Influence of island chains on the Kuroshio intrusion in the Luzon Strait

By applying a global high-resolution (0.1°) OGCM, the influence of the island chains in the Luzon Strait (LS) on the Kuroshio intrusion is studied systematically. The island chains in the LS are separated into three parts: the south island chain, the middle and north island chain, and Babuyan Island. One control and three sensitivity experiments are conducted by adding these three parts of the topography gradually. From comparisons of the circulation, temperature, and salinity structures, it is found that the south island chain decreases the westward bending of the main Kuroshio path, the middle and north island chain increases the westward bending, and Babuyan Island also increases the westward bending. These results are extremely clear in winter. Dynamic diagnoses suggest that the westward bending increases with an increase in the incidence angle of the Kuroshio and an increase in the Kuroshio east branch transport. Moreover, the middle and north island chain can split the Kuroshio into two parts, the Kuroshio west and east branches, which can be seen clearly in the satellite altimeter maps.