Summer Transport Estimates of the Kamchatka Current Derived As a Variational Inverse of Hydrophysical and Surface Drifter Data

The quasistationary summer Bering Sea circulation is reconstructed as a variational inverse of the hydrographic and atmospheric climatologies, transport estimates through the Bering Strait, and surface drifter data. Our results indicate the splitting of the Kamchatka Current in the vicinity of the Shirshov Ridge. This branching is in agreement with independent ARGO drifter observations. It was also found, that transport of the Kamchatka Current gradually increases downstream from 14 Sv in the Olyutorsky Gulf to 24 Sv in the Kamchatka Strait, which is twice higher than previous estimates

Summer Transport Estimates of the Kamchatka Current Derived As a Variational Inverse of Hydrophysical and Surface Drifter Data

The quasistationary summer Bering Sea circulation is reconstructed as a variational inverse of the hydrographic and atmospheric climatologies, transport estimates through the Bering Strait, and surface drifter data. Our results indicate the splitting of the Kamchatka Current in the vicinity of the Shirshov Ridge. This branching is in agreement with independent ARGO drifter observations. It was also found, that transport of the Kamchatka Current gradually increases downstream from 14 Sv in the Olyutorsky Gulf to 24 Sv in the Kamchatka Strait, which is twice higher than previous estimates

Reconstruction of summer Barents Sea circulation from climatological data

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

Reconstruction of the Circulation In Limited Regions of an Ocean With Open Boundaries: Climatic Circulation In the Tsushima Strait

Results of numerical modeling to reconstruct the circulation in the region of the Tsushima Strait using the variation method based oil a specially developed regional model of the general ocean circulation are presented in this paper. Optimal solutions describing the climatic mean circulation and synoptic circulation in 1999-2000 were obtained on the basis of climatic data and current measurements in the strait carried out in 1999-2000. The variation algorithm for the data assimilation was implemented on the basis of the modification of the general circulation model developed at the Laboratoire d\u27Oceanographie Dynamique et de Climatologie. Semi-implicit formulation of the finite difference model significantly simplifies the solution of the data assimilation problem. The results of the data assimilation during a 9-month-long period allow us to make conclusions about the applicability and efficiency of the developed variation algorithm for the data assimilation to reproduce the seasonal cycle in limited regions of the World Ocean with open boundaries