Measuring Oceanic Flow: From Microns to Kilometers

Abstract: In this talk Dr. Jaffe will present the technical development and field results from several systems that were created in his lab to measure oceanic flow. In one case, a swarm of 17, one-liter-sized vehicles were fabricated to provide quasi-Lagrangian measurements of 3-dimensional flow fields at kilometer scales with meter positional resolution. The vehicles were deployed adjacent to La Jolla over several afternoons, and the data reveals interesting features of the internal wave field. Prospects for further development, including several unsolved control problems, will be described. In another effort, an in-situ Particle Imaging Velocimetry system was developed for measuring flow at scales of 10’s of centimeters with millimeter resolution. The successful deployment of the system on an autonomous, free descent vehicle, demonstrated the feasibility of the technology, however, undisturbed measurement was hindered by the vehicle’s own bow wave. Nevertheless, our development points the way to future systems. Lastly, a soon to be deployed, multi-camera, underwater microscope that uses bi-orthogonal holographic imaging and fast focal plane scanning will be described. The system will be ideal for measuring the behavior of small oceanographic organisms and the flow around them. Bio: Born in Merrick, New York, Jaffe graduated cum laude from State University of New York, Buffalo with a bachelor’s degree in physics. He attended then the Georgia Institute of Technology, where he received a master’s degree in biomedical information science. He then went to the University of California, Berkeley, where he received a doctorate in biophysics. Following graduation, Jaffe was a software engineer at Diasonics, Inc., in Milpitas, Calif., and, concurrently, a postdoctoral fellow at the UC Lawrence Berkeley National Laboratory. Subsequently, he was a consultant to KLA Instruments Inc., in Santa Clara, Calif. In 1984, he joined the science staff at Woods Hole Oceanographic Institution where he held a research fellowship from the Pew Memorial Foundation. There, he became the resident physicist that helped design the ARGO vehicle that discovered the Titanic. He has been at the Scripps Inst. of Oceanography since 1988 where he is currently a Research Oceanographer. He was elected a fellow of the Acoustical Society of America in 2003, and was a visiting Miller Professor at Cal in 2005. He is currently editor-in-chief of a new journal that he founded: Methods in Oceanography.