Time series of ice conditions
The Barents Sea has floating and drifting ice, but it is never fully ice covered due to the inflow of warm Atlantic waters (Hydrometeorology, 1990 ; Mironov, 2004). Ice observations in the Barents Sea have been conducted for a long period of time (Figure 1).
This time series is based on published reference data for the period of 1900-1959 (Привальский, 1985)), as well as a database at MMBI KSC RAS. This database contains time series of monthly values of the total ice area for 1960–1976 (results of a joint study by MMBI KSC RAS, Russia and the University of Alaska Fairbanks,USA; Matishov, G.G. (Ed.) 2000. The Climatic Anomalies of the Barents Sea) and 408 monthly charts for the period of 1977-2010. These charts are the result of digitizing of charts from the National Snow and Ice Data Centre (USA) for 1977-1996, and the general ice charts of the Arctic Ocean from the Centre of Ice and Hydrometeoro¬logical Information of the AARI for 1997-2011.
Two long periods of increased and decreased ice concentration in the Barents Sea can be distinguished for the period of 1899-2010.
For the first three decades of the last century, apart from some years (1904, 1907, and 1922-1925), the ice conditions exceeded the standard pattern (were heavier when compared to the standard pattern). During the following three decades (1930-1961), the reduction of the total ice area in the Barents Sea was registered with the minimum values being in 1954-56. Only some years of the period (1932, 1941, 1942, and 1958) were characterized by increased ice concentrations (heavier ice conditions).
The next period of the increased ice concentration and heavier ice conditions lasted from 1962 to 1982. However, the mean ice concentrations during those years were less than in 1899-1929.
The results of observations demonstrate that ice conditions fluctuated in the Barents Sea during the last half of the century. Overall, two long periods may be indicated: before the early 1990s – a cold period (heavier ice conditions), followed by – a warm period (the dominance of light ice conditions). The ecosystem of the Barents Sea in the first decade of the 21st century is characterized by a high content of heat in water and low ice concentrations (light ice conditions). At the same time, gradual reduction of the total ice area took place in 2006 ( Matishov et al., 2007 ). This resulted in easier conditions for shipping, as well as longer feeding migrations of commercial fish species ( Zhichkin, 2009 ; Matishov et al., 2011 ). Starting with 2007, an increasing trend of the total ice area has been observed.
Monthly charts of the Barents Sea ice conditions for the period of 1977-2010
To view the map, click on the value of the corresponding year and month