Was the Atlantic water temperature in the West Spitsbergen Current predictable in the 1990s?

A major source of heat (and salt) for the Arctic Ocean is the Atlantic Water (AW) imported from the Norwegian Sea by the West Spitsbergen Current (WSC). Analysis of temperature records from the WSC has helped to link the warming of the Arctic Ocean to changes in the North Atlantic Oscillation (NAO) index. Here we analyze, using summer hydrographic data from a meridional section at 15°E in the northern Norwegian Sea, the interannual variability in the AW hydrography and its relation to the NAO index in the 1990s. We show that while the AW temperature exhibited a tendency to lag the NAO index, the AW salinity exhibited a tendency to lead the index. A surprising conclusion is that the AW temperature in the WSC was predictable one year in advance from the AW salinity.