Summary: | New parameterizations for physical processes that are related to the vertical transport of oil spills are implemented into the open source trajectory framework OpenDrift. These encompass the wave-entrainment of oil, two alternative formulations for the droplet size spectra, and turbulent mixing. The performance of the integrated oil spill model is evaluated by comparing model simulations with airborne observations of an oil slick. The results show that an accurate description of a chain of physical processes – in particular vertical mixing and oil weathering – is needed to represent the horizontal spreading of the oil spill. Using ensemble of simulations of a hypothetic oil spill, the general drift behavior of an oil spill is discussed. Vertical mixing of oil between the surface slick and entrained oil is identified as a crucial component for the horizontal transport of oil spills, and to explain the differences for drift of various oil types.
|