Comparison between two types of moored vertical profiler

Abstract

Moored vertical profiler is a device for collecting profiles of ocean data while its moving up and down. Two different types of profiler were deployed in the East/Japan Sea by KIOST in 2014-2015. The POPPS is composed of a moored subsurface winch system including battery packs and a profiling buoy installed with sensors. When the profiling buoy is released from the winch system to start measurements, it moves up to the surface freely by its own buoyancy and then the winch winds it back to the subsurface original position. It floats briefly at the sea surface to transmit the real-time profile measurements. The winch system consumes relatively large battery power, which limits its depth to ~300 m. The Aqualog is composed of a moored wire and a carrier which contains sensors, a glass buoy, battery packs, and an electric motor. The motor moves up and down the carrier that is pre-adjusted to have a neutral-buoyancy in the ocean, thus it consumes relatively small battery power. To make the moored wire as straight as possible, a relatively huge buoy (subsurface or surface) should be attached at the top of the wire. The carrier can dive up to 1000-m depth, but it typically misses the near surface layer shallower than ~5 m. In this study we present the observation results in the East/Japan Sea from the two types of moored vertical profiler and provide guidance for users in choosing an optimal moored profiling platform depending on their research objectives.