Barents Sea Atlantification Driven by a Shift in Atmospheric Synoptic Timescale

Climate change impinges on the Arctic Ocean, leading to sea ice loss and poten- tially drastic cascading ecosystem changes. Still, the underlying mechanisms are not yet comprehensively understood. A respective recent process is the Atlantifi- cation, coined to describe the growing influence of warm and salty waters from the Atlantic on the Arctic. A major contributor to this trend is the increasing ocean volume transport from the Nordic Seas to the Barents Sea. Despite its large importance and a multitude of hypotheses that have been put to test, this trend remains mainly unexplained. Here we explore non-linear effects and, for the first time, successfully link the flow trend through the Barents Sea opening to a frequency shift in the atmospheric synoptic.