Spatial and temporal variability of the sea level anomalies and mesoscale eddies in the region of the Kuroshio Extension
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.
国家科技期刊平台
NSTL
万方数据
维普
