OCEAN-OUTFALL MIXING ZONE DELINEATION USING DOPPLER RADAR

A methodology has been developed to use data collected by ocean surfac e current radar (OSCR) systems to predict the fate and transport of po llutants released from ocean outfalls. The proposed OSCR-based transpo rt model was validated at the Miami Central-District (MCD) outfall usi ng data collected during the Southeast Florida Outfall Experiment II ( SEFLOE II). A comparison between the measured dye concentration versus distance from the outfall and the predictions of the OSCR-based trans port model showed good agreement. A second validation test of the OSCR -based transport model compared the growth of variance versus time and diffusion coefficient versus length scale with the conventional Okubo diagrams for instantaneous tracer releases. This comparison indicated that the mixing characteristics simulated explicitly by the OSCR-base d transport model are in good agreement with field measurements in the coastal ocean. Mixing zones based on worst-case and probabilistic cri teria were delineated using the OSCR-based model. The results indicate that an OSCR-based transport model is a significant improvement over conventional models that are used to delineate mixing zones surroundin g ocean outfalls with surfacing plumes. This claim is strongly support ed by the field data collected during the SEFLOE II study in south Flo rida.