LONG-RANGE SOUND PROPAGATION ANALISYS IN THE WEST MEDITERRANEAN SEA CONSIDERING EFFECT OF THE OCEAN BOTTOM

摘要

Japan Marine Science and Technology Center (JAMSTEC) carried out the Ocean Acoustic Tomography (OAT) experiments with the U.S. and France at the distance of 255.4km (400Hz) in West Mediterranean Sea, 1994. To distinguish the propagation pulses observed, we made the theoretical calculation of sound propagation in the area of experimental sea. The propagation characteristics were calculated by the ray theory and Stickler's layer segmentation normal mode method. For calculation, an ocean model with two layers: the seawater and the ocean bottom basement layer, was assumed. Moreover , another model with three layers such as the sedimentary layer between the above two layers was supposed. And we compared the calculation results with the propagation pulses observed. It seems that not only investigation of the structure of sound velocity in the seawater layer, but also the structure under sea bottom, are very important in order to distinguish the propagation pulses.