Warm Ocean Water Intrusion into Kagoshima Bay

From the field observations and the buoy robot data, the warm ocean water is known to intrude into Kagoshima Bay intermittently in winter. We first visualize these phenomena using some satellite thermal infrared images. Then the numerical analysis is performed employing a multi-level finite difference method (FDM). It is found from the numerical analysis that the intrusion occurs when the warm water comes into touch with the bay water at the mouth of the bay. The calculated warm water distribution in the bay is similar to the satellite images and the velocity of the intrusion is the same order with the ones estimated by the buoy robot data and the satellite images. The intrusion occurs even without the tidal effect, the role of the tide is only to rectify some warm water distribution in the bay.