Spatio-Temporal Variability of the Eddy Kinetic Energy in the South Atlantic Ocean

Abstract

The spatio-temporal variability of the eddy kinetic energy (EKE) in the South Atlantic Ocean (SAO) is investigated using 19 years of satellite altimetry observations. The EKE in this region presents different significant frequency modes. The interannual to intrannual cycles dominate the EKE variability spectrum. Spatial patterns of the EKE variance were also determined and associated with the propagation of the Agulhas Current eddies across the SAO. At the annual frequency, EKE anomalies are generated in the Agulhas leakage (AL) region and propagate westward. The interannual signal was associated with the Antarctic oscillation and displays a stationary spatial oscillation pattern in the Agulhas eddy corridor (AEC). This is the first time that a full spectral analysis of the EKE variability in the SAO is produced. Results show that the AEC is an important feature in the SAO, with low (high) frequencies associated to the west (east) part of the basin. The AL is a significant source of mesoscale variability to the South Atlantic subtropical gyre.