Document Type : Research Paper
Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2, Canada.
In this paper, the performance of the MIKE21 numerical model in modeling the dispersion and transport of spilt oil related to the Deep-Water Horizon oil platform disaster in the northern part of the Gulf of Mexico is studied. Our model predicts the distribution and movement of spilt oil based on the wind-waves, current flows and vorticities taking into account evaporation, emulsion, and absorption. In this research, two types of large scale and local scale models are considered. The radiation stress of the waves, the water level and the flow speed in the Gulf are modeled using a large-scale model. After calibration and verification, the large-scale model is used to extract the boundary conditions for the local scale model and the dispersion and transport of the spilt oil is done in the local model. The accuracy of the numerical simulation using MIKE21 are confirmed by comparisons to observed satellite images. Results showed that the length of the oil spill reached 55 kilometers and covered an area of 2,800 Km2 by April 25. After two weeks, the oil spill had apparently divided into two slicks, each with an area of about 2420 and 960 Km2, respectively. Eventually, by May 28, the slick area appeared to reach over 48,400 Km2 which much of the oil evaporated because it was lightweight oil. Meanwhile, the Deep-Water Horizon oil spill occurred in spring and summer seasons; we also consider possible results assuming that the spill occurred at other times, such as autumn or winter.