Abstract
In order to evaluate the performance of structures for generating upwelling, a numerical physical-biological coupled model is presented. The model consists of two submodels: hydrodynamical model and phytoplankton dynamical model. Moreover the hydrodynamical model comprises two submodels tidal current (TC) submodel and residual current (RC) submodel. The TC and RC are computed by using multi-leveled prognostic and diagnostic models, respectively.
At first, the flow simulation is conducted in a large domain, which encompasses the study area, with large computational cells to obtain the boundary values of the study area, and then the computation is conducted in the study area with small cells by using resultant boundary values. The TC in the study area is driven by the water surface elevation at open boundaries, whose values are obtained in advance from the computation in the large domain. The RC in the study area is made by interpolating the result of RC in the large domain into the values of every small computational cell in the study area through MASCON model so as to satisfy the continuity condition.
In the phytoplankton dynamical model, the flux of phosphorus as a limiting nutrient of primary production, between two compartments: dissolved nutrient and phytoplankton, is computed in the resulting flow field. The phytoplankton uptakes the nutrient upwelled by the structures and increases. The growth rate of phytoplankton is controlled by nutrient availability, water temperature and solar radiation in this model.
This developed model is verified in comparison with the satellite observation data. This model will be a powerful tool for assessing the future projects of developing new fishing grounds with artificially generated upwelling.
