A new model is being used to support dispersant Ecological Risk Assessment (ERA) workshops. User-driven output includes trajectory maps for both chemically dispersed and undispersed oil, and concentration isopleths reported by depth and over time. To help make toxicological sense of the output, oil concentration isopleths were nominally fixed at concentrations and exposure times of concern developed by consensus during past ERA workshops. Two No. 6 fuel spill scenarios, each with alternative outcomes (not dispersed vs 80% dispersed) were developed, one in open ocean water (10,000 bbls spill), and the other in an estuary (2000 bbls spill). Plume epicenter maximum dispersed oil concentrations peaked in the range of 10–20 ppm but decreased within 24 hours to 1–2 ppm or less. Average concentrations in the most contaminated portions of the dispersion area never exceeded 3 ppm in either scenario. Plankton in a small (< 25%) fraction of the open ocean plume were at moderate risk at 24 hours. These effects must be compared to those of the non-dispersion alternative, which could impact wildlife and shorelines.
The oil spill trajectory prediction for the barge Buffalo 292 spill was provided by NOAA and TGLO. The bulk of the 5000 barrels of IFO 380 that was leaked moved rapidly through the Galveston Channel entrance and into the Gulf of Mexico as a result of a strong meteorological event. Because of the nature of the product, it was possible to track the resulting slicks for more than 3 weeks. Initially, the oil trailed east away from shore. Changing winds and currents moved the oil south and west, leading to sporadic impacts along the shore from east of Galveston to south of Corpus Christi. Trajectory forecasts were used to alert response personnel of impending beach impacts and to direct offshore skimming operations.
Real-time current and wind meters, oil-tracking drifters, visual overflights, and remote-sensing observations provided an unusual amount of calibrating data for trajectory forecasting. This fact, along with detailed analysis assisted by computer models, allowed for a surprisingly high degree of accuracy in trajectory prediction in spite of complex current and wind patterns and changing wind drift factors for the product as it weathered. In this paper, these favorable results are compared with results of an earlier spill in the region where fewer resources were available for trajectory analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.