IMPACTS OF INCIDENT WAVE CONDITIONS AND NEARSHORE BATHYMETRY ON SURFZONE VORTICITY

Nearshore circulation patterns such as rip currents and eddies transport bacteria, sediment, and people across and along the surf zone, affecting beach safety, coastal morphology, and marine wildlife (Grant et al. 2005). Recent phase-resolving modeling studies suggest nearshore circulation patterns and the associated vorticity are linked to bathymetric and incident wave conditions. Persistent eddies correspond to the length scales of the underlying bathymetric variations (order 100 m), whereas small-scale (order 10 m) vorticity increases with wave directional spread (O’Dea et al. 2021, Baker et al. 2021). However, these numerically generated hypotheses have not been tested with field observations, largely due to the challenge of instrumenting the surf zone with sufficient spatial resolution (Holman and Haller 2013). Here, remote sensing techniques provide high spatial resolution estimates of surface flows in the surfzone for a range of conditions, allowing hypotheses about the impacts of bathymetry and incident waves on surfzone vorticity to be examined with field data.