Ocean Climate Observation

The ocean moderates global temperature and atmospheric carbon dioxide, is subject to sea level rise, and plays a critical role in drought, and tropical cyclones. The Ocean Climate Observation program seeks to characterize the state of the global ocean in enough detail to understand its influence on climate variability and change.

The Ocean Climate Observation (OCO) Program sustains a global observing system to measure a range of important ocean parameters. With international partners, the program builds and maintains the in-water network of open-ocean observations around the world, contributing to the Global Climate Observing System (GCOS) and the U.S. Integrated Ocean Observing System (IOOS). OCO supports the advancement of climate science by providing high quality observational data for the climate research, modeling, and forecasting communities. OCO data and investigations also contribute to scientific climate assessments such as the Intergovernmental Panel on Climate Change (IPCC).

Every sector of society is affected by the ocean, either directly or indirectly. OCO provides benefits by delivering sustained observations that facilitate effective decision-making on climate-related issues. The OCO observing network also supports global and coastal weather and climate prediction, marine services, military applications, tsunami warning systems, and marine environmental monitoring. The majority of OCO’s work is accomplished by partners in NOAA labs and Cooperative Institutes.

High quality ocean observation data provided by the program to climate scientists include:

• Sea level changes and trends,
• Ocean temperature and salinity from the surface to 2000m depth,
• Ocean currents and circulation,
• Ocean surface winds,
• Air-sea exchanges of heat and freshwater, and
  
• Air-sea exchange of carbon dioxide, and ocean carbon uptake and storage
• Tropical oceanic and atmospheric conditions important for weather and regional climate predictions and research.

Why do we need ocean observations?

The following examples illustrate some of the value that ocean observations provide in the ongoing study and monitoring of the global climate system:

• Observed global sea level is currently rising faster than projected by models used for the IPCC. Spatially and temporally resolved data on ocean temperature and salinity are required to improve forecasting accuracy and to derive policies for mitigation and adaptation.
• Monitoring surface ocean temperature to a high degree of accuracy is fundamental to predicting El Niño Southern Oscillation and other climate variations that impact regional weather and climate including drought in the western United States.
• Oceanic currents such as the Gulf Stream and the deeper Atlantic thermohaline currents are major components of the global ocean circulation, transport great amounts of heat, and shape the climate of several continental regions.
• Monitoring ocean salinity is necessary to track the evolution of marine ecosystems habitats, and to understand and monitor changes in global precipitation and evaporation.
• International policy and national economic decisions that rest upon future projections of atmospheric greenhouse gases require accurate measurements of ocean uptake of carbon dioxide, which currently accounts for about one quarter of all human emitted CO₂.
• Depth-resolved profiles of temperature and salinity are necessary to determine ocean heat content; as much as 90% of the heat trapped in the atmosphere by human-emitted greenhouse gases is currently sequestered in the ocean, thereby slowing down the rate of global warming.  

OCO supports ongoing work to build, maintain, and operate a range of interdependent observing networks, represented by symbols on the map above. From lower left to upper right, the photographs illustrate Dedicated Ships, Tide Gauge Stations, Arctic Observing Systems, Ocean Reference Stations, Ships of Opportunity, Tropical Moored Buoys, Surface Drifting Buoys, Argo Profiling floats, and Continuous Satellite Missions for sea surface temperature, sea surface height, surface vector winds, ocean color, and sea ice. Not illustrated are Data & Assimilation Subsystems and Product Delivery. Though satellites are a critical element of this composite system, they are managed by other programs in NOAA and NASA.