Cross-shelf exchange driven by dipole eddy structures in the East Australian Current.
However, this eddy dipole mode is poorly understood in the context of cross-shelf exchange and the effect of these structures on shelf waters is uncertain. Using 25 years of satellite altimetry, as well as in-situ sampling of a typical dipole event we investigate the characteristics of eddy-driven cross-shelf exchange. We show that the maximum onshore velocity is driven by an eddy dipole structure and occurs in a defined latitudinal band between 33°S and 34°S more than 50% of the time. We sample a typical eddy dipole and find a strong onshore jet, 37km wide, with velocities up to 1.8m.s-1 and a transport of at least 16Sv. Hydrographic data from an autonomous underwater glider shows that this jet manifests on the shelf as a subsurface intrusion of warm salty water extending from offshore up to the midshelf. In the light of climatic changes in western boundary current transport and the increase in their eddy kinetic energy, understanding eddy-driven cross-shelf exchange is important to predict future changes to the shelf water-mass.