Oil Spill Trajectory Modelling in Ice

An oil spill trajectory model predicts the movement of spilled oil in and under ice, based on such input parameters 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. 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. In a real-time response application, the models are run to generate forecasts of generally no more than 3 to 5 days duration, recognising that beyond this time scale the wind forecast accuracy degrades quickly. This limitation is no different than how we look at our local weather forecast. Nobody expects a forecast 10 days out to produce reliable results.

Recognising that even the best forecast models (oil spill, weather, etc.) will produce ever larger error bounds after days and weeks, it becomes necessary to reinitialise the oil spill models on a frequent basis (tens of hours to days) with the most accurate real-time spill coordinates available, for example using satellite imagery, airborne surveillance data or GPS tracking buoys, and updated wind and ocean current forecasts. Models can indicate whether 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.