AUTHOR=Carlson Daniel F. , Özgökmen Tamay , Novelli Guillaume , Guigand Cedric , Chang Henry , Fox-Kemper Baylor , Mensa Jean , Mehta Sanchit , Fredj Erick , Huntley Helga , Kirwan A. D. , Berta Maristella , Rebozo Mike , Curcic Milan , Ryan Ed , Lund Björn , Haus Brian , Molemaker Jeroen , Hunt Cameron , Chen Shuyi , Bracken Laura , Horstmann Jochen TITLE=Surface Ocean Dispersion Observations From the Ship-Tethered Aerostat Remote Sensing System JOURNAL=Frontiers in Marine Science VOLUME=5 YEAR=2018 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2018.00479 DOI=10.3389/fmars.2018.00479 ISSN=2296-7745 ABSTRACT=

Oil slicks and sheens reside at the air-sea interface, a region of the ocean that is notoriously difficult to measure. Little is known about the velocity field at the sea surface in general, making predictions of oil dispersal difficult. The Ship-Tethered Aerostat Remote Sensing System (STARSS) was developed to measure Lagrangian velocities at the air-sea interface by tracking the transport and dispersion of bamboo dinner plates in the field of view of a high-resolution aerial imaging system. The camera had a field of view of approximately 300 × 200 m and images were obtained every 15 s over periods of up to 3 h. A series of experiments were conducted in the northern Gulf of Mexico in January-February 2016. STARSS was equipped with a GPS and inertial navigation system (INS) that was used to directly georectify the aerial images. A relative rectification technique was developed that translates and rotates the plates to minimize their total movement from one frame to the next. Rectified plate positions were used to quantify scale-dependent dispersion by computing relative dispersion, relative diffusivity, and velocity structure functions. STARSS was part of a nested observational framework, which included deployments of large numbers of GPS-tracked surface drifters from two ships, in situ ocean measurements, X-band radar observations of surface currents, and synoptic maps of sea surface temperature from a manned aircraft. Here we describe the STARSS system and image analysis techniques, and present results from an experiment that was conducted on a density front that was approximately 130 km offshore. These observations are the first of their kind and the methodology presented here can be adopted into existing and planned oceanographic campaigns to improve our understanding of small-scale and high-frequency variability at the air-sea interface and to provide much-needed benchmarks for numerical simulations.