A NUMERICAL-SIMULATION OF WIND STRESS AND TOPOGRAPHIC EFFECTS ON THE KUROSHIO CURRENT PATH NEAR TAIWAN

A semispectral primitive equation model is used to study the effects o f wind stress and bottom topography on the meandering of a jet over th e continental margin. The jet is specified initially as a geostrophic current (similar to the Kuroshio Current) supported by the temperature field. The intrusion of water from the meandering jet over the contin ental margin is not only dominated by topographic effects but also enh anced by northerly winds. The latter induces an onshore Ekman transpor t, which causes surface water in the meandering jet to intrude onto th e continental margin. Lighter water is then carried downward to the de eper ocean through the hydrostatic and topographic boundary layers. So me subsurface water in the meandering jet also intrudes onto the conti nental slope and shelf and then rejoins the main stream. Under the inf luence of southerly wind, surface water in the meandering jet migrates offshore toward the deeper ocean in the Ekman layer, while subsurface water in the meandering jet intrudes onto the continental slope and s helf in the topographic boundary layers. In this case, heavier water i s lifted to the sea surface through the topographic boundary and hydro static layers. The result suggests that the path of the Kuroshio north of Taiwan is strongly influenced by both the topographic effects and Ekman drift. The intrusions of the meandering Kuroshio surface and sub surface waters are steered and determined by wind directions.