Wind effect on chemical dispersion in San Andrew Bay

Abstract

A coupled hydrodynamic-chemical fate model is used to investigate mechanisms for chemical dispersion in the St Andrew Bay system. It is found that the time for the pollutants transporting outward the bay mainly relies on the winds and source location. If the application of the stochastic model somehow handles the wind factor, the release location must be shifted to other places in order to evaluate the relative weight of this factor. Because the flux originating from Gulf of Mexico predominantly flows westward, a release point located between St Andrew Bay and West Bay or even more inside West Bay is likely not to deeply impact East Bay. The pollution will only reach the end of East Bay after 15 days if the pollutant is spilled at point A, which only stands 8km away from the previous spot. As this chemical is not volatile, it does not evaporate and its mass is roughly conserved into the system until its natural decay acts. West Bay is much shallower than St. Andrew Bay, thus the small concentration decrease close to the Gulf entrance involves a large pollutant mass transfer into West Bay.