An Evaluation of Nearshore Sediment Data after the Deepwater Horizon Blowout

The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico （GOM）. Here the paper analyzes available sediment datasets to determine whether changes in petrogenic contaminants are evident in GOM sediment following the blowout. Locations sampled by EPA （Environmental Protection Agency）, British Petroleum （BP） and NOAA （National Oceanic and Atmospheric Administration） were reduced and grouped into 46 similar locations and analyzed. Eleven groups suggested an increase in PAIl （polycyclic aromatic hydrocarbon） and nickel, one group showed a statistically significant increase in Phenanthrene. Four locations were analyzed for time trends and differences between initial and peak concentrations of oil range organics （ORO）, diesel range organics （DRO）, vanadium and nickel. One location had significant increases in ORO, DRO and vanadium and a suggestive increase in nickel. Correlations between ORO/DRO, ORO/V, ORO/Ni, V/Ni were computed （RE= 0.85, 0.67, 0.64, 0.92, respectively）. Overall, the analyses suggest that future monitoring should employ a sampling strategy that coordinates response sampling to previously sampled locations, such that baseline datasets can be used in detection of event associated contamination.

Initial evaluations of a Gulf of Mexico/Caribbean ocean forecast system in the context of the Deepwater Horizon disaster

In response to the Deepwater Horizon （DwH） oil spill event in 2010, the Naval Oceanographic Office deployed a nowcast-forecast system covering the Gulf of Mexico and adjacent Caribbean Sea that was designated Americas Seas, or AMSEAS, which is documented in this manuscript. The DwH disaster provided a challenge to the application of available ocean-forecast capabilities, and also generated a historically large observational dataset. AMSEAS was evaluated by four complementary efforts, each with somewhat different aims and approaches： a university research consortium within an Integrated Ocean Observing System （IOOS） testbed; a petroleum industry consortium, the Gulf of Mexico 3-D Operational Ocean Forecast System Pilot Prediction Project （GOMEX-PPP）; a British Petroleum （BP） funded project at the Northern Gulf Institute in response to the oil spill; and the Navy itself. Validation metrics are presented in these different projects for water temperature and salinity profiles, sea surface wind, sea surface temperature, sea surface height, and volume transport, for different forecast time scales. The validation found certain geographic and time biases/errors, and small but systematic improvements relative to earlier regional and global modeling efforts. On the basis of these positive AMSEAS validation studies, an oil spill transport simulation was conducted using archived AMSEAS nowcasts to examine transport into the estuaries east of the Mississippi River. This effort captured the influences of Hurricane Alex and a non-tropical cyclone off the Louisiana coast, both of which pushed oil into the western Mississippi Sound, illustrating the importance of the atmospheric influence on oil spills such as DwH.

Determining the oil weighting factor of oil-water emulsion based on the fractional Weierstrass scattering model

The formation of oil-water emulsion often occurs when oil is spilled into the ocean. Oil weighting factor of oil-water emulsion is one of the most important parameters for emergent oil-spill microwave monitoring. A new method is proposed here to evaluate the oil weighting factor based on fractional Weierstrass scattering model. By using the proposed method, we analyze the Uninhabited Aerial Vehicle Synthetic Aperture Radar(UAVSAR) L-band fully polarimetric data acquired during 2010 Deepwater Horizon oil spill disaster event in the Gulf of Mexico. The result shows that our method performs well in evaluating oil weighting factor of oil-covered area.