The Oil Spill Recovery Institute Past, Present, and Future Directions (2003) / Chapter Skim
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7. Modeling
7. Modeling
Pages 73-88
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From page 73... ...
Thus, 33 percent of predictive ecology funding went to support direct Nowcast/Forecast work. As shown in Table 6-1, the Applied Technology program provided about $763,000 to Nowcast/Forecast projects in the same period, out of about $1.8 million total program funds, or 43 percent.
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From page 74... ...
The conceptual design of the PWS-NC/FC is that the atmospheric model is to operate in real-time (a "nowcast/forecast") and pass wind fields to the hydrodynamic model.
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From page 75... ...
The first deals with the accuracy and validity of the model predictions and the fact that the models have not been developed to the point that they can be reliably used in this mode. At the present time, the existing modeling predictions are unreliable because they are being based on either a single wind record from a buoy located in the center of the Prince William Sound or 30-kmgridded atmospheric model forecasts of winds at the water surface.
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From page 76... ...
, which it uses for contingency planning, drills, and spill impact evaluations, but it would defer to NOAA's modeling predictions in the event of a real spill response.
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From page 77... ...
This can be a useful planning tool, and is also useful in developing and implementing oil spill response drills. In a real-world spill response, however, it would be questionable whether the USCG would defer to OSRI's predictions over those provided by NOAA through its science support coordinator, at least given the present status of the atmospheric and hydrodynamic models.
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From page 78... ...
Potential Uses of the OSRI Model System ., .~ Rather than focus the modeling in a real-time response mode, a much more appropriate focus for OSRI's modeling effort is in support of scientific purposes, such as contingency planning, training and community outreach, ecological risk assessment, understanding the Prince William Sound ecosystem, identifying data gaps, and designing experiments to obtain additional data on ecosystem function. Predictive forecasts are not needed for any of these purposes; rather, the model would be used in a hindcast mode, where wind and current conditions and oil spill behavior can be validated, thereby adding credibility to other model predictions (such as water column concentrations)
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From page 79... ...
The role of model building by OSRI should be viewed as advancing the state of models for oil spill response and for the prediction of ecological consequences. OSRI can make a contribution to oil spill response modeling by improving the knowledge base used to develop model algorithms.
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From page 80... ...
the impact of coastal orography on the wind flow needs to be investigated and is likely to have a significant effect on any spill trajectory calculations. Finally, discrepancies in the predictions, mainly at the mesoscale and smaller scale compared with the basin scale, seem to reinforce the need for modeling the scale dependencies in the forcing functions using appropriate spatial models.
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From page 81... ...
OSCAR (Reed, 2002) is a fairly comprehensive model for spill trajectory and fates calculations, accounting for most major physical and chemical processes and using algorithms that are state of the art and used in other similar oil spill fates models (e.g., ASCE, 1996; French et al., 1999~.
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From page 82... ...
The trajectory predictions will only be as good as the imposed velocity field and other environmental inputs. Given the sparse forcing data for the hydrodynamic model and wind field and spatial variations and uncertainties, it is impossible to describe such velocity distribution in deterministic detail.
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From page 83... ...
The questions are (1) whether applying chemical dispersants will increase impacts on water column organisms, and (2)
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From page 84... ...
As part of the SEA program, there was a linkage between physical and biological modeling components. Plankton models (Eslinger et al., 2001; lin et al., submitted)
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From page 85... ...
Also, while there are redundant oil fates models, there is a lack of hydrodynamic and atmospheric models, and these areas provide opportunities for OSRI to contribute.
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From page 86... ...
has been modeled for more than 20 years using algorithms that are only appropriate for calm water surface conditions. The algorithm is augmented by slick drift, oil droplet entrainment, and resurfacing, but significant data gaps exist in our understanding of oil-slick-spreading behavior.
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From page 87... ...
Biological Effects Modeling of biological effects has not been included in the NC/FC system. However, model development and oil spill effects research generally have identified several areas where greater mechanistic and quantitative understanding is needed in order to develop predictive models.
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From page 88... ...
SUMMARY The Nowcast/Forecast model is conceptualized primarily as a realtime spill response tool, and this and related efforts have been a large OSRI financial commitment and focus. The OSRI Advisory Board, with input from the OSRI leadership and stakeholders, will need to judge whether the emphasis on this modeling activity is an accurate reflection of its priorities and its interpretation of the OSRI mission.
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