Ocean currents and coastal exposure to offshore releases of passively transported material in the Gulf of Mexico

Abstract

The Gulf of Mexico (GoM) is heavily exploited by the oil industry. Incidental oil releases, such as the 2010 blowout of the Deepwater Horizon platform, lead to a large scale dispersion of pollutants by ocean currents, contaminating the coastline and damaging the ecosystems. In order to determine whether the ocean dynamics hampers or conversely fosters the landing of material in the coastal regions, we simulate more than 29 000 individual tracer releases in the offshore waters of the GoM. We assume that the tracers are not decaying and transported passively by the ocean currents. In a first part of our study we focus on the mean dispersion pattern of 80 releases occurring at the location of the Deepwater Horizon. In a second part, we generalize the metrics that we defined to the whole GoM. Our study shows that releases occurring in specific regions, i.e. the bay of Campeche, off the Mississipi-Alabama-Florida and the West Florida shelfs are associated with higher environmental costs as the ocean currents steer the released material toward the productive coastal ecosystems and foster landings. Conversely, the tracers released off the Louisiana-Texas-shelfs and the center of the Gulf of Mexico are less threatening for coastal regions as the material recirculates offshore. We show that the coastline of the southwest part of the Bay of Campeche, the Mississipi's mouth and the Island of Cuba are particularly exposed as 70% of the landings occur in these 3 regions.

Ocean Monitoring and Prediction Network for the Sustainable Development of the Gulf of Mexico and the Caribbean

“…To forecast and visualize the evolution and fate of different oil spill scenarios at pre-defined locations, we employ several international operational models: the HYbrid Coordinate Ocean Model (HYCOM), the Regional Ocean Modeling System (ROMS), the Nucleus for European Modelling of the Ocean (NEMO), the Navy Coastal Ocean Model (NCOM), the Global Forecasting System model (GFS, NCEI-NOAA), and the Weather Research and Forecasting (WRF) and WRF-Chem for the atmosphere and WAVEWATCHIII for waves. An analysis of the differences and similarities among the modeling results has helped us understand their capabilities and guided their use for development of an ensemble-based system to generate oil spill scenarios and a probabilistic forecast system (Meza-Padilla et al, 2019;Duteil et al, 2019;Gómez-Valdivia and Parés-Sierra, 2020;Mazlo et al, 2020;Moreles et al, 2020;Guerrero et al, 2020;Damien et al, 2021). These et al, 2021).…”

Ocean monitoring, observation network and modelling of the Gulf of Mexico by CIGOM

“…These models, although based on other preexisting ones, have implemented different and innovative new routines, modifications and couplings, and stochastic theories or parameterizations that allow for the generation of new knowledge on the hydrocarbon weathering processes. In particular, the CIC-OIL model is highly sophisticated, since it couples a model to simulate the plume produced by the explosion of a well and its subsequent evolution by including several parameters, especially the nature and droplet size of the hydrocarbons which lead to very different dispersion trajectories (Anguiano-García et al, 2019;Duteil et al, 2019;Meza-Padilla et al, 2021).…”