Uptake and sequestration of atmospheric CO 2 in the Labrador Sea deep convection region

The Labrador Sea is an important area of deep water formation and is hypothesized to be a significant sink for atmospheric CO 2 to the deep ocean. Here we examine the dynamics of the CO 2 system in the Labrador Sea using time‐series data obtained from instrumentation deployed on a mooring near the former Ocean Weather Station Bravo. A 1‐D model is used to determine the air‐sea CO 2 uptake and penetration of the CO 2 into intermediate waters. The results support that mixed‐layer p CO 2 remained undersaturated throughout most of the year, ranging from 220 μ atm in mid‐summer to 375 μ atm in the late spring. Net community production in the summer offset the increase in p CO 2 expected from heating and air‐sea uptake. In the fall and winter, cooling counterbalanced a predicted increase in p CO 2 from vertical convection and air‐sea uptake. The predicted annual mean air to sea flux was 4.6 mol m −2 yr −1 resulting in an annual uptake of 0.011 ± 0.005 Pg C from the atmosphere within the convection region. In 2001, approximately half of the atmospheric CO 2 penetrated below 500 m due to deep convection.