Snowflakes Falling on Water: the Underwater SoundGenerated by Falling Snow

There have been a few reports that snow generates sound similar to that of rain when it strikes the ocean surface but it is hard to imagine that the mechanisms responsible for rain sounds could be the same as those that cause sound from falling snow. We explore the sound generated by falling snow through laboratory measurements under different atmospheric conditions that give rise to variety of snowflake types with different snowfall rates by using a small tank filled with tap water. We find that there is a well defined spectral peak at around 12 kHz (similar to that of rain) in sound generated by some snow types; other snow types do not produce appreciable underwater sound. The data suggest that the sound generated by falling snow is such that ocean snowfall rates could be estimated by evaluating spectral characteristics of the sound. More experiments need to be done for that purpose as sound levels depend on snowfall rate, snow types, sea state, and wind speed.