Surface Current Characteristics in the Taiwan Strait Observed by High-Frequency Radars

Abstract

In this paper, we focus on the characteristics of the surface currents in the Taiwan Strait observed by two high-frequency surface wave radars (HFSWRs). The current velocities correlate well with the in situ buoy records, which show the reliability of the radar data. Tidal constituents are then calculated from the 80-day-long sea current data. The current pattern in this area consists of a dominant semidiurnal tidal component and a mixed semidiurnal one. The influence of the shallow-water constituents is significant, and the bathymetry also produces an obvious effect on the spatial distribution characteristics of the tidal currents. The directions of the major axes of the ${M}_{2}$ tidal current ellipses coincide well with that of the strait axis. Besides, the east–west components of the residual current velocity and the wind speed are found to be highly correlated with a correlation coefficient up to 0.808, while the north–south components are nearly uncorrelated with a correlation coefficient down to 0.238. This study shows the great capability of the HFSWR in oceanographic researches and applications, especially for the tidal analysis and a further study of the wind–current relation.