Formation of Concentrated Benthic Suspension in a Time‐Dependent Salt Wedge Estuary

Ge, Jianzhong; Zhou, Zaiyang; Yang, Wei; Ding, Pingxing; Chen, Changsheng; Wang, Zheng Bing; Gu, Jie

doi:10.1029/2018jc013876

Cited by 19 publications

(48 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The estuarine turbidity maximum of the CE is located in the NP, resulting in strong sedimentation rates (Ge et al, , ; Liu et al, ). Many groynes have been buried since the construction of the Deepwater Navigation Channel.…”

Section: Study Site Observation Methods and Numerical Modelmentioning

confidence: 99%

Study of Lateral Flow in a Stratified Tidal Channel‐Shoal System: The Importance of Intratidal Salinity Variation

Zhou

Wang

et al. 2019

JGR Oceans

Self Cite

View full text Add to dashboard Cite

Lateral flow significantly contributes to the near-bottom mass transport of salinity in a channel-shoal system. In this study, an integrated tripod system was deployed in the transition zone of a channel-shoal system of the Changjiang Estuary (CE), China, to observe the near-bottom physics with high temporal/spatial resolution, particularly focusing on the lateral-flow-induced mass transport. These in situ observations revealed a small-scale salinity fluctuation around low water slack during moderate and spring tidal conditions. A simultaneous strong lateral current was also observed, which was responsible for this small-scale fluctuation. A high-resolution unstructured-grid Finite-Volume Community Ocean Model has been applied for the CE to better understand the mechanism of this lateral flow and its impact on salinity transport. The model results indicate that a significant southward near-bed shoal-to-channel current is generated by the salinity-driven baroclinic pressure gradient. This lateral current affects the salinity transport pattern and the residual current in the cross-channel direction. Cross-channel residual current shows a two-layer structure in the vertical, especially in the intermediate tide when the lateral flow notably occurred. Both observation and model results indicate that near-bottom residual transport of water moved consistently southward (shoal to channel). Mechanisms for this intratidal salinity variation and its implications can be extended to other estuaries with similar channel-shoal features.Plain Language Summary In channel-shoal systems, lateral processes sometimes can be of great significance, for example, influencing salinity and sediment transport, even some biogeochemical matters that influence the water environment. Salinity and sediment transport will have a further effect on navigability, ecology, and so on, for example, sediment deposition issues, which significantly decrease the shipping capacity. Consequently, knowing the accurate information about the flow field and finding a criterion for pronounced lateral processes are important to better understand hydrodynamics and sediment behaviors in channel-shoal systems. Here in this study, we conducted an in situ observation and used numerical simulation to detect and predict a strong lateral flow in the North Passage of the Changjiang Estuary. This shoal-to-channel lateral flow occurred around the end of ebb and caused an intratidal salinity variation at the observation site, close to the deep channel. Therefore, a link between pronounced lateral flows and typical salinity variation can be established. This link can also be found in other estuaries like Hudson River estuary. Findings presented here will help to easily distinguish pronounced lateral flows and better understand the effect of lateral flows.

show abstract

Section: Study Site Observation Methods and Numerical Modelmentioning

confidence: 99%

Study of Lateral Flow in a Stratified Tidal Channel‐Shoal System: The Importance of Intratidal Salinity Variation

Zhou

Wang

et al. 2019

JGR Oceans

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previous observational and modeling studies have confirmed that stratification via vertical mixing has strong effects on the FM dynamics (Ge et al, 2018; Geyer, 1993; Winterwerp, 1999;). Additionally, in an estuary, the lateral and vertical mixing between the low‐salinity freshwater and high‐salinity sea water can create complicated haloclines and establish a baroclinic pressure gradient force.…”

Section: Formation Transport and Breakdown Of Fmmentioning

confidence: 86%

“…Since the SSC was much greater in the FM than in the upper suspension layer, the complex dynamics were simplified into a two-layer system, with the FM being a thin layer at the bottom of the benthic column that is covered by the low-SSC water. This Computationally, the model then had three layers: suspension, FM, and seabed (Ge et al, 2018). The suspension layer represented the sediment dynamics for the low-to-medium SSC.…”

Section: The Fm Modelmentioning

confidence: 99%

“…The FM can sustain a very thin vertical thickness, which is not easily resolved through the shipboard observations. Ge et al (2018) developed a sophisticated monitoring system: a bottom‐mounted tripod equipped with various sensors. This system successfully captured the formation and variation of thin FM layers in the Changjiang River Estuary, thus identifying the associated hydro and sediment dynamics.…”

Section: Introductionmentioning

confidence: 99%

“…B Wang and Winterwerp (1992). and further used inWinterwerp (1999),Winterwerp et al (2002), andGe et al (2018) within their 1DV or two-layer modeling experiments.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Dynamic Response of the Fluid Mud to a Tropical Storm

Chen

Wang

et al. 2020

JGR Oceans

Self Cite

View full text Add to dashboard Cite

Fluid mud (FM) is a unique sedimentary feature in high‐turbidity estuaries, where it can make a rapid contribution to morphodynamics. Insufficient field measurements and fixed‐point monitoring lead to deficient understandings of the formation, transport, and breakdown of the FM under extreme weather conditions. A field survey was conducted in the Changjiang Estuary during the period of turbidity maximum, just after Typhoon Haikui. The measurements captured the formation of the FM beneath the suspended layers, particularly around the lower reach of the North Passage. The thickness of the observed FM gradually decreased landward along the channel, with the maximum value reaching ~0.9 m. The major features of the observed storm‐induced FM were simulated using the Finite‐Volume Community Ocean Model. The results indicated that the initial appearance of the FM was the result of a typhoon‐intensified, salinity‐induced stratification in the outlet region. The subsequent landward propagation of the FM was driven by the combined effects of the FM‐induced mud surface pressure gradient force and saltwater intrusion near the bottom. Weak mixing during the subsequent neap tidal period sustained the FM as it rapidly extended into the middle region of the North Passage. This produced a large velocity shear at the interface of the FM and upper suspension layer, increasing the entrainment from the FM to the upper suspension layer. As a result of the increased tidal mixing, the FM weakened and then finally broke down in the subsequent spring tidal period.

show abstract

Spatiotemporal Response of Currents and Mixing to the Interaction of Tides and River Runoff in a Mesotidal Estuary

et al. 2022

View full text Add to dashboard Cite

Formation of Concentrated Benthic Suspension in a Time‐Dependent Salt Wedge Estuary

Cited by 19 publications

References 55 publications

Study of Lateral Flow in a Stratified Tidal Channel‐Shoal System: The Importance of Intratidal Salinity Variation

Study of Lateral Flow in a Stratified Tidal Channel‐Shoal System: The Importance of Intratidal Salinity Variation

Dynamic Response of the Fluid Mud to a Tropical Storm

Spatiotemporal Response of Currents and Mixing to the Interaction of Tides and River Runoff in a Mesotidal Estuary

Contact Info

Product

Resources

About