Simulating Oil Droplet Dispersal From the Deepwater Horizon Spill With a Lagrangian Approach
Simulating Oil Droplet Dispersal From the Deepwater Horizon Spill With a Lagrangian Approach
复制标题
DOI：
10.1029/2011gm001102
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Elizabeth W. North;E. Eric Adams;Zachary Schlag;Christopher R. Sherwood;R. He;Kyung Hoon Hyun;S. Socolofsky
中科院分区：
文献类型：
--
作者：
Elizabeth W. North;E. Eric Adams;Zachary Schlag;Christopher R. Sherwood;R. He;Kyung Hoon Hyun;S. Socolofsky
结合三维南大西洋湾和墨西哥湾水动力模型（SABGOM）产生的时变流场和水文场，采用多相羽流分析模型作为拉格朗日输运模型（LTRANS）的输入，模拟了深水地平线MC 252漏油事故中分散在深处的油滴的输运过程。羽流模型预测了一个以分层为主导的近场，在这个近场中，小油滴从含有快速上升的大油滴和气泡的中心羽流中分离出来，并被密度分层所困。模拟侵入（圈闭）高度为310-370 m，与Q1电导率-温度-深度观测值的中间值吻合得很好，尽管圈闭高度的模拟变化低于实际观测值，部分原因可能是由于源成分（油气百分比）和位置（泄漏前半期多次泄漏）未解决的可变性。SABGOM-LTRANS模拟系统的液滴轨迹表明，直径在10 ~ 50 μm之间的液滴形成了明显的地下羽流，并在地下水平输送，并在地下停留了100 ~ 100个月。而直径≥90 μm的液滴则迅速上升到表面。直径≤50 μ mi n的液滴的模拟轨迹与Camilli等人[2010]在2010年6月下旬报道的西南向地下羽流的现场观测结果一致。模型结果表明，地下烟羽向东绕圈，潜在的地下石油输送到东北和东南。目前的工作重点是在模型中加入降解过程，以限制液滴的扩散。
An analytical multiphase plume model, combined with time-varying flow and hydrographic fields generated by the 3-D South Atlantic Bight and Gulf of Mexico model (SABGOM) hydrodynamic model, were used as input to a Lagrangian transport model (LTRANS), to simulate transport of oil droplets dispersed at depth from the recent Deepwater Horizon MC 252 oil spill. The plume model predicts a stratification-dominated near field, in which small oil droplets detrain from the central plume containing faster rising large oil droplets and gas bubbles and become trapped by density stratification. Simulated intrusion (trap) heights of ~ 310–370 m agree well with the midrange of Q1 conductivity-temperature-depth observations, though the simulated variation in trap height was lower than observed, presumably in part due to unresolved variability in source composition (percentage oil versus gas) and location (multiple leaks during first half of spill). Simulated droplet trajectories by the SABGOM-LTRANS modeling system showed that droplets with diameters between 10 and 50 μm formed a distinct subsurface plume, which was transported horizontally and remained in the subsurface for >1 month. In contrast, droplets with diameters ≥90 μm rose rapidly to the surface. Simulated trajectories of droplets ≤50 μ mi n diameter were found to be consistent with field observations of a southwest-tending subsurface plume in late June 2010 reported by Camilli et al. [2010]. Model results suggest that the subsurface plume looped around to the east, with potential subsurface oil transport to the northeast and southeast. Ongoing work is focusing on adding degradation processes to the model to constrain droplet dispersal.