Collaborative Research: Field Testing RAFOS-Enabled SOLO Floats (SGER)

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

0243325 Gille This proposal will build three new RAFOS-enabled isopycnal-following Sounding Oceanographic Lagrangian Observer (SOLO) floats and test them within a sound source array that is being deployed in the North Atlantic. The experiment is an important technology demonstration project that brings together software and hardware that have been developed for a number of other field programs to produce a novel float with important new capabilities. The floats will be based on the SOLO float design so that, at the least, they can be tracked every 10 days no matter where they go in the world and provide temperature and salinity profiles when they rise to the ocean surface. They will be equipped with RAFOS receivers so that when they are within acoustic range of sound sources, they can be tracked daily to provide higher frequency velocity trajectories that are of order 100 days in length. They will also be programmed to follow isopycnals, so that we can observe float displacements along isopycnal surfaces that are associated with the primary mixing in the ocean. Finally, the floats will be designed to take advantage of new two-way communication capabilities, so that they can be reprogrammed if experimental requirements change after deployment or if any of their sensors fail. Floats of this design will be particularly well-suited for eventual deployment in the Southern Ocean. The high velocities and rough sea state of the Antarctic Circumpolar Current (ACC) make it a difficult region to deploy and maintain current meters, meaning that floats are the preferred method for estimating eddy fluxes. Because of its strong flow, the ACC is likely to advect floats out of an ensonified basin long before the depletion of the float batteries, meaning that pure RAFOS floats may not provide useful data for significant portions of their missions. Isopycnal-following capabilities are important in the Southern Ocean, because the predominant mixing is thought to occur along the strongly tilted isopycnal surfaces of the ACC. This proposal will support development of technology that merges current RAFOS float capabilities with existing ARGO float technology. This development is likely to be useful in a wide range of research in physical oceanography and climate..