Carbon dynamics of the Weddell Gyre, Southern Ocean ...

• Main Authors: Brown, Peter J., Jullion, Loïc, Landschützer, Peter, Bakker, Dorothee C.E., Naveira Garabato, Alberto C., Meredith, Michael P., Torres-Valdés, Sinhue, Watson, Andrew J., Hoppema, Mario, Loose, Brice, Jones, Elizabeth M., Telszewski, Maciej, Jones, Steve D., Wanninkhof, Rik
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2015
• Subjects: Southern Ocean; Weddell Gyre; ocean carbon cycle; neural network; air-sea exchange of CO2; observations; Weddell Sea
• Online Access: https://dx.doi.org/10.3929/ethz-b-000101381; http://hdl.handle.net/20.500.11850/101381

The accumulation of carbon within the Weddell Gyre and its exchanges across the gyre boundaries are investigated with three recent full-depth oceanographic sections enclosing this climatically important region. The combination of carbon measurements with ocean circulation transport estimates from a box inverse analysis reveals that deepwater transports associated with Warm Deep Water (WDW) and Weddell Sea Deep Water dominate the gyre's carbon budget, while a dual-cell vertical overturning circulation leads to both upwelling and the delivery of large quantities of carbon to the deep ocean. Historical sea surface pCO2 observations, interpolated using a neural network technique, confirm the net summertime sink of 0.044 to 0.058 ± 0.010 Pg C yr−1 derived from the inversion. However, a wintertime outgassing signal similar in size results in a statistically insignificant annual air-to-sea CO2 flux of 0.002 ± 0.007 Pg C yr−1 (mean 1998–2011) to 0.012 ± 0.024 Pg C yr−1 (mean 2008–2010) to be diagnosed for the ... : Global Biogeochemical Cycles, 29 (3) ...