Influence of a western boundary current on shelf dynamics and upwelling from repeat glider deployments

The separation zone of a dynamically important western boundary current (WBC) is resolved through a series of sustained glider deployments along the coastal edge of the jet. The comprehensive data set from 23 missions (2008-2014) provides a new high-resolution hydrographic climatology which is exploited to understand the spatial extent of dense water uplift and the depth-averaged momentum balances across the East Australian Current (EAC) separation zone. The predominantly geostrophic shelf circulation and temperature fields are least (most) variable upstream (downstream), where encroachment (separation) dominates. For the first time we resolve the nonlinear advection terms which are considerable in the along-shelf momentum balance. Near bottom water masses indicate dense water uplift, as a result of the EAC encroachment and separation. The data provide both new insight into and a climatology of separation-induced uplift and demonstrate a successful model for repeat glider missions in a dynamic WBC environment. Key Points New high-resolution climatology in the EAC separation zone from gliders Upwelling associated with EAC encroachment and separation is mapped Depth-averaged momentum balance reveals the determinant role of advection