Hydrodynamic-sea ice couplings in the Barents Sea and their consequences for marine productivity

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During the past decades the Barents Sea experienced pronounced changes in hydrodynamic-, biogeochemical and higher trophic level conditions. The sea ice cover showed a long-term decreasing trend, which seems to have slightly stabilized during the recent years (Karaskov et al., 2013). Barents Sea temperature is characterized by significant multidecadal variability, which correlates to the Atlantic Multidecadal Oscillation AMO (e.g. Levitus, et al., 2009) and covariations with cyclone activity have been identified in earlier studies (e.g. Sorteberg and Kvingedal, 2006). These long-term variations in oceanographic conditions are accompanied by pronounced variations in the ecosystem with a.o. an increase in fish abundance and an expansion of key stocks northwards (e.g. Stiansen et al., 2009). Based on model simulations of contrasting years, it has earlier been suggested that sea ice retreat will result in increasing primary production in the Barents Sea (e.g. Wassmann et al., 2006). We investigate long-term variations in bottom up controls on the lower trophic level production in the Barents Sea by employing a regional physical-biological model for a multi-decadal simulation. We will illustrate the impact of climatic forcing on lower trophic level production in the Barents Sea and discuss the variations in dominant climatic drivers over the decades.