Oil spill modeling off the Brazilian eastern coast: the effect of tidal currents on oil fate

Abstract

ABSTRACT. This study presents a comparative analysis of several theoretical oil spill scenarios occurring in the vicinity of the Abrolhos Reefs, a preservation area located off the Brazilian east coast. The following petroleum blocks were considered in the study: BM-CUM-1, BM-CUM-2, J-M-259 and ES-M-418, to verify the effect of the tide on the oil spreading on the continental shelf in the eastern Brazilian. The probabilistic oil spill simulations were carried out for 30 days and considered an oil of intermediate API (American Petroleum Institute) type. The simulations were performed by the OSCAR (Oil Spill Contingency and Response) model which was fed by synoptic wind data and hydrodynamic data simulated by the POM (Princeton Ocean Model) model. Two distinct seasonal scenarios were studied: the austral winter and the austral summer of 1989 and the results were discussed in terms of seasonal variability caused by the winter/summer winds and differences in mesoscale instabilities.The effect caused by tidal currents was analyzed through the comparison between simulations with and without the tides. It was concluded that the tide strongly influenced foram discutidos em termos das variações de intensidade e direção do espalhamento causado pelo vento sinótico de cada estação, assim como pelos processos de mesoescala e pela maré. O efeito causado pela maré foi analisado através da comparação de simulações com e sem maré. Concluiu-se que a maré influenciou fortemente nos resultados probabilísticos de destino doóleo nos cenários de derramamento. Muitos fatores mostraram influenciar nesse destino do espalhamento doóleo com a ausência dos processos supra-inerciais, como a localização geográfica do derramamento, os ventos predominantes e o comportamento da maré na região. A ausência da maré nos dados hidrodinâmicos não permitiu encontrar os cenários de pior caso de derramamento em simulações nos blocos BM-CUM-1, BM-CUM-2 e J-M-259, principalmente no verão com a utilização deóleo intermediário, subestimando os cenários reais de derramamento.Palavras-chave: marés, modelagem,óleo, POM, OSCAR.

The fate of an oil spill in São Sebastião channel: a case study

“…However, knowing the area and judging from the sediment composition (almost 70% sand), St #14 may be considered to represent a high-energy area which received the contaminants and, after 7 months, had already begun a recovery process. The decrease of n-C 17 /pristane and n-C 18 /phytane ratios is commonly used as an early indicator of biodegradation (PETERS et al, 2005;LEMKAU et al, 2010). The observed decreased of the n-C 17 /pristane ratio for St #14 confirms the undergoing biodegradation process (Table 1).…”

“…However, values less than one are not indicative of the presence of petroleum (HUMPHREY et al, 1987). The biodegradation within samples can be examined by monitoring the loss of more labile n-alkanes relative to more recalcitrant branched isoprenoid alkanes (PETERS et al, 2005;LEMKAU et al, 2010). Another feature used as indicative of petroleum hydrocarbons is the presence of the unresolved complex mixture (UCM), which is the most abundant, ubiquitous, and understudied class of organic contaminants in estuarine and coastal sediments.…”

“…Predicting oil spill fate and the time necessary to recover the environment are important tools to help in taking actions during or right after the spillage to avoid or minimize the damage caused, even though it is a hard task to establish it correctly. Several modeling studies have been applied to understand the trajectory of an oil contamination episode and its effect on organisms (SOTILLO et al, 2008;GUO et al, 2009;LEMOS et al, 2009), but the various environmental parameters considered might make these models inapplicable or difficult to interpret. Another way to understand and predict an oil spill's fate is to observe actual cases occurring in the area concerned during preceding years (POFFO et al, 2001).…”

Risk assessment of small‐scale reef fisheries off the Abrolhos Bank: Snappers and groupers under a multidimensional evaluation

“…If such activity occurs, the whole region may be affected by oil spillages (Dominguez, ). The impacts may affect many biological communities, habitats and the marine ecosystem (Lemos, Soares, Ghisolfi, & Cirano, ; Marchioro, Nunes, Dutra, Moura, & Pereira, ). In this sense, the development and implementation of scientific research and technologies capable of rapid response to contain impacts are needed, as well as technologies to eliminate pollutants from the environment before dispersion.…”

Numerical simulation of oil spills based on the GNOME and ADIOS

“…This model designed to simulate oil spill fates both before and after a coastal contact [1]. The simulations of several theoretical oil spill scenarios occurring in the vicinity of the Brazilian east coast were performed by the OSCAR (Oil Spill Contingency and Response) [2]. OSCAR is model system provides a tool for quantitative, objective assessment of alternative oil spill response strategies.…”