Implementing the Gulf of Maine Ocean Observing System (GoMOOS)

The Gulf of Maine Ocean Observing System (GoMOOS) was established in the summer of 2001 as a prototype real-time observing system that includes a comprehensive array of moored physical and optical sensors, shore-based long-range HF radar systems, circulation and wave modeling, satellite observations, and hourly Web delivery of data and data products. The GoMOOS moored buoy array presently consists of 10 solar-powered, automated buoy systems that telemeter data hourly via cellular/iridium phone and GOES satellite transmitters. The locations of the buoys, which are replaced on a six-month maintenance schedule, range from bays and estuaries, the continental shelf, and the open Gulf of Maine. The buoys systems and their sensors are subjected to a broad range of wind, wave, bio-fouling, and icing conditions that have presented a significant challenge to the establishment of an operational integrated ocean observing system. Mounted on the surface buoys are sensors that measure wind speed and direction, atmospheric pressure, air temperature, visibility, solar insolation, and surface wave height and period. Subsurface measurements include near-surface currents, Doppler current profiles, temperature, conductivity, dissolved oxygen, spectral upwelling radiance and downwelling irradiance, chlorophyll fluorescence, and mufti-wavelength light attenuation, absorption, and backscattering. Data from deep sensors are telemetered up the mooring cable via an inductive modem to the buoy data system. The buoy system is designed with a flexible and modular architecture that is capable of handling on the order of one hundred sensors, and has relatively simple troubleshooting and maintenance procedures. The Gulf of Maine is a harsh and exacting environment in which to attempt to establish sustained real-time operations. The extreme cold, freezing spray, and high waves of winter have posed significant challenges to the wind and atmospheric pressure measurements, and to the dual telemetry system. In addition, the build up of sea ice on the buoy superstructure and on the solar panels has affected both the power systems and the buoy's wave response and sea-keeping ability. During spring and summer seasons, the productive waters of the Gulf of Maine often present a severe biofouling challenge, particularly to the optical sensors. The reality of the Integrated Ocean Observing System (IOOS) movement is that the conditions during which real-time data may be of greatest value, in terms of marine safety and search and rescue, correspond to the times of greatest difficulty in obtaining and transmitting those data. Similarly, the optical data are often of greatest interest during the season of highest productivity and biofouling. GoMOOS scientists and engineers have experienced successes and failures, and have developed strategies for dealing with environmental stresses to the sensors and systems.