Reaching for the surface: Spheroidal microswimmers in surface gravity waves

Abstract

The trajectories of microswimmers, such as plankton or artificial active particles, are altered by their interactions with the ambient flow. We show here that microswimmers swimming beneath surface gravity waves can resurface or swim to deep depths depending on their coupling to the flow. We obtain a system of equations describing wave-averaged microswimmer trajectories, from which we calculate the probability of reaching the surface as a function of swimming speed and body shape.