Integrating Marine Radar Observations into Nearshore Modeling Systems

The long-range goal of this research is to extend the scientific basis for extracting environmental information regarding the nearshore ocean from remote sensing data. In particular, we seek to quantify how both optical and remote sensors image the breaking of waves in shallow water. OBJECTIVES The objectives of this project are as follows: 1. Assemble a marine radar wave observation system suitable for the nearshore ocean. Deploy assembled system at Duck, NC. 2. Collect a long time series (weeks to months) of radar and video data, including both time-exposure and time-series products. 3. Assist/collaborate with the effort to incorporate radar time-exposures from an ongoing collection effort into the Beach Wizard data assimilation program and interpret differences in model outputs arising from the different input data sources. 4. Analyze the differences between the wave breaking signals at wave time scales (i.e. not time exposures) for both optical and microwave wavelengths and relate the different signals to the underlying nearshore wave field. 5. Investigate potential model parameterizations for predicting the coverage of whitewater and foam that will generate clutter at optical wavelengths. APPROACH Our approach has been twofold. The first approach has been to continue our analysis of the details of wave breaking as imaged by optical sensors. Specifically, thus far we have concentrated mostly on data we collected in a large-scale laboratory experiment. This approach is new for two reasons, first by using a laboratory facility of this size we are able to control our wave conditions and still operate at large scales; secondly, performing the analysis on a wave-by-wave basis (as opposed to the time exposure approach) is also new. In addition, since the data set includes a number of in-situ wave gage time series that are highly synchronized with the video cameras, we have been able to investigate both the effects of nonlinearity on wave kinematics and the details of the relationship between optical signals and wave conditions in the surf zone.