Quantifying the effects of hindcast surface winds and ocean currents on oil spill contact probability in the Gulf of Mexico

The U.S. Department of the Interior, Bureau of Ocean Energy Management conducts an oil spill risk analysis (OSRA) prior to oil and gas leasing, exploration, or development on the U.S. Outer Continental Shelf. The OSRA model uses hindcast surface winds and ocean currents to calculate hundreds of thousands of trajectories initiated from hypothetical oil spill locations and estimates contact probability of these trajectories with resources that are of biological, social and economic importance. Here, the map distributions of potential oil spill contact probability to entire waters in the Gulf of Mexico are generated every day from day 1 to day 30 using 6-hourly surface winds and 3-hourly ocean currents from time periods of 1993-1998 and 2000-2006. Results show that strong seasonal and annual variability exists in the contact probability estimates for these two time periods, and the effects of hindcast surface winds and ocean currents on the contact probability can be quantified.