TERRAPUB Journal of Oceanography

Journal of Oceanography, Vol. 62 (No. 5), pp. 649-655, 2006

Possible Source of the Antarctic Bottom Water in the Prydz Bay Region

Takashi Yabuki1*, Toshio Suga1, Kimio Hanawa1, Koji Matsuoka2, Hiroshi Kiwada2 and Tomowo Watanabe3

1Department of Geophysics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
2The Institute of Cetacean Research, Tokyo 104-0055, Japan
3National Research Institute of Fisheries Science, Yokohama 236-8648, Japan

(Received 8 August 2005; in revised form 9 May 2006; accepted 13 May 2006)

Abstract: It has been inferred that the Prydz Bay region is one of the source regions of Antarctic Bottom Water (AABW) based on rather indirect evidence. In order to examine this inference, we investigate the hydrographic condition of the bay based mainly on XCTD data obtained during the Japanese Whale Research Program in the Antarctic (JARPA). The JARPA hydrographic data reveal Circumpolar Deep Water (CDW), which is a salty, warm water mass approaching the shelf break, and capture Modified CDW (MCDW) intruding into the shelf water. AABW production requires mixing of CDW and cold shelf water saltier than 34.6 psu, which is a saltier type of Low Salinity Shelf Water (LSSW). Saltier LSSW is observed near the bottom over the shelf, being mixed with MCDW. We further identify saltier LSSW near the shelf break. This saltier LSSW appears close enough to unmodified CDW to be mixed with it over the continental slope, indicating a possible source of AABW in Prydz Bay.

*Corresponding author E-mail: yabuki@pol.geophys.tohoku.ac.jp

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