Less than three decades ago only a small fraction of the Arctic Ocean
(AO) was ice free and then only for short periods. The ice cover kept
sea surface COat levels lower relative to other ocean basins that have
been exposed year round to ever increasing atmospheric levels. In this
study, we evaluate sea surface COmeasurements collected over a 6-year
period along a fixed cruise track in the Canada Basin. The measurements
show that mean COlevels are significantly higher during low ice years.
The COincrease is likely driven by ocean surface heating and uptake of
atmospheric COwith large interannual variability in the contributions of
these processes. These findings suggest that increased ice-free periods
will further increase sea surface CO, reducing the Canada Basin’s
current role as a net sink of atmospheric CO.