Jacqueline McSweeney - Spatiotemporal Variability of Sediment Transport Processes in Delaware Estuary
Spatiotemporal Variability of Sediment Transport Processes in Delaware Estuary
Jacqueline McSweeney - Rutgers University, New Jersey, USA
The Estuarine Turbidity Maximum (ETM) zone is an important region for sediment trapping, deposition, and storage within an estuary. The ETM is classically thought to be generated by near-bottom convergence due to the along-channel baroclinic pressure gradient, and sediment transport within the ETM is typically described in terms of along-channel processes. However, recent studies have shown that lateral circulation contributes significantly to transport processes and that the ETM zone has important 3-dimensional structure, with differing processes dominant on the flanks and channel.
This study highlights the importance of lateral sediment processes in Delaware Estuary by utilizing observations from a mooring array deployed within the ETM and a Regional Ocean Modeling System (ROMS) coupled hydrodynamic and sediment model. We identify key mechanisms that facilitate sediment exchange between the channel and flanks. A decomposition analysis isolates the tidal pumping and mean advection terms, revealing the importance of tidal asymmetries of stratification and resuspension as well as spatiotemporal patterns of residual sediment fluxes. These findings ultimately provide insight about the 3-dimensional structure of the turbidity maximum and the trapping efficiency the ETM.