As the area of the sea ice cover has considerably reduced in the recent years, the Arctic Ocean surface layer has become more exposed to the effect of atmospheric processes. In order to evaluate the influence of the new conditions on the surface layer state, a large array of winter oceanographic data was used to calculate the Arctic Ocean mixed layer thickness and salinity along with the thickness and salinity of the halocline layer for the 1950-2013 period. Analysis of the interannual variability of the surface layer parameters listed has shown that the mixed layer thickness has increased in recent years, from 30-35 m in 1950-70s to 40-44m in 1980-2000s. The halocline thickness, conversely, has decreased from 65m in 1950-90s to 50 in the 2000s. At the same time, mixed layer salinity and the salinity of the halocline layer has become lower in the 2000s by about 0,5 % compared with 1950-90s. Three periods with distinctive configurations of the fields of the surface layer parameters have been identified. These quasi-20-year periods correspond to different climatic stages with different regimes of the atmospheric circulation. However, this is certainly not the only cause of the changes that occur in the surface layer condition. To reveal other causes of these changes, statistical methods were used to analyze the time series of the Arctic Ocean surface layer parameters. Linear regression equations allowed us to find out that the variability of the mixed layer thickness and salinity is almost equally determined by changes of the atmospheric circulation and fluctuations of the water exchange with the neighboring oceans along with river runoff and ice processes. At the same time, the thickness and salinity of the halocline layer strongly correlate with mixed layer parameters and, as there is no direct contact with the atmosphere, their variability is determined mostly by the mixed layer condition and the underlying Atlantic waters.