Rainfall at Sea: Using the Underwater Sounds of Raindrops as a Rain Gauge for Weather and Climate

Abstract

Listening to raindrops over the ocean surface using a hydrophone is analogous to listening to the rain under a tin roof. Raindrops hitting the sea surface generate loud sounds underwater. The ocean conducts sound very efficiently so that the sounds from the sea surface propagate down with little loss of energy; the sound environment of the ocean is much like a large echo chamber. The nature of the sound is unlike the plunking on a tin roof, however. Rain over the ocean sounds like the hiss of white noise underwater (Discovery of Sound in the Sea: Rainfall; see bit.ly/3KoN55m), with frequencies that extend well above the threshold of human hearing. In this article, we describe how those sounds convey considerable information about the nature of rainfall at sea.