A note on surface waves due to rain

Abstract

Surface waves due to rain are studied in the laboratory. The rms surface deviation is found to vary as κd/gv, where κ is rain kinetic energy flux, d is drop size, g is gravity, and v is viscosity. Wave spectra are quite sharp, and amplitude distributions appear to be Rayleigh in nature, at least in a qualitative sense. The logarithmic wind profile surface roughness z0 for rain in light winds is estimated and is found to be much larger than that due to the wind alone.