Display of the β-effect in the Black Sea Two-Layer Model

A.A. Pavlushin✉, N.B. Shapiro, E.N. Mikhailova

Marine Hydrophysical Institute, Russian Academy of Sciences, Sevastopol, Russian Federation

✉ e-mail: pavlushin@mhi-ras.ru

Abstract

The research is a continuation of a series of numerical experiments on modeling formation of wind currents and eddies in the Black Sea within the framework of a two-layer eddy-resolving model. The main attention is focused on studying the β-effect role. The stationary cyclonic wind is used as an external forcing and the bottom topography is not considered. It is shown that at the β-effect being taken into account, the Rossby waves propagating from east to west are observed both during the currents’ formation and at the statistical equilibrium mode when the mesoscale eddies are formed. In the integral flows’ field the waves are visually manifested in a form of the alternate large-scale cyclonic gyres and zones in which the meso-scale anti-cyclones are formed. This spatial pattern constantly propagates to the west that differs from the results of calculations using the constant Coriolis parameter when the spatially alternate cyclonic and anti-cyclonic vortices are formed, but hold a quasi-stationary position. The waves with the parameters of the Rossby wave first barotropic mode for the closed basin are most clearly pronounced. Interaction of the Rossby waves with large-scale circulation results in intensification of the of the currents’ hydrodynamic instability and in formation of the mesoscale eddies. Significant decrease of kinetic and available potential energy as compared to the values obtained at the constant Coriolis parameter is also a consequence of the eddy formation intensification.

Keywords

the Black Sea, eddy-resolving model, numerical experiment, β-effect, Rossby waves

For citation

Pavlushin, A.A., Shapiro, N.B. and Mikhailova, E.N., 2016. Display of the β-effect in the Black Sea Two-Layer Model. Physical Oceanography, (5), pp. 3-23. doi:10.22449/1573-160X-2016-5-3-23

DOI

10.22449/1573-160X-2016-5-3-23

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