Carbon dioxide sink in the Arctic Ocean from cross-shelf transport of dense Barents Sea water

Abstract Large amounts of atmospheric carbon can be exported and retained in the deep sea on millennial time scales, buffering global warming. However, while Barents Sea is one most biologically productive areas Arctic Ocean, retention times were thought to short. Here we present observations, complemented by numerical model simulations, that revealed a widespread lateral injection approximately 2.33 kt C d −1 from shelf some 1,200 m Nansen Basin, driven Bottom Water transport. With increasing distance outflow region, plume expanded penetrated into even deeper waters sediment. The seasonally fluctuating but continuous increases sequestration 1/3 feeds community Basin. Our findings combined with those other regions carbon-rich polar dense highlight importance as sink. Resolving uncertainties around negative feedbacks warming due ice decline will necessitate observation changes bottom water formation biological productivity at resolution high enough quantify future injection.