Design and deployment of the Bonne Bay Observatory (B20)

摘要

We have deployed the Bonne Bay Observatory (B20) in Bonne Bay, a fjord on the west coast of Newfoundland, in the spring of 2004. The scientific goal of this system is to provide continuous, year-round, real-time data to enhance our understanding of the coupling between the physical and biological environment in this sub-Arctic fjord, which is ice covered for several months each year. The Observatory permits investigators to schedule and interactively manage real time data acquisition and control of the network of sensors. Serving a multidisciplinary team, the instrument array is diverse, including acoustic sensors to determine currents, bubble distribution and plankton abundance, video to determine plankton and benthos species abundance, and sensors for temperature, salinity, chlorophyll fluorescence, carbon dioxide, oxygen, inorganic nutrient concentrations and spectral irradiance. Instruments are deployed on fixed and moveable structures and on an underwater profiling winch. The control and telemetry system includes a power distribution sub-system and TCP/IP based network consisting of two local area networks, one on shore linking data acquisition and control computers and one underwater connecting the sensors, joined by an armored 1.4 km electro-optic cable. The cable provides up to two 100BASE-FX network connections and 2 kW of power to the underwater systems. The system is designed to operate autonomously, and to be controlled remotely by the DACNet ocean observatory operating system. The underwater hardware elements are modular, accommodating guest instruments at spare Ethernet and serial ports. The paper describes the system design with description of instrumentation deployed underwater for the first time, lessons learned during design and deployment and presents preliminary samples of the data collected.