The wave event of January 20, 2024 resulted in severe infrastructure damage at the Reagan Test Site (RTS) on Roi-Namur Island and is just one example of the need for greater resiliency to weather events. The first step to greater resiliency is to more accurately predict these destructive weather events. The objectives of this project are to evaluate existing regional wave models, including at a minimum National Oceanic and Atmospheric Administration’s WaveWatch 3 model and the European Centre for Medium-Range Weather Forecasts (ECMWF) model, using in situ data measurements by Wave Gliders outfitted with CORDC wave sensing payloads. This effort will recommend operational conops for local meteorologists to use existing resources to most accurately forecast potential wave events.

The Liquid Robotics Wave Glider equipped with an Acoustic Doppler Current Profiler (ADCP) and Coastal Observing Research and Development Center (CORDC) wave sensing and meteorological payloads (Amador et al. 2023) will provide deep-water surface wave observations including wave spectra, significant wave height, peak period, directional wave parameters, and meteorological observations off the North coast of Roi-Namur. This autonomous, station-keeping, floating surface buoy provides a significant cost savings over a moored buoy given the challenge of mooring a buoy in deep waters (> 4km) off Roi. In addition, four pressure sensor/ADCP packages will be deployed in a cross-shore transect to capture detailed reef face and reef flat wave dynamics and transformation. The sensors will be deployed for 18 months – encompassing two windy/stormy seasons in order to measure the widest variety of strong wave fields. Data will be cross-validated with existing deep-water models in order to evaluate the accuracy of existing wave forecasts.

The in situ data provided by the Wave Glider will allow for the evaluation of the accuracy of regional wave models currently used in weather and wave predictions. The reef-based sensors will capture the energetics of the waves which propagate into the shore. This in conjunction with spectral refraction modeling will allow us to create an exposure map detailing the characteristics of the waves – as predicted in deep water by the existing wave models – will propagate to and impact the shore. Combined with the analysis of the wave forecast models this will describe not only which waves characteristics to be alert for, but also which forecast models will best predict those waves. In collaboration with the local meteorologists, this will allow us to develop a detailed CONOPS specific to the Atoll of how to evaluate the available forecasts, wave characteristics, and weather conditions to best predict critical wave impact events.

In addition, the high resolution, deep water wave modeling in conjunction with the intermediate-depth spectral refraction models will help inform the physics of why certain waves are accurately – or inaccurately – captured in the forecasts. This will provide a framework for applying the assessment for Kwajalein Atoll to other locations in the Pacific. (Anticipated Project Completion - 2027)