We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Turbulence, Sediment‐Induced Stratification, and Mixing Under Macrotidal Estuarine Conditions (Qiantang Estuary, China).
- Authors
Fan, Daidu; Zhang, Yue; Tu, Junbiao; Voulgaris, George
- Abstract
Time series of in situ measured velocity and suspended sediment concentration from Qiantang Estuary (China), and estimates of turbulence and sediment stratification parameters are presented. The data span a period of 9 days, and after phase averaged, they are used to explore spring‐neap tidal variations in flow, turbulence, and sediment stratification. A local balance between shear production, sediment‐induced buoyancy flux, and dissipation is found to hold during ebb for both neap and spring tides. During flood elevated turbulence dissipation rates are observed, attributed to nonlocal turbulence, most likely due to horizontal advection. Our results show that the effect of sediment stratification is successfully parameterized by adding the Monin‐Obukhov length scale to the classical logarithmic layer theory. Flood‐ebb asymmetry in both Rig and Rf is observed, with higher values attained during flood due to the higher sediment concentrations and the corresponding weaker velocity shear found at these times. Rf is found to increase with Rig when Rig < 0.25, and it attains a maximum value of ~0.2. Our estimates, consistently with those from previous studies, fall slightly below the commonly used theoretical predictions. Sediment stratification contributes to the decay of turbulence, and weak mixing still exists under high Rig numbers. Key Points: Turbulence and sediment load estimates show a tidal modulation at spring‐neap and ebb‐flood cyclesSuspended sediment modifies the flow structure, and although it reduces turbulence, it does not suppress it completelyExperimentally derived relationship between Rig and Rf for sediment laden flows generally agree with commonly used models
- Subjects
QIANTANG River (China); TIME series analysis; VELOCITY; TURBULENCE; STRATIGRAPHIC geology; PARAMETERS (Statistics); BUOYANCY
- Publication
Journal of Geophysical Research. Oceans, 2019, Vol 124, Issue 6, p4058
- ISSN
2169-9275
- Publication type
Article
- DOI
10.1029/2018JC014281