Proposal Title: COLLABORATIVE RESEARCH: Lagrangian studies of the transport, transformation, and biological impact of nutrients and contaminant metals in a buoyant plume
Project Summary The PIs propose a coordinated program of field and numerical experiments to examine processes that control the fate and transport of nutrients and chemical contaminants in the Hudson River plume. Urban estuarine plumes such as this one represent a major pathway for the transport of nutrients and chemical contaminants to the coastal ocean. The fates and transports of this material are controlled not only by the plume dynamics but also by biological and chemical processes coupled to the dynamics of the plume. To investigate these processes, the PIs propose to conduct a series of dye experiments along with continuous underway chemical and biological sampling using a towed vehicle. These experiments will occur within the framework of the LEO-15 Observatory to enable interpretation of the dye study by placing the Lagrangian surveys in context with shelf-wide observations from satellite imagery, surface currents and far-field subsurface hydrography. LEO-15 will be augmented by a cross shelf array of moored instruments to provide detailed estimates of subtidal circulation, stratification and Reynold stresses. In addition, data-assimilative numerical simulations will provide high resolution and realistic hindcasts of the coastal ocean during the field experiments. The modeling will assimilate the dye-tracer data into a 3-D coastal circulation model and guide future efforts to assimilate other tracers into circulation models with complex sources and sinks. The major aims of this work are to distinguish between physical processes that transport/mix material in a buoyant plume from biological and chemical transformation processes as well as the quantification of biological and chemical interactions in a Lagrangian perspective to provide a means to assess their importance in determining the fate and transport of nutrients and chemical contaminants in a buoyant plume. The proposed experimental plan will contrast the response of physical, biological, and chemical processes in the Hudson plume during upwelling and downwelling conditions. A major outcome of this work will be the determination of the extent and biological impact of contaminants in the plume along the New Jersey coast and Middle Atlantic Bight and will improve the ability to predict the fate and transport of contaminants and the rate that they enter the base of the food chain in the coastal ocean.
