The Ocean Observatories Initiative (OOI) is a National Science Foundation (NSF) Major Research Facility composed of a network of science-driven ocean observing platforms and sensors in the Atlantic and Pacific Oceans. This networked infrastructure measures physical, chemical, geological, and biological variables from the seafloor to the sea surface and overlying atmosphere, providing an integrated data collection system on coastal, regional and global scales. OOI's goal is to deliver data and data products for a 25-year-plus time period, enabling a better understanding of ocean environments and critical ocean issues.
History As early as 1987, the ocean sciences community began discussions about the science, design concepts, and engineering of ocean research observatories, leading to the formation of the International Ocean Network (ION) in 1993. The ION national committee was formed in 1995 and later expanded into the Dynamics of Earth and Ocean Systems (DEOS) committee, tasked with providing a focus for exploratory planning for an ocean observatory network. In 2003 the Pew Oceans Commission recommended changes designed to improve society's use and stewardship of, and impact on, the coastal and global ocean.
Momentum for research-oriented ocean observing built with two National Research Council (NRC) studies in 2000 and 2003 ("Illuminating the Hidden Planet: The Future of Seafloor Observatory Science" and "Enabling Ocean Research in the 21st Century" ), and a series of community workshops. In 2000, the National Science Board (NSB) approved the OOI as a potential Major Research Equipment and Facilities Construction project for inclusion in a future National Science Foundation budget, which allowed for focused planning efforts.
In 2004, the NSF Division of Ocean Sciences (NSF OCE) established the OOI Project Office under the Ocean Research Interactive Observatory Network (ORION) to coordinate further OOI planning between two independent but complementary groups, Joint Oceanographic Institutions (JOI) and Consortium for Ocean Research and Education (CORE). The Program Office subsequently transitioned solely to JOI, which then merged with CORE to form the Consortium for Ocean Leadership in 2007. In 2005, the OOI Project Office asked for the ocean research community's help in developing the OOI network design by soliciting Request for Assistance (RFA) proposals that resulted in 48 proposals, representing the thoughts and ideas of more than 550 investigators and direct participants, and the involvement of over 130 separate educational and research institutions. Using the responses from the RFA process and associated review results, the OOI ORION Project Office and the external Science & Technical Advisory Committee developed an initial Conceptual Network Design (CND) for the OOI, which then served as the focus of an OOI Design and Implementation Workshop in March 2006.
In August 2006, NSF convened a Conceptual Design Review (CDR) to assess the project's technical feasibility and budget, the Project's Management Plan, including schedules and milestones, and education and outreach plans. The CDR Panel affirmed that the OOI, as proposed, would transform oceanographic research in the coming decades, and that the CND provided a good starting point for developing the OOI network.
Further refinement of the design based on engineering best-practices and financial reviews caused the initial CND to be revisited. The OOI Project Office working with the OOI advisory committees, consisting of unconflicted members of the community, and in consultation with NSF, then generated a revised CND.
In 2007, the National Science and Technology Council's Joint Subcommittee on Ocean Science and Technology developed an Ocean Research Priorities Strategy (ORPS), which provides a research investment framework to advance understanding of ocean processes and interactions that facilitate responsible use of the ocean environment. The ORPS identified three cross-cutting elements, one of which is ocean observing for research and management.
In late 2007, the OOI project completed its Preliminary Design Review and in 2008 completed its Final Network Design Review resulting in the Final Network Design. In May 2009, the National Science Board authorized the Director of NSF to award funds for the construction and initial operation of the OOI. In September 2009, NSF and the Consortium for Ocean Leadership signed a Cooperative Agreement that initiated the construction phase of the OOI.
Locations of OOI's global arrays were selected by a team of roughly 300 scientists to target regions that were under-sampled and subject to extreme conditions (e.g., high winds and sea states) that were challenging for continuous or even frequent ship-based measurements. The originally planned global study sites include instrumented moorings and gliders in four locations: Argentine Basin, Irminger Sea, Southern Ocean, and Station Papa.
The first year of funding under the cooperative agreement supported a range of construction efforts performed by the Marine Implementing Organizations (Woods Hole Oceanographic Institution, University of Washington, and Oregon State University), including production, engineering, and prototyping of key coastal and open-ocean components (moorings, buoys, sensors), award of the primary seafloor cable contract, completion of a shore station for power and data, and software development for sensor interfaces to the network. Subsequent years of funding supported the design, build, and deployment of coastal, deep-ocean, and seafloor systems.
The OOI was commissioned and accepted by the NSF in 2016 and data from more than 900 sensors at the seven sites became freely available for download in and near-real time online. The annual budget is approximately $44 million.
