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The Ocean Observatories Initiative (OOI) is a National Science Foundation (NSF) funded set of ocean observing arrays whose data are free to anyone. This guide is for researchers who want to find OOI data, cite it correctly, and understand what the 2026 descoping means for data they already use. Status statements below reflect the OOI website pages read on 2026-11-07.
What the Ocean Observatories Initiative is
OOI is described by its own site as a major facility fully funded by the U.S. National Science Foundation. It delivers real-time and archived data from more than 900 instruments deployed across ocean arrays, and the data are free to use. The OOI website lists eleven arrays: Global Irminger Sea, Global Station Papa, Global Argentine Basin, Global Southern Ocean, Coastal Endurance, Coastal Pioneer Mid-Atlantic Bight, Coastal Pioneer New England Shelf, Regional Cabled, Cabled Continental Margin, Cabled Axial Seamount and Cabled Endurance. The site’s map notes that some arrays have been discontinued, so the list describes the program’s history as well as its current footprint.
Who runs it and what it covers
NSF funds OOI. The recommended acknowledgement wording names the Woods Hole Oceanographic Institution (WHOI) OOI Program Office alongside NSF, and cites Cooperative Agreement No. 2244833. The array names show three families: Global, Coastal (Endurance and Pioneer) and Regional Cabled (including the Cabled Continental Margin, Axial Seamount and Endurance arrays). The Regional Cabled Array provides real-time data, while the Coastal and Global arrays provide telemetered and recovered data.
How to find and access OOI data
OOI data are reached through several routes. The sign-in for the Data Portal is on the OOI website; it uses a home-organisation account (through CILogon) or a local OOI account.
- Open the Data Portal from the OOI site’s data section.
- Search by location, time and ocean parameter.
- Plot and visualise the results in the portal.
- Note which kind of data you are using: the Regional Cabled Array provides real-time data, while Coastal and Global arrays provide telemetered and recovered data.
- For quick plots, use the separate Data Explorer at dataexplorer.oceanobservatories.org.
- For tutorials, FAQs and the Data HelpDesk, use the OOI Knowledge Base and help pages.
The OOI citation page also names the Raw Data Archive, THREDDS and the machine-to-machine (M2M) API as access routes. Water sampling data are also available through BCO-DMO, the Biological and Chemical Oceanography Data Management Office.
How to cite and acknowledge OOI data
OOI asks users to acknowledge OOI, cite the data, and acknowledge NSF. The wording OOI provides is: “This material is based upon work supported by the Ocean Observatories Initiative (OOI), a major facility fully funded by the US National Science Foundation under Cooperative Agreement No. 2244833, and the Woods Hole Oceanographic Institution OOI Program Office.”
Since 2025 OOI assigns DOIs to Platforms, and users cite the subset of data they used. The Platform and Node DOIs are listed on the OOI Platforms and Nodes page. Citations follow ESIP guidelines, with these elements:
- Author: NSF OOI
- Publication date (see the table below)
- Platform title
- Instruments and data products used, with their reference designators (found in the Data Explorer under More information or the Source tab)
- Date range of the data used
- Repository and URL
- Platform DOI
- Access date, written YYYY-MM-DD
| Where you obtained the data | Date to use as publication date |
|---|---|
| Data Portal or M2M API | The access date |
| Raw Data Archive, THREDDS or Data Explorer ERDDAP | The last-modified date |
| Cruise data | The date in the README or filename |
A DOI is a kind of persistent identifier, and the pattern above is an instance of repository citation. See also the FAIR data principles for why reference designators and date ranges matter for reuse.
2026 descoping and data continuity
On 22 May 2026 the OOI site posted an update stating that NSF had initiated a major descoping of the program, phased over roughly 15 months. As stated in that notice:
| Array | Recovery timing stated in the notice |
|---|---|
| Endurance | Final recovery June 2026 |
| Pioneer | Planned June 2027 |
| Irminger and Station Papa | Summer 2027, subject to ship scheduling |
| Regional Cabled Array | Not listed for recovery; operates through 30 September 2028 |
Real-time streams end when an array’s infrastructure is recovered. The notice states that all previously collected OOI data will remain accessible through the OOI Data Center, and that the Data Center, the Program Management Office and Community Engagement continue through 30 September 2028. The OOI home page also carried news items dated 30 July 2026 and 23 October 2026 about the Endurance Array redeployment. Because the situation has changed more than once, check the OOI news page for the current state before building a project on a specific array.
Strengths and limits
- Strength: open access. Data are free to anyone, with a stated citation and acknowledgement pattern.
- Strength: DOIs on Platforms allow citing exactly the subset of data used.
- Strength: continuity of the archive. The descoping notice says previously collected data stay accessible.
- Limit: no new data after recovery. Real-time streams end when infrastructure is recovered, so long time series on an affected array stop on its recovery date.
- Limit: account needed for the Data Portal, though the Data Explorer is a separate tool.
Related data routes
| Route | What the OOI pages say it is for |
|---|---|
| Data Portal | Search by location, time and parameter, then plot; requires sign-in |
| Data Explorer | Separate OOI tool; source of reference designators for citation |
| Raw Data Archive, THREDDS, M2M API | Named on the citation page as access routes with their own date convention |
| BCO-DMO | Also holds OOI water sampling data |
For marine biodiversity records rather than sensor data, see the guide to OBIS, the Ocean Biodiversity Information System. For the wider field, see what marine biology is.
FAQ
What is OOI data?
OOI data are measurements from the 900+ instruments on OOI arrays, available free through the Data Portal, Data Explorer and other routes, with real-time data from the Regional Cabled Array and telemetered or recovered data from Coastal and Global arrays.
What is the OOI “major facility”?
The OOI describes itself as a major facility fully funded by the U.S. National Science Foundation, which is why acknowledgements name NSF and Cooperative Agreement No. 2244833.
Are ocean sensors being removed?
The OOI’s 22 May 2026 update says NSF initiated a descoping, with array recoveries phased over about 15 months, while the Regional Cabled Array is not listed for recovery and operates through 30 September 2028. Previously collected data remain accessible.
How do I cite OOI data?
Acknowledge OOI and NSF, cite the Platform DOI for the subset you used, and include reference designators, date range, repository URL and access date, as described above.
Sources
- Ocean Observatories Initiative home page, oceanobservatories.org (read 2026-11-07)
- OOI Data Portal page, oceanobservatories.org/data-portal/ (read 2026-11-07)
- OOI, How to use, acknowledge and cite data, oceanobservatories.org/data/how-to-use-acknowledge-and-cite-data/ (read 2026-11-07)
- OOI, NSF OOI descoping update for the community, 22 May 2026, oceanobservatories.org/2026/05/nsf-ooi-descoping-update-for-the-community/ (read 2026-11-07)
