An Analysis of Energy Transfer Across Scales in the Leeward Intensification of a Standing Eddy

As the only major ocean basin that allows for fully circumpolar flow, the Southern Ocean has been identified as a region in which transient mesoscale eddies are especially important. Recent evidence indicates, however, that transient eddies alone do not generate the entire poleward heat transport that must dominate over the equatorward heat transport forced by the prevailing westerly winds. Instead, fixed meanders in the flow, which can be referred to as stationary waves or standing eddies, deliver much of the poleward heat transport.

In our simplified problem a standing eddy sets up over the ridge which serves as the only bathymetry in a reentrant channel. In the lee of the ridge, the main jet becomes narrowly focussed. We apply a new analysis technique, described in Abstract id# 87364, that allows one to unambiguously quantify the energy transfer across length scales while retaining full temporal and spatial resolution, to better understand the interaction between transient eddies and the standing eddy. As it is the latter that delivers the majority of the poleward heat transport, our aim is to better understand how the transient eddies contribute to the poleward heat transport indirectly through this eddy-mean flow influence.