Tracing upper waters of the Nansen Basin in the Arctic Ocean

Measurements of chemical tracers obtained during the 1987 cruise of F.S. Polarstern across the Nansen Basin of the Arctic Ocean are used to suggest the general flow of upper waters in the Arctic Ocean. In surface water, total carbonate concentrations distinguish between a northern freshwater component whose origin is river run-off and a southern freshwater component whose origin is sea ice meltwater. Below the surface layer, sub-surface water formed in the Barents-Kara Seas with low concentrations of “NO” must divide, some flowing with the Atlantic layer to the east and north before flowing in the same direction as the Transpolar Drift to Fram Strait, and some flowing to the west and south. The former characterizes the lower halocline water observed at the CESAR and LOREX ice camps in the central Arctic Ocean. The latter can be traced in a general way to Fram Strait where the two meet and the two low NO waters merge.