Scaling surf zone turbulence

Turbulence in the surf zone, the shallow region adjacent to the shoreline, has a key role in beach erosion, fertilization, dispersal, and larval settlement of marine invertebrates, and microbial contamination dilution in beach waters. Breaking‐wave generated (the dominant source) surf zone turbulence is understood poorly. A new surf zone turbulent dissipation rateϵ scaling is derived, that collapses new field surf zone ϵobservations with relatively high skill compared to other scalings. The vertically‐uniform length‐scale is 1/6 the water depth, and 15% of the wave‐energy flux gradient is dissipated below the mean surface. Field and laboratory surf zone turbulence observations are shown to be consistent using the scaling. The non‐dimensional surf zone diffusivity and suspended sediment profile can be applied to sediment transport and a range of biological processes including microbial pathogen contamination of beach waters. Key Points A new surf zone turbulence scaling is derived that collapses observations With the scaling field and lab surf zone turbulence are shown consistent The scaling can be applied to sediment transport and biological processes