Abstract: In summer 2007 we have established a new atmospheric monitoring station in Ivittuut (61.21°N, 48.17°W), on the western coast of South Greenland. The motivation for choosing this location was to study the role of the North Atlantic Ocean in the global and regional carbon cycle and to add a continuous measurement site in a still uncovered area. This work is part of the EU CarboOcean IP project, and was endorsed by the International Polar Year through the Polarcat project.
High precision CO2 and O2 analyzers have been developed at LSCE and installed on site together with meteorological sensors. Regular flask samples are done and independently analyzed at LSCE and MPI-BGC for quality control, and to provide complementary trace gases and isotopic measurements. Since September 2007, continuous measurements of CO2 and O2 have been recorded.
We will present the Ivittuut continuous CO2 and O2 data as well as the flask measurements, and compare both data sets to illustrate their reliability and precision. A preliminary data filtering attempt based on meteorological criteria (wind speed and direction) used to identify the origin of air masses (and corresponding CO2 and O2 concentration levels) will be compared to back trajectories from the Hysplit4 model. Concurrent measurements of atmospheric CO2 and O2 allow to calculate the Atmospheric Potential Oxygen (APO), a tracer of air-sea gas exchange of O2, and from which, given certain assumptions, the strength of marine biological activity can be elucidated. A comparison of the data-derived APO and the one obtained with the OPA-PISCES coupled ocean circulation/biogeochemical model will be presented. Based on our APO results, we will suggest an estimate of oceanic and land biotic carbon fluxes.