Observed and computed lateral circulation patterns in a partly mixed estuary
In: Estuarine, Coastal and Shelf Science. Academic Press: London; New York. ISSN 0272-7714; e-ISSN 1096-0015, meer
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| Trefwoorden |
Anchor stations
Estuarine circulation
Numerical models
Water balance
ANE, British Isles, England [Marine Regions]
Marien/Kust |
| Auteurs | | Top |
- Uncles, R.J., meer
- Elliott, R.C.A.
- Weston, S.A.
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| Abstract |
Observations of lateral residual circulation patterns are presented for three sections in the upper reaches of the Tamar Estuary. The data include measurements over spring and neap tidal cycles, and are compared with predictions from a depth-averaged, numerical model of the lateral circulation.The model shows features of the lateral structure which also occur in the observed data. The computed mass-transport Stokes drift has a similar lateral structure at spring and neap tides for all sections, and is up-estuary in the deeper, central part of a section, and down-estuary on the intertidal areas near the banks. A distinctive feature of this drift is the reduction in lateral structure when axial density gradients are ignored.The mass-transport residual current has a characteristic lateral structure when the run-off is not too high. The current in the central part of a section is slow (less than a few cm s−1), and may be up- or down-estuary, depending on the magnitude of the run-off. The current over the intertidal areas is faster (not, vert, similar 10 cm s−1) and directed down-estuary. This distribution consists of three components: (a) a run-off induced current which has a river-like form, (b) density currents which are up-estuary in the deeper part of a section and down-estuary over the intertidal and shallow areas, and (c) tidally-driven currents which have a similar form to density currents, and whose formation depends strongly on the existence of intertidal areas.Results from this paper are compared with published observations of lateral circulation patterns for several other estuaries. |
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