ASA 124th Meeting New Orleans 1992 October

5pUW11. Predicted surface zone scattering from measured bubble clouds in the Gulf of Alaska.

Svein Vagle

Bergen Environmental Ctr., Bergen, Norway

David M. Farmer

Inst. for Ocean Sci., Sidney, BC, Canada

Frank S. Henyey

Univ. of Washington, Seattle, WA

Using previously described techniques, the tenuous bubble cloud field was measured during the 1992 Gulf of Alaska reverberation experimental program. These measurements are used to predict the low-frequency reverberation, which was simultaneously measured nearby. The predictions show a great deal of variability, consistent with the reverberation measurements. Most often the predictions are considerably less than the average scattering strength, but one measurement was obtained during stormy conditions, that, when averaged with all the small values obtained during stormy conditions, still exceeds the phenomenological Ogden--Erskine formula. The conclusion from this work is that there is probably adequate scattering from the tenuous clouds to explain the reverberation measurements, but that the more deterministic comparisons of planned experiments are required. [Work supported by ONR.]