Summary: | An estimate of the summer Barents Sea circulation is constructed as a four-dimensional variational inverse of the monthly hydrographic and atmospheric climatologies. The reconstructed evolution of temperature, salinity, and velocity fields provides the best fit to climatological data and satisfies dynamical and kinematic constraints of a primitive equation ocean circulation model. The data-optimized Barents Sea state is in general agreement with the existing schemes of circulation in the region. The circulation is characterized by the 3.2 Sv inflow from the Norwegian Sea with the Norwegian Atlantic Current. Approximately 1.5 Sv of this inflow recirculates along the northern flank of Bear Island Trough, while the major branch of the current crosses the Barents Sea and outflows through Franz Josef Land-Novaya Zemliya and the Kara Gate straits with transports of 1.1 Sv and 0.6 Sv, respectively. The data assimilation reveals an eastward current between the Great and Central banks and cyclonic circulation in the region between Central Bank and Novaya Zemliya. These two circulation features have recently been confirmed in a number of publications. The reconstructed surface heat and salt fluxes are in qualitative and quantitative agreement with the known observational estimates. The posterior error analysis and sensitivity experiments provide additional arguments in support of the reliability of the data assimilation results.
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