Carbon fluxes in the Arctic Ocean - potential impact by climate change

Because of its ice cover the central Arctic Ocean has not been considered as a sink of atmospheric carbon dioxide. With recent observations of decreasing ice cover there is the potential for an increased air-sea carbon dioxide flux. Though the sensitivity of the carbon fluxes to a climate change can at present only be speculated, we know the responses to some of the forcing, including: melting of the sea ice cover make the air-sea flux operate towards equilibrium; increased temperature of the surface water will decrease the solubility and thus the air-sea flux; and an open ocean might increase primary production through better utilization of the nutrients. The potential change in air-sea CO2 fluxes caused by different forcing as a result of climate change is quantified based on measured data. If the sea ice melts, the top 100 m water column of the Eurasian Basin has, with the present conditions, a potential to take up close to 50 g C m(-2). The freshening of the Surface water caused by a sea ice melt will increase the CO2 solubility corresponding to an uptake of similar to3 g C m(-2), while a temperature increase of 1 degreesC in the same waters will out-gas 8 g C m(-2), and a utilization of all phosphate will increase primary production by 75 g C m(-2).