188
Among all of the modeled case studies, the DB_control and DB_tempBiodegrad
scenarios (Fig. 11.5) seem to agree best with the observational studies in several
aspects: first, in modeled high oil residue deposits around the DWH site and reflecting the SW-NE orientation of the area with the elevated deposition levels including
DeSoto Canyon; second, elevated deposits along the northern GoM coastline; and
third, distinctively, indication of higher values of oil residue patch in the coastline
stretch between 94 and 95
°
W.
11.5 Summary
This chapter presented modeling case studies of deep-sea oil spills based on the
Deepwater Horizon 2010 incident. The oil transport and fate application of the
CMS trajectory model results were analyzed using well-founded post-processing
algorithms and allowed for a quantitative estimate of oil concentrations and mass in
both 3D space and time. CMS oil application model configuration parameters are
backed by earlier laboratory and field studies. In addition to the deep-blowout control, DB_control, scenario, several additional case studies were conducted to investigate effects of modified initial conditions, different DSDs, and several other model
parameters affecting oil weathering and transport.
One of the major findings of the modeling results was that the differences in
interior GoM circulation, such as Loop Current development during different seasons, mesoscale ocean eddies, and Florida Straights position, appear to have a
primary effect on the surface oil spread. Depending on circulation, an oil droplet
could either travel considerable distances away from the oil spill site or be trapped
within small-scale eddies. Variations in the DSD primarily yield first-order effects
in surface of oil concentrations, but did not have qualitative effects on surface oil
slick formation. Furthermore, the cumulative effect of the SSDI treatment thus
appeared to slightly reduce oil content at and below the surface but contributed to
shifting the deep oil plume to greater depths. This suggested that the use of dispersants is unlikely to help remove oil from the environment more rapidly.
Furthermore, good agreement in spatial details of the modeled oil residue sediments in the control DWH case with the observational studies further confirms the
robustness of the CMS oil application and the analysis methods to simulate deepsea blowout scenario.
Acknowledgments This research was made possible by a grant from The Gulf of Mexico
Research Initiative/C-IMAGE II to Steve Murawski. Data are publicly available through the Gulf
of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org (doi: https://doi.org/10.7266/N7KD1WDB).
The authors are thankful to Matthieu Le Hénaff for the discussion on the wind drift effects and
to Paul Bubenheim and Juan Viamonte for their insight into biodegradation laboratory experiments
and studies.
N. Perlin et al.
Among all of the modeled case studies, the DB_control and DB_tempBiodegrad
scenarios (Fig. 11.5) seem to agree best with the observational studies in several
aspects: first, in modeled high oil residue deposits around the DWH site and reflecting the SW-NE orientation of the area with the elevated deposition levels including
DeSoto Canyon; second, elevated deposits along the northern GoM coastline; and
third, distinctively, indication of higher values of oil residue patch in the coastline
stretch between 94 and 95
°
W.
11.5 Summary
This chapter presented modeling case studies of deep-sea oil spills based on the
Deepwater Horizon 2010 incident. The oil transport and fate application of the
CMS trajectory model results were analyzed using well-founded post-processing
algorithms and allowed for a quantitative estimate of oil concentrations and mass in
both 3D space and time. CMS oil application model configuration parameters are
backed by earlier laboratory and field studies. In addition to the deep-blowout control, DB_control, scenario, several additional case studies were conducted to investigate effects of modified initial conditions, different DSDs, and several other model
parameters affecting oil weathering and transport.
One of the major findings of the modeling results was that the differences in
interior GoM circulation, such as Loop Current development during different seasons, mesoscale ocean eddies, and Florida Straights position, appear to have a
primary effect on the surface oil spread. Depending on circulation, an oil droplet
could either travel considerable distances away from the oil spill site or be trapped
within small-scale eddies. Variations in the DSD primarily yield first-order effects
in surface of oil concentrations, but did not have qualitative effects on surface oil
slick formation. Furthermore, the cumulative effect of the SSDI treatment thus
appeared to slightly reduce oil content at and below the surface but contributed to
shifting the deep oil plume to greater depths. This suggested that the use of dispersants is unlikely to help remove oil from the environment more rapidly.
Furthermore, good agreement in spatial details of the modeled oil residue sediments in the control DWH case with the observational studies further confirms the
robustness of the CMS oil application and the analysis methods to simulate deepsea blowout scenario.
Acknowledgments This research was made possible by a grant from The Gulf of Mexico
Research Initiative/C-IMAGE II to Steve Murawski. Data are publicly available through the Gulf
of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org (doi: https://doi.org/10.7266/N7KD1WDB).
The authors are thankful to Matthieu Le Hénaff for the discussion on the wind drift effects and
to Paul Bubenheim and Juan Viamonte for their insight into biodegradation laboratory experiments
and studies.
N. Perlin et al.