  Significant salinity anomalies have been observed in the Arctic Ocean surface
layer during the last decade. Using gridded data of winter salinity in the
upper 50 m layer of the Arctic Ocean for the period 1950-1993 and 2007-2012, we
investigated the inter-annual variability of the salinity fields, attempted to
identify patterns and anomalies, and developed a statistical model for the
prediction of surface layer salinity. The statistical model is based on linear
regression equations linking the principal components with environmental
factors, such as atmospheric circulation, river runoff, ice processes, and
water exchange with neighboring oceans. Using this model, we obtained
prognostic fields of the surface layer salinity for the winter period
2013-2014. The prognostic fields demonstrated the same tendencies of surface
layer freshening that were observed previously. A phase portrait analysis
involving the first two principal components exhibits a dramatic shift in
behavior of the 2007-2012 data in comparison to earlier observations.
