Oceanic uptake of atmospheric carbon dioxide depends on climatically sensitive physical factors, such as winds and ocean currents, reports a study published online in Nature Geoscience this week. The oceans slow the rate of climate change by absorbing around 25% of the carbon dioxide emitted by human activities each year, but the exact mechanism of uptake has remained unclear. The current findings suggest that this uptake could potentially be sensitive to climate variability and change.

Jean-Baptiste Sallee and colleagues examined the physical processes governing the sequestration of carbon dioxide in the Southern Ocean, using observation-based estimates of water mass movements and carbon dioxide concentrations. They show that human-derived carbon dioxide is transported into the ocean interior at specific locations in the Southern Ocean, due to the interplay between currents, winds and local mixing.