Reconstruction and analysis of surface velocity from drifters in the Kuroshio region east of Taiwan

In this study, sea surface velocities derived from drifters were gridded to 0.25° latitude by 0.25° longitude for analysis of the Kuroshio region east of Taiwan. The data for each grid that were originally missing were obtained using the Data Interpolating Empirical Orthogonal Functions (DINEOF) method, which can precisely reconstruct missing data. Compared with the original data, the error of the reconstructed Kuroshio velocity is 0.18 ± 0.03 m/s. By analyzing the reconstructed data, we defined the Kuroshio axis at its maximum surface velocity in the zonal direction of 0.25° latitude along the east coast of Taiwan. The results indicate that the Kuroshio flows faster in summer than it does in winter because of monsoon effects. With the exception of 2010, the Kuroshio was observed to commonly move inshore in winter and offshore in summer in the time span of this study.