Trends in the Agulhas Return Current

Recent observations report a poleward shift in several of the world’s western boundary current extensions in response to a warming climate. However, the nature and variability of the Agulhas Return Current (ARC) is still relatively unknown, leading to uncertainty in its response to gyre intensification. The objective of this work is to investigate meridional migration and eddy kinetic energy (EKE) trends in the ARC over the past 27 years using satellite-derived altimetry products. A difference is seen between the western and eastern regions of the ARC, the former exhibiting a predominantly equatorward migration and the latter moving predominantly poleward. The ARC is shown to be a region highly influenced by its bathymetry. Additionally, we show that the regional EKE peaks during austral summer months and that there has been a significant rise in summertime EKE levels between 1994–2011.