Abstract:

The underwater ambient sound field can be inverted to detect, classify, and quantify rainfall at the ocean surface. This application of the ambient sound field is explained and used to produce rainfall statistics and event- specific rainfall records over a three-month period from a deep-ocean mooring. The influence of rain at the ocean surface is explored using measurements of near-surface salinity, the surface wave and wind fields, and subsurface acoustic backscatter. Enhanced injection of bubbles into the mixed layer by rain in the presence of high wind is indicated by changes to the shape of the underwater sound spectrum. [Work supported by ONR and NSF.]