A mathematical model of the fate of oil spills in marine environment

A dynamic mathematical model describing the fate of oil spilt into the marine environment was developed. State-of-the-art formulations were reviewed and appropriate ones were used for modelling the different processes responsible for the transport and mixing of oil, including initial spreading, evaporation, dissolution, emulsification, dispersion and photo-oxidation. An oil spill program that calculated the amount of oil lost from the surface slick as a function of time was developed in the MS-FORTRAN language. Model simulations were obtained for different sea states, wind speeds and water temperatures. The type and composition of oil and the size of spill were modified for different crudes. It was observed that alkanol components with lower molecular mass tend to be weathered much faster than those with higher molecular mass. For example, one hour after the spill, all butanes and hexanes were lost, but most (99%) of the hexadecanes remained in the slick. A similar trend was detected for the aromatics. In the short term, much of weathering of spilt oil is due to evaporation, however in the long term vertical dispersion becomes comparable. 20 refs., 4 figs., 2 tabs