Abstract
A two-way multi-nesting ocean model of the Pacific Ocean is developed in order to construct a high-resolution marine ecosystem model of the Japanese coastal area. In the present study, the focused area is Otsuchi Bay located at Sanriku ria coast. We developed the Pacific Model and the Bay Model, respectively. Each model is composed of a two-way nested model, and connected in a one-way nesting manner. The finest model of the Bay Model is gridded by about 14-m spacing as the horizontal resolution. A simulation using this model shows that the circulation of Otsuchi Bay in winter is different from in other seasons. This is mainly controlled by the seasonal variation of the river discharge. Intrusion processes of Pacific water into the bay also have seasonal variation. Especially in summer, the temperature and salinity of the bottom layer in the bay are dominated by
semidiurnal and diurnal variations. This implies that tides encourage the exchange between the bay water and the Pacific Water in summer.
