The influence of wind on the underwater sound generated by light rain

The dominant feature of the underwater sound generated by light rain is a broad spectral peak at 15 kHz. The spectral location of this feature is proportional to raindrop impact velocity. Wind adds a horizontal component to the raindrop velocities, increasing their net impact velocities and shifting the spectral peak to a higher frequency. The surface velocities of waves generated by the wind distribute the raindrop impact velocities and thus broaden the spectral peak. Observations show that the spectral level of the peak drops as the wind increases, suggesting that the efficiency of the drop impact as a sound source has been reduced.