Abstract:
The dynamics modification originating from the non-uniform complex microscale features over the ocean and land can significantly impact the flow and mass balance within the boundary layers. These impacts can be further passed to upper scales through multi-scale interactions. This presentation explored three cases about the flow structures and pollutant transports in the oceanic and atmospheric boundary layers using high-resolution large eddy simulation (LES). Despite the different surface characteristics, substantial modifications associated with the mean flow and turbulence structures have been observed. So do the direction, mixing depth, and mass flux of the pollutant transport. Mainly, a study focusing on the unique challenges associated with the world-largest oil spill accident—The Deepwater Horizon accident in the Gulf of Mexico (2010) is introduced. During this event, plumes of oil droplets and gas bubbles generated from deep-water blowouts rose through various ocean layers with different dominant physical processes (e.g., stratification, Langmuir turbulence, Ekman transport, surface gravity waves, and submeso-/meso-scale eddies). To accurately represent all these complex physical processes crossing different length scales, a low-cost multi-scale coupling approach—ENDLESS was developed. Effects of dispersant application were investigated using this method. The results show a significant reduction of the mean advection velocity of oil plume and horizontal diffusivity increment. These effects of dispersant application should be considered in the remediation planning of future spills.
