[A-OS13] Marine ecosystems and biogeochemical cycles: theory, observation and modeling

[AOS13-P08] Future Projection of Physical-Biogeochemical Environment in the Deep Japan Sea

*Tianran Liu¹, Naoki Hirose¹, Katsumi Takayama² (1.Research Institute for Applied Mechanics, Kyushu University, 2.Institute of Environmental Informatics, IDEA Consultants, Inc.)

Keywords:global warming, Japan Sea, physical-biogeochemical coupled model, Green’s function method

We attempt to create a physical-biogeochemical coupled model and predict the environment in the deep Japan Sea under global warming scenarios. The representation of physical-biogeochemical variations is improved by adjusting the model parameters and initial conditions based on the Green’s function method and WOD18 data. The root-mean-square differences of simulation with optimal parameters decrease by 37% for dissolved oxygen (DO) and 11% for nutrient (N). Then, the prediction experiments extended to 150 more years show that the deep layer temperature increases abruptly under RCP8.5 scenario after 100 years from now. On the other hand, the concentration of DO decreases by a rate of 0.67 μmol/kg, and N increases by a rate of 0.08 mmol/m³ for RCP2.6 (RCP8.5) scenario until 2090 (2120). After that, the concentrations become unstable. It is noted that the DO concentration of RCP8.5 scenario is much higer than that of RCP2.6 in the 22^nd century.