Researchers from the British Antarctic Survey (BAS) and the Commonwealth Scientific and Industrial Research Organisation in Australia found 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.
The Southern Ocean acts as an important carbon sink as around 40 per cent of the annual global carbon dioxide (CO2) absorbed by the world's oceans enter through this region.
Until now it was not known exactly how carbon ends up being stored deep in the ocean. 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.
"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," Jean-Baptiste Sallee from BAS said.
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.
In 2002, 80 floats were deployed in the Southern Ocean to collect information on the temperature and salinity, according to a BAS statement.
"Now that we have an improved understanding of the mechanisms for carbon draw-down we are better placed to understand the effects of changing climate and future carbon absorption by the ocean," he added.
The study was published in journal Nature Geoscience.