Front Resolving Observational Network with Telemetry: Turbulence Characterization from an AUV
A Front-Resolving Observational Network with Telemetry (FRONT) is being developed for a region of the coastal ocean. The long term goal is to demonstrate and evaluate an easily deployed, easily serviced, and cost-effective observation system. OBJECTIVES The specific objectives of the AUV-based turbulence characterization component of this research are to contribute to the evaluation the overall performance of the observation system in this challenging environment. We will provide the
... ure scale comparison with assimilated data products, as part of results from a series of ship surveys designed to resolve multiple scales of variability. APPROACH The FRONT system includes data-assimilative models that will mitigate the impact of sampling error by producing dynamically consistent maps from the data. Furthermore, real-time coordination of the diverse range of physical and biological data will allow forecasting. Data telemetry and instrument control for the bottom-mounted instrument array employs a wireless acoustic communications network with redundant data paths. The demonstration site lies in a region of strongly varying bathymetry on the shelf near Long Island Sound (Fig. 1) . Tides and energetic wind-and buoyancy-forced motions combine to produce a complex flow field. Satellite measurements of surface temperature and color show recurrent front-like features at the FRONT site (Ullman and Cornillon, 1999) . To evaluate the observation system fidelity, we will compare model results to observational results on multiple scales from microstructure through the mesoscale. IMPACT/APPLICATION The AUV-based turbulence measurements provide a unique horizontal profiling view of the variability of the mixing environment that cannot be obtained by more conventionally sampling measurements, and this approach can be further exploited in yo-yoed horizontal sections. These techniques will be invaluable in frontal process studies utilizing the coastal version of the MITgcm model. TRANSITIONS Our AUV sensor technologies, hardware and software, are being considered for inclusion as tactical oceanography payloads for the Manta UUV Initiative. RELATED PROJECTS My AUV-based turbulence measurement system is also being utilized in NOPP/ONR studies with the Rutgers University led LEO-15 and Harvard University led LOOPS projects.