Climate researchers have never before had such an expansive look at the enigmatic Southern Ocean. This area is key to global ocean circulation and one of our planet’s largest carbon sinks. Consequently, for years researchers have found it difficult to collect measurements in this domain. The heavy Arctic sea ice has made it very difficult to even reach these areas. A recent study utilizing 212 autonomous BGC-Argo floats has provided new insights into carbon export across the Southern Ocean basin.
The Southern Ocean is critical to maintaining the Earth’s climate. It is home to one of the largest carbon sinks on earth. It stores more than 32 billion metric tons of atmospheric carbon dioxide. Despite its importance, the complexities of this ocean region have made it difficult for scientists to gather accurate data on its carbon export mechanisms.
BGC-Argo Floats Revolutionize Data Collection
The BGC-Argo floats are emblematic of a new era in state, federal, and international oceanographic research. These autonomous instruments freely surf their way around the upper 2,000 meters of the ocean. They are uniquely built to navigate under sea ice, allowing for data collection in places that were once beyond reach. The sophisticated sensors on the floats continuously take measurements of physical and biogeochemical properties of seawater. This data provides us a holistic snapshot on the health of our ocean.
From 2014-2022, pilot Guillaume Liniger and his team used every ounce of data collected by these floats. They were hands on in monitoring and measuring carbon export across the Southern Ocean. Overall, the researchers developed an innovative new way to estimate carbon export. They were able to do this by examining sinking particulate organic carbon and tracking changes in dissolved oxygen through time. This out-of-the-box thinking made it possible for them to measure how much carbon is being sequestered to the deep sea.
“Fronts and all BGC-Argo profile locations with co-located backscatter and dissolved oxygen data used in this study.” – Source from Global Biogeochemical Cycles
Insights into Carbon Dynamics
The findings reveal that the Southern Ocean exports approximately 2.69 billion tons of carbon to the deep sea each year. The new study shows that carbon export can be quite different from one region of the Southern Ocean to the next. A surprising little amount, less than 8%, of this carbon export occurs within seasonally ice-covered regions. This simple fact opens up amazing questions regarding what is happening behind the scenes in these extraordinary settings.
It is evident from their results that regions with sea ice pose unique challenges and opportunities for understanding and modeling carbon export. When ice melts and moves, they change the biological processes that allow carbon to sink. Knowing the basis for these differences is key to forecasting how climate change will affect carbon cycling in the years to come.
Implications for Climate Science
The new steps taken by the proactive application of BGC-Argo floats come with large implications for understanding climate change impacts and general ocean health. By providing detailed measurements of carbon export, scientists can better model the role of the Southern Ocean in global climate regulation.
These perspectives couldn’t come at a better time, as the impacts of climate change begin to take hold. With an improved understanding of how oceans absorb and store carbon, researchers can make more informed predictions about future climate scenarios. The Southern Ocean’s role as a carbon sink is essential for mitigating climate change impacts, making studies like this crucial.
