Oceanic CO2 produced by the precipitation of CaCO3 from brines in sea ice

Carbon dioxide is produced in brines formed during the growth of sea ice as a result of preferential precipitation of calcium carbonate. This process can explain the observed CO2 supersaturation in some arctic waters and could produce a CO2 flux into the ocean in ice‐covered waters of 1.5 mol m−2 y−1 or a total of 6×1013 mol y−1 for both the arctic and antarctic regions.