Volume flux in the Barents Sea varies within periods of several years, and was significantly lower during 1997–2002 than during 2003–2006 (Figure 4.2.3). During winter 2006, volume flux was at a maximum throuhout 1997-2013; whereas, during fall volume flux was anomalously low. After 2006, volume flux has been relatively low, particularly during spring and summer. During 2013, volume flux was generally larger than the 1997–2013 average.
On annual time scales, volume flux and temperature of inflowing Atlantic Water do not vary in syncrony. Temperature showed a decreasing trend throughout 2013.
Figure 4.2.3. Observed Atlantic Water volume flux anomalies through the Fugløya–Bear Island section estimated from current meter moorings (upper) and temperature anomalies in the 50–200m layer of the water column (lower). Three-month (blue) and 12-month (red) running averages are shown.
During 2012 and 2013, monthly and annual volume-flux anomalies were calculated using a numerical model (Trofimov, 2000) for the major currents of the Barents Sea (Figure 4.2.4a, b). In 2012, volume fluxes were 0.7–1.9σ (Sv = Sverdrup = 1 million m3/s) higher than the long-term average, and were 0.7–1.7σ higher than those calculated in 2011. Only in the northern branch of the North Cape Current was the 2012 annual mean volume flux close to both the long-term average and the 2011 value. Throughout 2012, large positive volume-flux anomalies (ranging between 2012 and 2011 values) were observed in the Novaya Zemlya Current; during May 2012 similar anomalies were observed in all currents. In 2013, volume flux in warm currents was generally higher than the long-term average, but lower than in 2012. Mean annual volume flux in the central branch of the North Cape Current, Murman Current, and Novaya Zemlya Current was 0.5σ higher than average, while in the northern branch of the North Cape Current volume flux was lower than average, and in the North Cape and Bear Island currents volume flux was close to the long-term average. Maximum positive volume flux anomalies (1.2–1.8σ) were observed in the central branch of the North Cape Current, as well as in the Murman and Novaya Zemlya currents during June-August. Maximum negative volume flux anomalies (1.4–1.8σ) were found in the northern branch of the North Cape Current in June and July.
Figure 4.2.4a. Calculated monthly volume-flux anomalies in the Barents Sea during 2012, , 2013, Normalized by standard deviation (σ), the vertical scale range is 5σ and the vertical scale interval is 1σ, respectively.
Figure 4.2.4b. Calculated and annual volume-flux anomalies in the Barents Sea during the 2001–2013 period, Normalized by standard deviation (σ), the vertical scale range is 5σ and the vertical scale interval is 1σ, respectively.