Southern Ocean’s role in climate regulation, ocean health goal of $21 million federal grant

Sept. 9, 2014
The Southern Ocean that encircles Antarctica lends a considerable hand in keeping Earth’s temperature hospitable, accounting for half of the ocean’s uptake of human-made carbon from the atmosphere and the majority of its uptake of heat. Yet, the inner workings — and global importance — of this ocean that accounts for 30 percent of the world’s ocean area remains relatively unknown to scientists, as observations remain hindered by dangerous seas.

Princeton University(Link is external) and 10 partner institutions now seek to make the Southern Ocean better known scientifically and publicly through a $21 million program that will create a biogeochemical and physical portrait of the ocean using hundreds of robotic floats deployed around Antarctica and an expanded computational capacity. The Southern Ocean Carbon and Climate Observations and Modeling program(Link is external), or SOCCOM, is a six-year initiative headquartered at Princeton and funded by the National Science Foundation’s Division of Polar Programs(Link is external), with additional support from the National Oceanic and Atmospheric Administration(Link is external) (NOAA) and NASA(Link is external). 

“SOCCOM will enable top scientists from institutions around the country to work together on Southern Ocean research in ways that would not otherwise be possible,” said SOCCOM director Jorge Sarmiento(Link is external), Princeton’s George J. Magee Professor of Geoscience and Geological Engineering and director of the Program in Atmospheric and Oceanic Sciences.

“The scarcity of observations in the Southern Ocean and inadequacy of earlier models, combined with its importance to the Earth’s carbon and climate systems, means there is tremendous potential for groundbreaking research in this region,” Sarmiento said.

Central to the program are roughly 200 floats outfitted with biogeochemical sensors that will provide almost continuous information related to the ocean’s carbon, nutrient (nitrate, in particular) and oxygen content, both at and deep beneath the surface. The floats are augmented biogeochemical versions of the nearly 4,000 Argo floats deployed worldwide to measure ocean salinity and temperature. SOCCOM marks the first large-scale deployment of these biogeochemical floats.

“These floats are revolutionary and this major new observational initiative will give us unprecedented year-round coverage of biogeochemistry in the Southern Ocean,” Sarmiento said.

The floats will increase the monthly data currently coming out of the Southern Ocean by 10 to 30 times, Sarmiento said. That data will be used to improve recently developed high-resolution earth-system models, which will allow for a better understanding of the Southern Ocean and for better projections of Earth’s climate and biogeochemical trajectory. In keeping with SOCCOM’s knowledge sharing, or “broader impacts,” component, all the information collected will be freely available to the public, researchers and industry.

SOCCOM will provide direct observations to further understand the importance of the Southern Ocean as suggested by models and ocean studies. Aside from carbon and heat uptake, models have indicated that the Southern Ocean delivers nutrients to lower-latitude surface waters that are critical to ocean ecosystems around the world. In addition, the impacts of ocean acidification as levels of carbon dioxide in atmosphere increase are projected to be most severe in the Southern Ocean.

Other than administering the project, Sarmiento and other Princeton researchers will co-lead the modeling and broader impacts components, as well as coordinated data management. Researchers from NOAA’s Geophysical Fluid Dynamics Laboratory(Link is external) housed on Princeton’s Forrestal Campus will carry out high-resolution earth-system simulations in support of the modeling effort, which is led by the University of Arizona(Link is external) and includes collaborators from the University of Miami(Link is external).

The floats will be constructed at the University of Washington(Link is external) with sensors from the Monterey Bay Aquarium Research Institute(Link is external); NOAA’s Climate Program Office(Link is external) will provide half of the basic Argo floats. Float deployment, observation analysis and data assimilation will be led by the Scripps Institution of Oceanography(Link is external) at the University of California-San Diego. Climate Central, a non-profit science and journalism organization based in Princeton, will oversee the broader-impacts component. Researchers from Oregon State University(Link is external) and NOAA will develop the floats’ carbon algorithms.

In addition, NASA will support a complementary project involving researchers at the University of Maine(Link is external) and Rutgers University(Link is external) that will equip the floats with bio-optical sensors intended to gather data about biological processes in the water column.