In 2018, in keeping with some of the recommendations laid out in Sea Change: 2015-2025 Decadal Survey of Ocean Sciences, the Argentine Basin Array was descoped and the Southern Ocean Array was reduced in scope to the surface mooring only, which was later removed in 2020. All OOI data collected at the Argentine Basin and Southern Ocean sites continue to be served on the OOI website.
In October 2018, the Program Management Office of the OOI shifted from the Consortium for Ocean Leadership to the Woods Hole Oceanographic Institution.
In May 2026, the National Science Foundation began retrieving the buoys and shutting down the program under the Trump administration. The Senate had previously restored the funding twice and then opposed the dismantling. The effort was stopped in mid-June and the buoys already removed would be serviced and returned to the ocean.
Organizational structure The OOI Program is managed and coordinated by the OOI Project Office at the Woods Hole Oceanographic Institution (WHOI), with four organizations responsible for operations and maintenance of specific components of the OOI system.
Woods Hole Oceanographic Institution is responsible for the Coastal & Global Scale Nodes, which includes the Coastal Pioneer Array and two Global Arrays, including their associated moorings, autonomous vehicles, and sensors. Oregon State University is responsible for the Coastal Endurance Array moorings, autonomous vehicles, and sensors. University of Washington is responsible for the Regional Cabled Array, including its cabled seafloor systems, moorings, and sensors. Oregon State University is responsible for the OOI data center.
Themes The sites and platforms of the OOI components target the following key scientific processes:
Ocean-atmosphere exchange Quantifying the air-sea exchange of energy and mass, especially during high winds (greater than 20 meters-per-second), is critical to providing estimates of energy and gas exchange between the surface and deep ocean and improving the predictive capability of storm forecasting and climate change models.
Climate variability, ocean circulation and ecosystems Climate variability affects ocean circulation, weather patterns, the ocean's biochemical environment and marine ecosystems. Understanding how these processes change in current and future conditions is a key motivation for collecting multidisciplinary observations.
Turbulent mixing and biophysical interactions Turbulent mixing plays a critical role in the transfer of materials within the ocean and in the exchange of energy and gases between the ocean and atmosphere. Horizontal and vertical mixing within the ocean can have a profound effect on a wide variety of biological processes.
Coastal ocean dynamics and ecosystems The coastal ocean is host to a variety of dynamic and heterogeneous processes, including human influences, which often strongly interact. Better understanding of these complex and intertwined relationships and their impacts will aid mastery and management of coastal resources in a changing climate.
Plate-scale, ocean geodynamics Active tectonic plate boundaries influence the ocean from physical, chemical and biological perspectives to varying degrees. Lithospheric movements and interactions at plate boundaries at or beneath the seafloor are responsible for short-term events such as earthquakes, tsunamis and volcanic eruptions. These regions are also host to the densest hydrothermal and biological activity in the ocean basins.
Fluid-rock interactions and the subseafloor biosphere The oceanic crust contains the largest aquifer on Earth and supports a vast deep biosphere. Thermal circulation and reactivity of seawater-derived fluids can modify the composition of oceanic plates, lead to the formation of hydrothermal vents that support unique micro- and macro-biological communities and concentrate methane to form massive methane gas and methane hydrate reservoirs.
Components The OOI is composed of two coastal arrays (Coastal Pioneer Array and Coastal Endurance Array), two global arrays (Global Irminger Sea Array and Global Station Papa Array), the Regional Cabled Array (RCA), and Cyberinfrastructure. Data continue to be served from the discontinued arrays in the Argentine Basin and Southern Ocean.
Coastal and Global Arrays Coastal arrays provide sustained, adaptable access to complex coastal systems. Coastal arrays extend from the continental shelf to the continental slope, allowing scientists to examine coastal processes including upwelling, hypoxia, shelf break fronts, and the role of filaments and eddies in cross-shelf exchange. Technologies that gather data in the coastal region include moored buoys with fixed sensors, moored vertical profilers, seafloor cables, gliders and autonomous underwater vehicles.
The coastal observatory includes a long-term Endurance Array in the Eastern Pacific and a re-locatable Pioneer Array in the Western Atlantic. Woods Hole Oceanographic Institution installed and operates the Pioneer Array. Oregon State University installed and operates the Endurance Array.
There are two global arrays currently in operation (Global Irminger Sea Array and Global Station Papa Array). The Argentine Basin and the Southern Ocean Arrays were removed, but their data remain available through OOI's data portal.
Coastal Pioneer Array
The Coastal Pioneer Array is a network of platforms and sensors that operate on the continental shelf and slope south of New England. A moored array was centered at the shelf break in the Mid-Atlantic Bight south of Cape Cod, Massachusetts. In 2024, the Coastal Pioneer Array was relocated to the southern Mid-Atlantic Bight, between Cape Hatteras and Norfolk Canyon off the coast of North Carolina.