Decrease in the CO_2 Uptake Capacity in an Ice-Free Arctic Ocean Basin

摘要

It has been predicted that the Arctic Ocean will sequester much greater amounts of carbon dioxide (CO_2)rnfrom the atmosphere as a result of sea ice melt and increasing primary productivity. However,rnthis prediction was made on the basis of observations from either highly productive ocean margins orrnice-covered basins before the recent major ice retreat. We report here a high-resolution surveyrnof sea-surface CO_2 concentration across the Canada Basin, showing a great increase relative to earlierrnobservations. Rapid CO_2 invasion from the atmosphere and low biological CO_2 drawdown are the mainrncauses for the higher CO_2, which also acts as a barrier to further CO_2 invasion. Contrary to the currentrnview, we predict that the Arctic Ocean basin will not become a large atmospheric CO_2 sink underrnice-free conditions.