A symposium with the title given above took place at the Naval Physical and Oceanographic Laboratory in Cochin, India, on February 19–20, 1987. Scientists from 18 different universities, colleges, and governmental laboratories presented papers. This is indicative of the widespread interest in the subject matter in India.

Because of the length of the meeting, it will be impossible to discuss all of the papers that were presented. Only a few of the papers that seemed most cogent to me will be discussed.