Air temperature data from the NOMADS (NOAA Operational Model Archive Distribution System http://nomad2.ncep.noaa.gov) website were averaged over the western (70–76°N, 15–35°E) and eastern (69–77°N, 35–55°E) Barents Sea. During 2012, positive air temperature anomalies prevailed in the Barents Sea, with the largest values (4–7°C) in the eastern part of the sea from January to April (Figure 4.2.2).
Abiotic Ecosystem components - data from 2013
In 2012, the oxygen saturation (dissolved oxygen) level at the bottom layer of the southern Barents Sea was much lower than the 1958-2012 long-term average, and was lower than observed in 2011. The oxygen-saturation anomaly — averaged fromJanuary to September — was –2.14% in 2012, compared to –0.79% in 2011 (Figure 4.2.12). The largest negative anomaly occurred during the first half of the year. In 2013, oxygen saturation in the Kola section increased and was slightly above the long-term average.
Temperature at the surface, 100 meters, and bottom layer
Throughout 2013, positive surface water temperature anomalies prevailed in the Barents Sea. The largest anomalies (up to 4.0°C) were found in the eastern sea. Compared to 2012, the surface temperatures were much higher (by 1.3–2.7°C) in most of the Barents Sea, especially in its central and southern parts. In August–September 2013, during the joint Norwegian-Russian ecosystem survey, the surface temperatures were the highest since 1951 in about 50% of the surveyed area (ICES AFWG, 2014).
North Atlantic Oscillation
During 2013, the NAO index changed from negative values in January–March to slightly positive values which lasted the rest of the year. During winter (2012 –2013) northerly, northwesterly and northeasterly winds prevailed over the Barents Sea; during summer (April–August) southerly, southwesterly, and southeasterly winds prevailed. During autumn (September–October) wind direction shifted to easterly and northeasterly.
Meteorological conditions over the Barents Sea during winter 2011/2012, resulted in decreasing sea-ice coverage. From January through July 2012, ice coverage (expressed as a percentage of the sea area) was 17–32% below average and 7–25% lessthan in 2011 (Figure 4.2.11). During February and July 2012, sea-ice coverage was the smallest observed since 1951 for these months. In August and September 2012, there was no ice in the Barents Sea; the ice edge was located much farther
Currents and transport
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.
Marine sediments are mixtures of grains of varying sizes on the seabed; they serve as functionally important habitats for benthic organisms. The relative proportion of grains in different categories used to describe sediment can be classified as: mud (clay and silt) <0.063 mm; sand 0.063-2 mm; gravel 2-64 mm; cobbles 64-256 mm; and boulders >256 mm. The present day sedimentation pattern in the Barents Sea shows low or no sediment deposition on the shallow bank areas due to relatively strong bottom currents.
Temperature and salinity in the standard sections
The Fugløya–Bear Island section receives all Atlantic Water entering the Barents Sea from the southwest. Throughout 2013, Atlantic Water temperature was 0.2°C - 0.5°C above the 1977-2014 long-term average (Figure 4.2.10). Similar to temperature, water salinity also was above the 1977-2014 long-term average throughout 2013, with the anomalies ranging between 0.02 and 0.05, and trending downwards throughout the year (Figure 4.2.11).