London, July 31 (IANS) The Southern Ocean re-routes as much as 40 percent of the annual global carbon dioxide (CO2) emissions, helping the world’s oceans absorb them, according to a UK survey.
It’s the combination of winds, currents and eddies that create these carbon-capturing pathways, drawing waters down into the deep ocean from the ocean surface.
Human activities are altering the carbon cycle — both by adding more CO2 to the atmosphere and by influencing the ability of natural sinks, like forests and oceans, to remove CO2 from the atmosphere, thus contributing to global warming and climate change.
Due to the size and remote location of the Southern Ocean, scientists have only recently been able to explore the workings of the ocean with the help of small robotic probes – known as Argo floats, the journal Nature Geoscience reports.
In 2002, 80 floats were deployed in the Southern Ocean to collect information on the temperature and salinity. This unique set of observations spanning 10 years has enabled scientists to investigate this remote region of the world for the first time, according to a British Antarctic Survey (BAS) statement.
The floats are just over a metre in length and dive to depths of two km. Today, there are over 3,000 floats in the oceans worldwide providing detailed information used in oceanic climate models.
Scientists from the BAS and Australia’s national research agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), reveal that rather than carbon being absorbed uniformly into the deep ocean in vast areas, it is drawn down and locked away from the atmosphere by plunging currents a thousand kilometres wide.
Jean-Baptiste Sallee from BAS says: “The Southern Ocean is a large window by which the atmosphere connects to the interior of the ocean below. Until now we didn’t know exactly the physical processes of how carbon ends up being stored deep in the ocean.”
