Climate change in the Barents Sea: Ice-ocean interactions, water mass formation and variability
Winter sea ice has declined in the Barents Sea and there is growing evidence that the low sea ice here coincides with cold, winter surface air temperature in Europe and Asia. Atlantic Water (AW) transported into the Barents Sea is warming and its temperature variability is correlated with variability in sea ice extent. As AW extends into the Barents Sea it is modified into a cooler, fresher water mass called Barents Sea Water (BSW). There are limited observations of BSW despite its importance in the Arctic Ocean system, leading to the question, how does the seasonal sea ice impact ocean stratification and mean flow? First, by combining data from a range of satellites, heat and freshwater content can be estimated, showing the potential for remote monitoring of BSW properties. Second, satellite observations are used to find the Polar Front, a water mass boundary between BSW and fresher Arctic Water to the north. The sea ice extent was found to be independent of the Polar Front until the mid-2000s when warming AW prevented the extension of winter sea ice south of the front. Third, a high-resolution model is used to calculate the freshwater budget within the AW and BSW domain south of the Polar Front. The model shows an anomaly in BSW volume in the mid-2000s, an event which is preceded by substantial freshwater flux from summer sea ice melt. This event allowed warming AW to occupy a greater proportion of the Barents Sea.