RAPID: Effects of the Mississippi River plume on the spread of the Deepwater Horizon oil slick

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

Predicting the migration of the oil slick in the Gulf of Mexico is crucial for protecting sensitive wetlands and coastal fisheries from contamination. Ocean and shelf models make daily forecasts of landfall of the surface slick that are invaluable for coastal managers, however there have been several events of anomalous surface slick migration that were not forecast. Recent analysis indicates that discharge from the Mississippi River pushes oil offshore by deforming the sea surface height (SSH). This study proposes to describe pressure-driven flows of the buoyant oil slick using a two-layer, 2D Bernoulli model with friction. Combined with satellite data of SSH, sea surface temperature (SST) and ocean currents, and daily river discharge and weather data, this research will quantify the plume effect on oil slick dynamics. This modeling approach is simple and generalizable, and therefore could be adopted for other oil spills. The ongoing oil spill resulting from the Deepwater Horizon explosion is the worst environmental disaster in US history. The location of the spill is such that, under some conditions, the Mississippi River plume can exert a strong control. This model will provide a simple, quantitative estimate of this plume effect on oil slick dynamics each day using daily satellite data; if significant, this effect of sea-surface height could easily be incorporated into more complex daily ocean/shelf model forecasts. Quantifying the plume effect will provide the science needed to determine whether strategic river diversions are effective for preventing landfall of oil slick in sensitive Louisiana wetlands. The model could also project longer-term changes in the plume effect resulting from anticipated seasonal changes in river stage.