The surface water masses in the North Atlantic region of Iceland are of contrasting origins and character, on the one hand the northward-flowing North Atlantic Drift, a Gulf Stream offspring, on the other hand southward moving cold low salinity Polar and Arctic Waters with signatures from Arctic freshwater sources. We have studied by observations, the CO₂  air-sea flux of the relevant water masses in the vicinity of Iceland in all seasons and in different years. Here we report on the flux variations associated with the three main water masses. We examine all seasons, the importance of wind strength and relations to biological nutrient cycles. The results reveal distinct differences between the three water masses. The Polar Water originating from the Arctic is a strong CO₂ sink and so is also the Arctic Water in the Iceland Sea. The annual mean flux of the Atlantic Water south and west of Iceland shows it to be a weak or neutral CO₂ sink. We discuss the Polar Water influence on the North Atlantic CO₂ sink in light of the connection to developments in the rapidly warming and changing Arctic.

Primary Presenter: Jon Olafsson, University of Iceland (jo@hi.is)

Authors:

Solveig Olafsdottir, Marine and Freshwater Research Institute  (solveig.rosa.olafsdottir@hafogvatn.is)