Positively buoyant particle dynamics in wave run-up

Plastic pollution remains a significant threat to the health of ocean ecosystems. Given that the majority of plastic pollution originates from land-based sources, understanding the transport of plastic debris in nearshore regions is crucial. And yet, while coastal sediment transport is a longstanding area of research, there are minimal research efforts for positively buoyant microplastic transport at the coastline. Specifically, we consider the transport of microplastics in the swash zone, which encompasses the region where broken waves travel up and down the slope, (known as uprush and backwash). In this talk, we present results from an experiment designed to study the transport of positively buoyant particles in an idealized swash flow. We track particles starting from rest on a sloped, impermeable boundary during one wave event. Our results indicate the importance of initial condition on particle transport, as well as the size of the particle relative to the incoming wave.