Understanding the variability of the Barents Sea Water: a high resolution model study

Over the satellite record, the Barents Sea winter maximum in sea ice extent has declined and was prohibited by warming Barents Sea Water (BSW) south of the Polar Front after 2005. Sea ice extent here is correlated with extreme winter weather in Europe and Asia. Previous models studies suggest there is a possibility that natural variability will cause re-expansion of the lost sea ice cover but suggest a need to refine the source of BSW variability. To understand the variability in BSW, a high-resolution model validated with observations for 1985 to 2014, is used to calculate the volume, transport and flux budgets within the AW and BSW domain south of the Polar Front. Lag regressions show AW temperature anomalies as the source of anomalies in AW volume, sea ice melt, ocean-to-atmosphere heat flux and BSW salinity, while BSW temperature lags BSW volume anomalies. The model shows BSW volume minimum years in 1990 and 2004, events that reduce the Barents Sea's "memory" of the previous years BSW properties. Both events were preceded by extensive winter sea ice and substantial summer sea ice melt, a result of preceding, cool AW. The event in 2004 was more extreme and allowed warming AW to occupy a greater volume in the Barents Sea after 2005. The lag regressions suggest a return to the more extensive winter sea ice regime or further reduction could occur with respective AW cooling or warming.