The Ross Sea, an anthropogenic CO2 sink affected by climate change
A recent paper investigates physical and biological controls on anthropogenic CO2 (Cant) sink of the Ross Sea during the summer season through the integration of carbonate system observations with biogeochemical properties of the water masses. It was published in Frontiers in Marina Science by an international team including OGS researchers.
The results suggest that summer biological activity over the Ross Sea shelf is pivotal for the shunt of anthropogenic CO2 between the organic and inorganic carbon pools, enhancing the ocean acidification of the upper mesopelagic zone and the long-term anthropogenic CO2 sequestration into the deep ocean.
The Antarctic continental shelf is known as a critical Cant sink due to its cold waters, high primary productivity, and unique circulation, which allow it to sequester large amounts of organic and inorganic carbon into the deep ocean. However, climate change is currently causing significant alteration to the Antarctic marine carbon cycle, with unknown consequences on the Cant uptake capacity, making model-based estimates of future ocean acidification of polar regions highly uncertain.
Improved understanding of anthropogenic carbon dynamics and sink capacity of the coastal Southern Ocean to future environmental changes (i.e., increased atmospheric CO2, rising temperatures, sea-ice reduction, ocean circulation change, and modification of biological CO2 drawdown) will require intensified long-term observations of the carbonate system and ocean biogeochemistry to be combined into holistic models.