The Japanese group, based in JAMSTEC, is one of the largest and best equipped. In addition, there are participating scientists in India, Australia, New Zealand, Norway and Australia. Experiments have been conducted in the Atlantic, Pacific, Indian and Arctic Oceans, and in the Greenland, Labrador, Barents, Philippine and Mediterranean Seas, as well as smaller bodies of water such as Monterey Bay and the Straits of Florida. A brief description and history of these experiments can be found in (24).
These experiments have shown that acoustic methods can provide precision long-range, basin-scale, in situ, path-averaged ocean measurements. The Acoustic Thermometry of Ocean Climate (ATOC) program in the North Pacific has demonstrated temperature measurements of a few millidegrees over 5,000 km paths (25). Reports during this symposium discuss similar measurements in the Mediterranean, the Japanese Sea and the Western Pacific.
The present initiatives to develop operational global ocean observing systems presages well for acoustic tomography. Its demonstrated unique ability to measure currents, temperature and heat storage, essential parameters in weather and climate models, and the fact that there are active groups world-wide now using the technique, are positive indications that it has a bright future, and that it will become a component of future ocean observing systems.
References
1. A good example is: physics, Physics of Sound in the sea, Department of the Navy, Washington, DC,1969 which is a reprint of Summary Technical Report of Division 6, National Defense Research Committee, V8, Washington, DC, 1946.
2. Liebermann, L.. Effect of temperature inhomogeneities in the ocean on the propagation of sound. J. Acoust. Soc. Amer., 23,561, 1951
3. Chernov,L.A., Wave Propagation in a Random Medium, Dover Publications, NY, 1960.
4. Tatarski,V.I.,Wave Propagation in a Turbulent Medium, Dover Publications, NY, 1961.
5. Potter, D.S. and S.R. Murphy, On wave propagation in a random medium, J. Acoust. Soc. Amer., 29, 197, 1957.
6. Mintzer, D., Wave propagation in a random inhomogeneous medium I and II, J. Acoust. Soc. Amer., 25, 922-929, 1107-1111, 1953, and Part III, J. Acoust. Soc. Amer., 26, 186-190, 1954.
7. Clay, C.S., et.al., “Propagation of sound between a fixed source and a fixed receiver in the ocean,” J. Acoust. Soc. Amer., 31, 1572(A), 1959.
8. Nichols, R.H. and H.J. Young, “Fluctuations in low frequency propagation in the ocean,” J. Acoust. Soc. Amer., 43,4, 716-722, 1968.
