Relations between salinity in the northwestern Bering Sea, the Bering Strait throughflow and sea surface height in the Arctic Ocean

摘要

The correlation between transport via the Bering Strait throughflow (BTF) and sea surface salinity (SSS) in the Bering Sea has been examined mainly using an atmosphere-ocean-ice coupled climate model that has an eddy-permitting ocean component. The SSS anomaly in the northwestern Bering Sea is high from winter to spring when the BTF transport anomaly is large in the cold season. Similar features can be seen in an observation dataset and two kinds of ocean data assimilation product. BTF transport is strongly correlated with sea surface height (SSH) in the northeastern Bering Sea, the southwestern Chukchi Sea and the East Siberian Sea. The SSH along the Russian coast in the Arctic Ocean is uncorrelated with the SSH in the Bering Sea, the meaning being that the Arctic SSH affects the BTF and the SSS independently of the SSH in the Bering Sea. The low SSH along the Siberian coast is correlated with easterly wind anomalies over the Laptev Sea and north of the New Siberian Islands. The relationship between the low Siberian-coast SSH and the high SSS in the Bering Sea, however, is not confirmed in 10 years of satellite-derived SSH. Mixed-layer salt budget analysis has revealed that the high SSS anomalies are mainly caused by the increases of horizontal advective salt convergence north of 62.5A degrees N, and by the decreases of sea-ice melting south of 62.5A degrees N, through the strengthening of the near-surface northeastward currents. In the warm season, these two factors fade and the salinization disappears.