The ONR-funded MURI, ROXSI (ROcky shores eXperiments and SImulations) is to study the coastal ocean dynamical processes of rocky shores essential to Navy operations through combined in situ and remote sensing observations, and high-fidelity CFD and community models. 75% of the world’s coastlines are rocky, limiting current Naval accessibility. By avoiding these rocky shores, the Navy is predictable. In contrast to well-studied sandy shores, rocky shores are inherently multiscale with complex three-dimensional geometries at scales of cm to 100s m. Multiscale bottom variability strongly affects wave processes, such as scattering, reflection, nonlinear energy transfers, and dissipation that are dramatically different from sandy beaches. Rocky shores will strongly affect water-column turbulence, wave-driven inner shelf, and surf zone currents.
See the ROXSI PROJECT WEBPAGE for project information and blog posts from our field experiments.
OSU’s ROXSI effort is focusing on the dissipation of wave energy by wave breaking and bottom roughness, and the subsequent effects on nearshore circulation. We are using remote sensing methods to measure wave transformation, and acoustic Doppler sonar to measure the near-bed flow.
One of the ways our group is studying rocky shores is using Argus cameras — video remote sensing from shore-based towers, a technique widely used on sandy beaches. Video data allows us to capture the highly complex circulation that occurs in the rocky intertidal and embayments.
We are also using UAS (drone) remote sensing to get a much closer view of the wave transformation and breaking over the highly rough rocky bottom. The OSU “Pantera” UAS combines LIDAR and high-resolution video to track small-scale surface features like bubbles and foam, while simultaneously recording the 3d water surface with LIDAR. The UAS allows us to collect data where in-situ measurements would be impractical, such as amongst the nearshore rocks and in crashing waves.
