japan). Cont. Shelf Res., 26, 1295–1306.CrossRefGoogle Scholar
  11. Millot, C. (1990): The Gulf of Lions’ hydrodynamics. Cont. Shelf Res., 10, 885–894.CrossRefGoogle Scholar
  12. Takashi, T., T. Fujiwara, T. Sumitomo and W. Sakamoto (2006): Prediction of slope water intrusion into the Kii Channel. J. Oceanogr., 62, 105–113.CrossRefGoogle Scholar
  13. Takeuchi, J. (2001): Interannual and interdecadal variations in plankton biomass and intrusion of bottom cold water into Kii Channel. Umi to Sora, 77, 91–98 (in Japanese with English abstract).Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Kyoto UniversityKyotoJapan

Personalised recommendations