Evolving properties of the East Greenland Current in Fram Strait: signals and impacts of Arctic Ocean change.

The Fram Strait is the main gateway of the Arctic Ocean where cold and fresh Polar Water and sea ice is exported from the Arctic with the East Greenland Current. Changes in the properties of the East Greenland Current and the returning Atlantic Water can modulate surface properties and mid-depth water masses further downstream in the Nordic Seas and Subpolar North Atlantic Ocean. Results obtained from six ocean moorings in the Arctic Outflow observatory in Fram Strait from 1997 to 2019 show that Arctic Ocean change impacts the salinity and temperature properties of the East Greenland Current in recent years. While variations in the export of low salinity Polar Water are large and there is no year-round trend, record low salinities were observed on the shelf west of the East Greenland Current throughout the whole of 2017. The last five years are marked with significant warming of the Polar Water associated with the strong decline of the sea ice cover in summer, decreasing the density here. Also, the length of the period that the upper ocean is warmer is significantly longer in recent years than prior to 2012. In the eastern part of the East Greenland Current and the recirculation area the upper ocean is also marked by increased temperatures, however, this is associated with higher salinities, and hence upper ocean density is seen to increase. These emerging trends in the Fram Strait imply that watermass properties further south in the Nordic Seas and Subpolar North Atlantic will be modulated by ongoing changes in the Arctic Ocean.