An oil spill trajectory model predicts the movement of spilled oil in and under ice, based on such factors as type and quantity of oil spilled and the rate of release, ocean currents, wind speed and direction, and air and sea temperatures. In Arctic conditions, the predictive task is complicated by the presence of ice in a variety of forms. Models are used for contingency planning where they are useful for decision makers. Modelling a series of the most likely oil spill scenarios allows decisions concerning suitable response measures and strategic locations for stockpiling equipment and materials to be made. Locations shown to be the most vulnerable can be identified and response equipment sited accordingly.
Effective use of models during an actual emergency response requires numerous input parameters, for which data may not be readily available at short notice. Accuracy and availability of this data can often be an issue. As an incident develops, more precise data will improve the output of the model. Models can indicate whether an oil is likely to dissipate naturally or whether it is likely to reach the shoreline. This information can be used by spill responders to decide on the scope of initial aerial surveillance flights and/or the most effective spill response techniques to employ.