Observing various characteristics of the ocean currents and water to improve understanding oil movement
The movement of spilled oil depends on the winds and currents. Models of circulation that are used in spill trajectory models depend on having good observations of ocean properties and currents. The oceaongraphic observations also provide information needed to understand the recovery of populations of marine organisms impacted by spills.
Moorings were used in the entrances to Prince William Sound to understand exchange with the Gulf of Alaska. Surveys of temperature and salinity provided a means to estimate larger scale circulation. Drifters drogued at various depths were used to follow the flow of water. Intenive observation periods were used to test the circulation model skill.
The moorings showed the seasonal changes in exchange between the Gulf of Alaska and Prince William Sound, with most of the deepwater exchange occuring during the summer. Drifters showed a cyclonic (counterclockwise) eddy in PWS during the summer. Drifters released in PWS made it to Cook Inlet and as far as the Bering Sea. Surface currents are much stronger than at 40 m. Storms were seen to change the circulation pattern. Ship-based surveys were used to describe the seasonal changes in the surface mixed layer and the general oceanographic properties around PWS.