Semi-automatic determination of the Azores Current axis using satellite altimetry: Application to the study of the current variability during 1995-2006

The time-mean position of the AzC axis shows a good agreement with the highest root-mean-square values of sea level anomaly in the Azores Current region. Zonal means of axis position, SLA and U and V have been calculated over the longitude range of the current (35°W-15°W) to assess the AzC variability. The decomposition of the time series of the zonal mean of AzC position into trend and seasonal components shows the existence of significant inter-annual variability in the axis position, while seasonal variability is small. The AzC is found at its southernmost position from the beginning of the period to mid-1998, the minimum value occurring in late summer of 1996, and a northward displacement of the jet position is clearly visible up to the end of 2006.