Mixing and flushing in the Persian Gulf (Arabian Gulf)

Abstract

The assimilative capacities of estuaries and coastal seas for effluent discharges are predominantly determined by the rates at which pollutant-bearing effluents are first dispersed and then flushed from the coastal region into the open ocean. The dispersion coefficients and flushing, as measured by the water residence time in the Persian Gulf (Arabian Gulf), were investigated using the three-dimensional numerical model Estuary, Lake and Coastal Ocean Model (ELCOM). The model was first validated using the R/V Mt. Mitchell expedition profile data, collected from 27 January to 26 February 1992 and from 13 May to 12 June 1992. The validated model was then used to compute the geographic variability of the horizontal dispersion coefficients Kx throughout the gulf. Model results revealed that dispersion was principally driven by the shear associated with the tides, but along the Arabian coast, wind was an additional significant energy source for dispersion. The water residence time was found to be more than 3 years along the Arabian coast, but shorter along the Iranian coast.