Simulation of the 2003 Foss Barge - Point Wells Oil Spill: A Comparison between BLOSOM and GNOME Oil Spill Models

Abstract

The Department of Energy’s (DOE’s) National Energy Technology Laboratory’s (NETL’s) Blowout and Spill Occurrence Model (BLOSOM), and the National Oceanic and Atmospheric Administration’s (NOAA’s) General NOAA Operational Modeling Environment (GNOME) are compared. Increasingly complex simulations are used to assess similarities and differences between the two models’ components. The simulations presented here are forced by ocean currents from a Finite Volume Community Ocean Model (FVCOM) implementation that has excellent skill in representing tidal motion, and with observed wind data that compensates for a coarse vertical ocean model resolution. The comprehensive comparison between GNOME and BLOSOM presented here, should aid modelers in interpreting their results. Beyond many similarities, aspects where both models are distinct are highlighted. Some suggestions for improvement are included, e.g., the inclusion of temporal interpolation of the forcing fields (BLOSOM) or the inclusion of a deflection angle option when parameterizing wind-driven processes (GNOME). Overall, GNOME and BLOSOM perform similarly, and are found to be complementary oil spill models. This paper also sheds light on what drove the historical Point Wells spill, and serves the additional purpose of being a learning resource for those interested in oil spill modeling. The increasingly complex approach used for the comparison is also used, in parallel, to illustrate the approach an oil spill modeler would typically follow when trying to hindcast or forecast an oil spill, including detailed technical information on basic aspects, like choosing a computational time step. We discuss our successful hindcast of the 2003 Point Wells oil spill that, to our knowledge, had remained unexplained. The oil spill models’ solutions are compared to the historical Point Wells’ oil trajectory, in time and space, as determined from overflight information. Our hindcast broadly replicates the correct locations at the correct times, using accurate tide and wind forcing. While the choice of wind coefficient we use is unconventional, a simplified analytic model supported by observations, suggests that it is justified under this study’s circumstances. We highlight some of the key oceanographic findings as they may relate to other oil spills, and to the regional oceanography of the Salish Sea, including recommendations for future studies.

Oil Spill Modeling: A Critical Review on Current Trends, Perspectives, and Challenges

“…BLOSOM (blowout and spill occurrence model) has been developed by the National Energy Technology Laboratory (NETL) of the USA. The model is written in Java programming language [239] and it is an extensive modeling suite that displaces the fate and transport of both subsurface oil blowouts and surface spills [240]. Moreover, this model is developed to predict offshore oil spills resulting from deep water (>150 m) and ultra-deepwater (>1500 m) well blowouts [155].…”

“…Duran et al [240] have implemented and compared GNOME and BLOSOM for the hindcast of the 2003 Point Wells oil spill. BLOSOM provides more accurate results due to the inclusion of an internally calculated deformation angle for the formation of wind energy.…”

“…BLOSOM provides more accurate results due to the inclusion of an internally calculated deformation angle for the formation of wind energy. GNOME uses a random walk with a constant diffusion coefficient in order to simulate spreading of oil due to turbulent diffusion, while BLOSOM considering both the diffusion scheme and the diffusion coefficient provides another option as described in Duran [240]. A random walk with constant diffusion coefficient was also used for BLOSOM, in order to provide the predictions absolutely comparable, affecting the way oil beaches along the coast.…”

Simulating the Trajectory and Biomass Growth of Free-Floating Macroalgal Cultivation Platforms along the U.S. West Coast

“…There are many trajectory models available, including General NOAA Operational Modeling Environment (GNOME) [10], Surface Currents from Diagnostic (SCUD) [11], multivariate ocean variational estimation (MOVE) [12], and Blowout and Spill Occurrence Model (BLOSOM) [13]. Several papers have also explored the ability of these models in recreating hindcasted trajectories of floating debris and oil spills while altering model input parameters such as windage [14,15].…”

Multi-Criteria Analysis of Different Approaches to Protect the Marine and Coastal Environment from Oil Spills

“…A complex approach was used for the comparison of the two models. This proposed methodology could be used to illustrate the approach an oil spill modeller would typically follow when trying to hindcast or forecast an oil spill, including detailed technical information on basic aspects [10].…”