Influence of underwater hydrodynamics on oil and gas blowouts off Amazon River Mouth

Abstract

RESUMO.O estudo está focado na análise do comportamento das plumas de vazamento de óleo/gás em águas profundas, localizadas na plataforma continental do norte do Brasil. O modelo Regional Ocean Modeling System (ROMS) é utilizado para simular a dinâmica oceânica na região 60.5°-24°W/5°S-16°N com 0.25° de resolução, 32 níveis verticais e considerando as descargas dos rios Amazonas e Pará. A saída do modelo ROMS é comparada com o conjunto de dados SODA (Simple Ocean Data Assimilation). ABSTRACT. This study is focused on analyzing the behavior of oil/gas plumes from blowouts into deepwater, located at the northern Brazil continental shelf. The Regional Ocean Modeling System (ROMS) model is used to simulate ocean dynamics in the region 60.5°-24.0°W/5°S-16°N with 0.25° of resolution, 32 vertical levels and considering the discharges of the Amazon and Pará Rivers. The ROMS output are compared to Simple Ocean Data Assimilation (SODA) dataset. Three points were selected to make the numerical simulations, located at (50°W, 5.25°N), (44.5°W, 0.5°N) and (42.75°W, 1°S). The time step suggested by Lee and Cheung (1990) was adjusted due to the particular oceanographic conditions at each point, in which, the initial velocity tends to zero and the coefficient 0.1 of the original equation was replaced by 0.0250 and 0.0375. All the plumes behaved as type 3. The seasonal current speed was small from the bottom to the surface, usually not exceeding 0.25 ms -1 ; the maximum displacement of the plumes from its point of origin was not greater than 1 m. The mean plumes diameter on the surface ranged 54 -79.7 m and the arrival time to the surface was from 7.25 to 8.05 hours.

Hydro-thermodynamic dataset of the Amazon River Plume and North Brazil Current retroflection

“…In this dataset, we have simulated the hydro-thermodynamics of the Amazon River plume as close to reality as possible. The Regional Ocean Modeling System model (ROMS AGRIF)has been used, which integrates the primitive Reynolds equations in a free-surface rotational system through the Boussinesq approximation, the hydrostatic approximation and the balance of the vertical momentum [3 , 4] . The official ROMS model website is at http://www.myroms.org/ , the AGRIF version is based on this version and has been developed by the ROMS community and by the Institute of Research for Development (IRD), France.…”

“…There are many free and proprietary software tools to handle this format, which facilitates the handling of this dataset. Both NetCDF files are products of an output from the ROMS AGRIF model [2] and they were the dataset used for the articles published [1] and [3] .…”

High-resolution hydrodynamics and TS structure database of the Brazilian continental shelf and adjacent waters

“…It is also remarkable that ROMS has already been extensively used in our geographic area of interest [7] , [8] , [9] , [10] , [11] , [12] and tested by a team of Brazilian modellers placed at the Federal University of Recife, some of which areco-authors of this paper greatly contributing to the choice of the best configuration of the model (in terms of advection, dissipation and turbulent mixing schemes). ROMS has the important advantage of having been designed for runs at regional scales, both within an idealised and realistic frameworks.…”