A note on the driving mechanisms of current in the Taiwan Strait

摘要

Current measurements made in the Taiwan Strait from March to July 1984, confirmed old ship reports that flow was toward the north in both summer and winter. The flow consists of three parts: a steady current which is about 27 cm sec?1 in both seasons, a long-period (period longer than 20 days) fluctuating component which varies with the reverse of wind direction between seasons (monsoon wind), and a short-period (period in the range of 3 to 20 days) fluctuating component which is closely related to the frontal passages and appears only in winter. Thus, a permanent source must exist at the southern end of the strait that drives the steady flow to the north regardless of season. The northward mean flow is then modulated by the seasonal wind field, and hence, shows different characteristics between seasons.