The goal of this project is to develop and deploy seafloor marine observatories called OceanCubes in mid and high latitudes where upwelling of cold, nutrient rich and hypoxic water is expected on a seasonal basis. The control volume design allows for measurement of the flux of materials and energy from the water column to the benthos at a rate of several times per minute. Currently, OceanCubes are being proposed for a variety oflocations in Japan, Panama, India, the Antarctic and Arctic.
Each of the observatories will consist of an instrument package on the seafloor ~2 km from a research station at a depth of about 20 m (Fig. 1). The package will be connected by electro-optical cable to shore providing the capability for internet-based teleoperation by scientists from anywhere in the world. The main observatory node will consist of a CTD to measure temperature, salinity, and pressure, and ADCP current meter, sensors for chlorophyll and CDOM fluorescence, oxygen, nitrate, pCO2, pH, a bio-optical package for irradiance and radiance, a Continuous Plankton Imaging and Classification Sensor (CPICS), a phytoplankton and microplankton imaging system, and two panand tilt stereo cameras to observe fish communities. The node will be located in the center of a control volume through which the flux of material (plankton, carbon, energy) will be measured. The control volume will be established with temperature strings and Acoustic Doppler Current Profiler (ADCP) sensors at each corner 100m on a side.
The node, and its sensors will be part of an extensive underwater Local Area Network (LAN) with each sensor provided with an exclusive IP address. All data from the sensors and cameras will stream back to shore in Ethernet format where computers will log the data and provide initial processing. The database will consist of a database backbone so efficient queries can be made over the internet. A second set of computers will then access the database and images and provide a primary level of Quality Control and processing. All data both raw and processed will be accessible over the internet through a web-enabled Graphical User Interface (GUI).
The OceanCube observatories will provide year-round biological and physical data to support both educational and research objectives related to understanding biodiversity, biophysical and geochemical processes, particularly Ocean Acidification and its impact on coral reef communities.
To study carbonate saturation state and the impact of Ocean Acidification on coral reef systems, information on four primary variables (total dissolved inorganic carbon, total alkalinity, carbon dioxide, and pH) are required. Thermodynamic relationships between these variables allow for the measurement of two variables and the calculation of the other two. The OceanCube observatories will measure pH and pCO2 thereby allowing inorganic carbon and alkalinity to be calculated.
They will also monitor primary (phytoplankton and chlorophyll) and secondary (mesoplankton and fish) production to provide a means for observing the impact of corrosive water on coral communities. Measurements of these variables and parameters within a control volume where the motion of water through the volume will be known, will allow calculation of a flux of carbon cycle materials through the volume and into the benthos. The observatories are designed to provide for expansion by adding experimental sensors, such as for alkalinity and total dissolved carbon as they become available. This unique approach to measuring components of the carbon cycle at high frequencies comparatively between many sites, globally, will provide a transformative view of the impact of Ocean Acidification on coral reef dynamics.
OceanCube Observatories are made up of Woods Hole Oceanographic Institution engineers, biologists, and chemists who have a vision of observing pieces of the ocean at a very high resolution in order to answer scientific question we could never answer before. Each OceanCube has a unique set of collaborators dedicated to the operations, data use, and success of their OceanCube observatory. For contact info please see the "PEOPLE" section to the right.