Using acoustic tomography to monitor deep ocean currents in the eastern Gulf of Mexico

Toward the improved prediction and monitoring of deep-water currents and eddies in the Gulf of Mexico, the Gulf Eddy Monitoring System group (GEMS; researchers from University of Southern Mississippi, University of New Orleans, University of Louisiana at Lafayette, and the Naval Research Laboratory) proposes that a network of acoustic transmitter-receiver pairs be deployed in the northeastern Gulf of Mexico. Acoustic travel times are inverted to recover temperature and velocity between transmitter-receiver pairs. This data can be fed into ocean dynamical models to improve simulation and prediction of the circulation in the deep ocean. While a proven technique, it has only recently been used successfully in deeper waters. The location is ideal for this type of tomographic application for its predictable oceanic parameters and convenient geomorphology. With a sound-channel axis at about 900 m, a lower power output transmission is required, thus providing negligible impact on marine mammals. Because no other technology can be used to monitor for similar events, we are introducing this method to the marine technology community.