A Submerged Upper-Ocean Multidisciplinary Timeseries Profiler

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

Investigators

Abstract

Project Title: A submerged upper-ocean multidisciplinary timeseries profiler Project Summary The PIs request funds for a development project whose costs are being shared with a funded European project and Bedford Institute of Oceanography. This activity will develop a moored profiling system for the upper layer of the water column in remote deep-ocean regions. The goal is a capability to provide timeseries observations from approximately 150 m depth to the surface in real-time, of physical and biogeochemical variables, such as those required by carbon cycle science and NPZD-type models. Some of those sensors currently are large and heavy, and cannot be incorporated into floats, gliders, or existing moored profilers. The approach chosen avoids having a moored buoy at the surface, in order to facilitate operation in harsh conditions, prevent vandalism, reduce fouling of sensors, and to minimize the assemblage of biological communities around the mooring. The proposed development is intended to provide a state-of-the art technology option for emerging programs for ocean observatories, addressing a wide range of science needs for long timeseries in physical and climate research, carbon cycle science, geochemistry, and biology. The system to be developed as a prototype would fill a niche for low-bandwidth stations in deep water and remote locations, where the focus is on the upper-layer biogeochemistry and ecosystem in conjunction with the controlling physical processes. It could provide a basis on which future OOI infrastructure work and proposals could build. The data handling and telemetry will be open and modular, and compatible with the ORION data infrastructure being developed. The chosen approach consists of an underwater winch, connected to the top float of a typical subsurface mooring, at approximately 150m depth. A buoyant sensor package is parked at this depth, but 1-2 times per day ascends to the surface on an electromechanical wire, which is kept taut by the winch. The package can control the winch for sampling stops, when reaching the surface, or to avoid the surface under unfavorable conditions. The profile data would be telemetered when the package reaches the surface, including data from other instruments deeper on the mooring. The sensor package will carry commercially available instruments and will be ready for a Laser Optical Plankton Counter, which will be re-designed for this application under a separate proposal. The winch itself will be adapted from one of the existing underwater winches, to fulfill the requirements of the anticipated applications.