To understand the effects of wind, tides, and the Kuroshio on cold-water upwelling around the Taiwan Bank, a series of experiments—including in situ observations, satellite remote sensing, and numerical modeling—was designed and conducted to address these scientific questions. This study employs a numerical model to identify the dominant forcing mechanisms, specifically, winds, tides, and the Kuroshio Current, and to evaluate how they individually and collectively drive this upwelling. Through a series of sensitivity experiments (Experiments A–G), we isolated each physical forcing to examine its impact on the modeled surface temperature fields, time-series variations at specified temperature sites, and vertical thermal profiles. The model results demonstrate that the Kuroshio Current plays a crucial role in the cold-water upwelling; in scenarios where the Kuroshio acts as the sole forcing (Exp. C), a distinct cold-water band forms along the southeastern edge of the bank, lifting the 26.5 °C isotherm to within approximately 2.5 m below the sea surface. Tidal forcing is found to play a critical enhancing role; the combination of the Kuroshio and tides (Exp. F) produces the most intense upwelling recorded, causing cold-water isotherms (26.5 °C) to protrude through the sea surface. Conversely, wind stress suppresses the cold band; in all cases where wind is included (Exps. D, E, and G), the intensity of the upwelling decreases, and the vertical rise of the 26.5 °C isotherm is reduced. The fully integrated model (Exp. G), incorporating all three forces, successfully reproduces the prominent banana-shaped cold-water band (akin to observations in nature), confirming that while the Kuroshio and tides provide the primary upward energy, wind stress weakens the strength of cold-water upwelling.
Lee et al. (Thu,) studied this question.