Circulation in the Northern Japan Sea Studied Chiefly with Radiocarbon

• Published in: Radiocarbon
• Main Authors: Aramaki, T, Senjyu, T, Togawa, O, Otosaka, S, Suzuki, T, Kitamura, T, Amano, H, Volkov, Y N
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2007
• Subjects: Okhotsk; Pacific; okhotsk sea
• Online Access: https://doi.org/10.1017/s0033822200042788; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033822200042788

Radiocarbon concentrations in the northernmost region of the Japan Sea were observed during the summer of 2002. The averaged surface δ 14 C (above 100 m depth) was 52 ± 8%, which is significantly higher compared with the values of the Pacific Ocean and Okhotsk Sea. The δ 14 C in the deep water decreased with density, and the minimum value was −70%. By analyzing 14 C and other hydrographic data, we found that i) the Tsushima Warm Current Water reaches to the surface layer in the southern Tatarskiy Strait; ii) deep convection did not occur in the northernmost region, at least not after the winter of 2001–2002; and iii) the bottom water that was previously formed in this region may step down southward along the bottom slope and mix with the Japan Sea Bottom Water. Furthermore, a new water mass characterized by high salinity (>34.09 psu) was found in the subsurface layer in the area north of 46°N.