Numerical Experiment on the Fortnight Variation of the Residual Current in the Ariake Sea

The fortnight variations of the residual current in the Ariake Sea, a partly mixed estuary located in the western part of Japan, are investigated with a three-dimensional numerical ocean model. Regardless of season, lateral shear dominates at spring tide and vertical shear is intensified at neap tide. The densitydriven current dominates the overall structure of the residual current. The Ekman number is the dominant parameter that controls the overall structure of the densitydriven current, indicating that the magnitude of the tidal mixing is the most important factor that controls the structure of the density-driven current. The current structure is not sensitive to the Kelvin number, which suggests the bay width is not a constraint on the density-driven current.Nagasaki University Major Research Project: Restoration of Marine Environment and Resources in East Asi