Estuarine residual flow induced by eddy viscosity-shear covariance: Dependence on axial bottom slope, tidal intensity and constituents
| Autor: | Chen, W., de Swart, H. E., Helmholtz Institute, Sub Physical Oceanography |
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| Přispěvatelé: | Helmholtz Institute, Sub Physical Oceanography |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
geography
geography.geographical_feature_category Tidal straining 010504 meteorology & atmospheric sciences 010505 oceanography Estuary Turbulence modeling Stratification (water) Geology Covariance Vorticity Aquatic Science Atmospheric sciences Oceanography 01 natural sciences Amplitude Estuarine water circulation Taverne Aquatic science Estuarine circulation 0105 earth and related environmental sciences |
| Zdroj: | Continental Shelf Research, 167, 1. Elsevier Limited |
| ISSN: | 0278-4343 |
| Popis: | Residual flow generated by Eddy viscosity-Shear Covariance (ESCO) in a narrow estuary is investigated with a numerical model. New aspects concern the dependence of the spatial structure of ESCO flow on (1) longitudinal depth variation for fixed semi-diurnal tidal forcing, (2) varying amplitude of the semi-diurnal tidal forcing, and (3) mixed tidal forcing for fixed stratification at the mouth. Regarding (1) and (2), it appears that ESCO flow merely involves the components due to the semi-diurnal tide ( u τ , M 2 ) and quarter-diurnal tide ( u τ , M 4 ) . For a periodically stratified estuary, u τ , M 2 is stronger than u τ , M 4 in the middle reach, and weaker in the other reaches, while both show a two-layer structure with seaward flow near the surface. For weak stratification, u τ , M 2 has a three-layer structure with seaward flow in the middle layer, while u τ , M 4 has a two-layer structure and contributes significantly to the total residual flow in the upper and lower reach. For a highly stratified estuary, u τ , M 2 dominates the ESCO flow (being weak compared to the total residual flow), and it has a reversed two-layer structure (seaward flow near the bottom). Regarding (3), if diurnal and semi-diurnal tides are of similar order, the ESCO flow due to diurnal tides dominates and it has a two-layer structure. If diurnal tides prevail, the ESCO flow induced by the long-periodic tide (due to joint action of two diurnal tides) is the main contributor to the total residual flow in the upper and lower reach of the estuary. |
| Databáze: | OpenAIRE |
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