Ocean Acoustic Tomography Programs : Accomplishments And Plans

Since the concept of acoustic tomography for mapping ocean mesoscale variability was first articulated by Walter Munk and Carl Wunsch in 1978,1 there has been a continually growing research program aimed at understanding the capabilities and limits of tomographic techniques in the ocean. Along with this, there has been an evolving technology program directed at developing instruments for tomographic measurements. These programs have been conducted at a variety of institutions, starting with the Massachusetts Institute of Technology, the Scripps Institution of Oceanography, the University of Michigan, and the Woods Hole Oceanographic Institution. Today, these have been joined by others, including the University of Miami, the University of California at Santa Cruz, the University of Washington, the Naval Research Laboratory, the Naval Postgraduate School, NOAA laboratories, IFREMER in France, the Japan Marine Science and Technology Center, and several businesses. This paper presents a brief review of the accomplishments of these tomography programs in the past decade and outlines plans for the future. Table I provides a summary of major tomographic experiments. The principal accomplishments have been to demonstrate that acoustic tomography can be used to map ocean mesoscale variability and that acoustic transmissions can be used for integrating measurements.