A numerical study of currents in the Taiwan strait during winter

Hydrographic data acquired in the Taiwan Strait during the past decade sugg est that, in winter, a zonal oceanic front develops over the Chang-yuen Rid ge implying that the northward moving Kuroshio branch current cannot persis tently hug the west coast of Taiwan as it flows toward the East China Sea a s previous suggested. A three dimensional numerical model is used to study the dynamic process leading to the hydrographic pattern observed in the Tai wan Strait in winter. Model results show that the warm Kuroshio branch wate r in the Peng-hu Channel is blocked and then is forced to deflect westward as it impinges on the southern flank of the ridge, On the other hand, the m onsoon-driven southward flowing cold China coastal water spreads southeastw ard into the northern Taiwan Strait when it passes around the Dal-tan Islan d. The cold water bulge occupies the upper layer of the area north of the r idge in time as winter progresses. The overall flow behavior in the strait in winter favors the formation of the oceanic front over the ridge between the two water masses.