Coherent and incoherent scattering from oceanic bubbles

In recent years, an effective medium theory has been applied to model the contribution of bubbles for low‐frequency oceanic backscattering [Prosperetti et al. and Sarkar and Prosperetti, both submitted to J. Acoust. Soc. Am.] This approach differs from the more traditional one used to account for the effect of bubbles at higher frequencies, in which bubbles are treated as individual scatterers. Here, the relationship between these two apparently different approaches is clarified and a unified theory is presented. In this way, a better understanding of the rationale and limitations for the older theory is achieved. Applications to scattering and bubble counting are described. [Work supported by ONR.]