Title: Effects of Surfactants on Plunging Breaking Water Waves

Description: In this image, we show the 2-dimensional surface profile of a plunging breaking water wave created in a laboratory wave tank at the time when the jet of the wave impacts the water surface. The four images demonstrate the effects of a chemical (called a surfactant) that alters the surface tension properties of the water surface. We found that when we used clean water (blue wave, top left) the shape of the plunging jet is very smooth. When we added a small amount of surfactants to the water, the shape of the jet became highly irregular (green wave) and in some cases, a jet could not form on the water surface (yellow wave). When we added a large amount of surfactants, the jet became very smooth, just like in the clean water condition. This result was surprising. For reference, the wave length of these waves is approximately 1 meter.

Notes: This image was originally captured during my Ph.D. at the Hydrodynamics Laboratory at the University of Maryland. I am now working on a manuscript to describe the physics of the effect demonstrated in this image. My advisor at Princeton and my Ph.D. advisor from Maryland will both be co-authors of this work.

M. A. Erinin, D. Wang, R. Liu, D. Towle, X. Liu, & J. H. Duncan (2019), Spray Generation by a Plunging Breaker. Geophysical Research Letters