caa a22 4500 465792960 CHVBK 20180323112030.0 cr unu---uuuuu 170327e19900601xx s 000 0 eng 10.2307/1351582 doi (NATIONALLICENCE)springer-10.2307/1351582 Computed and observed currents, elevations, and salinity in a branching estuary [Elektronische Daten] [R. Uncles, J. Stephens] A one-dimensional, hydrodynamical model of the Tamar Estuary shows good agreement with measured tidal elevations and currents. Computed currents are used to drive a one-dimensional moving-element model of the salt balance. The moving-element model overcomes the numerical difficulties associated with strong tidal advection. Axial distributions of salinity at high water, computed using the moving-element model, compare well with measurements. The modelled and observed high water salinity distributions in this macrotidal estuary show little dependence on tidal range. The major variability in salinity is due to runoff. This strong and rapid dependence on runoff is a consequence of short residence (or flushing) times. Typically, residence times are less than one day throughout the year in the upper 10 km of estuary. The residence times maximize in summer, reaching 14 d for the whole estuary. During high runoff winter periods residence times are less than 5 d. Mixing coefficients for the moving-element salinity model are deduced from salinity measurements. Dispersion coefficients at fixed locations along the estuary are deduced from solutions of the salinity model. The spatially-averaged coefficients at mean spring and neap tides are 180 and 240 m2 s−1, respectively, for average runoff. Therefore, spring-neap variations in dispersion are fairly small and show a negative correlation with tidal range. The spatially-averaged dispersion coefficients at mean tides vary from 150 to 300 m2 s−1 for typical summer and winter runoff, respectively. The increase in dispersion with runoff and the decrease with tidal range implies that buoyancy-driven currents generate an important component of the shear dispersion in this estuary. Estuarine Research Federation, 1990 Uncles R. Plymouth Marine Laboratory, Prospect Place The Hoe, PL1 3DH, Plymouth, UK aut Stephens J. Plymouth Marine Laboratory, Prospect Place The Hoe, PL1 3DH, Plymouth, UK aut Estuaries Springer-Verlag 13/2(1990-06-01), 133-144 0160-8347 13:2<133 1990 13 12237 https://doi.org/10.2307/1351582 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.2307/1351582 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Uncles R. Plymouth Marine Laboratory, Prospect Place The Hoe, PL1 3DH, Plymouth, UK aut NATIONALLICENCE 700 1- Stephens J. Plymouth Marine Laboratory, Prospect Place The Hoe, PL1 3DH, Plymouth, UK aut NATIONALLICENCE 773 0- Estuaries Springer-Verlag 13/2(1990-06-01), 133-144 0160-8347 13:2<133 1990 13 12237 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer