[A-OS12] Marine ecosystems and biogeochemical cycles: theory, observation and modeling

[AOS12-11] Development of a combined Eulerian tracer and Lagrangian particle ocean model for evaluating biogeochemical cycle and transport in regions of freshwater influence

*Yasuhiro Hoshiba¹, Yoshimasa Matsumura¹, Yoshihiko Ohashi², Hiroyasu Hasumi¹, Sachihiko Itoh¹ (1.Atmosphere and Ocean Research Institute , The University of Tokyo, 2.Tokyo University of Marine Science and Technology)

Keywords:biogeochemical modeling, coastal area, freshwater input

Currently, we are developing a new biogeochemical model focusing on coastal areas affected by freshwater inflow from the land. The model, which is still under development, will be a complex model of Eulerian tracers and Lagrangian particles including suspended sediment matter (SSM), the lower trophic level marine ecosystem, and microplastics. The present presentation will show the ongoing application of the model to a region of river water influence (Tango Sea, Japan) and a region of glacial meltwater influence (Bowdoin Fjord, Greenland). This model, which employs a non-hydrostatic ocean model (kinaco) in its physical part, can reproduce hyperpycnal plumes (the density of river water plus SSM exceeds the seawater density falls to the seafloor) that occurs when large floods occur, and the process of glacial meltwater discharging out from the lower layer to the coastal area and upward to the surface. We would like you to see the results of our quantitative estimation of the impact of these processes on the ecosystem (nutrients, net primary production, etc.), even though it is still under development. Furthermore, if time permits, we will talk about our goals for future research that will be possible as the model is completed.