Scientists unlock ocean CO2 secrets key to climate: study

The team of British and Australian scientists found that currents that take carbon from the surface to the depths occur at specific locations, not uniformly across the ocean as previously thought.

They found that a combination of winds, currents and whirlpools create conditions for carbon to be drawn down into the deep ocean to be locked away for decades to centuries. Some of the plunging currents were up to 1,000 km (600 miles) wide.

In other areas, currents return carbon to the atmosphere as part of a natural cycle.

But overall, the Southern Ocean is large net carbon sink, the authors say, calculating the area between 35 and 65 degrees south takes up the equivalent of 1.5 billion tonnes of CO2 a year, or more than the annual greenhouse gas emissions of Japan.

Scientists worry that a warming planet could disrupt this natural pattern by changing wind patterns and ocean currents.

Matear said by figuring how the Southern Ocean worked and using a new monitoring network of robotic ocean-going devices researchers will get a much better handle on how the seas between Australia and Antarctica are changing.