Kim, Jae-Yeon¹, Dong-Jin Kang², Tongsup Lee¹ and Kyung-Ryul Kim²

¹Department of Marine Science, Busan National University, Busan, 609-735, Korea, Tel: 82-51-510-3369, Fax: 82-51-581-4591, E-mail: yeony@pusan.ac.kr and ²OCEAN Laboratory, Research Institute of Oceanography, School of Earth and Environment Sciences, Seoul National University, Seoul 151-742, Korea

The response of deep interior of the East/Japan Sea to recent climate forcing

The East/Japan Sea becomes a focus for a research because of its oceanic characteristics. Its thermohaline circulation is considerably smaller but much faster than the global one. Nowadays the issue of the change of its ventilation system becomes the proxy of the climate and global change. Recently, the Moving-Boundary Box Model (MBBM), which can simulate the change in the ventilation system of the East/Japan Sea, was developed and calibrated using various chemical tracers. This model reproduced faithfully the variation of ventilation and the dissolved oxygen concentration of the past 50 years in the East/Japan Sea. To understand carbon flux variation related to biology with shift of the ventilation system, we estimate the approximately size of the biological pump of the East/Japan Sea with the phosphate cycle embedded Moving-Boundary Box Model (P-MBBM). This model was calibrated with available historical phosphate data set. The in-situ remineralized phosphate is estimated by the oxygen consumption rate and the stoichiometric ratio. Remineralized phosphate should be equal to the export production under the steady-state assumption and we regard biological pump as export production. From the model results, the size of biological pump in the East/Japan Sea is estimated about 0.02 GtC yr^-1 and P-MBBM describes that the export production has been increased in response to the structural change of deep interior of the East/Japan Sea.