Review of Metocean Forecast Datasets and a Case Study of Consensus Modelling

Abstract

Metocean forecast datasets are essential for the timely response to search and rescue (SAR) incidents and pollutant spill mitigation at sea. To effectively model the possible drift pattern of a person lost at sea, or to approximate the area of impact for a marine spill, both wind and ocean current forecast datasets are required. There are two ocean current forecast datasets currently used in the Australia and Asia Pacific region: these are the American Navy Coastal Ocean Model (NCOM) and the Australian BLUElink model. These forecast models were developed for large scale ocean circulation. Neither of the models incorporate the effects of tidal currents. An aggregation tool, which enables the addition of tidal currents to the ocean currents to both of these models has been produced, thus increasing their effectiveness in coastal regions. There are several wind forecast datasets available including the US Global Forecast System (GFS) and the US Navy Operational Global Atmospheric Prediction System (NOGAPS). The availability of several different forecast datasets provides a unique opportunity to compare the outcome of a particular modelling exercise with the outcome of another using a different dataset. If the two exercises provide similar results, there is a consensus between the datasets and the modeller can be confident that the outcome is as accurate as possible. If there is a difference between the two results, then there is no consensus, which suggests that the outcome may not be as reliable. Two recent modelling exercises, the oil spill resulting from the damaged Pacific Adventurer (in Queensland) and the oil spill from the West Atlas well blowout (in Western Australia) are presented as case studies to examine consensus modelling and the use of the EDS within OILMAP.