Ambient sound in the ocean produced by heavy precipitation and the subsequent predictability of rainfall rate.

Results from an experiment in the Gulf of Mexico to characterize the underwater sound generated by heavy convective precipitation are reported. For a given rainfall rate, the sound levels are higher at the beginning of the storm or when the rainfall rate is increasing than at the end of the storm or when rainfall rates are decreasing. This is likely to be due to changing storm characteristics during the lifetime of the storm. Very heavy rainfall (rate ≳150 mm/h) generates near surface bubble layers or bubble clouds which attenuate sound energy at higher frequencies (≳15 kHz). The distinctive 15‐kHz peak in the sound spectrum for light rain is absent during heavy rain suggesting that the sound production mechanism previously identified for small drops (0.8‐ to 1.1‐ mm diameter) is suppressed by heavy rain even though small drops are undoubtedly present during heavy rainfall. These data show a very high correlation between underwater sound levels and rainfall rate. Algorithms for measuring rainfall rate fro...