Carbon dioxide levels influenced by winds around Antarctica

Ancient fossil coral skeletons in the Drake Passage reveal that wind conditions influence ocean circulation and carbon dioxide release into the atmosphere, according to an international team involving UCL researchers. The discovery suggests that future climate change could lead to increases in the release of carbon dioxide (CO₂) from deep waters of the Southern Ocean into the atmosphere. The study, published in Proceedings of the National Academy of Sciences , analysed fossil coral skeletons to reveal that significant changes in deep water circulation occurred in the Drake Passage, a narrow strait between Antarctica and South America, around six to seven thousand years ago. The sea encircling Antarctica acts as a huge mixer for water from all the ocean basins, so what happens there is critical for the global conveyor belt of ocean currents, which distributes heat, salt, nutrients, and CO₂ over great distances. It is one of the few places on Earth where water from great depths rises to the surface and at the same time surface water sinks. This circulation pattern influences the exchange of carbon dioxide between the ocean and the atmosphere. The new study involving Dr David Wilson from UCL Earth Sciences and led by Dr Torben Struve from the University of Oldenburg, shows that this complex equilibrium of water masses reacts highly sensitively to wind conditions over the Southern Ocean, influencing CO₂ levels in the atmosphere.