Абстракт
Purpose. The paper is purposed at studying the characteristics and evolution of submesoscale cyclonic eddies attached to the Batumi anticyclone. Methods and Results. The results of numerical simulation based on the NEMO model data for 2008– 2009 and on the algorithm for automatic eddy identification, permitted to obtain the data on evolution of the dynamic and thermohaline structure of such eddies, and the reasons for their formation and dissipation. When in 2008 the Batumi anticyclone was passing, seven pronounced stable submesoscale rounded cyclonic eddies were detected on its periphery. The lifetime of some eddies achieves 20 days, vorticity anomalies in them can reach the 200 m depth, and vertical velocities can exceed 10 m/day. Conclusions. The submesoscale cyclonic eddies are formed at intensification of the Batumi anticyclone and at its displacement to the west towards Cape Fener. Increase of velocity shear arising during interaction of the Batumi anticyclone with the cape, results in formation of the cyclonic vorticity area which in some cases transforms into a submesoscale cyclonic eddy. Further, such eddies separate from the coast and move along the Batumi anticyclone periphery in the anticyclonic direction. The highest energy of submesoscale cyclonic eddies is observed at the moment of their formation, and then follows their slow dissipation, that is related to the process of their elongation due to the velocity shear at the Batumi anticyclone periphery. This process gradually intensifies with weakening of a cyclonic vortex and results in its transformation into a vortex filament. © A. A. Bogdanov, A. I. Mizyuk, A. A. Kubryakov, 2022.
Ключевые слова
anticyclone, Batumi anticyclone, Black Sea, eddy, NEMO, numerical modeling, submesoscale cyclonic eddies,