Welcome to LaTTE's Website! 
This website is to inform our users, participants, and interested audiences about the progress and status of  various activities of the five-year long research project known as LaTTE. LaTTE stands for Lagrangian Transport and Transformation Experiment. The more formal title of this project is known as the "Lagrangian studies of transport transformation and biological impact of nutrients and contaminant metals in a buoyant plume: a process study in an operational ocean observatory". The research work is being funded by the National Science Foundation, under the Buoyancy-Driven Transport Processes Program.  

The principle investigators involved in this project are Drs. Robert Chant, John Reinfelder, Scott Glenn, Oscar Schofield, John Wilkin, Bob Houghton, Bob Chen, Meng Zhou, Mark Moline, Paul Bissett, Tom Frazer. They are from Rutgers, The State University of New Jersey - New Brunswick Campus, Lamont-Doherty Earth Observatory, University of Massachusetts-Boston, Florida Environmental Research Institute, California Polytechnic State University - San Luis Obispo, and the University of Florida - Gainsville.

Basic objective of the La-TTE project is to quantify mixing and the rate that biological and chemical processes transforms material in a buoyant coastal current, including:

• Biological production rates and community composition,

• Zooplankton community response,

• Bioavailability and bio-accumulation of metals, and

• CDOM photobleaching rates.

Link these rates to wind forced changes in the structure of the plume.

Background Information
LaTTE is 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, a plume that emanates from one of the nation’s most urban estuaries -- the New York/New Jersey Harbor complex. Urban estuarine plumes represent a major pathway for the transport of nutrients and chemical contaminants to the coastal ocean. However, the fate and transport of this material is controlled not only by the plumes dynamics but also by biological and chemical processes that are coupled to the dynamics of the plume. By conducting a series of dye experiments featuring continuous underway chemical and biological sampling with a state-of-the-art towed vehicle within the well sampled framework of an operational ocean observatory, we will be able to distinguish between physical processes that transport/mix material in a buoyant plume from biological and chemical transformation processes. This will allow us to quantify biological and chemical interactions in a Lagrangian perspective, and provide a means to assess their importance in determining the fate and transport of nutrients and chemical contaminants in a buoyant plume. 
                                          


The program will contrast the response of physical, biological, and chemical processes in the plume during upwelling and downwelling conditions. We hypothesize that the cross-shelf transport of material is determined not only by Ekman transport and diapycnal mixing, but also by biological and chemical processes all of which differ between upwelling and downwelling conditions. In particular, we will quantifiably relate biological production rates, the bioavailability and bio-accumulation of metals, and chromophoric dissolved organic matter (CDOM) photobleaching rates in the plume, to the physical characteristics of the plume, such as plume thickness, optical depth, and mixing rates.

An ocean observatory will aid the interpretation of the dye study by placing the Lagrangian surveys in context with shelf-wide observations from satellite imagery, surface currents and subsurface hydrography. The observatory will be augmented by a cross shelf array of moored instruments that provide data to characterize dynamics of the plume. Assimilation of data from the observatory and process study into a physical 3-D model will provide a high resolution and realistic hindcasts of the coastal ocean during the field experiments. The proposed work will pioneer the assimilation of dye-tracer data into a 3-D coastal circulation model and will guide future efforts to assimilate tracers into circulation models that possess more complex sources and sinks. Model hindcasts will be used to interpolate observations in space and time for interpretation and test turbulent and biological parameterizations used in the model.

Our study will address the geographic extent and biological impact of plume contaminants along the New Jersey coast and Middle Atlantic Bight. Results will improve our 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. Episodic nutrient inputs from the plume may be to linked nearshore phytoplankton blooms that may be linked to recurrent low dissolved oxygen levels in this region (Figure 1). Results could guide future strategies for sewage disposal in the region. Finally, quantification of contaminant uptake into the base of
the coastal ocean food chain is the first step in predicting contaminant bioaccumulation into higher tropic levels.

This program will provide traditional research and thesis opportunities for a state-funded Ph.D. program and NOAA-funded undergraduate internships. Moreover, it will provide focus for the first 5 years a new Masters in Operational Oceanography program initiated in 2002 by project PI’s. Finally, ongoing collaboration with the Mid-Atlantic Center for Ocean Science Education Excellence (COSEE) will be strengthened by adding components on biological and chemical processes in buoyant river plumes. COSEE integrates oceanographic research and education programs to audiences that includes, coastal managers, K-12 teachers and students--especially underrepresented groups in the marine science.