Abstracr Applied Sciences Associates, Inc. (ASA) is developing a stand alone, state-of-the-art oil spill model system for use in oil spill response, planning, research, training, and contingency planning. The model is being developed for operation on personal and lap-top computers and provides deterministic and stochastic spill forecasts and receptor mode simulations for spill sites throughout the world. The model is applicable worldwide at low environmental data resolution, and in selected areas using high resolution data. The system features rapid setup and response times, alternate procedures to specify environmental data (digitization, painting, keyboard entry, electronic links), modules to allow easy interfacing with selected private/government oil spill databases, menus and mouse or keyboard controlled operation, and extensive use of graphics and animations for data input/output.

At 18:20 on November 28, 1989, a New England Airlines commuter plane left the Block Island, Rhode Island, airport on a seventeen mile, fifteen minute flight to Westerly, Rhode Island. The aircraft was reported missing later that evening. Using a floating debris trajectory model, in conjunction with the observed debris sighting data, the most probable search area was delineated based on time of travel between potential crash sites and the observed debris locations and times of retrieval. Wind data for the model were available from Green Airport, Warwick, Rhode Island; Nantucket Island, Massachusetts; and a NOAA offshore buoy. Tidal current data were obtained from a numerical hydrodynamic model of the area. Model predictions were made and the probable search area delineated within four hours of the initiation of the study. The aircraft was found by a fishing vessel three to five nautical miles northwest of Block Island along the most probable flight path. The location of the aircraft parts, strewn over a mile long path, was within the model predicted search area. Improvements in the spatial resolution of the tidal currents in the vicinity of Block Island and in the wind field would have allowed a more accurate estimate of the search area.

A numerical model system was developed to quantify the probability of endangered bowhead and gray whales encountering spilled oil in Alaskan waters. Migration and diving-surfacing models for bowhead and gray whales, and an oil spill trajectory model comprise the system. The migration models were developed from conceptual considerations, then calibrated with and tested against observations. The distribution of whales is represented in space and time by discrete points, each of which may represent one or more whales. The movement of a whale point is governed by a random walk algorithm which stochastically follows a migratory pathway. Stochastic diving-surfacing models are used to stimulate surfacing behavior sequences for each species. The oil spill model accounts for oil transport and spreading in open water and in the presence of sea ice. Historical wind records and ice cover data sets provide the environmental conditions to generate stochastic oil spill scenarios. The oil spill, whale migration and diving-surfacing models are linked to provide quantitative estimates of whale-oil interactions. The model system was applied to the Alaskan Beaufort Sea to investigate the probability that bowhead whales would encounter oil spilled in this region.

Numerical models of migrating bowhead and gray whales were developed as part of a larger project to assess the probability that these endangered marine mammals will encounter spilled oil in Alaskan waters. The distribution of animals is represented in space and time by discrete points, each of which may represent one or more whales. The movement of a whale point is governed by a random walk algorithm which follows stochastically a migratory pathway. The migration models rely on sightings of whales to define mean migration pathways. Distances traveled over 3–6 months, divided by the travel time, were used to estimate mean migratory speeds over appropriate sections of the migration route. Stochastic velocity components were added such that maximum instanteneous swimming speeds did not exceed those observed. Modeled whale densities were then compared with field estimates at various times and locations, as available, and mean migration speeds were adjusted locally to calibrate the model. The model proved to be an extremely useful tool for exploring the raw observational data, making clear a number of inconsistencies therein.

A numerical model which solves the simplified equations for water mass, salt, and constituent transport has been developed and preliminary application made to Narragansett Bay, Rhode Island. The hydrodynamic component of the model solves the time averaged equations for a series of grids or boxes simulating the geometry of the Bay. Two layers in the vertical allow representation of typical estuarine flows. The water quality component solves the mass transport equation, including first order decay, settling, atmospheric flux, and bottom flux as additional terms. Model output includes exchange coefficients between adjacent boxes in both horizontal and vertical directions, and the distribution of pollutant concentrations.

A four level atmospheric - ocean - sediments transport model has been coupled to an ecosystem model to estimate the magnitude of effects of ocean-based incineration of PCB wastes. The atmospheric (top) layer of the model has a seasonally variable thickness, a reflecting boundary at the top, and an absorbing boundary at the air-water interface. Upper and lower layers of the oceanic water column constitute the second and third layers of the transport model, while the fourth layer represents the sediments on the seafloor. The ecosystem model focuses on linkages among major trophic compartments, and includes predation, metabolic, and pollutant assimilation and depuration components. Simulation results suggest that, for destruction and removal efficiencies on the order of 0.9999 (four nines), measurable bioaccumulation effects may occur in the benthos over a 50 year policy horizon.

A set of physical, chemical, and biological numerical models has been coupled to form a wholistic marine pollution hazard assessment tool. This paper presents an application of the model system to the New York Bight Apex. PCB is used as a tracer to demonstrate the system's ability to compute the dynamic mass balance of a pollutant in the physical system. Uncertainties in loading rates and model parameters make definitive model validation difficult at the present stage of model system development.

The Coastal Management Section (CMS) of Dubai Municipality (DM) has been operating a coastal zone monitoring program since 2002 with initial emphasis on data collection and establishment of an in-house survey capability. The program has evolved to focus on data analysis and generation of products and interfacing with CMS-operated predictive numerical models. A further evolution is the establishment of a hydrodynamic and water quality forecasting system for the Dubai Coast. One of the uses of high resolution forecasting in Dubai coastal waters is for emergency response to pollution events. DM is working with a number of private consulting companies to integrate monitoring programs and high resolution hydrodynamic models with oil and chemical spill models. This paper discusses the use of oil spill models in the Dubai region with discussion of previous spills and new technology being implemented to improve oil spill predictions in the coastal region.