Evaluating remotely sensed alongshore currents with in situ observations and model simulations

Sarah Margaret Trimble, National Research Council Postdoctoral Fellow, U.S. Naval Research Laboratory, Stennis Space Center, MS, United States, Allison Penko, Naval Research Lab Stennis Space Center, Stennis Space Center, MS, United States and Margaret Palmsten, U.S. Naval Research Laboratory, Washington, DC, United States
One established method for observing surface current velocities in the surf zone is to derive them from optical cameras. This can be a less expensive and more easily deployed method than in situ instrumentation, while also providing current velocities over a larger study space than the single discrete location of a field instrument. In this study, longshore current velocities are derived for a 100 m x 1500 m grid in the surfzone of the U.S. Army Corps of Engineers Field Research Facility in Duck, NC during the passing of several storms in October 2015. These optically derived currents, along with in situ current measurements from acoustic wave and current profilers (AWACs), are then used to evaluate multiple Delft3D model simulations. The aim is to use field observations, including these remotely sensed currents, to optimizing the parameterization of the Delft3D model. By including the optically sensed currents, this method provides a more spatially diverse picture of surfzone currents during these storms than in situ instruments alone. This process can be used when and where site managers need spatially varied evaluations of model results.