In the preceding part of this study (ZIMMERMAN, 1976) salinity obser- vations obtained during so called "stationary periods" were used to calculate exchange coefficients of a compartment model of the western Dutch Wadden Sea. Taking advantage of assumptions concerning the salt balance in the area, these exchange coefficients could be obtained without having a knowledge of the physical processes controlling the dispersion. In the present part of the study we shall try to relate the effective longitudinal diffusivity, as used in a one-dimensional treat- ment of tidal mixing, to the complicated current velocity field in the western Dutch Wadden Sea. In the next section the concept of effective longitudinal diffusivity is discussed, mainly by reviewing part of the existing literature. Then follows a section in which an approximation of the Eulerian tidal velocity field in a topographically complicated area is proposed, which is shown to lead to the Lagrangian concept of "tidal random walk". The relationship of the latter with the effective longitudinal diffusivity is discussed. Finally an application of the theory to the western Dutch Wadden Sea is presented in the last section, in which diffusivities calculated by means of the observed salinity distribution are compared with those derived from observations of the current velocity field.
Zimmerman, J. T. F. (1976). Mixing and flushing of tidal embayments in the Western Dutch Wadden Sea, part II: Analysis of mixing processes. Netherlands Journal of Sea Research. https://doi.org/10.1016/0077-7579(76)90019-3