Journal of Oceanography

, Volume 69, Issue 2, pp 245–258 | Cite as

Characteristics of outer shelf water in the East China Sea

  • Shigefumi Yanao
  • Takeshi Matsuno
Original Article


Water mass properties along cross-sections of the Kuroshio in the East China Sea (ECS) are investigated in detail. We used temperature, salinity and dissolved oxygen data from 2000 and 2002, together with historical temperature and salinity data from 1987 to 2004. Water properties were divided into two groups: high and low salinities or oxygen at temperatures warmer than 15 and 12 °C, respectively. We found the existence of outer shelf water W2, as defined by clear modes in frequency distributions of salinity and oxygen within various temperature segments. The outer shelf water was different from both Kuroshio Tropical Water (KTW) and coastal water. We mapped horizontal and vertical distributions of W2, along with W1 and KTW. The outer shelf water was distributed with density σ t = 22.5–25.5 over a relatively broad area, from the outer continental shelf to the continental slope, particularly in autumn. Vertical distribution of the water suggests that W2 spread from the outer shelf to just the shelf side of the Kuroshio Current velocity maximum. Seasonal variations are examined with historical data along PN section over 17 years, and suggest that the appearance of W2 is distinct in summer and autumn. By comparing temperature–salinity (T–S) diagrams from Taiwan Strait and east of Taiwan, the outer shelf water (W2) originates from South China Sea Tropical Water (SCSTW), as suggested by Chen, J Geophys Res 110:C05012 (2005). The present study of the ECS clearly shows that SCSTW is transported along the east coast of Taiwan or through the Taiwan Strait into the ECS. It then spreads over a relatively wide area from the outer shelf to just the shelf side of the Kuroshio axis, and there is some horizontal mixing between SCSTW and KTW around the shelf break.


East China Sea South China Sea  Continental shelf Shelf break Water masses Water mixing Taiwan Warm Current Kuroshio 



“Hakuho-maru” cruises (KH-00-4 and KH-02-3) in 2000 and 2002 were conducted by Hiroshi Ichikawa and the late Masaki Kawabe, and we are grateful for their support and encouragement in data analysis. Thanks are extended to all participants of the cruises, plus officers and crews of the “Hakuho-maru”. We also thank Nagasaki Marine Observatory for providing original data along the PN line. We appreciate C.T.A. Chen for his fruitful suggestions on the earlier version of this study, as well as reviewers for their helpful comments to improve the manuscript.


  1. Beardsley RC, Limeburner R, Yu H, Cannon GA (1985) Discharge of the Changjiang (Yangtze River) into the East China Sea. Cont Shelf Res 4(1):57–76CrossRefGoogle Scholar
  2. Chen CTA (2005) Tracing tropical and intermediate waters from the South China Sea to the Okinawa Trough and beyond. J Geophys Res 110:C05012 doi: 10.1029/2004JC002494
  3. Chen CTA, Huang MH (1996) A mid-depth front separating the South China Sea water and Philippine Sea water. J Oceanogr 52:17–25CrossRefGoogle Scholar
  4. Chen C, Beardsley RC, Limeburner R, Kim K (1994) Comparison of winter and summer hydrographic observations in the Yellow and East China Seas and adjacent Kuroshio during. Cont Shelf Res 14(7):909–929CrossRefGoogle Scholar
  5. Han IS, Kamio K, Matsuno T, Manda A, Isobe A (2001) High frequency current fluctuations and cross shelf flows around the pycnocline near the shelf break in the East China Sea. J Oceanogr 57(2):235–249CrossRefGoogle Scholar
  6. Hur HB, Jacobs GA, Teague WJ (1999) Monthly variations of water masses in the Yellow and East China Seas, November 6, 1998. J Oceanogr 55:171–184CrossRefGoogle Scholar
  7. Isobe A (1999) The Taiwan-Tsushima warm current system: its path and the transformation of the water mass in the East China Sea. J Oceanogr 55:185–195CrossRefGoogle Scholar
  8. Isobe A (2008) Recent advances in ocean-circulation research on the Yellow Sea and East China Sea shelves. J Oceanogr 64(4):569–584CrossRefGoogle Scholar
  9. Jacobsen JP (1929) Contribution to the hydrography of the North Atlantic. The Danish Dana Exped 1920-22, 1(3):98Google Scholar
  10. Nakao T (1977) Oceanic variability in relation to fisheries in the East China Sea and the Yellow Sea. J Fac Mar Sci Technol, Tokai Univ, Special Number, pp 199–367Google Scholar
  11. Sawara T, Hanzawa Y (1979) Distribution of water type in the East China Sea. Umi to Sora (Sea and Sky) 54(4):135–148 (in Japanese with English abstract)Google Scholar
  12. Su YS, Weng XC (1994) Water masses in China Seas. In: Zhou et al. (eds) Oceanology of China Seas, vol 1. Kluwer, Boston, pp 3-16Google Scholar
  13. Tawara S, Yamagata T (1991) Seasonal formation of bottom water in the Yellow Sea and its interannual variability. Umi to Sora (Sea and Sky) 66(Special Number):273–282 (in Japanese with English abstract)Google Scholar
  14. Zhang L, Liu Z, Zhang J, Hong GH, Park Y, Zhang HF (2007) Reevaluation of mixing among multiple water masses in the shelf: an example from the East China Sea. Cont Shelf Res 27:1969–1979CrossRefGoogle Scholar

Copyright information

© The Oceanographic Society of Japan and Springer Japan 2013

Authors and Affiliations

  1. 1.Department of Earth System Science and TechnologyKyushu UniversityKasugaJapan
  2. 2.Research Institute for Applied MechanicsKyushu UniversityKasugaJapan

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