Dispersão de óleo proveniente das bacias de exploração de petróleo do Ceará e Rio Grande do Norte

Abstract

The Brazilian Equatorial Margin has attracted increasing interest for oil exploration, which highlights the need to better understand the potential environmental impacts associated with oil spill events. In this context, this study aimed to analyze the dispersion of oils originating from the Ceará and Rio Grande do Norte oil exploration basins, considering the influence of seasonal and interannual variability of ocean circulation, as well as differences related to the physicochemical properties of oil. Numerical dispersion simulations were performed using a Lagrangian model, considering representative scenarios for January and August of the years 2010 and 2020, selected to represent contrasting hydrodynamic conditions. The adopted methodology allowed the evaluation of spatial and temporal patterns of oil transport, trajectory recurrence, and dispersion extent under different circulation regimes. The results indicated that pollutant dispersion is strongly modulated by ocean circulation, with distinct behaviors between periods characterized by more stable and more energetic hydrodynamic conditions. More intense currents were associated with a wider spatial spreading of oil, reducing local trajectory recurrence, whereas more stable conditions resulted in higher spatial concentration of oil near the continental shelf. The comparison between light and heavy oils revealed contrasting behaviors, with light oil presenting greater dispersion capacity and spatial reach, while heavy oil tended to produce more localized impacts under less energetic conditions. The simulations also indicated the possibility of impacts on oceanic and coastal regions distant from the release points, highlighting the vulnerability of environmentally sensitive areas, such as the Amazon River mouth. It is emphasized, however, that this behavior is directly associated with the time of year, since the seasonal variability of ocean circulation, particularly the strengthening of currents during certain periods, favors the transport of oil over longer distances. These findings demonstrate that numerical modeling is a fundamental tool for assessing environmental impacts associated with oil exploration in the Brazilian Equatorial Margin, supporting environmental management, monitoring strategies, and mitigation planning.