Book chapter
5 - Stratification asymmetries and its impacts on residual flows in the Sydney Estuary, New South Wales
Current Trends in Estuarine and Coastal Dynamics: observations and modelling, pp.99-134
Estuarine and Coastal Sciences Series, Volume 4, Elsevier
2024
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Abstract
Estuaries are primarily defined by intricate interactions among the ocean, freshwater, land, and atmosphere, fostering frequent exchanges of materials and energy. The hydrodynamics within estuaries establish the fundamental physical basis for the temporal and spatial evolution of biological, chemical, and environmental processes. A thorough understanding of the varying magnitudes of distinct forcing mechanisms (such as tides, winds, river discharges, and horizontal salinity gradients) responsible for temporal changes in mixing and stratification conditions within Sydney Estuary is essential. A three-dimensional coastal ocean model was used to reproduce the intratidal and spring-neap variations of current velocity, salinity, and residual currents in the water column, and data were compared with field measurements where available. River discharges and a horizontal salinity gradient were found to induce prolonged stratification during neap tides. A marked asymmetry on the stratification between the spring and the neap tides resulted in significant variations in the current velocity and residual flow distribution. The presence of a longitudinal salinity gradient, along with tidal forcing, resulted in shear that decreased the eddy viscosity and enhanced stratification during ebb tides. Conversely, during flood tides, this phenomenon weakened the stratification, a phenomenon known as the tidal straining effect. Residual flows were generated due to the spring-neap and flood-ebb asymmetric stratification occurring within these tidal cycles.
Details
- Title
- 5 - Stratification asymmetries and its impacts on residual flows in the Sydney Estuary, New South Wales
- Creators
- Ziyu Xiao - CSIRO EnvironmentXiao Hua Wang - UNSW CanberraGavin Birch - The University of SydneyMoninya Roughan - University of New South WalesYoun-Jong Sun - UNSW Canberra
- Contributors
- Xiao Hua Wang (Editor) - UNSW SydneyLulu Qiao (Editor) - Ocean University of China
- Publication Details
- Current Trends in Estuarine and Coastal Dynamics: observations and modelling, pp.99-134
- Series
- Estuarine and Coastal Sciences Series; Volume 4
- Publisher
- Elsevier; Netherlands
- Identifiers
- 991013310218102368
- Copyright
- © 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
- Academic Unit
- Faculty of Science and Engineering
- Language
- English
- Resource Type
- Book chapter