The polar ocean and glacial cycles in atmospheric CO_2 concentration

摘要

Global climate and the atmospheric partial pressure of carbon dioxide (p_((CO)_2)~(atm))) are correlated over recent glacial cycles, with lower p_((CO_2)~(atm)) during ice ages, but the causes of the p_((CO)_2)~(atm)) changes are unknown. The modern Southern Ocean releases deeply sequestered CO_2 to the atmosphere. Growing evidence suggests that the Southern Ocean CO_2 'leak' was stemmed during ice ages, increasing ocean CO_2 storage. Such a change would also have made the global ocean more alkaline, driving additional ocean CO_2 uptake. This explanation for lower ice-age p_((CO)_2)~(atm)), if correct, has much to teach us about the controls on current ocean processes.