Spatial variability and magnitude of surface pCO2 and air-sea carbon fluxes in the Amundsen Sea Polynya, Antarctica

Abstract

The Amundsen Sea Polynya (ASP) is one of the most biologically productive regions in the Southern Ocean characterized by high air-sea CO2 gradients and carbon fluxes. In this study, partial pressure of CO2 (pCO2) in the surface waters of the ASP was determined during the early austral summer. Air-sea carbon flux was estimated using average shipboard wind measurements and compared with other studies in the same and nearby areas. The saturation states of surface pCO2 and dissolved oxygen (DO) are compared to distinguish the dominant factors (including biological activity, temperature, upwelling and sea ice coverage) determining pCO2 across different regions of the polynya. Overall, the study indicates that the entire ASP is a large net sink for atmospheric CO2 with high spatial variability, and provides further insights to the patterns of carbon cycling in a climate-sensitive Antarctic polynya.