Tracing Arctic outflow through the Fram Strait and its interaction with North Atlantic waters

The Arctic region is warming four times quicker than the global average, a phenomenon known as the Arctic amplification. Some studies suggested that this warming may lead to seasonally ice-free Arctic Ocean by ≈ 2050 which will have potentially devastating consequences for Arctic oceanography, marine ecosystems and the Atlantic Meridional Overturning Circulation (AMOC). The relation between the slowdown of the AMOC and the Arctic Ocean is believed to be linked with enhanced freshwater outflow primarily through the Fram Strait which increases the stratification over sites of deep convection in the Irminger Sea. Earlier studies have also confirmed a link between deep water formation and freshwater release from the Arctic. In the current study, our objectives are to understand how and where the Arctic outflow is changing temperature, salinity and density, moving into the North Atlantic, during the historical period and in a warmer future climate. We use the Lagrangian parcel tracing algorithm, TRACMASS, to trace both the southward flows from Fram Strait and North Atlantic flows into the Nordic Sea. The results quantify how and where Arctic outflow increases temperature and salinity, and decreases density, in transit. This is primarily associated with mixing between the cold, fresh outflow and the relatively warmer, saltier Atlantic waters at Denmark Strait, despite some surface cooling in transit from Fram to Denmark Straits that is due to net surface heat loss and sea ice melting.