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Along southeastern Australia, the East Australian Current (EAC) strongly influences the circulation and watermass characteristics of the adjacent continental shelf. Dense water uplift resulting from its intrusions onto the shelf have been elucidated and quantified using moored in situ measurements, both upstream (30oS) and downstream (34oS) of the EAC separation zone. However, these results were spatially limited, and sustained observations are lacking in the separation zone where upwelling has been observed, with great implications for biological productivity.
The comprehensive dataset from 23 glider deployments along the inshore edge of the jet (2008-2014) provides a new high resolution hydrographic climatology which is exploited to understand the spatial variability of uplift and 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. The advection terms in the alongshelf momentum balance are of the order of magnitude of the baroclinic pressure gradients, highlighting the non-linearity of the flow. Near bottom measurements indicate dense water uplift, as a result of the EAC encroachment and separation, influencing the biogeochemical properties of the watermass. 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 western boundary current environment.