EPSONDE: A Deep Ocean Microstructure Profiler

EPSONDE is a tethered free-fall profiling system used to obtain temperature microstructure and velocity turbulence data to a depth of at least 1500 m. EPSONDE, which carries a variety of slow and fast sensors, is deployed on a loose kevlar multiconductor cable by a specialized wire handling system. Data are transmitted from this underwater unit (1792 samples per second) to a deck-board system which includes a dedicated micro-computer for data Logging and on-Line data processing. The performance of the system will be demonstrated by discussing a study of turbulent mixing processes in a lens of Mediterranean water (a MEDDY) found at a depth of 1000 m in the Canary Basin. These studies indicate that turbulent kinetic energy dissipation may be an important mechanism in determining the decay and lifetime of a MEDDY.