Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inlet
The secondary circulation in a predominantly well-mixed estuarine tidal inlet is examined with three-dimensional numerical simulations of the currents and density field in the German Bight. Simulations analyze two complete neap and spring tidal cycles, inspired by cross-section measurements in the t...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-04-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2023.1105626/full |
| _version_ | 1797837919730270208 |
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| author | Wei Chen Benjamin Jacob Arnoldo Valle-Levinson Emil Stanev Joanna Staneva Thomas H. Badewien |
| author_facet | Wei Chen Benjamin Jacob Arnoldo Valle-Levinson Emil Stanev Joanna Staneva Thomas H. Badewien |
| author_sort | Wei Chen |
| collection | DOAJ |
| description | The secondary circulation in a predominantly well-mixed estuarine tidal inlet is examined with three-dimensional numerical simulations of the currents and density field in the German Bight. Simulations analyze two complete neap and spring tidal cycles, inspired by cross-section measurements in the tidal inlet, with a focus on subtidal time scales. The study scrutinizes the lateral momentum balance and quantifies the individual forces that drive the residual flow on the cross-section. Forces (per unit mass) from the covariance between eddy viscosity and tidal vertical shear (ESCO) play a role in the lateral momentum budget. During neap tide, the ESCO-driven flow is weak. Accelerations driven by advection dominate the subtidal secondary circulation, which shows an anti-clockwise rotation. During spring tide, the ESCO acceleration, together with the baroclinicity and centrifugal acceleration, drives a clockwise circulation (looking seaward). This structure counteracts the advection-induced flow, leading to the reversal of the secondary circulation. The decomposition of the lateral ESCO term contributors reveals that the difference in ESCO between neap and spring tides is attributed to the change in the vertical structure of lateral tidal currents, which are maximum near the bottom in spring tide. The findings highlight the role of the tidally varying vertical shears in the ESCO mechanism. |
| first_indexed | 2024-04-09T15:33:28Z |
| format | Article |
| id | doaj.art-9281a3b3a17048a09949ea5645ac97e4 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-04-09T15:33:28Z |
| publishDate | 2023-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-9281a3b3a17048a09949ea5645ac97e42023-04-28T04:59:42ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452023-04-011010.3389/fmars.2023.11056261105626Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inletWei Chen0Benjamin Jacob1Arnoldo Valle-Levinson2Emil Stanev3Joanna Staneva4Thomas H. Badewien5Institute of Coastal Systems-Analysis and Modeling, Helmholtz-Zentrum Hereon, Geesthacht, GermanyInstitute of Coastal Systems-Analysis and Modeling, Helmholtz-Zentrum Hereon, Geesthacht, GermanyCivil and Coastal Engineering Department, University of Florida, Gainesville, FL, United StatesInstitute of Coastal Systems-Analysis and Modeling, Helmholtz-Zentrum Hereon, Geesthacht, GermanyInstitute of Coastal Systems-Analysis and Modeling, Helmholtz-Zentrum Hereon, Geesthacht, GermanyInstitute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, GermanyThe secondary circulation in a predominantly well-mixed estuarine tidal inlet is examined with three-dimensional numerical simulations of the currents and density field in the German Bight. Simulations analyze two complete neap and spring tidal cycles, inspired by cross-section measurements in the tidal inlet, with a focus on subtidal time scales. The study scrutinizes the lateral momentum balance and quantifies the individual forces that drive the residual flow on the cross-section. Forces (per unit mass) from the covariance between eddy viscosity and tidal vertical shear (ESCO) play a role in the lateral momentum budget. During neap tide, the ESCO-driven flow is weak. Accelerations driven by advection dominate the subtidal secondary circulation, which shows an anti-clockwise rotation. During spring tide, the ESCO acceleration, together with the baroclinicity and centrifugal acceleration, drives a clockwise circulation (looking seaward). This structure counteracts the advection-induced flow, leading to the reversal of the secondary circulation. The decomposition of the lateral ESCO term contributors reveals that the difference in ESCO between neap and spring tides is attributed to the change in the vertical structure of lateral tidal currents, which are maximum near the bottom in spring tide. The findings highlight the role of the tidally varying vertical shears in the ESCO mechanism.https://www.frontiersin.org/articles/10.3389/fmars.2023.1105626/fullestuarine circulationGerman Bighteddy viscositycoastal dynamicsphysical processeslateral momentum balance |
| spellingShingle | Wei Chen Benjamin Jacob Arnoldo Valle-Levinson Emil Stanev Joanna Staneva Thomas H. Badewien Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inlet Frontiers in Marine Science estuarine circulation German Bight eddy viscosity coastal dynamics physical processes lateral momentum balance |
| title | Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inlet |
| title_full | Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inlet |
| title_fullStr | Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inlet |
| title_full_unstemmed | Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inlet |
| title_short | Subtidal secondary circulation induced by eddy viscosity-velocity shear covariance in a predominantly well-mixed tidal inlet |
| title_sort | subtidal secondary circulation induced by eddy viscosity velocity shear covariance in a predominantly well mixed tidal inlet |
| topic | estuarine circulation German Bight eddy viscosity coastal dynamics physical processes lateral momentum balance |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2023.1105626/full |
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