Asymmetry of motion: vortex rings crossing a density gradient

Vortex rings are critical for thrust production underwater. In the ocean, self-propelled mesozooplankton generate vortices while swimming within a weakly stratified fluid. While large-scale biogenic transport has been observed during vertical migration in wild and lab experiments, little focus given to evolution of induced vortex as function their propagation direction relative density gradient. this study, an isolated ring crossing interface stable two-layer system is examined its translation with respect gravity. The size position visualized using planar laser-induced fluorescence (PLIF) vorticity field derived from particle image velocimetry (PIV) examined. It found that baroclinic significantly affects interface. As result, any expected symmetry between travelling dense light fluids breaks down. turn, maximum penetration depth occurs case which propagates against gradient due misalignment pressure gradients. Our results have far-reaching implications characterization local ecosystems marine environments.