Based on the satellite altimeter data from 1993 to 2010, the temporal and spatial variations of the sea level anomalies and mesoscale eddies in the region of the Kuroshio Extension has been studied by EOF and wavelet spectrums analysis. The result of EOF analysis is as following: the first EOF mode of the sea level is a seasonal mode, which indicates that it tends to increase in the total region. Compared to the first EOF mode of the wind stress curl, it is found that the spatial and temporal variability is similar, and the correlation is high. It can be concluded that the wind stress plays a key role in the seasonal variations of the sea level in the Kuroshio Extension. The second EOF mode of the SLA shows the variation of the southern sub-circulation gyre, whose significant cycle is 8-10 years. It is suggested that the decadal variation of the southern sub-circulation gyre is associated with the PDO. It is also found that the decadal modulation needs 4 years oceanic adjustment time for the baroclinic Rossby waves propagating from the eastern North Pacific to the Kuroshio. The third EOF mode of the SLA reveals the meandering state of the Kuroshio. The cyclonic and anti-cyclonic eddies in the south of Japan can characterize the formation of the meandering state of the Kuroshio, and the strength of the meandering state is related to the duration time, intensity and locations of the eddies.%利用1993-2010年间的卫星高度计资料,用EOF方法及小波分析研究了黑潮延伸体区域的海平面异常和中尺度涡的时空变化特征.研究结果表明:海平面EOF第一模态是季节模态,与该海域风应力旋度第一模态类似,相关系数达0.65.EOF第二模态主要反映了黑潮南部次级环流的变化情况,显著性周期是8-10年.通过相关分析发现黑潮延伸体南部次级环流的年代际变化与PDO有关,同时它又与风应力旋度第二模态有关；该海域的海面高度受到北太平洋东部SSH信号西传的影响,信号的传播需要大约3-4年时间.EOF第三模态是黑潮弯曲模态.日本南部的气旋涡和反气旋涡可以表征黑潮弯曲的形成,而且弯曲强度和涡的持续时间、强度和位置有关.
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